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diff --git a/agent/agent.h b/agent/agent.h
index 01e675b52..b95df5700 100644
--- a/agent/agent.h
+++ b/agent/agent.h
@@ -1,589 +1,593 @@
/* agent.h - Global definitions for the agent
* Copyright (C) 2001, 2002, 2003, 2005, 2011 Free Software Foundation, Inc.
* Copyright (C) 2015 g10 Code GmbH.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#ifndef AGENT_H
#define AGENT_H
#ifdef GPG_ERR_SOURCE_DEFAULT
#error GPG_ERR_SOURCE_DEFAULT already defined
#endif
#define GPG_ERR_SOURCE_DEFAULT GPG_ERR_SOURCE_GPGAGENT
#include <gpg-error.h>
#define map_assuan_err(a) \
map_assuan_err_with_source (GPG_ERR_SOURCE_DEFAULT, (a))
#include <errno.h>
#include <gcrypt.h>
#include "../common/util.h"
#include "../common/membuf.h"
#include "../common/sysutils.h" /* (gnupg_fd_t) */
#include "../common/session-env.h"
#include "../common/shareddefs.h"
/* To convey some special hash algorithms we use algorithm numbers
reserved for application use. */
#ifndef GCRY_MODULE_ID_USER
#define GCRY_MODULE_ID_USER 1024
#endif
#define MD_USER_TLS_MD5SHA1 (GCRY_MODULE_ID_USER+1)
/* Maximum length of a digest. */
#define MAX_DIGEST_LEN 64
/* The maximum length of a passphrase (in bytes). Note: this is
further contrained by the Assuan line length (and any other text on
the same line). However, the Assuan line length is 1k bytes so
this shouldn't be a problem in practice. */
#define MAX_PASSPHRASE_LEN 255
/* A large struct name "opt" to keep global flags */
struct
{
unsigned int debug; /* Debug flags (DBG_foo_VALUE) */
int verbose; /* Verbosity level */
int quiet; /* Be as quiet as possible */
int dry_run; /* Don't change any persistent data */
int batch; /* Batch mode */
/* True if we handle sigusr2. */
int sigusr2_enabled;
/* Environment settings gathered at program start or changed using the
Assuan command UPDATESTARTUPTTY. */
session_env_t startup_env;
char *startup_lc_ctype;
char *startup_lc_messages;
/* Enable pinentry debugging (--debug 1024 should also be used). */
int debug_pinentry;
/* Filename of the program to start as pinentry. */
const char *pinentry_program;
/* Filename of the program to handle smartcard tasks. */
const char *scdaemon_program;
int disable_scdaemon; /* Never use the SCdaemon. */
int no_grab; /* Don't let the pinentry grab the keyboard */
/* The name of the file pinentry shall touch before exiting. If
this is not set the file name of the standard socket is used. */
const char *pinentry_touch_file;
/* A string where the first character is used by the pinentry as a
custom invisible character. */
char *pinentry_invisible_char;
/* The timeout value for the Pinentry in seconds. This is passed to
the pinentry if it is not 0. It is up to the pinentry to act
upon this timeout value. */
unsigned long pinentry_timeout;
/* The default and maximum TTL of cache entries. */
unsigned long def_cache_ttl; /* Default. */
unsigned long def_cache_ttl_ssh; /* for SSH. */
unsigned long max_cache_ttl; /* Default. */
unsigned long max_cache_ttl_ssh; /* for SSH. */
/* Flag disallowing bypassing of the warning. */
int enforce_passphrase_constraints;
/* The require minmum length of a passphrase. */
unsigned int min_passphrase_len;
/* The minimum number of non-alpha characters in a passphrase. */
unsigned int min_passphrase_nonalpha;
/* File name with a patternfile or NULL if not enabled. */
const char *check_passphrase_pattern;
/* If not 0 the user is asked to change his passphrase after these
number of days. */
unsigned int max_passphrase_days;
/* If set, a passphrase history will be written and checked at each
passphrase change. */
int enable_passphrase_history;
/* If set the extended key format is used for new keys. */
int enable_extended_key_format;
int running_detached; /* We are running detached from the tty. */
/* If this global option is true, the passphrase cache is ignored
for signing operations. */
int ignore_cache_for_signing;
/* If this global option is true, the user is allowed to
interactively mark certificate in trustlist.txt as trusted. */
int allow_mark_trusted;
/* If this global option is true, the Assuan command
PRESET_PASSPHRASE is allowed. */
int allow_preset_passphrase;
/* If this global option is true, the Assuan option
pinentry-mode=loopback is allowed. */
int allow_loopback_pinentry;
/* Allow the use of an external password cache. If this option is
enabled (which is the default) we send an option to Pinentry
to allow it to enable such a cache. */
int allow_external_cache;
/* If this global option is true, the Assuan option of Pinentry
allow-emacs-prompt is allowed. */
int allow_emacs_pinentry;
int keep_tty; /* Don't switch the TTY (for pinentry) on request */
int keep_display; /* Don't switch the DISPLAY (for pinentry) on request */
/* This global option indicates the use of an extra socket. Note
that we use a hack for cleanup handling in gpg-agent.c: If the
value is less than 2 the name has not yet been malloced. */
int extra_socket;
/* This global option indicates the use of an extra socket for web
browsers. Note that we use a hack for cleanup handling in
gpg-agent.c: If the value is less than 2 the name has not yet
been malloced. */
int browser_socket;
+
+ /* The digest algorithm to use for ssh fingerprints when
+ * communicating with the user. */
+ int ssh_fingerprint_digest;
} opt;
/* Bit values for the --debug option. */
#define DBG_MPI_VALUE 2 /* debug mpi details */
#define DBG_CRYPTO_VALUE 4 /* debug low level crypto */
#define DBG_MEMORY_VALUE 32 /* debug memory allocation stuff */
#define DBG_CACHE_VALUE 64 /* debug the caching */
#define DBG_MEMSTAT_VALUE 128 /* show memory statistics */
#define DBG_HASHING_VALUE 512 /* debug hashing operations */
#define DBG_IPC_VALUE 1024 /* Enable Assuan debugging. */
/* Test macros for the debug option. */
#define DBG_CRYPTO (opt.debug & DBG_CRYPTO_VALUE)
#define DBG_MEMORY (opt.debug & DBG_MEMORY_VALUE)
#define DBG_CACHE (opt.debug & DBG_CACHE_VALUE)
#define DBG_HASHING (opt.debug & DBG_HASHING_VALUE)
#define DBG_IPC (opt.debug & DBG_IPC_VALUE)
/* Forward reference for local definitions in command.c. */
struct server_local_s;
/* Declaration of objects from command-ssh.c. */
struct ssh_control_file_s;
typedef struct ssh_control_file_s *ssh_control_file_t;
/* Forward reference for local definitions in call-scd.c. */
struct scd_local_s;
/* Collection of data per session (aka connection). */
struct server_control_s
{
/* Private data used to fire up the connection thread. We use this
structure do avoid an extra allocation for only a few bytes while
spawning a new connection thread. */
struct {
gnupg_fd_t fd;
} thread_startup;
/* Flag indicating the connection is run in restricted mode.
A value of 1 if used for --extra-socket,
a value of 2 is used for --browser-socket. */
int restricted;
/* Private data of the server (command.c). */
struct server_local_s *server_local;
/* Private data of the SCdaemon (call-scd.c). */
struct scd_local_s *scd_local;
/* Environment settings for the connection. */
session_env_t session_env;
char *lc_ctype;
char *lc_messages;
unsigned long client_pid;
/* The current pinentry mode. */
pinentry_mode_t pinentry_mode;
/* The TTL used for the --preset option of certain commands. */
int cache_ttl_opt_preset;
/* Information on the currently used digest (for signing commands). */
struct {
int algo;
unsigned char value[MAX_DIGEST_LEN];
int valuelen;
int raw_value: 1;
} digest;
unsigned char keygrip[20];
int have_keygrip;
/* A flag to enable a hack to send the PKAUTH command instead of the
PKSIGN command to the scdaemon. */
int use_auth_call;
/* A flag to inhibit enforced passphrase change during an explicit
passwd command. */
int in_passwd;
/* The current S2K which might be different from the calibrated
count. */
unsigned long s2k_count;
};
/* Information pertaining to pinentry requests. */
struct pin_entry_info_s
{
int min_digits; /* min. number of digits required or 0 for freeform entry */
int max_digits; /* max. number of allowed digits allowed*/
int max_tries; /* max. number of allowed tries. */
int failed_tries; /* Number of tries so far failed. */
int with_qualitybar; /* Set if the quality bar should be displayed. */
int with_repeat; /* Request repetition of the passphrase. */
int repeat_okay; /* Repetition worked. */
gpg_error_t (*check_cb)(struct pin_entry_info_s *); /* CB used to check
the PIN */
void *check_cb_arg; /* optional argument which might be of use in the CB */
const char *cb_errtext; /* used by the cb to display a specific error */
size_t max_length; /* Allocated length of the buffer PIN. */
char pin[1]; /* The buffer to hold the PIN or passphrase.
It's actual allocated length is given by
MAX_LENGTH (above). */
};
/* Types of the private keys. */
enum
{
PRIVATE_KEY_UNKNOWN = 0, /* Type of key is not known. */
PRIVATE_KEY_CLEAR = 1, /* The key is not protected. */
PRIVATE_KEY_PROTECTED = 2, /* The key is protected. */
PRIVATE_KEY_SHADOWED = 3, /* The key is a stub for a smartcard
based key. */
PROTECTED_SHARED_SECRET = 4, /* RFU. */
PRIVATE_KEY_OPENPGP_NONE = 5 /* openpgp-native with protection "none". */
};
/* Values for the cache_mode arguments. */
typedef enum
{
CACHE_MODE_IGNORE = 0, /* Special mode to bypass the cache. */
CACHE_MODE_ANY, /* Any mode except ignore matches. */
CACHE_MODE_NORMAL, /* Normal cache (gpg-agent). */
CACHE_MODE_USER, /* GET_PASSPHRASE related cache. */
CACHE_MODE_SSH, /* SSH related cache. */
CACHE_MODE_NONCE /* This is a non-predictable nonce. */
}
cache_mode_t;
/* The TTL is seconds used for adding a new nonce mode cache item. */
#define CACHE_TTL_NONCE 120
/* The TTL in seconds used by the --preset option of some commands.
This is the default value changeable by an OPTION command. */
#define CACHE_TTL_OPT_PRESET 900
/* The type of a function to lookup a TTL by a keygrip. */
typedef int (*lookup_ttl_t)(const char *hexgrip);
/* This is a special version of the usual _() gettext macro. It
assumes a server connection control variable with the name "ctrl"
and uses that to translate a string according to the locale set for
the connection. The macro LunderscoreIMPL is used by i18n to
actually define the inline function when needed. */
#ifdef ENABLE_NLS
#define L_(a) agent_Lunderscore (ctrl, (a))
#define LunderscorePROTO \
static inline const char *agent_Lunderscore (ctrl_t ctrl, \
const char *string) \
GNUPG_GCC_ATTR_FORMAT_ARG(2);
#define LunderscoreIMPL \
static inline const char * \
agent_Lunderscore (ctrl_t ctrl, const char *string) \
{ \
return ctrl? i18n_localegettext (ctrl->lc_messages, string) \
/* */: gettext (string); \
}
#else
#define L_(a) (a)
#endif
/*-- gpg-agent.c --*/
void agent_exit (int rc)
GPGRT_ATTR_NORETURN; /* Also implemented in other tools */
void agent_set_progress_cb (void (*cb)(ctrl_t ctrl, const char *what,
int printchar, int current, int total),
ctrl_t ctrl);
gpg_error_t agent_copy_startup_env (ctrl_t ctrl);
const char *get_agent_socket_name (void);
const char *get_agent_ssh_socket_name (void);
int get_agent_active_connection_count (void);
#ifdef HAVE_W32_SYSTEM
void *get_agent_scd_notify_event (void);
#endif
void agent_sighup_action (void);
int map_pk_openpgp_to_gcry (int openpgp_algo);
/*-- command.c --*/
gpg_error_t agent_inq_pinentry_launched (ctrl_t ctrl, unsigned long pid,
const char *extra);
gpg_error_t agent_write_status (ctrl_t ctrl, const char *keyword, ...)
GPGRT_ATTR_SENTINEL(0);
gpg_error_t agent_print_status (ctrl_t ctrl, const char *keyword,
const char *format, ...)
GPGRT_ATTR_PRINTF(3,4);
void bump_key_eventcounter (void);
void bump_card_eventcounter (void);
void start_command_handler (ctrl_t, gnupg_fd_t, gnupg_fd_t);
gpg_error_t pinentry_loopback (ctrl_t, const char *keyword,
unsigned char **buffer, size_t *size,
size_t max_length);
#ifdef HAVE_W32_SYSTEM
int serve_mmapped_ssh_request (ctrl_t ctrl,
unsigned char *request, size_t maxreqlen);
#endif /*HAVE_W32_SYSTEM*/
/*-- command-ssh.c --*/
ssh_control_file_t ssh_open_control_file (void);
void ssh_close_control_file (ssh_control_file_t cf);
gpg_error_t ssh_read_control_file (ssh_control_file_t cf,
char *r_hexgrip, int *r_disabled,
int *r_ttl, int *r_confirm);
gpg_error_t ssh_search_control_file (ssh_control_file_t cf,
const char *hexgrip,
int *r_disabled,
int *r_ttl, int *r_confirm);
void start_command_handler_ssh (ctrl_t, gnupg_fd_t);
/*-- findkey.c --*/
gpg_error_t agent_modify_description (const char *in, const char *comment,
const gcry_sexp_t key, char **result);
int agent_write_private_key (const unsigned char *grip,
const void *buffer, size_t length, int force);
gpg_error_t agent_key_from_file (ctrl_t ctrl,
const char *cache_nonce,
const char *desc_text,
const unsigned char *grip,
unsigned char **shadow_info,
cache_mode_t cache_mode,
lookup_ttl_t lookup_ttl,
gcry_sexp_t *result,
char **r_passphrase);
gpg_error_t agent_raw_key_from_file (ctrl_t ctrl, const unsigned char *grip,
gcry_sexp_t *result);
gpg_error_t agent_public_key_from_file (ctrl_t ctrl,
const unsigned char *grip,
gcry_sexp_t *result);
int agent_is_dsa_key (gcry_sexp_t s_key);
int agent_is_eddsa_key (gcry_sexp_t s_key);
int agent_key_available (const unsigned char *grip);
gpg_error_t agent_key_info_from_file (ctrl_t ctrl, const unsigned char *grip,
int *r_keytype,
unsigned char **r_shadow_info);
gpg_error_t agent_delete_key (ctrl_t ctrl, const char *desc_text,
const unsigned char *grip,
int force, int only_stubs);
/*-- call-pinentry.c --*/
void initialize_module_call_pinentry (void);
void agent_query_dump_state (void);
void agent_reset_query (ctrl_t ctrl);
int pinentry_active_p (ctrl_t ctrl, int waitseconds);
gpg_error_t agent_askpin (ctrl_t ctrl,
const char *desc_text, const char *prompt_text,
const char *inital_errtext,
struct pin_entry_info_s *pininfo,
const char *keyinfo, cache_mode_t cache_mode);
int agent_get_passphrase (ctrl_t ctrl, char **retpass,
const char *desc, const char *prompt,
const char *errtext, int with_qualitybar,
const char *keyinfo, cache_mode_t cache_mode);
int agent_get_confirmation (ctrl_t ctrl, const char *desc, const char *ok,
const char *notokay, int with_cancel);
int agent_show_message (ctrl_t ctrl, const char *desc, const char *ok_btn);
int agent_popup_message_start (ctrl_t ctrl,
const char *desc, const char *ok_btn);
void agent_popup_message_stop (ctrl_t ctrl);
int agent_clear_passphrase (ctrl_t ctrl,
const char *keyinfo, cache_mode_t cache_mode);
/*-- cache.c --*/
void initialize_module_cache (void);
void deinitialize_module_cache (void);
void agent_flush_cache (void);
int agent_put_cache (const char *key, cache_mode_t cache_mode,
const char *data, int ttl);
char *agent_get_cache (const char *key, cache_mode_t cache_mode);
void agent_store_cache_hit (const char *key);
/*-- pksign.c --*/
int agent_pksign_do (ctrl_t ctrl, const char *cache_nonce,
const char *desc_text,
gcry_sexp_t *signature_sexp,
cache_mode_t cache_mode, lookup_ttl_t lookup_ttl,
const void *overridedata, size_t overridedatalen);
int agent_pksign (ctrl_t ctrl, const char *cache_nonce,
const char *desc_text,
membuf_t *outbuf, cache_mode_t cache_mode);
/*-- pkdecrypt.c --*/
int agent_pkdecrypt (ctrl_t ctrl, const char *desc_text,
const unsigned char *ciphertext, size_t ciphertextlen,
membuf_t *outbuf, int *r_padding);
/*-- genkey.c --*/
int check_passphrase_constraints (ctrl_t ctrl, const char *pw,
char **failed_constraint);
gpg_error_t agent_ask_new_passphrase (ctrl_t ctrl, const char *prompt,
char **r_passphrase);
int agent_genkey (ctrl_t ctrl, const char *cache_nonce,
const char *keyparam, size_t keyparmlen,
int no_protection, const char *override_passphrase,
int preset, membuf_t *outbuf);
gpg_error_t agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey,
char **passphrase_addr);
/*-- protect.c --*/
unsigned long get_standard_s2k_count (void);
unsigned char get_standard_s2k_count_rfc4880 (void);
int agent_protect (const unsigned char *plainkey, const char *passphrase,
unsigned char **result, size_t *resultlen,
unsigned long s2k_count, int use_ocb);
int agent_unprotect (ctrl_t ctrl,
const unsigned char *protectedkey, const char *passphrase,
gnupg_isotime_t protected_at,
unsigned char **result, size_t *resultlen);
int agent_private_key_type (const unsigned char *privatekey);
unsigned char *make_shadow_info (const char *serialno, const char *idstring);
int agent_shadow_key (const unsigned char *pubkey,
const unsigned char *shadow_info,
unsigned char **result);
int agent_get_shadow_info (const unsigned char *shadowkey,
unsigned char const **shadow_info);
gpg_error_t parse_shadow_info (const unsigned char *shadow_info,
char **r_hexsn, char **r_idstr, int *r_pinlen);
gpg_error_t s2k_hash_passphrase (const char *passphrase, int hashalgo,
int s2kmode,
const unsigned char *s2ksalt,
unsigned int s2kcount,
unsigned char *key, size_t keylen);
gpg_error_t agent_write_shadow_key (const unsigned char *grip,
const char *serialno, const char *keyid,
const unsigned char *pkbuf, int force);
/*-- trustlist.c --*/
void initialize_module_trustlist (void);
gpg_error_t agent_istrusted (ctrl_t ctrl, const char *fpr, int *r_disabled);
gpg_error_t agent_listtrusted (void *assuan_context);
gpg_error_t agent_marktrusted (ctrl_t ctrl, const char *name,
const char *fpr, int flag);
void agent_reload_trustlist (void);
/*-- divert-scd.c --*/
int divert_pksign (ctrl_t ctrl, const char *desc_text,
const unsigned char *digest, size_t digestlen, int algo,
const unsigned char *shadow_info, unsigned char **r_sig,
size_t *r_siglen);
int divert_pkdecrypt (ctrl_t ctrl, const char *desc_text,
const unsigned char *cipher,
const unsigned char *shadow_info,
char **r_buf, size_t *r_len, int *r_padding);
int divert_generic_cmd (ctrl_t ctrl,
const char *cmdline, void *assuan_context);
int divert_writekey (ctrl_t ctrl, int force, const char *serialno,
const char *id, const char *keydata, size_t keydatalen);
/*-- call-scd.c --*/
void initialize_module_call_scd (void);
void agent_scd_dump_state (void);
int agent_scd_check_running (void);
void agent_scd_check_aliveness (void);
int agent_reset_scd (ctrl_t ctrl);
int agent_card_learn (ctrl_t ctrl,
void (*kpinfo_cb)(void*, const char *),
void *kpinfo_cb_arg,
void (*certinfo_cb)(void*, const char *),
void *certinfo_cb_arg,
void (*sinfo_cb)(void*, const char *,
size_t, const char *),
void *sinfo_cb_arg);
int agent_card_serialno (ctrl_t ctrl, char **r_serialno, const char *demand);
int agent_card_pksign (ctrl_t ctrl,
const char *keyid,
int (*getpin_cb)(void *, const char *,
const char *, char*, size_t),
void *getpin_cb_arg,
const char *desc_text,
int mdalgo,
const unsigned char *indata, size_t indatalen,
unsigned char **r_buf, size_t *r_buflen);
int agent_card_pkdecrypt (ctrl_t ctrl,
const char *keyid,
int (*getpin_cb)(void *, const char *,
const char *, char*,size_t),
void *getpin_cb_arg,
const char *desc_text,
const unsigned char *indata, size_t indatalen,
char **r_buf, size_t *r_buflen, int *r_padding);
int agent_card_readcert (ctrl_t ctrl,
const char *id, char **r_buf, size_t *r_buflen);
int agent_card_readkey (ctrl_t ctrl, const char *id, unsigned char **r_buf);
int agent_card_writekey (ctrl_t ctrl, int force, const char *serialno,
const char *id, const char *keydata,
size_t keydatalen,
int (*getpin_cb)(void *, const char *,
const char *, char*, size_t),
void *getpin_cb_arg);
gpg_error_t agent_card_getattr (ctrl_t ctrl, const char *name, char **result);
gpg_error_t agent_card_cardlist (ctrl_t ctrl, strlist_t *result);
int agent_card_scd (ctrl_t ctrl, const char *cmdline,
int (*getpin_cb)(void *, const char *,
const char *, char*, size_t),
void *getpin_cb_arg, void *assuan_context);
/*-- learncard.c --*/
int agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context, int force);
/*-- cvt-openpgp.c --*/
gpg_error_t
extract_private_key (gcry_sexp_t s_key, int req_private_key_data,
const char **r_algoname, int *r_npkey, int *r_nskey,
const char **r_format,
gcry_mpi_t *mpi_array, int arraysize,
gcry_sexp_t *r_curve, gcry_sexp_t *r_flags);
#endif /*AGENT_H*/
diff --git a/agent/command-ssh.c b/agent/command-ssh.c
index b8edd1a3f..e450aed30 100644
--- a/agent/command-ssh.c
+++ b/agent/command-ssh.c
@@ -1,3830 +1,3830 @@
/* command-ssh.c - gpg-agent's implementation of the ssh-agent protocol.
* Copyright (C) 2004-2006, 2009, 2012 Free Software Foundation, Inc.
* Copyright (C) 2004-2006, 2009, 2012-2014 Werner Koch
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
/* Only v2 of the ssh-agent protocol is implemented. Relevant RFCs
are:
RFC-4250 - Protocol Assigned Numbers
RFC-4251 - Protocol Architecture
RFC-4252 - Authentication Protocol
RFC-4253 - Transport Layer Protocol
RFC-5656 - ECC support
The protocol for the agent is defined in OpenSSH's PROTOCL.agent
file.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <assert.h>
#ifndef HAVE_W32_SYSTEM
#include <sys/socket.h>
#include <sys/un.h>
#endif /*!HAVE_W32_SYSTEM*/
#ifdef HAVE_UCRED_H
#include <ucred.h>
#endif
#include "agent.h"
#include "../common/i18n.h"
#include "../common/util.h"
#include "../common/ssh-utils.h"
/* Request types. */
#define SSH_REQUEST_REQUEST_IDENTITIES 11
#define SSH_REQUEST_SIGN_REQUEST 13
#define SSH_REQUEST_ADD_IDENTITY 17
#define SSH_REQUEST_REMOVE_IDENTITY 18
#define SSH_REQUEST_REMOVE_ALL_IDENTITIES 19
#define SSH_REQUEST_LOCK 22
#define SSH_REQUEST_UNLOCK 23
#define SSH_REQUEST_ADD_ID_CONSTRAINED 25
/* Options. */
#define SSH_OPT_CONSTRAIN_LIFETIME 1
#define SSH_OPT_CONSTRAIN_CONFIRM 2
/* Response types. */
#define SSH_RESPONSE_SUCCESS 6
#define SSH_RESPONSE_FAILURE 5
#define SSH_RESPONSE_IDENTITIES_ANSWER 12
#define SSH_RESPONSE_SIGN_RESPONSE 14
/* Other constants. */
#define SSH_DSA_SIGNATURE_PADDING 20
#define SSH_DSA_SIGNATURE_ELEMS 2
#define SPEC_FLAG_USE_PKCS1V2 (1 << 0)
#define SPEC_FLAG_IS_ECDSA (1 << 1)
#define SPEC_FLAG_IS_EdDSA (1 << 2) /*(lowercase 'd' on purpose.)*/
#define SPEC_FLAG_WITH_CERT (1 << 7)
/* The name of the control file. */
#define SSH_CONTROL_FILE_NAME "sshcontrol"
/* The blurb we put into the header of a newly created control file. */
static const char sshcontrolblurb[] =
"# List of allowed ssh keys. Only keys present in this file are used\n"
"# in the SSH protocol. The ssh-add tool may add new entries to this\n"
"# file to enable them; you may also add them manually. Comment\n"
"# lines, like this one, as well as empty lines are ignored. Lines do\n"
"# have a certain length limit but this is not serious limitation as\n"
"# the format of the entries is fixed and checked by gpg-agent. A\n"
"# non-comment line starts with optional white spaces, followed by the\n"
"# keygrip of the key given as 40 hex digits, optionally followed by a\n"
"# caching TTL in seconds, and another optional field for arbitrary\n"
"# flags. Prepend the keygrip with an '!' mark to disable it.\n"
"\n";
/* Macros. */
/* Return a new uint32 with b0 being the most significant byte and b3
being the least significant byte. */
#define uint32_construct(b0, b1, b2, b3) \
((b0 << 24) | (b1 << 16) | (b2 << 8) | b3)
/*
* Basic types.
*/
/* Type for a request handler. */
typedef gpg_error_t (*ssh_request_handler_t) (ctrl_t ctrl,
estream_t request,
estream_t response);
struct ssh_key_type_spec;
typedef struct ssh_key_type_spec ssh_key_type_spec_t;
/* Type, which is used for associating request handlers with the
appropriate request IDs. */
typedef struct ssh_request_spec
{
unsigned char type;
ssh_request_handler_t handler;
const char *identifier;
unsigned int secret_input;
} ssh_request_spec_t;
/* Type for "key modifier functions", which are necessary since
OpenSSH and GnuPG treat key material slightly different. A key
modifier is called right after a new key identity has been received
in order to "sanitize" the material. */
typedef gpg_error_t (*ssh_key_modifier_t) (const char *elems,
gcry_mpi_t *mpis);
/* The encoding of a generated signature is dependent on the
algorithm; therefore algorithm specific signature encoding
functions are necessary. */
typedef gpg_error_t (*ssh_signature_encoder_t) (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t sig);
/* Type, which is used for boundling all the algorithm specific
information together in a single object. */
struct ssh_key_type_spec
{
/* Algorithm identifier as used by OpenSSH. */
const char *ssh_identifier;
/* Human readable name of the algorithm. */
const char *name;
/* Algorithm identifier as used by GnuPG. */
int algo;
/* List of MPI names for secret keys; order matches the one of the
agent protocol. */
const char *elems_key_secret;
/* List of MPI names for public keys; order matches the one of the
agent protocol. */
const char *elems_key_public;
/* List of MPI names for signature data. */
const char *elems_signature;
/* List of MPI names for secret keys; order matches the one, which
is required by gpg-agent's key access layer. */
const char *elems_sexp_order;
/* Key modifier function. Key modifier functions are necessary in
order to fix any inconsistencies between the representation of
keys on the SSH and on the GnuPG side. */
ssh_key_modifier_t key_modifier;
/* Signature encoder function. Signature encoder functions are
necessary since the encoding of signatures depends on the used
algorithm. */
ssh_signature_encoder_t signature_encoder;
/* The name of the ECC curve or NULL. */
const char *curve_name;
/* The hash algorithm to be used with this key. 0 for using the
default. */
int hash_algo;
/* Misc flags. */
unsigned int flags;
};
/* Definition of an object to access the sshcontrol file. */
struct ssh_control_file_s
{
char *fname; /* Name of the file. */
FILE *fp; /* This is never NULL. */
int lnr; /* The current line number. */
struct {
int valid; /* True if the data of this structure is valid. */
int disabled; /* The item is disabled. */
int ttl; /* The TTL of the item. */
int confirm; /* The confirm flag is set. */
char hexgrip[40+1]; /* The hexgrip of the item (uppercase). */
} item;
};
/* Prototypes. */
static gpg_error_t ssh_handler_request_identities (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_sign_request (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_add_identity (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_remove_identity (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_remove_all_identities (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_lock (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_handler_unlock (ctrl_t ctrl,
estream_t request,
estream_t response);
static gpg_error_t ssh_key_modifier_rsa (const char *elems, gcry_mpi_t *mpis);
static gpg_error_t ssh_signature_encoder_rsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t signature);
static gpg_error_t ssh_signature_encoder_dsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t signature);
static gpg_error_t ssh_signature_encoder_ecdsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t signature);
static gpg_error_t ssh_signature_encoder_eddsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t signature);
static gpg_error_t ssh_key_extract_comment (gcry_sexp_t key, char **comment);
/* Global variables. */
/* Associating request types with the corresponding request
handlers. */
static const ssh_request_spec_t request_specs[] =
{
#define REQUEST_SPEC_DEFINE(id, name, secret_input) \
{ SSH_REQUEST_##id, ssh_handler_##name, #name, secret_input }
REQUEST_SPEC_DEFINE (REQUEST_IDENTITIES, request_identities, 1),
REQUEST_SPEC_DEFINE (SIGN_REQUEST, sign_request, 0),
REQUEST_SPEC_DEFINE (ADD_IDENTITY, add_identity, 1),
REQUEST_SPEC_DEFINE (ADD_ID_CONSTRAINED, add_identity, 1),
REQUEST_SPEC_DEFINE (REMOVE_IDENTITY, remove_identity, 0),
REQUEST_SPEC_DEFINE (REMOVE_ALL_IDENTITIES, remove_all_identities, 0),
REQUEST_SPEC_DEFINE (LOCK, lock, 0),
REQUEST_SPEC_DEFINE (UNLOCK, unlock, 0)
#undef REQUEST_SPEC_DEFINE
};
/* Table holding key type specifications. */
static const ssh_key_type_spec_t ssh_key_types[] =
{
{
"ssh-ed25519", "Ed25519", GCRY_PK_EDDSA, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_eddsa,
"Ed25519", 0, SPEC_FLAG_IS_EdDSA
},
{
"ssh-rsa", "RSA", GCRY_PK_RSA, "nedupq", "en", "s", "nedpqu",
ssh_key_modifier_rsa, ssh_signature_encoder_rsa,
NULL, 0, SPEC_FLAG_USE_PKCS1V2
},
{
"ssh-dss", "DSA", GCRY_PK_DSA, "pqgyx", "pqgy", "rs", "pqgyx",
NULL, ssh_signature_encoder_dsa,
NULL, 0, 0
},
{
"ecdsa-sha2-nistp256", "ECDSA", GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp256", GCRY_MD_SHA256, SPEC_FLAG_IS_ECDSA
},
{
"ecdsa-sha2-nistp384", "ECDSA", GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp384", GCRY_MD_SHA384, SPEC_FLAG_IS_ECDSA
},
{
"ecdsa-sha2-nistp521", "ECDSA", GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp521", GCRY_MD_SHA512, SPEC_FLAG_IS_ECDSA
},
{
"ssh-ed25519-cert-v01@openssh.com", "Ed25519",
GCRY_PK_EDDSA, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_eddsa,
"Ed25519", 0, SPEC_FLAG_IS_EdDSA | SPEC_FLAG_WITH_CERT
},
{
"ssh-rsa-cert-v01@openssh.com", "RSA",
GCRY_PK_RSA, "nedupq", "en", "s", "nedpqu",
ssh_key_modifier_rsa, ssh_signature_encoder_rsa,
NULL, 0, SPEC_FLAG_USE_PKCS1V2 | SPEC_FLAG_WITH_CERT
},
{
"ssh-dss-cert-v01@openssh.com", "DSA",
GCRY_PK_DSA, "pqgyx", "pqgy", "rs", "pqgyx",
NULL, ssh_signature_encoder_dsa,
NULL, 0, SPEC_FLAG_WITH_CERT | SPEC_FLAG_WITH_CERT
},
{
"ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA",
GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp256", GCRY_MD_SHA256, SPEC_FLAG_IS_ECDSA | SPEC_FLAG_WITH_CERT
},
{
"ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA",
GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp384", GCRY_MD_SHA384, SPEC_FLAG_IS_ECDSA | SPEC_FLAG_WITH_CERT
},
{
"ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA",
GCRY_PK_ECC, "qd", "q", "rs", "qd",
NULL, ssh_signature_encoder_ecdsa,
"nistp521", GCRY_MD_SHA512, SPEC_FLAG_IS_ECDSA | SPEC_FLAG_WITH_CERT
}
};
/*
General utility functions.
*/
/* A secure realloc, i.e. it makes sure to allocate secure memory if A
is NULL. This is required because the standard gcry_realloc does
not know whether to allocate secure or normal if NULL is passed as
existing buffer. */
static void *
realloc_secure (void *a, size_t n)
{
void *p;
if (a)
p = gcry_realloc (a, n);
else
p = gcry_malloc_secure (n);
return p;
}
/* Lookup the ssh-identifier for the ECC curve CURVE_NAME. Returns
NULL if not found. */
static const char *
ssh_identifier_from_curve_name (const char *curve_name)
{
int i;
for (i = 0; i < DIM (ssh_key_types); i++)
if (ssh_key_types[i].curve_name
&& !strcmp (ssh_key_types[i].curve_name, curve_name))
return ssh_key_types[i].ssh_identifier;
return NULL;
}
/*
Primitive I/O functions.
*/
/* Read a byte from STREAM, store it in B. */
static gpg_error_t
stream_read_byte (estream_t stream, unsigned char *b)
{
gpg_error_t err;
int ret;
ret = es_fgetc (stream);
if (ret == EOF)
{
if (es_ferror (stream))
err = gpg_error_from_syserror ();
else
err = gpg_error (GPG_ERR_EOF);
*b = 0;
}
else
{
*b = ret & 0xFF;
err = 0;
}
return err;
}
/* Write the byte contained in B to STREAM. */
static gpg_error_t
stream_write_byte (estream_t stream, unsigned char b)
{
gpg_error_t err;
int ret;
ret = es_fputc (b, stream);
if (ret == EOF)
err = gpg_error_from_syserror ();
else
err = 0;
return err;
}
/* Read a uint32 from STREAM, store it in UINT32. */
static gpg_error_t
stream_read_uint32 (estream_t stream, u32 *uint32)
{
unsigned char buffer[4];
size_t bytes_read;
gpg_error_t err;
int ret;
ret = es_read (stream, buffer, sizeof (buffer), &bytes_read);
if (ret)
err = gpg_error_from_syserror ();
else
{
if (bytes_read != sizeof (buffer))
err = gpg_error (GPG_ERR_EOF);
else
{
u32 n;
n = uint32_construct (buffer[0], buffer[1], buffer[2], buffer[3]);
*uint32 = n;
err = 0;
}
}
return err;
}
/* Write the uint32 contained in UINT32 to STREAM. */
static gpg_error_t
stream_write_uint32 (estream_t stream, u32 uint32)
{
unsigned char buffer[4];
gpg_error_t err;
int ret;
buffer[0] = uint32 >> 24;
buffer[1] = uint32 >> 16;
buffer[2] = uint32 >> 8;
buffer[3] = uint32 >> 0;
ret = es_write (stream, buffer, sizeof (buffer), NULL);
if (ret)
err = gpg_error_from_syserror ();
else
err = 0;
return err;
}
/* Read SIZE bytes from STREAM into BUFFER. */
static gpg_error_t
stream_read_data (estream_t stream, unsigned char *buffer, size_t size)
{
gpg_error_t err;
size_t bytes_read;
int ret;
ret = es_read (stream, buffer, size, &bytes_read);
if (ret)
err = gpg_error_from_syserror ();
else
{
if (bytes_read != size)
err = gpg_error (GPG_ERR_EOF);
else
err = 0;
}
return err;
}
/* Skip over SIZE bytes from STREAM. */
static gpg_error_t
stream_read_skip (estream_t stream, size_t size)
{
char buffer[128];
size_t bytes_to_read, bytes_read;
int ret;
do
{
bytes_to_read = size;
if (bytes_to_read > sizeof buffer)
bytes_to_read = sizeof buffer;
ret = es_read (stream, buffer, bytes_to_read, &bytes_read);
if (ret)
return gpg_error_from_syserror ();
else if (bytes_read != bytes_to_read)
return gpg_error (GPG_ERR_EOF);
else
size -= bytes_to_read;
}
while (size);
return 0;
}
/* Write SIZE bytes from BUFFER to STREAM. */
static gpg_error_t
stream_write_data (estream_t stream, const unsigned char *buffer, size_t size)
{
gpg_error_t err;
int ret;
ret = es_write (stream, buffer, size, NULL);
if (ret)
err = gpg_error_from_syserror ();
else
err = 0;
return err;
}
/* Read a binary string from STREAM into STRING, store size of string
in STRING_SIZE. Append a hidden nul so that the result may
directly be used as a C string. Depending on SECURE use secure
memory for STRING. If STRING is NULL do only a dummy read. */
static gpg_error_t
stream_read_string (estream_t stream, unsigned int secure,
unsigned char **string, u32 *string_size)
{
gpg_error_t err;
unsigned char *buffer = NULL;
u32 length = 0;
if (string_size)
*string_size = 0;
/* Read string length. */
err = stream_read_uint32 (stream, &length);
if (err)
goto out;
if (string)
{
/* Allocate space. */
if (secure)
buffer = xtrymalloc_secure (length + 1);
else
buffer = xtrymalloc (length + 1);
if (! buffer)
{
err = gpg_error_from_syserror ();
goto out;
}
/* Read data. */
err = stream_read_data (stream, buffer, length);
if (err)
goto out;
/* Finalize string object. */
buffer[length] = 0;
*string = buffer;
}
else /* Dummy read requested. */
{
err = stream_read_skip (stream, length);
if (err)
goto out;
}
if (string_size)
*string_size = length;
out:
if (err)
xfree (buffer);
return err;
}
/* Read a binary string from STREAM and store it as an opaque MPI at
R_MPI, adding 0x40 (this is the prefix for EdDSA key in OpenPGP).
Depending on SECURE use secure memory. If the string is too large
for key material return an error. */
static gpg_error_t
stream_read_blob (estream_t stream, unsigned int secure, gcry_mpi_t *r_mpi)
{
gpg_error_t err;
unsigned char *buffer = NULL;
u32 length = 0;
*r_mpi = NULL;
/* Read string length. */
err = stream_read_uint32 (stream, &length);
if (err)
goto leave;
/* To avoid excessive use of secure memory we check that an MPI is
not too large. */
if (length > (4096/8) + 8)
{
log_error (_("ssh keys greater than %d bits are not supported\n"), 4096);
err = GPG_ERR_TOO_LARGE;
goto leave;
}
/* Allocate space. */
if (secure)
buffer = xtrymalloc_secure (length+1);
else
buffer = xtrymalloc (length+1);
if (!buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Read data. */
err = stream_read_data (stream, buffer + 1, length);
if (err)
goto leave;
buffer[0] = 0x40;
*r_mpi = gcry_mpi_set_opaque (NULL, buffer, 8*(length+1));
buffer = NULL;
leave:
xfree (buffer);
return err;
}
/* Read a C-string from STREAM, store copy in STRING. */
static gpg_error_t
stream_read_cstring (estream_t stream, char **string)
{
return stream_read_string (stream, 0, (unsigned char **)string, NULL);
}
/* Write a binary string from STRING of size STRING_N to STREAM. */
static gpg_error_t
stream_write_string (estream_t stream,
const unsigned char *string, u32 string_n)
{
gpg_error_t err;
err = stream_write_uint32 (stream, string_n);
if (err)
goto out;
err = stream_write_data (stream, string, string_n);
out:
return err;
}
/* Write a C-string from STRING to STREAM. */
static gpg_error_t
stream_write_cstring (estream_t stream, const char *string)
{
gpg_error_t err;
err = stream_write_string (stream,
(const unsigned char *) string, strlen (string));
return err;
}
/* Read an MPI from STREAM, store it in MPINT. Depending on SECURE
use secure memory. */
static gpg_error_t
stream_read_mpi (estream_t stream, unsigned int secure, gcry_mpi_t *mpint)
{
unsigned char *mpi_data;
u32 mpi_data_size;
gpg_error_t err;
gcry_mpi_t mpi;
mpi_data = NULL;
err = stream_read_string (stream, secure, &mpi_data, &mpi_data_size);
if (err)
goto out;
/* To avoid excessive use of secure memory we check that an MPI is
not too large. */
if (mpi_data_size > 520)
{
log_error (_("ssh keys greater than %d bits are not supported\n"), 4096);
err = GPG_ERR_TOO_LARGE;
goto out;
}
err = gcry_mpi_scan (&mpi, GCRYMPI_FMT_STD, mpi_data, mpi_data_size, NULL);
if (err)
goto out;
*mpint = mpi;
out:
xfree (mpi_data);
return err;
}
/* Write the MPI contained in MPINT to STREAM. */
static gpg_error_t
stream_write_mpi (estream_t stream, gcry_mpi_t mpint)
{
unsigned char *mpi_buffer;
size_t mpi_buffer_n;
gpg_error_t err;
mpi_buffer = NULL;
err = gcry_mpi_aprint (GCRYMPI_FMT_STD, &mpi_buffer, &mpi_buffer_n, mpint);
if (err)
goto out;
err = stream_write_string (stream, mpi_buffer, mpi_buffer_n);
out:
xfree (mpi_buffer);
return err;
}
/* Copy data from SRC to DST until EOF is reached. */
static gpg_error_t
stream_copy (estream_t dst, estream_t src)
{
char buffer[BUFSIZ];
size_t bytes_read;
gpg_error_t err;
int ret;
err = 0;
while (1)
{
ret = es_read (src, buffer, sizeof (buffer), &bytes_read);
if (ret || (! bytes_read))
{
if (ret)
err = gpg_error_from_syserror ();
break;
}
ret = es_write (dst, buffer, bytes_read, NULL);
if (ret)
{
err = gpg_error_from_syserror ();
break;
}
}
return err;
}
/* Open the ssh control file and create it if not available. With
APPEND passed as true the file will be opened in append mode,
otherwise in read only mode. On success 0 is returned and a new
control file object stored at R_CF. On error an error code is
returned and NULL is stored at R_CF. */
static gpg_error_t
open_control_file (ssh_control_file_t *r_cf, int append)
{
gpg_error_t err;
ssh_control_file_t cf;
cf = xtrycalloc (1, sizeof *cf);
if (!cf)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Note: As soon as we start to use non blocking functions here
(i.e. where Pth might switch threads) we need to employ a
mutex. */
cf->fname = make_filename_try (gnupg_homedir (), SSH_CONTROL_FILE_NAME, NULL);
if (!cf->fname)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* FIXME: With "a+" we are not able to check whether this will
be created and thus the blurb needs to be written first. */
cf->fp = fopen (cf->fname, append? "a+":"r");
if (!cf->fp && errno == ENOENT)
{
estream_t stream = es_fopen (cf->fname, "wx,mode=-rw-r");
if (!stream)
{
err = gpg_error_from_syserror ();
log_error (_("can't create '%s': %s\n"),
cf->fname, gpg_strerror (err));
goto leave;
}
es_fputs (sshcontrolblurb, stream);
es_fclose (stream);
cf->fp = fopen (cf->fname, append? "a+":"r");
}
if (!cf->fp)
{
err = gpg_error_from_syserror ();
log_error (_("can't open '%s': %s\n"),
cf->fname, gpg_strerror (err));
goto leave;
}
err = 0;
leave:
if (err && cf)
{
if (cf->fp)
fclose (cf->fp);
xfree (cf->fname);
xfree (cf);
}
else
*r_cf = cf;
return err;
}
static void
rewind_control_file (ssh_control_file_t cf)
{
fseek (cf->fp, 0, SEEK_SET);
cf->lnr = 0;
clearerr (cf->fp);
}
static void
close_control_file (ssh_control_file_t cf)
{
if (!cf)
return;
fclose (cf->fp);
xfree (cf->fname);
xfree (cf);
}
/* Read the next line from the control file and store the data in CF.
Returns 0 on success, GPG_ERR_EOF on EOF, or other error codes. */
static gpg_error_t
read_control_file_item (ssh_control_file_t cf)
{
int c, i, n;
char *p, *pend, line[256];
long ttl = 0;
cf->item.valid = 0;
clearerr (cf->fp);
do
{
if (!fgets (line, DIM(line)-1, cf->fp) )
{
if (feof (cf->fp))
return gpg_error (GPG_ERR_EOF);
return gpg_error_from_syserror ();
}
cf->lnr++;
if (!*line || line[strlen(line)-1] != '\n')
{
/* Eat until end of line */
while ( (c=getc (cf->fp)) != EOF && c != '\n')
;
return gpg_error (*line? GPG_ERR_LINE_TOO_LONG
: GPG_ERR_INCOMPLETE_LINE);
}
/* Allow for empty lines and spaces */
for (p=line; spacep (p); p++)
;
}
while (!*p || *p == '\n' || *p == '#');
cf->item.disabled = 0;
if (*p == '!')
{
cf->item.disabled = 1;
for (p++; spacep (p); p++)
;
}
for (i=0; hexdigitp (p) && i < 40; p++, i++)
cf->item.hexgrip[i] = (*p >= 'a'? (*p & 0xdf): *p);
cf->item.hexgrip[i] = 0;
if (i != 40 || !(spacep (p) || *p == '\n'))
{
log_error ("%s:%d: invalid formatted line\n", cf->fname, cf->lnr);
return gpg_error (GPG_ERR_BAD_DATA);
}
ttl = strtol (p, &pend, 10);
p = pend;
if (!(spacep (p) || *p == '\n') || (int)ttl < -1)
{
log_error ("%s:%d: invalid TTL value; assuming 0\n", cf->fname, cf->lnr);
cf->item.ttl = 0;
}
cf->item.ttl = ttl;
/* Now check for key-value pairs of the form NAME[=VALUE]. */
cf->item.confirm = 0;
while (*p)
{
for (; spacep (p) && *p != '\n'; p++)
;
if (!*p || *p == '\n')
break;
n = strcspn (p, "= \t\n");
if (p[n] == '=')
{
log_error ("%s:%d: assigning a value to a flag is not yet supported; "
"flag ignored\n", cf->fname, cf->lnr);
p++;
}
else if (n == 7 && !memcmp (p, "confirm", 7))
{
cf->item.confirm = 1;
}
else
log_error ("%s:%d: invalid flag '%.*s'; ignored\n",
cf->fname, cf->lnr, n, p);
p += n;
}
/* log_debug ("%s:%d: grip=%s ttl=%d%s%s\n", */
/* cf->fname, cf->lnr, */
/* cf->item.hexgrip, cf->item.ttl, */
/* cf->item.disabled? " disabled":"", */
/* cf->item.confirm? " confirm":""); */
cf->item.valid = 1;
return 0; /* Okay: valid entry found. */
}
/* Search the control file CF from the beginning until a matching
HEXGRIP is found; return success in this case and store true at
DISABLED if the found key has been disabled. If R_TTL is not NULL
a specified TTL for that key is stored there. If R_CONFIRM is not
NULL it is set to 1 if the key has the confirm flag set. */
static gpg_error_t
search_control_file (ssh_control_file_t cf, const char *hexgrip,
int *r_disabled, int *r_ttl, int *r_confirm)
{
gpg_error_t err;
assert (strlen (hexgrip) == 40 );
if (r_disabled)
*r_disabled = 0;
if (r_ttl)
*r_ttl = 0;
if (r_confirm)
*r_confirm = 0;
rewind_control_file (cf);
while (!(err=read_control_file_item (cf)))
{
if (!cf->item.valid)
continue; /* Should not happen. */
if (!strcmp (hexgrip, cf->item.hexgrip))
break;
}
if (!err)
{
if (r_disabled)
*r_disabled = cf->item.disabled;
if (r_ttl)
*r_ttl = cf->item.ttl;
if (r_confirm)
*r_confirm = cf->item.confirm;
}
return err;
}
/* Add an entry to the control file to mark the key with the keygrip
HEXGRIP as usable for SSH; i.e. it will be returned when ssh asks
for it. FMTFPR is the fingerprint string. This function is in
general used to add a key received through the ssh-add function.
We can assume that the user wants to allow ssh using this key. */
static gpg_error_t
add_control_entry (ctrl_t ctrl, ssh_key_type_spec_t *spec,
const char *hexgrip, gcry_sexp_t key,
int ttl, int confirm)
{
gpg_error_t err;
ssh_control_file_t cf;
int disabled;
char *fpr_md5 = NULL;
char *fpr_sha256 = NULL;
(void)ctrl;
err = open_control_file (&cf, 1);
if (err)
return err;
err = search_control_file (cf, hexgrip, &disabled, NULL, NULL);
if (err && gpg_err_code(err) == GPG_ERR_EOF)
{
struct tm *tp;
time_t atime = time (NULL);
err = ssh_get_fingerprint_string (key, GCRY_MD_MD5, &fpr_md5);
if (err)
goto out;
err = ssh_get_fingerprint_string (key, GCRY_MD_SHA256, &fpr_sha256);
if (err)
goto out;
/* Not yet in the file - add it. Because the file has been
opened in append mode, we simply need to write to it. */
tp = localtime (&atime);
fprintf (cf->fp,
("# %s key added on: %04d-%02d-%02d %02d:%02d:%02d\n"
"# Fingerprints: %s\n"
"# %s\n"
"%s %d%s\n"),
spec->name,
1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday,
tp->tm_hour, tp->tm_min, tp->tm_sec,
fpr_md5, fpr_sha256, hexgrip, ttl, confirm? " confirm":"");
}
out:
xfree (fpr_md5);
xfree (fpr_sha256);
close_control_file (cf);
return 0;
}
/* Scan the sshcontrol file and return the TTL. */
static int
ttl_from_sshcontrol (const char *hexgrip)
{
ssh_control_file_t cf;
int disabled, ttl;
if (!hexgrip || strlen (hexgrip) != 40)
return 0; /* Wrong input: Use global default. */
if (open_control_file (&cf, 0))
return 0; /* Error: Use the global default TTL. */
if (search_control_file (cf, hexgrip, &disabled, &ttl, NULL)
|| disabled)
ttl = 0; /* Use the global default if not found or disabled. */
close_control_file (cf);
return ttl;
}
/* Scan the sshcontrol file and return the confirm flag. */
static int
confirm_flag_from_sshcontrol (const char *hexgrip)
{
ssh_control_file_t cf;
int disabled, confirm;
if (!hexgrip || strlen (hexgrip) != 40)
return 1; /* Wrong input: Better ask for confirmation. */
if (open_control_file (&cf, 0))
return 1; /* Error: Better ask for confirmation. */
if (search_control_file (cf, hexgrip, &disabled, NULL, &confirm)
|| disabled)
confirm = 0; /* If not found or disabled, there is no reason to
ask for confirmation. */
close_control_file (cf);
return confirm;
}
/* Open the ssh control file for reading. This is a public version of
open_control_file. The caller must use ssh_close_control_file to
release the returned handle. */
ssh_control_file_t
ssh_open_control_file (void)
{
ssh_control_file_t cf;
/* Then look at all the registered and non-disabled keys. */
if (open_control_file (&cf, 0))
return NULL;
return cf;
}
/* Close an ssh control file handle. This is the public version of
close_control_file. CF may be NULL. */
void
ssh_close_control_file (ssh_control_file_t cf)
{
close_control_file (cf);
}
/* Read the next item from the ssh control file. The function returns
0 if a item was read, GPG_ERR_EOF on eof or another error value.
R_HEXGRIP shall either be null or a BUFFER of at least 41 byte.
R_DISABLED, R_TTLm and R_CONFIRM return flags from the control
file; they are only set on success. */
gpg_error_t
ssh_read_control_file (ssh_control_file_t cf,
char *r_hexgrip,
int *r_disabled, int *r_ttl, int *r_confirm)
{
gpg_error_t err;
do
err = read_control_file_item (cf);
while (!err && !cf->item.valid);
if (!err)
{
if (r_hexgrip)
strcpy (r_hexgrip, cf->item.hexgrip);
if (r_disabled)
*r_disabled = cf->item.disabled;
if (r_ttl)
*r_ttl = cf->item.ttl;
if (r_confirm)
*r_confirm = cf->item.confirm;
}
return err;
}
/* Search for a key with HEXGRIP in sshcontrol and return all
info. */
gpg_error_t
ssh_search_control_file (ssh_control_file_t cf,
const char *hexgrip,
int *r_disabled, int *r_ttl, int *r_confirm)
{
gpg_error_t err;
int i;
const char *s;
char uphexgrip[41];
/* We need to make sure that HEXGRIP is all uppercase. The easiest
way to do this and also check its length is by copying to a
second buffer. */
for (i=0, s=hexgrip; i < 40 && *s; s++, i++)
uphexgrip[i] = *s >= 'a'? (*s & 0xdf): *s;
uphexgrip[i] = 0;
if (i != 40)
err = gpg_error (GPG_ERR_INV_LENGTH);
else
err = search_control_file (cf, uphexgrip, r_disabled, r_ttl, r_confirm);
if (gpg_err_code (err) == GPG_ERR_EOF)
err = gpg_error (GPG_ERR_NOT_FOUND);
return err;
}
/*
MPI lists.
*/
/* Free the list of MPIs MPI_LIST. */
static void
mpint_list_free (gcry_mpi_t *mpi_list)
{
if (mpi_list)
{
unsigned int i;
for (i = 0; mpi_list[i]; i++)
gcry_mpi_release (mpi_list[i]);
xfree (mpi_list);
}
}
/* Receive key material MPIs from STREAM according to KEY_SPEC;
depending on SECRET expect a public key or secret key. CERT is the
certificate blob used if KEY_SPEC indicates the certificate format;
it needs to be positioned to the end of the nonce. The newly
allocated list of MPIs is stored in MPI_LIST. Returns usual error
code. */
static gpg_error_t
ssh_receive_mpint_list (estream_t stream, int secret,
ssh_key_type_spec_t *spec, estream_t cert,
gcry_mpi_t **mpi_list)
{
const char *elems_public;
unsigned int elems_n;
const char *elems;
int elem_is_secret;
gcry_mpi_t *mpis = NULL;
gpg_error_t err = 0;
unsigned int i;
if (secret)
elems = spec->elems_key_secret;
else
elems = spec->elems_key_public;
elems_n = strlen (elems);
elems_public = spec->elems_key_public;
/* Check that either both, CERT and the WITH_CERT flag, are given or
none of them. */
if (!(!!(spec->flags & SPEC_FLAG_WITH_CERT) ^ !cert))
{
err = gpg_error (GPG_ERR_INV_CERT_OBJ);
goto out;
}
mpis = xtrycalloc (elems_n + 1, sizeof *mpis );
if (!mpis)
{
err = gpg_error_from_syserror ();
goto out;
}
elem_is_secret = 0;
for (i = 0; i < elems_n; i++)
{
if (secret)
elem_is_secret = !strchr (elems_public, elems[i]);
if (cert && !elem_is_secret)
err = stream_read_mpi (cert, elem_is_secret, &mpis[i]);
else
err = stream_read_mpi (stream, elem_is_secret, &mpis[i]);
if (err)
goto out;
}
*mpi_list = mpis;
mpis = NULL;
out:
if (err)
mpint_list_free (mpis);
return err;
}
/* Key modifier function for RSA. */
static gpg_error_t
ssh_key_modifier_rsa (const char *elems, gcry_mpi_t *mpis)
{
gcry_mpi_t p;
gcry_mpi_t q;
gcry_mpi_t u;
if (strcmp (elems, "nedupq"))
/* Modifying only necessary for secret keys. */
goto out;
u = mpis[3];
p = mpis[4];
q = mpis[5];
if (gcry_mpi_cmp (p, q) > 0)
{
/* P shall be smaller then Q! Swap primes. iqmp becomes u. */
gcry_mpi_t tmp;
tmp = mpis[4];
mpis[4] = mpis[5];
mpis[5] = tmp;
}
else
/* U needs to be recomputed. */
gcry_mpi_invm (u, p, q);
out:
return 0;
}
/* Signature encoder function for RSA. */
static gpg_error_t
ssh_signature_encoder_rsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t s_signature)
{
gpg_error_t err = 0;
gcry_sexp_t valuelist = NULL;
gcry_sexp_t sublist = NULL;
gcry_mpi_t sig_value = NULL;
gcry_mpi_t *mpis = NULL;
const char *elems;
size_t elems_n;
int i;
unsigned char *data;
size_t data_n;
gcry_mpi_t s;
valuelist = gcry_sexp_nth (s_signature, 1);
if (!valuelist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
elems = spec->elems_signature;
elems_n = strlen (elems);
mpis = xtrycalloc (elems_n + 1, sizeof *mpis);
if (!mpis)
{
err = gpg_error_from_syserror ();
goto out;
}
for (i = 0; i < elems_n; i++)
{
sublist = gcry_sexp_find_token (valuelist, spec->elems_signature + i, 1);
if (!sublist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
break;
}
sig_value = gcry_sexp_nth_mpi (sublist, 1, GCRYMPI_FMT_USG);
if (!sig_value)
{
err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
break;
}
gcry_sexp_release (sublist);
sublist = NULL;
mpis[i] = sig_value;
}
if (err)
goto out;
/* RSA specific */
s = mpis[0];
err = gcry_mpi_aprint (GCRYMPI_FMT_USG, &data, &data_n, s);
if (err)
goto out;
err = stream_write_string (signature_blob, data, data_n);
xfree (data);
out:
gcry_sexp_release (valuelist);
gcry_sexp_release (sublist);
mpint_list_free (mpis);
return err;
}
/* Signature encoder function for DSA. */
static gpg_error_t
ssh_signature_encoder_dsa (ssh_key_type_spec_t *spec,
estream_t signature_blob,
gcry_sexp_t s_signature)
{
gpg_error_t err = 0;
gcry_sexp_t valuelist = NULL;
gcry_sexp_t sublist = NULL;
gcry_mpi_t sig_value = NULL;
gcry_mpi_t *mpis = NULL;
const char *elems;
size_t elems_n;
int i;
unsigned char buffer[SSH_DSA_SIGNATURE_PADDING * SSH_DSA_SIGNATURE_ELEMS];
unsigned char *data = NULL;
size_t data_n;
valuelist = gcry_sexp_nth (s_signature, 1);
if (!valuelist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
elems = spec->elems_signature;
elems_n = strlen (elems);
mpis = xtrycalloc (elems_n + 1, sizeof *mpis);
if (!mpis)
{
err = gpg_error_from_syserror ();
goto out;
}
for (i = 0; i < elems_n; i++)
{
sublist = gcry_sexp_find_token (valuelist, spec->elems_signature + i, 1);
if (!sublist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
break;
}
sig_value = gcry_sexp_nth_mpi (sublist, 1, GCRYMPI_FMT_USG);
if (!sig_value)
{
err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
break;
}
gcry_sexp_release (sublist);
sublist = NULL;
mpis[i] = sig_value;
}
if (err)
goto out;
/* DSA specific code. */
/* FIXME: Why this complicated code? Why collecting boths mpis in a
buffer instead of writing them out one after the other? */
for (i = 0; i < 2; i++)
{
err = gcry_mpi_aprint (GCRYMPI_FMT_USG, &data, &data_n, mpis[i]);
if (err)
break;
if (data_n > SSH_DSA_SIGNATURE_PADDING)
{
err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
break;
}
memset (buffer + (i * SSH_DSA_SIGNATURE_PADDING), 0,
SSH_DSA_SIGNATURE_PADDING - data_n);
memcpy (buffer + (i * SSH_DSA_SIGNATURE_PADDING)
+ (SSH_DSA_SIGNATURE_PADDING - data_n), data, data_n);
xfree (data);
data = NULL;
}
if (err)
goto out;
err = stream_write_string (signature_blob, buffer, sizeof (buffer));
out:
xfree (data);
gcry_sexp_release (valuelist);
gcry_sexp_release (sublist);
mpint_list_free (mpis);
return err;
}
/* Signature encoder function for ECDSA. */
static gpg_error_t
ssh_signature_encoder_ecdsa (ssh_key_type_spec_t *spec,
estream_t stream, gcry_sexp_t s_signature)
{
gpg_error_t err = 0;
gcry_sexp_t valuelist = NULL;
gcry_sexp_t sublist = NULL;
gcry_mpi_t sig_value = NULL;
gcry_mpi_t *mpis = NULL;
const char *elems;
size_t elems_n;
int i;
unsigned char *data[2] = {NULL, NULL};
size_t data_n[2];
size_t innerlen;
valuelist = gcry_sexp_nth (s_signature, 1);
if (!valuelist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
elems = spec->elems_signature;
elems_n = strlen (elems);
mpis = xtrycalloc (elems_n + 1, sizeof *mpis);
if (!mpis)
{
err = gpg_error_from_syserror ();
goto out;
}
for (i = 0; i < elems_n; i++)
{
sublist = gcry_sexp_find_token (valuelist, spec->elems_signature + i, 1);
if (!sublist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
break;
}
sig_value = gcry_sexp_nth_mpi (sublist, 1, GCRYMPI_FMT_USG);
if (!sig_value)
{
err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
break;
}
gcry_sexp_release (sublist);
sublist = NULL;
mpis[i] = sig_value;
}
if (err)
goto out;
/* ECDSA specific */
innerlen = 0;
for (i = 0; i < DIM(data); i++)
{
err = gcry_mpi_aprint (GCRYMPI_FMT_STD, &data[i], &data_n[i], mpis[i]);
if (err)
goto out;
innerlen += 4 + data_n[i];
}
err = stream_write_uint32 (stream, innerlen);
if (err)
goto out;
for (i = 0; i < DIM(data); i++)
{
err = stream_write_string (stream, data[i], data_n[i]);
if (err)
goto out;
}
out:
for (i = 0; i < DIM(data); i++)
xfree (data[i]);
gcry_sexp_release (valuelist);
gcry_sexp_release (sublist);
mpint_list_free (mpis);
return err;
}
/* Signature encoder function for EdDSA. */
static gpg_error_t
ssh_signature_encoder_eddsa (ssh_key_type_spec_t *spec,
estream_t stream, gcry_sexp_t s_signature)
{
gpg_error_t err = 0;
gcry_sexp_t valuelist = NULL;
gcry_sexp_t sublist = NULL;
const char *elems;
size_t elems_n;
int i;
unsigned char *data[2] = {NULL, NULL};
size_t data_n[2];
size_t totallen = 0;
valuelist = gcry_sexp_nth (s_signature, 1);
if (!valuelist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
elems = spec->elems_signature;
elems_n = strlen (elems);
if (elems_n != DIM(data))
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
for (i = 0; i < DIM(data); i++)
{
sublist = gcry_sexp_find_token (valuelist, spec->elems_signature + i, 1);
if (!sublist)
{
err = gpg_error (GPG_ERR_INV_SEXP);
break;
}
data[i] = gcry_sexp_nth_buffer (sublist, 1, &data_n[i]);
if (!data[i])
{
err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
break;
}
totallen += data_n[i];
gcry_sexp_release (sublist);
sublist = NULL;
}
if (err)
goto out;
err = stream_write_uint32 (stream, totallen);
if (err)
goto out;
for (i = 0; i < DIM(data); i++)
{
err = stream_write_data (stream, data[i], data_n[i]);
if (err)
goto out;
}
out:
for (i = 0; i < DIM(data); i++)
xfree (data[i]);
gcry_sexp_release (valuelist);
gcry_sexp_release (sublist);
return err;
}
/*
S-Expressions.
*/
/* This function constructs a new S-Expression for the key identified
by the KEY_SPEC, SECRET, CURVE_NAME, MPIS, and COMMENT, which is to
be stored at R_SEXP. Returns an error code. */
static gpg_error_t
sexp_key_construct (gcry_sexp_t *r_sexp,
ssh_key_type_spec_t key_spec, int secret,
const char *curve_name, gcry_mpi_t *mpis,
const char *comment)
{
gpg_error_t err;
gcry_sexp_t sexp_new = NULL;
void *formatbuf = NULL;
void **arg_list = NULL;
estream_t format = NULL;
char *algo_name = NULL;
if ((key_spec.flags & SPEC_FLAG_IS_EdDSA))
{
/* It is much easier and more readable to use a separate code
path for EdDSA. */
if (!curve_name)
err = gpg_error (GPG_ERR_INV_CURVE);
else if (!mpis[0] || !gcry_mpi_get_flag (mpis[0], GCRYMPI_FLAG_OPAQUE))
err = gpg_error (GPG_ERR_BAD_PUBKEY);
else if (secret
&& (!mpis[1]
|| !gcry_mpi_get_flag (mpis[1], GCRYMPI_FLAG_OPAQUE)))
err = gpg_error (GPG_ERR_BAD_SECKEY);
else if (secret)
err = gcry_sexp_build (&sexp_new, NULL,
"(private-key(ecc(curve %s)"
"(flags eddsa)(q %m)(d %m))"
"(comment%s))",
curve_name,
mpis[0], mpis[1],
comment? comment:"");
else
err = gcry_sexp_build (&sexp_new, NULL,
"(public-key(ecc(curve %s)"
"(flags eddsa)(q %m))"
"(comment%s))",
curve_name,
mpis[0],
comment? comment:"");
}
else
{
const char *key_identifier[] = { "public-key", "private-key" };
int arg_idx;
const char *elems;
size_t elems_n;
unsigned int i, j;
if (secret)
elems = key_spec.elems_sexp_order;
else
elems = key_spec.elems_key_public;
elems_n = strlen (elems);
format = es_fopenmem (0, "a+b");
if (!format)
{
err = gpg_error_from_syserror ();
goto out;
}
/* Key identifier, algorithm identifier, mpis, comment, and a NULL
as a safeguard. */
arg_list = xtrymalloc (sizeof (*arg_list) * (2 + 1 + elems_n + 1 + 1));
if (!arg_list)
{
err = gpg_error_from_syserror ();
goto out;
}
arg_idx = 0;
es_fputs ("(%s(%s", format);
arg_list[arg_idx++] = &key_identifier[secret];
algo_name = xtrystrdup (gcry_pk_algo_name (key_spec.algo));
if (!algo_name)
{
err = gpg_error_from_syserror ();
goto out;
}
strlwr (algo_name);
arg_list[arg_idx++] = &algo_name;
if (curve_name)
{
es_fputs ("(curve%s)", format);
arg_list[arg_idx++] = &curve_name;
}
for (i = 0; i < elems_n; i++)
{
es_fprintf (format, "(%c%%m)", elems[i]);
if (secret)
{
for (j = 0; j < elems_n; j++)
if (key_spec.elems_key_secret[j] == elems[i])
break;
}
else
j = i;
arg_list[arg_idx++] = &mpis[j];
}
es_fputs (")(comment%s))", format);
arg_list[arg_idx++] = &comment;
arg_list[arg_idx] = NULL;
es_putc (0, format);
if (es_ferror (format))
{
err = gpg_error_from_syserror ();
goto out;
}
if (es_fclose_snatch (format, &formatbuf, NULL))
{
err = gpg_error_from_syserror ();
goto out;
}
format = NULL;
err = gcry_sexp_build_array (&sexp_new, NULL, formatbuf, arg_list);
}
if (!err)
*r_sexp = sexp_new;
out:
es_fclose (format);
xfree (arg_list);
xfree (formatbuf);
xfree (algo_name);
return err;
}
/* This function extracts the key from the s-expression SEXP according
to KEY_SPEC and stores it in ssh format at (R_BLOB, R_BLOBLEN). If
WITH_SECRET is true, the secret key parts are also extracted if
possible. Returns 0 on success or an error code. Note that data
stored at R_BLOB must be freed using es_free! */
static gpg_error_t
ssh_key_to_blob (gcry_sexp_t sexp, int with_secret,
ssh_key_type_spec_t key_spec,
void **r_blob, size_t *r_blob_size)
{
gpg_error_t err = 0;
gcry_sexp_t value_list = NULL;
gcry_sexp_t value_pair = NULL;
char *curve_name = NULL;
estream_t stream = NULL;
void *blob = NULL;
size_t blob_size;
const char *elems, *p_elems;
const char *data;
size_t datalen;
*r_blob = NULL;
*r_blob_size = 0;
stream = es_fopenmem (0, "r+b");
if (!stream)
{
err = gpg_error_from_syserror ();
goto out;
}
/* Get the type of the key extpression. */
data = gcry_sexp_nth_data (sexp, 0, &datalen);
if (!data)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
if ((datalen == 10 && !strncmp (data, "public-key", 10))
|| (datalen == 21 && !strncmp (data, "protected-private-key", 21))
|| (datalen == 20 && !strncmp (data, "shadowed-private-key", 20)))
elems = key_spec.elems_key_public;
else if (datalen == 11 && !strncmp (data, "private-key", 11))
elems = with_secret? key_spec.elems_key_secret : key_spec.elems_key_public;
else
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
/* Get key value list. */
value_list = gcry_sexp_cadr (sexp);
if (!value_list)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
/* Write the ssh algorithm identifier. */
if ((key_spec.flags & SPEC_FLAG_IS_ECDSA))
{
/* Parse the "curve" parameter. We currently expect the curve
name for ECC and not the parameters of the curve. This can
easily be changed but then we need to find the curve name
from the parameters using gcry_pk_get_curve. */
const char *mapped;
const char *sshname;
gcry_sexp_release (value_pair);
value_pair = gcry_sexp_find_token (value_list, "curve", 5);
if (!value_pair)
{
err = gpg_error (GPG_ERR_INV_CURVE);
goto out;
}
curve_name = gcry_sexp_nth_string (value_pair, 1);
if (!curve_name)
{
err = gpg_error (GPG_ERR_INV_CURVE); /* (Or out of core.) */
goto out;
}
/* Fixme: The mapping should be done by using gcry_pk_get_curve
et al to iterate over all name aliases. */
if (!strcmp (curve_name, "NIST P-256"))
mapped = "nistp256";
else if (!strcmp (curve_name, "NIST P-384"))
mapped = "nistp384";
else if (!strcmp (curve_name, "NIST P-521"))
mapped = "nistp521";
else
mapped = NULL;
if (mapped)
{
xfree (curve_name);
curve_name = xtrystrdup (mapped);
if (!curve_name)
{
err = gpg_error_from_syserror ();
goto out;
}
}
sshname = ssh_identifier_from_curve_name (curve_name);
if (!sshname)
{
err = gpg_error (GPG_ERR_UNKNOWN_CURVE);
goto out;
}
err = stream_write_cstring (stream, sshname);
if (err)
goto out;
err = stream_write_cstring (stream, curve_name);
if (err)
goto out;
}
else
{
/* Note: This is also used for EdDSA. */
err = stream_write_cstring (stream, key_spec.ssh_identifier);
if (err)
goto out;
}
/* Write the parameters. */
for (p_elems = elems; *p_elems; p_elems++)
{
gcry_sexp_release (value_pair);
value_pair = gcry_sexp_find_token (value_list, p_elems, 1);
if (!value_pair)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
if ((key_spec.flags & SPEC_FLAG_IS_EdDSA))
{
data = gcry_sexp_nth_data (value_pair, 1, &datalen);
if (!data)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
if (*p_elems == 'q' && datalen)
{ /* Remove the prefix 0x40. */
data++;
datalen--;
}
err = stream_write_string (stream, data, datalen);
if (err)
goto out;
}
else
{
gcry_mpi_t mpi;
/* Note that we need to use STD format; i.e. prepend a 0x00
to indicate a positive number if the high bit is set. */
mpi = gcry_sexp_nth_mpi (value_pair, 1, GCRYMPI_FMT_STD);
if (!mpi)
{
err = gpg_error (GPG_ERR_INV_SEXP);
goto out;
}
err = stream_write_mpi (stream, mpi);
gcry_mpi_release (mpi);
if (err)
goto out;
}
}
if (es_fclose_snatch (stream, &blob, &blob_size))
{
err = gpg_error_from_syserror ();
goto out;
}
stream = NULL;
*r_blob = blob;
blob = NULL;
*r_blob_size = blob_size;
out:
gcry_sexp_release (value_list);
gcry_sexp_release (value_pair);
xfree (curve_name);
es_fclose (stream);
es_free (blob);
return err;
}
/*
Key I/O.
*/
/* Search for a key specification entry. If SSH_NAME is not NULL,
search for an entry whose "ssh_name" is equal to SSH_NAME;
otherwise, search for an entry whose algorithm is equal to ALGO.
Store found entry in SPEC on success, return error otherwise. */
static gpg_error_t
ssh_key_type_lookup (const char *ssh_name, int algo,
ssh_key_type_spec_t *spec)
{
gpg_error_t err;
unsigned int i;
for (i = 0; i < DIM (ssh_key_types); i++)
if ((ssh_name && (! strcmp (ssh_name, ssh_key_types[i].ssh_identifier)))
|| algo == ssh_key_types[i].algo)
break;
if (i == DIM (ssh_key_types))
err = gpg_error (GPG_ERR_NOT_FOUND);
else
{
*spec = ssh_key_types[i];
err = 0;
}
return err;
}
/* Receive a key from STREAM, according to the key specification given
as KEY_SPEC. Depending on SECRET, receive a secret or a public
key. If READ_COMMENT is true, receive a comment string as well.
Constructs a new S-Expression from received data and stores it in
KEY_NEW. Returns zero on success or an error code. */
static gpg_error_t
ssh_receive_key (estream_t stream, gcry_sexp_t *key_new, int secret,
int read_comment, ssh_key_type_spec_t *key_spec)
{
gpg_error_t err;
char *key_type = NULL;
char *comment = NULL;
estream_t cert = NULL;
gcry_sexp_t key = NULL;
ssh_key_type_spec_t spec;
gcry_mpi_t *mpi_list = NULL;
const char *elems;
char *curve_name = NULL;
err = stream_read_cstring (stream, &key_type);
if (err)
goto out;
err = ssh_key_type_lookup (key_type, 0, &spec);
if (err)
goto out;
if ((spec.flags & SPEC_FLAG_WITH_CERT))
{
/* This is an OpenSSH certificate+private key. The certificate
is an SSH string and which we store in an estream object. */
unsigned char *buffer;
u32 buflen;
char *cert_key_type;
err = stream_read_string (stream, 0, &buffer, &buflen);
if (err)
goto out;
cert = es_fopenmem_init (0, "rb", buffer, buflen);
xfree (buffer);
if (!cert)
{
err = gpg_error_from_syserror ();
goto out;
}
/* Check that the key type matches. */
err = stream_read_cstring (cert, &cert_key_type);
if (err)
goto out;
if (strcmp (cert_key_type, key_type) )
{
xfree (cert_key_type);
log_error ("key types in received ssh certificate do not match\n");
err = gpg_error (GPG_ERR_INV_CERT_OBJ);
goto out;
}
xfree (cert_key_type);
/* Skip the nonce. */
err = stream_read_string (cert, 0, NULL, NULL);
if (err)
goto out;
}
if ((spec.flags & SPEC_FLAG_IS_EdDSA))
{
/* The format of an EdDSA key is:
* string key_type ("ssh-ed25519")
* string public_key
* string private_key
*
* Note that the private key is the concatenation of the private
* key with the public key. Thus there's are 64 bytes; however
* we only want the real 32 byte private key - Libgcrypt expects
* this.
*/
mpi_list = xtrycalloc (3, sizeof *mpi_list);
if (!mpi_list)
{
err = gpg_error_from_syserror ();
goto out;
}
err = stream_read_blob (cert? cert : stream, 0, &mpi_list[0]);
if (err)
goto out;
if (secret)
{
u32 len = 0;
unsigned char *buffer;
/* Read string length. */
err = stream_read_uint32 (stream, &len);
if (err)
goto out;
if (len != 32 && len != 64)
{
err = gpg_error (GPG_ERR_BAD_SECKEY);
goto out;
}
buffer = xtrymalloc_secure (32);
if (!buffer)
{
err = gpg_error_from_syserror ();
goto out;
}
err = stream_read_data (stream, buffer, 32);
if (err)
{
xfree (buffer);
goto out;
}
mpi_list[1] = gcry_mpi_set_opaque (NULL, buffer, 8*32);
buffer = NULL;
if (len == 64)
{
err = stream_read_skip (stream, 32);
if (err)
goto out;
}
}
}
else if ((spec.flags & SPEC_FLAG_IS_ECDSA))
{
/* The format of an ECDSA key is:
* string key_type ("ecdsa-sha2-nistp256" |
* "ecdsa-sha2-nistp384" |
* "ecdsa-sha2-nistp521" )
* string ecdsa_curve_name
* string ecdsa_public_key
* mpint ecdsa_private
*
* Note that we use the mpint reader instead of the string
* reader for ecsa_public_key. For the certificate variante
* ecdsa_curve_name+ecdsa_public_key are replaced by the
* certificate.
*/
unsigned char *buffer;
const char *mapped;
err = stream_read_string (cert? cert : stream, 0, &buffer, NULL);
if (err)
goto out;
curve_name = buffer;
/* Fixme: Check that curve_name matches the keytype. */
/* Because Libgcrypt < 1.6 has no support for the "nistpNNN"
curve names, we need to translate them here to Libgcrypt's
native names. */
if (!strcmp (curve_name, "nistp256"))
mapped = "NIST P-256";
else if (!strcmp (curve_name, "nistp384"))
mapped = "NIST P-384";
else if (!strcmp (curve_name, "nistp521"))
mapped = "NIST P-521";
else
mapped = NULL;
if (mapped)
{
xfree (curve_name);
curve_name = xtrystrdup (mapped);
if (!curve_name)
{
err = gpg_error_from_syserror ();
goto out;
}
}
err = ssh_receive_mpint_list (stream, secret, &spec, cert, &mpi_list);
if (err)
goto out;
}
else
{
err = ssh_receive_mpint_list (stream, secret, &spec, cert, &mpi_list);
if (err)
goto out;
}
if (read_comment)
{
err = stream_read_cstring (stream, &comment);
if (err)
goto out;
}
if (secret)
elems = spec.elems_key_secret;
else
elems = spec.elems_key_public;
if (spec.key_modifier)
{
err = (*spec.key_modifier) (elems, mpi_list);
if (err)
goto out;
}
if ((spec.flags & SPEC_FLAG_IS_EdDSA))
{
if (secret)
{
err = gcry_sexp_build (&key, NULL,
"(private-key(ecc(curve \"Ed25519\")"
"(flags eddsa)(q %m)(d %m))"
"(comment%s))",
mpi_list[0], mpi_list[1],
comment? comment:"");
}
else
{
err = gcry_sexp_build (&key, NULL,
"(public-key(ecc(curve \"Ed25519\")"
"(flags eddsa)(q %m))"
"(comment%s))",
mpi_list[0],
comment? comment:"");
}
}
else
{
err = sexp_key_construct (&key, spec, secret, curve_name, mpi_list,
comment? comment:"");
if (err)
goto out;
}
if (key_spec)
*key_spec = spec;
*key_new = key;
out:
es_fclose (cert);
mpint_list_free (mpi_list);
xfree (curve_name);
xfree (key_type);
xfree (comment);
return err;
}
/* Write the public key from KEY to STREAM in SSH key format. If
OVERRIDE_COMMENT is not NULL, it will be used instead of the
comment stored in the key. */
static gpg_error_t
ssh_send_key_public (estream_t stream, gcry_sexp_t key,
const char *override_comment)
{
ssh_key_type_spec_t spec;
int algo;
char *comment = NULL;
void *blob = NULL;
size_t bloblen;
gpg_error_t err = 0;
algo = get_pk_algo_from_key (key);
if (algo == 0)
goto out;
err = ssh_key_type_lookup (NULL, algo, &spec);
if (err)
goto out;
err = ssh_key_to_blob (key, 0, spec, &blob, &bloblen);
if (err)
goto out;
err = stream_write_string (stream, blob, bloblen);
if (err)
goto out;
if (override_comment)
err = stream_write_cstring (stream, override_comment);
else
{
err = ssh_key_extract_comment (key, &comment);
if (err)
err = stream_write_cstring (stream, "(none)");
else
err = stream_write_cstring (stream, comment);
}
if (err)
goto out;
out:
xfree (comment);
es_free (blob);
return err;
}
/* Read a public key out of BLOB/BLOB_SIZE according to the key
specification given as KEY_SPEC, storing the new key in KEY_PUBLIC.
Returns zero on success or an error code. */
static gpg_error_t
ssh_read_key_public_from_blob (unsigned char *blob, size_t blob_size,
gcry_sexp_t *key_public,
ssh_key_type_spec_t *key_spec)
{
gpg_error_t err;
estream_t blob_stream;
blob_stream = es_fopenmem (0, "r+b");
if (!blob_stream)
{
err = gpg_error_from_syserror ();
goto out;
}
err = stream_write_data (blob_stream, blob, blob_size);
if (err)
goto out;
err = es_fseek (blob_stream, 0, SEEK_SET);
if (err)
goto out;
err = ssh_receive_key (blob_stream, key_public, 0, 0, key_spec);
out:
es_fclose (blob_stream);
return err;
}
/* This function calculates the key grip for the key contained in the
S-Expression KEY and writes it to BUFFER, which must be large
enough to hold it. Returns usual error code. */
static gpg_error_t
ssh_key_grip (gcry_sexp_t key, unsigned char *buffer)
{
if (!gcry_pk_get_keygrip (key, buffer))
{
gpg_error_t err = gcry_pk_testkey (key);
return err? err : gpg_error (GPG_ERR_INTERNAL);
}
return 0;
}
static gpg_error_t
card_key_list (ctrl_t ctrl, char **r_serialno, strlist_t *result)
{
gpg_error_t err;
*r_serialno = NULL;
*result = NULL;
err = agent_card_serialno (ctrl, r_serialno, NULL);
if (err)
{
if (gpg_err_code (err) != GPG_ERR_ENODEV && opt.verbose)
log_info (_("error getting serial number of card: %s\n"),
gpg_strerror (err));
/* Nothing available. */
return 0;
}
err = agent_card_cardlist (ctrl, result);
if (err)
{
xfree (*r_serialno);
*r_serialno = NULL;
}
return err;
}
/* Check whether a smartcard is available and whether it has a usable
key. Store a copy of that key at R_PK and return 0. If no key is
available store NULL at R_PK and return an error code. If CARDSN
is not NULL, a string with the serial number of the card will be
a malloced and stored there. */
static gpg_error_t
card_key_available (ctrl_t ctrl, gcry_sexp_t *r_pk, char **cardsn)
{
gpg_error_t err;
char *authkeyid;
char *serialno = NULL;
unsigned char *pkbuf;
size_t pkbuflen;
gcry_sexp_t s_pk;
unsigned char grip[20];
*r_pk = NULL;
if (cardsn)
*cardsn = NULL;
/* First see whether a card is available and whether the application
is supported. */
err = agent_card_getattr (ctrl, "$AUTHKEYID", &authkeyid);
if ( gpg_err_code (err) == GPG_ERR_CARD_REMOVED )
{
/* Ask for the serial number to reset the card. */
err = agent_card_serialno (ctrl, &serialno, NULL);
if (err)
{
if (opt.verbose)
log_info (_("error getting serial number of card: %s\n"),
gpg_strerror (err));
return err;
}
log_info (_("detected card with S/N: %s\n"), serialno);
err = agent_card_getattr (ctrl, "$AUTHKEYID", &authkeyid);
}
if (err)
{
log_error (_("no authentication key for ssh on card: %s\n"),
gpg_strerror (err));
xfree (serialno);
return err;
}
/* Get the S/N if we don't have it yet. Use the fast getattr method. */
if (!serialno && (err = agent_card_getattr (ctrl, "SERIALNO", &serialno)) )
{
log_error (_("error getting serial number of card: %s\n"),
gpg_strerror (err));
xfree (authkeyid);
return err;
}
/* Read the public key. */
err = agent_card_readkey (ctrl, authkeyid, &pkbuf);
if (err)
{
if (opt.verbose)
log_info (_("no suitable card key found: %s\n"), gpg_strerror (err));
xfree (serialno);
xfree (authkeyid);
return err;
}
pkbuflen = gcry_sexp_canon_len (pkbuf, 0, NULL, NULL);
err = gcry_sexp_sscan (&s_pk, NULL, (char*)pkbuf, pkbuflen);
if (err)
{
log_error ("failed to build S-Exp from received card key: %s\n",
gpg_strerror (err));
xfree (pkbuf);
xfree (serialno);
xfree (authkeyid);
return err;
}
err = ssh_key_grip (s_pk, grip);
if (err)
{
log_debug ("error computing keygrip from received card key: %s\n",
gcry_strerror (err));
xfree (pkbuf);
gcry_sexp_release (s_pk);
xfree (serialno);
xfree (authkeyid);
return err;
}
if ( agent_key_available (grip) )
{
/* (Shadow)-key is not available in our key storage. */
err = agent_write_shadow_key (grip, serialno, authkeyid, pkbuf, 0);
if (err)
{
xfree (pkbuf);
gcry_sexp_release (s_pk);
xfree (serialno);
xfree (authkeyid);
return err;
}
}
if (cardsn)
{
char *dispsn;
/* If the card handler is able to return a short serialnumber,
use that one, else use the complete serialno. */
if (!agent_card_getattr (ctrl, "$DISPSERIALNO", &dispsn))
{
*cardsn = xtryasprintf ("cardno:%s", dispsn);
xfree (dispsn);
}
else
*cardsn = xtryasprintf ("cardno:%s", serialno);
if (!*cardsn)
{
err = gpg_error_from_syserror ();
xfree (pkbuf);
gcry_sexp_release (s_pk);
xfree (serialno);
xfree (authkeyid);
return err;
}
}
xfree (pkbuf);
xfree (serialno);
xfree (authkeyid);
*r_pk = s_pk;
return 0;
}
/*
Request handler. Each handler is provided with a CTRL context, a
REQUEST object and a RESPONSE object. The actual request is to be
read from REQUEST, the response needs to be written to RESPONSE.
*/
/* Handler for the "request_identities" command. */
static gpg_error_t
ssh_handler_request_identities (ctrl_t ctrl,
estream_t request, estream_t response)
{
u32 key_counter;
estream_t key_blobs;
gcry_sexp_t key_public;
gpg_error_t err;
int ret;
ssh_control_file_t cf = NULL;
gpg_error_t ret_err;
(void)request;
/* Prepare buffer stream. */
key_public = NULL;
key_counter = 0;
key_blobs = es_fopenmem (0, "r+b");
if (! key_blobs)
{
err = gpg_error_from_syserror ();
goto out;
}
/* First check whether a key is currently available in the card
reader - this should be allowed even without being listed in
sshcontrol. */
if (!opt.disable_scdaemon)
{
char *serialno;
strlist_t card_list, sl;
err = card_key_list (ctrl, &serialno, &card_list);
if (err)
{
if (opt.verbose)
log_info (_("error getting list of cards: %s\n"),
gpg_strerror (err));
goto scd_out;
}
for (sl = card_list; sl; sl = sl->next)
{
char *serialno0;
char *cardsn;
err = agent_card_serialno (ctrl, &serialno0, sl->d);
if (err)
{
if (opt.verbose)
log_info (_("error getting serial number of card: %s\n"),
gpg_strerror (err));
continue;
}
xfree (serialno0);
if (card_key_available (ctrl, &key_public, &cardsn))
continue;
err = ssh_send_key_public (key_blobs, key_public, cardsn);
gcry_sexp_release (key_public);
key_public = NULL;
xfree (cardsn);
if (err)
{
xfree (serialno);
free_strlist (card_list);
goto out;
}
key_counter++;
}
xfree (serialno);
free_strlist (card_list);
}
scd_out:
/* Then look at all the registered and non-disabled keys. */
err = open_control_file (&cf, 0);
if (err)
goto out;
while (!read_control_file_item (cf))
{
unsigned char grip[20];
if (!cf->item.valid)
continue; /* Should not happen. */
if (cf->item.disabled)
continue;
assert (strlen (cf->item.hexgrip) == 40);
hex2bin (cf->item.hexgrip, grip, sizeof (grip));
err = agent_public_key_from_file (ctrl, grip, &key_public);
if (err)
{
log_error ("%s:%d: key '%s' skipped: %s\n",
cf->fname, cf->lnr, cf->item.hexgrip,
gpg_strerror (err));
continue;
}
err = ssh_send_key_public (key_blobs, key_public, NULL);
if (err)
goto out;
gcry_sexp_release (key_public);
key_public = NULL;
key_counter++;
}
err = 0;
ret = es_fseek (key_blobs, 0, SEEK_SET);
if (ret)
{
err = gpg_error_from_syserror ();
goto out;
}
out:
/* Send response. */
gcry_sexp_release (key_public);
if (!err)
{
ret_err = stream_write_byte (response, SSH_RESPONSE_IDENTITIES_ANSWER);
if (!ret_err)
ret_err = stream_write_uint32 (response, key_counter);
if (!ret_err)
ret_err = stream_copy (response, key_blobs);
}
else
{
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
}
es_fclose (key_blobs);
close_control_file (cf);
return ret_err;
}
/* This function hashes the data contained in DATA of size DATA_N
according to the message digest algorithm specified by MD_ALGORITHM
and writes the message digest to HASH, which needs to large enough
for the digest. */
static gpg_error_t
data_hash (unsigned char *data, size_t data_n,
int md_algorithm, unsigned char *hash)
{
gcry_md_hash_buffer (md_algorithm, hash, data, data_n);
return 0;
}
/* This function signs the data described by CTRL. If HASH is not
NULL, (HASH,HASHLEN) overrides the hash stored in CTRL. This is to
allow the use of signature algorithms that implement the hashing
internally (e.g. Ed25519). On success the created signature is
stored in ssh format at R_SIG and it's size at R_SIGLEN; the caller
must use es_free to releaase this memory. */
static gpg_error_t
data_sign (ctrl_t ctrl, ssh_key_type_spec_t *spec,
const void *hash, size_t hashlen,
unsigned char **r_sig, size_t *r_siglen)
{
gpg_error_t err;
gcry_sexp_t signature_sexp = NULL;
estream_t stream = NULL;
void *blob = NULL;
size_t bloblen;
char hexgrip[40+1];
*r_sig = NULL;
*r_siglen = 0;
/* Quick check to see whether we have a valid keygrip and convert it
to hex. */
if (!ctrl->have_keygrip)
{
err = gpg_error (GPG_ERR_NO_SECKEY);
goto out;
}
bin2hex (ctrl->keygrip, 20, hexgrip);
/* Ask for confirmation if needed. */
if (confirm_flag_from_sshcontrol (hexgrip))
{
gcry_sexp_t key;
char *fpr, *prompt;
char *comment = NULL;
err = agent_raw_key_from_file (ctrl, ctrl->keygrip, &key);
if (err)
goto out;
- err = ssh_get_fingerprint_string (key, GCRY_MD_MD5, &fpr);
+ err = ssh_get_fingerprint_string (key, opt.ssh_fingerprint_digest, &fpr);
if (!err)
{
gcry_sexp_t tmpsxp = gcry_sexp_find_token (key, "comment", 0);
if (tmpsxp)
comment = gcry_sexp_nth_string (tmpsxp, 1);
gcry_sexp_release (tmpsxp);
}
gcry_sexp_release (key);
if (err)
goto out;
prompt = xtryasprintf (L_("An ssh process requested the use of key%%0A"
" %s%%0A"
" (%s)%%0A"
"Do you want to allow this?"),
fpr, comment? comment:"");
xfree (fpr);
gcry_free (comment);
err = agent_get_confirmation (ctrl, prompt, L_("Allow"), L_("Deny"), 0);
xfree (prompt);
if (err)
goto out;
}
/* Create signature. */
ctrl->use_auth_call = 1;
err = agent_pksign_do (ctrl, NULL,
L_("Please enter the passphrase "
"for the ssh key%%0A %F%%0A (%c)"),
&signature_sexp,
CACHE_MODE_SSH, ttl_from_sshcontrol,
hash, hashlen);
ctrl->use_auth_call = 0;
if (err)
goto out;
stream = es_fopenmem (0, "r+b");
if (!stream)
{
err = gpg_error_from_syserror ();
goto out;
}
err = stream_write_cstring (stream, spec->ssh_identifier);
if (err)
goto out;
err = spec->signature_encoder (spec, stream, signature_sexp);
if (err)
goto out;
err = es_fclose_snatch (stream, &blob, &bloblen);
if (err)
goto out;
stream = NULL;
*r_sig = blob; blob = NULL;
*r_siglen = bloblen;
out:
xfree (blob);
es_fclose (stream);
gcry_sexp_release (signature_sexp);
return err;
}
/* Handler for the "sign_request" command. */
static gpg_error_t
ssh_handler_sign_request (ctrl_t ctrl, estream_t request, estream_t response)
{
gcry_sexp_t key = NULL;
ssh_key_type_spec_t spec;
unsigned char hash[MAX_DIGEST_LEN];
unsigned int hash_n;
unsigned char key_grip[20];
unsigned char *key_blob = NULL;
u32 key_blob_size;
unsigned char *data = NULL;
unsigned char *sig = NULL;
size_t sig_n;
u32 data_size;
u32 flags;
gpg_error_t err;
gpg_error_t ret_err;
int hash_algo;
/* Receive key. */
err = stream_read_string (request, 0, &key_blob, &key_blob_size);
if (err)
goto out;
err = ssh_read_key_public_from_blob (key_blob, key_blob_size, &key, &spec);
if (err)
goto out;
/* Receive data to sign. */
err = stream_read_string (request, 0, &data, &data_size);
if (err)
goto out;
/* FIXME? */
err = stream_read_uint32 (request, &flags);
if (err)
goto out;
hash_algo = spec.hash_algo;
if (!hash_algo)
hash_algo = GCRY_MD_SHA1; /* Use the default. */
ctrl->digest.algo = hash_algo;
if ((spec.flags & SPEC_FLAG_USE_PKCS1V2))
ctrl->digest.raw_value = 0;
else
ctrl->digest.raw_value = 1;
/* Calculate key grip. */
err = ssh_key_grip (key, key_grip);
if (err)
goto out;
ctrl->have_keygrip = 1;
memcpy (ctrl->keygrip, key_grip, 20);
/* Hash data unless we use EdDSA. */
if ((spec.flags & SPEC_FLAG_IS_EdDSA))
{
ctrl->digest.valuelen = 0;
}
else
{
hash_n = gcry_md_get_algo_dlen (hash_algo);
if (!hash_n)
{
err = gpg_error (GPG_ERR_INTERNAL);
goto out;
}
err = data_hash (data, data_size, hash_algo, hash);
if (err)
goto out;
memcpy (ctrl->digest.value, hash, hash_n);
ctrl->digest.valuelen = hash_n;
}
/* Sign data. */
if ((spec.flags & SPEC_FLAG_IS_EdDSA))
err = data_sign (ctrl, &spec, data, data_size, &sig, &sig_n);
else
err = data_sign (ctrl, &spec, NULL, 0, &sig, &sig_n);
out:
/* Done. */
if (!err)
{
ret_err = stream_write_byte (response, SSH_RESPONSE_SIGN_RESPONSE);
if (ret_err)
goto leave;
ret_err = stream_write_string (response, sig, sig_n);
if (ret_err)
goto leave;
}
else
{
log_error ("ssh sign request failed: %s <%s>\n",
gpg_strerror (err), gpg_strsource (err));
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
if (ret_err)
goto leave;
}
leave:
gcry_sexp_release (key);
xfree (key_blob);
xfree (data);
es_free (sig);
return ret_err;
}
/* This function extracts the comment contained in the key
s-expression KEY and stores a copy in COMMENT. Returns usual error
code. */
static gpg_error_t
ssh_key_extract_comment (gcry_sexp_t key, char **r_comment)
{
gcry_sexp_t comment_list;
*r_comment = NULL;
comment_list = gcry_sexp_find_token (key, "comment", 0);
if (!comment_list)
return gpg_error (GPG_ERR_INV_SEXP);
*r_comment = gcry_sexp_nth_string (comment_list, 1);
gcry_sexp_release (comment_list);
if (!*r_comment)
return gpg_error (GPG_ERR_INV_SEXP);
return 0;
}
/* This function converts the key contained in the S-Expression KEY
into a buffer, which is protected by the passphrase PASSPHRASE.
Returns usual error code. */
static gpg_error_t
ssh_key_to_protected_buffer (gcry_sexp_t key, const char *passphrase,
unsigned char **buffer, size_t *buffer_n)
{
unsigned char *buffer_new;
unsigned int buffer_new_n;
gpg_error_t err;
buffer_new_n = gcry_sexp_sprint (key, GCRYSEXP_FMT_CANON, NULL, 0);
buffer_new = xtrymalloc_secure (buffer_new_n);
if (! buffer_new)
{
err = gpg_error_from_syserror ();
goto out;
}
gcry_sexp_sprint (key, GCRYSEXP_FMT_CANON, buffer_new, buffer_new_n);
/* FIXME: guarantee? */
err = agent_protect (buffer_new, passphrase, buffer, buffer_n, 0, -1);
out:
xfree (buffer_new);
return err;
}
/* Callback function to compare the first entered PIN with the one
currently being entered. */
static gpg_error_t
reenter_compare_cb (struct pin_entry_info_s *pi)
{
const char *pin1 = pi->check_cb_arg;
if (!strcmp (pin1, pi->pin))
return 0; /* okay */
return gpg_error (GPG_ERR_BAD_PASSPHRASE);
}
/* Store the ssh KEY into our local key storage and protect it after
asking for a passphrase. Cache that passphrase. TTL is the
maximum caching time for that key. If the key already exists in
our key storage, don't do anything. When entering a key also add
an entry to the sshcontrol file. */
static gpg_error_t
ssh_identity_register (ctrl_t ctrl, ssh_key_type_spec_t *spec,
gcry_sexp_t key, int ttl, int confirm)
{
gpg_error_t err;
unsigned char key_grip_raw[20];
char key_grip[41];
unsigned char *buffer = NULL;
size_t buffer_n;
char *description = NULL;
const char *description2 = L_("Please re-enter this passphrase");
char *comment = NULL;
char *key_fpr = NULL;
const char *initial_errtext = NULL;
struct pin_entry_info_s *pi = NULL;
struct pin_entry_info_s *pi2 = NULL;
err = ssh_key_grip (key, key_grip_raw);
if (err)
goto out;
bin2hex (key_grip_raw, 20, key_grip);
- err = ssh_get_fingerprint_string (key, GCRY_MD_MD5, &key_fpr);
+ err = ssh_get_fingerprint_string (key, opt.ssh_fingerprint_digest, &key_fpr);
if (err)
goto out;
/* Check whether the key is already in our key storage. Don't do
anything then besides (re-)adding it to sshcontrol. */
if ( !agent_key_available (key_grip_raw) )
goto key_exists; /* Yes, key is available. */
err = ssh_key_extract_comment (key, &comment);
if (err)
goto out;
if ( asprintf (&description,
L_("Please enter a passphrase to protect"
" the received secret key%%0A"
" %s%%0A"
" %s%%0A"
"within gpg-agent's key storage"),
key_fpr, comment ? comment : "") < 0)
{
err = gpg_error_from_syserror ();
goto out;
}
pi = gcry_calloc_secure (1, sizeof (*pi) + MAX_PASSPHRASE_LEN + 1);
if (!pi)
{
err = gpg_error_from_syserror ();
goto out;
}
pi2 = gcry_calloc_secure (1, sizeof (*pi2) + MAX_PASSPHRASE_LEN + 1);
if (!pi2)
{
err = gpg_error_from_syserror ();
goto out;
}
pi->max_length = MAX_PASSPHRASE_LEN + 1;
pi->max_tries = 1;
pi->with_repeat = 1;
pi2->max_length = MAX_PASSPHRASE_LEN + 1;
pi2->max_tries = 1;
pi2->check_cb = reenter_compare_cb;
pi2->check_cb_arg = pi->pin;
next_try:
err = agent_askpin (ctrl, description, NULL, initial_errtext, pi, NULL, 0);
initial_errtext = NULL;
if (err)
goto out;
/* Unless the passphrase is empty or the pinentry told us that
it already did the repetition check, ask to confirm it. */
if (*pi->pin && !pi->repeat_okay)
{
err = agent_askpin (ctrl, description2, NULL, NULL, pi2, NULL, 0);
if (gpg_err_code (err) == GPG_ERR_BAD_PASSPHRASE)
{ /* The re-entered one did not match and the user did not
hit cancel. */
initial_errtext = L_("does not match - try again");
goto next_try;
}
}
err = ssh_key_to_protected_buffer (key, pi->pin, &buffer, &buffer_n);
if (err)
goto out;
/* Store this key to our key storage. */
err = agent_write_private_key (key_grip_raw, buffer, buffer_n, 0);
if (err)
goto out;
/* Cache this passphrase. */
err = agent_put_cache (key_grip, CACHE_MODE_SSH, pi->pin, ttl);
if (err)
goto out;
key_exists:
/* And add an entry to the sshcontrol file. */
err = add_control_entry (ctrl, spec, key_grip, key, ttl, confirm);
out:
if (pi2 && pi2->max_length)
wipememory (pi2->pin, pi2->max_length);
xfree (pi2);
if (pi && pi->max_length)
wipememory (pi->pin, pi->max_length);
xfree (pi);
xfree (buffer);
xfree (comment);
xfree (key_fpr);
xfree (description);
return err;
}
/* This function removes the key contained in the S-Expression KEY
from the local key storage, in case it exists there. Returns usual
error code. FIXME: this function is a stub. */
static gpg_error_t
ssh_identity_drop (gcry_sexp_t key)
{
unsigned char key_grip[21] = { 0 };
gpg_error_t err;
err = ssh_key_grip (key, key_grip);
if (err)
goto out;
key_grip[sizeof (key_grip) - 1] = 0;
/* FIXME: What to do here - forgetting the passphrase or deleting
the key from key cache? */
out:
return err;
}
/* Handler for the "add_identity" command. */
static gpg_error_t
ssh_handler_add_identity (ctrl_t ctrl, estream_t request, estream_t response)
{
gpg_error_t ret_err;
ssh_key_type_spec_t spec;
gpg_error_t err;
gcry_sexp_t key;
unsigned char b;
int confirm;
int ttl;
confirm = 0;
key = NULL;
ttl = 0;
/* FIXME? */
err = ssh_receive_key (request, &key, 1, 1, &spec);
if (err)
goto out;
while (1)
{
err = stream_read_byte (request, &b);
if (gpg_err_code (err) == GPG_ERR_EOF)
{
err = 0;
break;
}
switch (b)
{
case SSH_OPT_CONSTRAIN_LIFETIME:
{
u32 n = 0;
err = stream_read_uint32 (request, &n);
if (! err)
ttl = n;
break;
}
case SSH_OPT_CONSTRAIN_CONFIRM:
{
confirm = 1;
break;
}
default:
/* FIXME: log/bad? */
break;
}
}
if (err)
goto out;
err = ssh_identity_register (ctrl, &spec, key, ttl, confirm);
out:
gcry_sexp_release (key);
if (! err)
ret_err = stream_write_byte (response, SSH_RESPONSE_SUCCESS);
else
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
return ret_err;
}
/* Handler for the "remove_identity" command. */
static gpg_error_t
ssh_handler_remove_identity (ctrl_t ctrl,
estream_t request, estream_t response)
{
unsigned char *key_blob;
u32 key_blob_size;
gcry_sexp_t key;
gpg_error_t ret_err;
gpg_error_t err;
(void)ctrl;
/* Receive key. */
key_blob = NULL;
key = NULL;
err = stream_read_string (request, 0, &key_blob, &key_blob_size);
if (err)
goto out;
err = ssh_read_key_public_from_blob (key_blob, key_blob_size, &key, NULL);
if (err)
goto out;
err = ssh_identity_drop (key);
out:
xfree (key_blob);
gcry_sexp_release (key);
if (! err)
ret_err = stream_write_byte (response, SSH_RESPONSE_SUCCESS);
else
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
return ret_err;
}
/* FIXME: stub function. Actually useful? */
static gpg_error_t
ssh_identities_remove_all (void)
{
gpg_error_t err;
err = 0;
/* FIXME: shall we remove _all_ cache entries or only those
registered through the ssh-agent protocol? */
return err;
}
/* Handler for the "remove_all_identities" command. */
static gpg_error_t
ssh_handler_remove_all_identities (ctrl_t ctrl,
estream_t request, estream_t response)
{
gpg_error_t ret_err;
gpg_error_t err;
(void)ctrl;
(void)request;
err = ssh_identities_remove_all ();
if (! err)
ret_err = stream_write_byte (response, SSH_RESPONSE_SUCCESS);
else
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
return ret_err;
}
/* Lock agent? FIXME: stub function. */
static gpg_error_t
ssh_lock (void)
{
gpg_error_t err;
/* FIXME */
log_error ("ssh-agent's lock command is not implemented\n");
err = 0;
return err;
}
/* Unock agent? FIXME: stub function. */
static gpg_error_t
ssh_unlock (void)
{
gpg_error_t err;
log_error ("ssh-agent's unlock command is not implemented\n");
err = 0;
return err;
}
/* Handler for the "lock" command. */
static gpg_error_t
ssh_handler_lock (ctrl_t ctrl, estream_t request, estream_t response)
{
gpg_error_t ret_err;
gpg_error_t err;
(void)ctrl;
(void)request;
err = ssh_lock ();
if (! err)
ret_err = stream_write_byte (response, SSH_RESPONSE_SUCCESS);
else
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
return ret_err;
}
/* Handler for the "unlock" command. */
static gpg_error_t
ssh_handler_unlock (ctrl_t ctrl, estream_t request, estream_t response)
{
gpg_error_t ret_err;
gpg_error_t err;
(void)ctrl;
(void)request;
err = ssh_unlock ();
if (! err)
ret_err = stream_write_byte (response, SSH_RESPONSE_SUCCESS);
else
ret_err = stream_write_byte (response, SSH_RESPONSE_FAILURE);
return ret_err;
}
/* Return the request specification for the request identified by TYPE
or NULL in case the requested request specification could not be
found. */
static const ssh_request_spec_t *
request_spec_lookup (int type)
{
const ssh_request_spec_t *spec;
unsigned int i;
for (i = 0; i < DIM (request_specs); i++)
if (request_specs[i].type == type)
break;
if (i == DIM (request_specs))
{
if (opt.verbose)
log_info ("ssh request %u is not supported\n", type);
spec = NULL;
}
else
spec = request_specs + i;
return spec;
}
/* Process a single request. The request is read from and the
response is written to STREAM_SOCK. Uses CTRL as context. Returns
zero in case of success, non zero in case of failure. */
static int
ssh_request_process (ctrl_t ctrl, estream_t stream_sock)
{
const ssh_request_spec_t *spec;
estream_t response = NULL;
estream_t request = NULL;
unsigned char request_type;
gpg_error_t err;
int send_err = 0;
int ret;
unsigned char *request_data = NULL;
u32 request_data_size;
u32 response_size;
/* Create memory streams for request/response data. The entire
request will be stored in secure memory, since it might contain
secret key material. The response does not have to be stored in
secure memory, since we never give out secret keys.
Note: we only have little secure memory, but there is NO
possibility of DoS here; only trusted clients are allowed to
connect to the agent. What could happen is that the agent
returns out-of-secure-memory errors on requests in case the
agent's owner floods his own agent with many large messages.
-moritz */
/* Retrieve request. */
err = stream_read_string (stream_sock, 1, &request_data, &request_data_size);
if (err)
goto out;
if (opt.verbose > 1)
log_info ("received ssh request of length %u\n",
(unsigned int)request_data_size);
if (! request_data_size)
{
send_err = 1;
goto out;
/* Broken request; FIXME. */
}
request_type = request_data[0];
spec = request_spec_lookup (request_type);
if (! spec)
{
send_err = 1;
goto out;
/* Unknown request; FIXME. */
}
if (spec->secret_input)
request = es_mopen (NULL, 0, 0, 1, realloc_secure, gcry_free, "r+b");
else
request = es_mopen (NULL, 0, 0, 1, gcry_realloc, gcry_free, "r+b");
if (! request)
{
err = gpg_error_from_syserror ();
goto out;
}
ret = es_setvbuf (request, NULL, _IONBF, 0);
if (ret)
{
err = gpg_error_from_syserror ();
goto out;
}
err = stream_write_data (request, request_data + 1, request_data_size - 1);
if (err)
goto out;
es_rewind (request);
response = es_fopenmem (0, "r+b");
if (! response)
{
err = gpg_error_from_syserror ();
goto out;
}
if (opt.verbose)
log_info ("ssh request handler for %s (%u) started\n",
spec->identifier, spec->type);
err = (*spec->handler) (ctrl, request, response);
if (opt.verbose)
{
if (err)
log_info ("ssh request handler for %s (%u) failed: %s\n",
spec->identifier, spec->type, gpg_strerror (err));
else
log_info ("ssh request handler for %s (%u) ready\n",
spec->identifier, spec->type);
}
if (err)
{
send_err = 1;
goto out;
}
response_size = es_ftell (response);
if (opt.verbose > 1)
log_info ("sending ssh response of length %u\n",
(unsigned int)response_size);
err = es_fseek (response, 0, SEEK_SET);
if (err)
{
send_err = 1;
goto out;
}
err = stream_write_uint32 (stream_sock, response_size);
if (err)
{
send_err = 1;
goto out;
}
err = stream_copy (stream_sock, response);
if (err)
goto out;
err = es_fflush (stream_sock);
if (err)
goto out;
out:
if (err && es_feof (stream_sock))
log_error ("error occurred while processing request: %s\n",
gpg_strerror (err));
if (send_err)
{
if (opt.verbose > 1)
log_info ("sending ssh error response\n");
err = stream_write_uint32 (stream_sock, 1);
if (err)
goto leave;
err = stream_write_byte (stream_sock, SSH_RESPONSE_FAILURE);
if (err)
goto leave;
}
leave:
es_fclose (request);
es_fclose (response);
xfree (request_data);
return !!err;
}
/* Return the peer's pid. */
static unsigned long
get_client_pid (int fd)
{
pid_t client_pid = (pid_t)0;
#ifdef SO_PEERCRED
{
#ifdef HAVE_STRUCT_SOCKPEERCRED_PID
struct sockpeercred cr;
#else
struct ucred cr;
#endif
socklen_t cl = sizeof cr;
if (!getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &cr, &cl))
{
#if defined (HAVE_STRUCT_SOCKPEERCRED_PID) || defined (HAVE_STRUCT_UCRED_PID)
client_pid = cr.pid;
#elif defined (HAVE_STRUCT_UCRED_CR_PID)
client_pid = cr.cr_pid;
#else
#error "Unknown SO_PEERCRED struct"
#endif
}
}
#elif defined (LOCAL_PEERPID)
{
socklen_t len = sizeof (pid_t);
getsockopt (fd, SOL_LOCAL, LOCAL_PEERPID, &client_pid, &len);
}
#elif defined (LOCAL_PEEREID)
{
struct unpcbid unp;
socklen_t unpl = sizeof unp;
if (getsockopt (fd, 0, LOCAL_PEEREID, &unp, &unpl) != -1)
client_pid = unp.unp_pid;
}
#elif defined (HAVE_GETPEERUCRED)
{
ucred_t *ucred = NULL;
if (getpeerucred (fd, &ucred) != -1)
{
client_pid= ucred_getpid (ucred);
ucred_free (ucred);
}
}
#else
(void)fd;
#endif
return (unsigned long)client_pid;
}
/* Start serving client on SOCK_CLIENT. */
void
start_command_handler_ssh (ctrl_t ctrl, gnupg_fd_t sock_client)
{
estream_t stream_sock = NULL;
gpg_error_t err;
int ret;
err = agent_copy_startup_env (ctrl);
if (err)
goto out;
ctrl->client_pid = get_client_pid (FD2INT(sock_client));
/* Create stream from socket. */
stream_sock = es_fdopen (FD2INT(sock_client), "r+");
if (!stream_sock)
{
err = gpg_error_from_syserror ();
log_error (_("failed to create stream from socket: %s\n"),
gpg_strerror (err));
goto out;
}
/* We have to disable the estream buffering, because the estream
core doesn't know about secure memory. */
ret = es_setvbuf (stream_sock, NULL, _IONBF, 0);
if (ret)
{
err = gpg_error_from_syserror ();
log_error ("failed to disable buffering "
"on socket stream: %s\n", gpg_strerror (err));
goto out;
}
/* Main processing loop. */
while ( !ssh_request_process (ctrl, stream_sock) )
{
/* Check whether we have reached EOF before trying to read
another request. */
int c;
c = es_fgetc (stream_sock);
if (c == EOF)
break;
es_ungetc (c, stream_sock);
}
/* Reset the SCD in case it has been used. */
agent_reset_scd (ctrl);
out:
if (stream_sock)
es_fclose (stream_sock);
}
#ifdef HAVE_W32_SYSTEM
/* Serve one ssh-agent request. This is used for the Putty support.
REQUEST is the mmapped memory which may be accessed up to a
length of MAXREQLEN. Returns 0 on success which also indicates
that a valid SSH response message is now in REQUEST. */
int
serve_mmapped_ssh_request (ctrl_t ctrl,
unsigned char *request, size_t maxreqlen)
{
gpg_error_t err;
int send_err = 0;
int valid_response = 0;
ssh_request_spec_t *spec;
u32 msglen;
estream_t request_stream, response_stream;
if (agent_copy_startup_env (ctrl))
goto leave; /* Error setting up the environment. */
if (maxreqlen < 5)
goto leave; /* Caller error. */
msglen = uint32_construct (request[0], request[1], request[2], request[3]);
if (msglen < 1 || msglen > maxreqlen - 4)
{
log_error ("ssh message len (%u) out of range", (unsigned int)msglen);
goto leave;
}
spec = request_spec_lookup (request[4]);
if (!spec)
{
send_err = 1; /* Unknown request type. */
goto leave;
}
/* Create a stream object with the data part of the request. */
if (spec->secret_input)
request_stream = es_mopen (NULL, 0, 0, 1, realloc_secure, gcry_free, "r+");
else
request_stream = es_mopen (NULL, 0, 0, 1, gcry_realloc, gcry_free, "r+");
if (!request_stream)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* We have to disable the estream buffering, because the estream
core doesn't know about secure memory. */
if (es_setvbuf (request_stream, NULL, _IONBF, 0))
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Copy the request to the stream but omit the request type. */
err = stream_write_data (request_stream, request + 5, msglen - 1);
if (err)
goto leave;
es_rewind (request_stream);
response_stream = es_fopenmem (0, "r+b");
if (!response_stream)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (opt.verbose)
log_info ("ssh request handler for %s (%u) started\n",
spec->identifier, spec->type);
err = (*spec->handler) (ctrl, request_stream, response_stream);
if (opt.verbose)
{
if (err)
log_info ("ssh request handler for %s (%u) failed: %s\n",
spec->identifier, spec->type, gpg_strerror (err));
else
log_info ("ssh request handler for %s (%u) ready\n",
spec->identifier, spec->type);
}
es_fclose (request_stream);
request_stream = NULL;
if (err)
{
send_err = 1;
goto leave;
}
/* Put the response back into the mmapped buffer. */
{
void *response_data;
size_t response_size;
/* NB: In contrast to the request-stream, the response stream
includes the message type byte. */
if (es_fclose_snatch (response_stream, &response_data, &response_size))
{
log_error ("snatching ssh response failed: %s",
gpg_strerror (gpg_error_from_syserror ()));
send_err = 1; /* Ooops. */
goto leave;
}
if (opt.verbose > 1)
log_info ("sending ssh response of length %u\n",
(unsigned int)response_size);
if (response_size > maxreqlen - 4)
{
log_error ("invalid length of the ssh response: %s",
gpg_strerror (GPG_ERR_INTERNAL));
es_free (response_data);
send_err = 1;
goto leave;
}
request[0] = response_size >> 24;
request[1] = response_size >> 16;
request[2] = response_size >> 8;
request[3] = response_size >> 0;
memcpy (request+4, response_data, response_size);
es_free (response_data);
valid_response = 1;
}
leave:
if (send_err)
{
request[0] = 0;
request[1] = 0;
request[2] = 0;
request[3] = 1;
request[4] = SSH_RESPONSE_FAILURE;
valid_response = 1;
}
/* Reset the SCD in case it has been used. */
agent_reset_scd (ctrl);
return valid_response? 0 : -1;
}
#endif /*HAVE_W32_SYSTEM*/
diff --git a/agent/findkey.c b/agent/findkey.c
index 1f547b06d..cff0a7df8 100644
--- a/agent/findkey.c
+++ b/agent/findkey.c
@@ -1,1591 +1,1592 @@
/* findkey.c - Locate the secret key
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007,
* 2010, 2011 Free Software Foundation, Inc.
* Copyright (C) 2014 Werner Koch
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <assert.h>
#include <unistd.h>
#include <sys/stat.h>
#include <assert.h>
#include <npth.h> /* (we use pth_sleep) */
#include "agent.h"
#include "../common/i18n.h"
#include "../common/ssh-utils.h"
#include "../common/name-value.h"
#ifndef O_BINARY
#define O_BINARY 0
#endif
/* Helper to pass data to the check callback of the unprotect function. */
struct try_unprotect_arg_s
{
ctrl_t ctrl;
const unsigned char *protected_key;
unsigned char *unprotected_key;
int change_required; /* Set by the callback to indicate that the
user should change the passphrase. */
};
/* Note: Ownership of FNAME and FP are moved to this function. */
static gpg_error_t
write_extended_private_key (char *fname, estream_t fp, int update,
const void *buf, size_t len)
{
gpg_error_t err;
nvc_t pk = NULL;
gcry_sexp_t key = NULL;
int remove = 0;
if (update)
{
int line;
err = nvc_parse_private_key (&pk, &line, fp);
if (err && gpg_err_code (err) != GPG_ERR_ENOENT)
{
log_error ("error parsing '%s' line %d: %s\n",
fname, line, gpg_strerror (err));
goto leave;
}
}
else
{
pk = nvc_new_private_key ();
if (!pk)
{
err = gpg_error_from_syserror ();
goto leave;
}
}
es_clearerr (fp);
err = gcry_sexp_sscan (&key, NULL, buf, len);
if (err)
goto leave;
err = nvc_set_private_key (pk, key);
if (err)
goto leave;
err = es_fseek (fp, 0, SEEK_SET);
if (err)
goto leave;
err = nvc_write (pk, fp);
if (err)
{
log_error ("error writing '%s': %s\n", fname, gpg_strerror (err));
remove = 1;
goto leave;
}
if (ftruncate (es_fileno (fp), es_ftello (fp)))
{
err = gpg_error_from_syserror ();
log_error ("error truncating '%s': %s\n", fname, gpg_strerror (err));
remove = 1;
goto leave;
}
if (es_fclose (fp))
{
err = gpg_error_from_syserror ();
log_error ("error closing '%s': %s\n", fname, gpg_strerror (err));
remove = 1;
goto leave;
}
else
fp = NULL;
bump_key_eventcounter ();
leave:
es_fclose (fp);
if (remove)
gnupg_remove (fname);
xfree (fname);
gcry_sexp_release (key);
nvc_release (pk);
return err;
}
/* Write an S-expression formatted key to our key storage. With FORCE
passed as true an existing key with the given GRIP will get
overwritten. */
int
agent_write_private_key (const unsigned char *grip,
const void *buffer, size_t length, int force)
{
char *fname;
estream_t fp;
char hexgrip[40+4+1];
bin2hex (grip, 20, hexgrip);
strcpy (hexgrip+40, ".key");
fname = make_filename (gnupg_homedir (), GNUPG_PRIVATE_KEYS_DIR,
hexgrip, NULL);
/* FIXME: Write to a temp file first so that write failures during
key updates won't lead to a key loss. */
if (!force && !access (fname, F_OK))
{
log_error ("secret key file '%s' already exists\n", fname);
xfree (fname);
return gpg_error (GPG_ERR_EEXIST);
}
fp = es_fopen (fname, force? "rb+,mode=-rw" : "wbx,mode=-rw");
if (!fp)
{
gpg_error_t tmperr = gpg_error_from_syserror ();
if (force && gpg_err_code (tmperr) == GPG_ERR_ENOENT)
{
fp = es_fopen (fname, "wbx,mode=-rw");
if (!fp)
tmperr = gpg_error_from_syserror ();
}
if (!fp)
{
log_error ("can't create '%s': %s\n", fname, gpg_strerror (tmperr));
xfree (fname);
return tmperr;
}
}
else if (force)
{
gpg_error_t rc;
char first;
/* See if an existing key is in extended format. */
if (es_fread (&first, 1, 1, fp) != 1)
{
rc = gpg_error_from_syserror ();
log_error ("error reading first byte from '%s': %s\n",
fname, strerror (errno));
xfree (fname);
es_fclose (fp);
return rc;
}
rc = es_fseek (fp, 0, SEEK_SET);
if (rc)
{
log_error ("error seeking in '%s': %s\n", fname, strerror (errno));
xfree (fname);
es_fclose (fp);
return rc;
}
if (first != '(')
{
/* Key is already in the extended format. */
return write_extended_private_key (fname, fp, 1, buffer, length);
}
if (first == '(' && opt.enable_extended_key_format)
{
/* Key is in the old format - but we want the extended format. */
return write_extended_private_key (fname, fp, 0, buffer, length);
}
}
if (opt.enable_extended_key_format)
return write_extended_private_key (fname, fp, 0, buffer, length);
if (es_fwrite (buffer, length, 1, fp) != 1)
{
gpg_error_t tmperr = gpg_error_from_syserror ();
log_error ("error writing '%s': %s\n", fname, gpg_strerror (tmperr));
es_fclose (fp);
gnupg_remove (fname);
xfree (fname);
return tmperr;
}
/* When force is given, the file might have to be truncated. */
if (force && ftruncate (es_fileno (fp), es_ftello (fp)))
{
gpg_error_t tmperr = gpg_error_from_syserror ();
log_error ("error truncating '%s': %s\n", fname, gpg_strerror (tmperr));
es_fclose (fp);
gnupg_remove (fname);
xfree (fname);
return tmperr;
}
if (es_fclose (fp))
{
gpg_error_t tmperr = gpg_error_from_syserror ();
log_error ("error closing '%s': %s\n", fname, gpg_strerror (tmperr));
gnupg_remove (fname);
xfree (fname);
return tmperr;
}
bump_key_eventcounter ();
xfree (fname);
return 0;
}
/* Callback function to try the unprotection from the passphrase query
code. */
static gpg_error_t
try_unprotect_cb (struct pin_entry_info_s *pi)
{
struct try_unprotect_arg_s *arg = pi->check_cb_arg;
ctrl_t ctrl = arg->ctrl;
size_t dummy;
gpg_error_t err;
gnupg_isotime_t now, protected_at, tmptime;
char *desc = NULL;
assert (!arg->unprotected_key);
arg->change_required = 0;
err = agent_unprotect (ctrl, arg->protected_key, pi->pin, protected_at,
&arg->unprotected_key, &dummy);
if (err)
return err;
if (!opt.max_passphrase_days || ctrl->in_passwd)
return 0; /* No regular passphrase change required. */
if (!*protected_at)
{
/* No protection date known - must force passphrase change. */
desc = xtrystrdup (L_("Note: This passphrase has never been changed.%0A"
"Please change it now."));
if (!desc)
return gpg_error_from_syserror ();
}
else
{
gnupg_get_isotime (now);
gnupg_copy_time (tmptime, protected_at);
err = add_days_to_isotime (tmptime, opt.max_passphrase_days);
if (err)
return err;
if (strcmp (now, tmptime) > 0 )
{
/* Passphrase "expired". */
desc = xtryasprintf
(L_("This passphrase has not been changed%%0A"
"since %.4s-%.2s-%.2s. Please change it now."),
protected_at, protected_at+4, protected_at+6);
if (!desc)
return gpg_error_from_syserror ();
}
}
if (desc)
{
/* Change required. */
if (opt.enforce_passphrase_constraints)
{
err = agent_get_confirmation (ctrl, desc,
L_("Change passphrase"), NULL, 0);
if (!err)
arg->change_required = 1;
}
else
{
err = agent_get_confirmation (ctrl, desc,
L_("Change passphrase"),
L_("I'll change it later"), 0);
if (!err)
arg->change_required = 1;
else if (gpg_err_code (err) == GPG_ERR_CANCELED
|| gpg_err_code (err) == GPG_ERR_FULLY_CANCELED)
err = 0;
}
xfree (desc);
}
return err;
}
/* Modify a Key description, replacing certain special format
characters. List of currently supported replacements:
%% - Replaced by a single %
%c - Replaced by the content of COMMENT.
%C - Same as %c but put into parentheses.
%F - Replaced by an ssh style fingerprint computed from KEY.
The functions returns 0 on success or an error code. On success a
newly allocated string is stored at the address of RESULT.
*/
gpg_error_t
agent_modify_description (const char *in, const char *comment,
const gcry_sexp_t key, char **result)
{
size_t comment_length;
size_t in_len;
size_t out_len;
char *out;
size_t i;
int special, pass;
char *ssh_fpr = NULL;
char *p;
*result = NULL;
if (!comment)
comment = "";
comment_length = strlen (comment);
in_len = strlen (in);
/* First pass calculates the length, second pass does the actual
copying. */
/* FIXME: This can be simplified by using es_fopenmem. */
out = NULL;
out_len = 0;
for (pass=0; pass < 2; pass++)
{
special = 0;
for (i = 0; i < in_len; i++)
{
if (special)
{
special = 0;
switch (in[i])
{
case '%':
if (out)
*out++ = '%';
else
out_len++;
break;
case 'c': /* Comment. */
if (out)
{
memcpy (out, comment, comment_length);
out += comment_length;
}
else
out_len += comment_length;
break;
case 'C': /* Comment. */
if (!comment_length)
;
else if (out)
{
*out++ = '(';
memcpy (out, comment, comment_length);
out += comment_length;
*out++ = ')';
}
else
out_len += comment_length + 2;
break;
case 'F': /* SSH style fingerprint. */
if (!ssh_fpr && key)
- ssh_get_fingerprint_string (key, GCRY_MD_MD5, &ssh_fpr);
+ ssh_get_fingerprint_string (key, opt.ssh_fingerprint_digest,
+ &ssh_fpr);
if (ssh_fpr)
{
if (out)
out = stpcpy (out, ssh_fpr);
else
out_len += strlen (ssh_fpr);
}
break;
default: /* Invalid special sequences are kept as they are. */
if (out)
{
*out++ = '%';
*out++ = in[i];
}
else
out_len+=2;
break;
}
}
else if (in[i] == '%')
special = 1;
else
{
if (out)
*out++ = in[i];
else
out_len++;
}
}
if (!pass)
{
*result = out = xtrymalloc (out_len + 1);
if (!out)
{
xfree (ssh_fpr);
return gpg_error_from_syserror ();
}
}
}
*out = 0;
log_assert (*result + out_len == out);
xfree (ssh_fpr);
/* The ssh prompt may sometimes end in
* "...%0A ()"
* The empty parentheses doesn't look very good. We use this hack
* here to remove them as well as the indentation spaces. */
p = *result;
i = strlen (p);
if (i > 2 && !strcmp (p + i - 2, "()"))
{
p += i - 2;
*p-- = 0;
while (p > *result && spacep (p))
*p-- = 0;
}
return 0;
}
/* Unprotect the canconical encoded S-expression key in KEYBUF. GRIP
should be the hex encoded keygrip of that key to be used with the
caching mechanism. DESC_TEXT may be set to override the default
description used for the pinentry. If LOOKUP_TTL is given this
function is used to lookup the default ttl. If R_PASSPHRASE is not
NULL, the function succeeded and the key was protected the used
passphrase (entered or from the cache) is stored there; if not NULL
will be stored. The caller needs to free the returned
passphrase. */
static int
unprotect (ctrl_t ctrl, const char *cache_nonce, const char *desc_text,
unsigned char **keybuf, const unsigned char *grip,
cache_mode_t cache_mode, lookup_ttl_t lookup_ttl,
char **r_passphrase)
{
struct pin_entry_info_s *pi;
struct try_unprotect_arg_s arg;
int rc;
unsigned char *result;
size_t resultlen;
char hexgrip[40+1];
if (r_passphrase)
*r_passphrase = NULL;
bin2hex (grip, 20, hexgrip);
/* Initially try to get it using a cache nonce. */
if (cache_nonce)
{
char *pw;
pw = agent_get_cache (cache_nonce, CACHE_MODE_NONCE);
if (pw)
{
rc = agent_unprotect (ctrl, *keybuf, pw, NULL, &result, &resultlen);
if (!rc)
{
if (r_passphrase)
*r_passphrase = pw;
else
xfree (pw);
xfree (*keybuf);
*keybuf = result;
return 0;
}
xfree (pw);
}
}
/* First try to get it from the cache - if there is none or we can't
unprotect it, we fall back to ask the user */
if (cache_mode != CACHE_MODE_IGNORE)
{
char *pw;
retry:
pw = agent_get_cache (hexgrip, cache_mode);
if (pw)
{
rc = agent_unprotect (ctrl, *keybuf, pw, NULL, &result, &resultlen);
if (!rc)
{
if (cache_mode == CACHE_MODE_NORMAL)
agent_store_cache_hit (hexgrip);
if (r_passphrase)
*r_passphrase = pw;
else
xfree (pw);
xfree (*keybuf);
*keybuf = result;
return 0;
}
xfree (pw);
}
else if (cache_mode == CACHE_MODE_NORMAL)
{
/* The standard use of GPG keys is to have a signing and an
encryption subkey. Commonly both use the same
passphrase. We try to help the user to enter the
passphrase only once by silently trying the last
correctly entered passphrase. Checking one additional
passphrase should be acceptable; despite the S2K
introduced delays. The assumed workflow is:
1. Read encrypted message in a MUA and thus enter a
passphrase for the encryption subkey.
2. Reply to that mail with an encrypted and signed
mail, thus entering the passphrase for the signing
subkey.
We can often avoid the passphrase entry in the second
step. We do this only in normal mode, so not to
interfere with unrelated cache entries. */
pw = agent_get_cache (NULL, cache_mode);
if (pw)
{
rc = agent_unprotect (ctrl, *keybuf, pw, NULL,
&result, &resultlen);
if (!rc)
{
if (r_passphrase)
*r_passphrase = pw;
else
xfree (pw);
xfree (*keybuf);
*keybuf = result;
return 0;
}
xfree (pw);
}
}
/* If the pinentry is currently in use, we wait up to 60 seconds
for it to close and check the cache again. This solves a common
situation where several requests for unprotecting a key have
been made but the user is still entering the passphrase for
the first request. Because all requests to agent_askpin are
serialized they would then pop up one after the other to
request the passphrase - despite that the user has already
entered it and is then available in the cache. This
implementation is not race free but in the worst case the
user has to enter the passphrase only once more. */
if (pinentry_active_p (ctrl, 0))
{
/* Active - wait */
if (!pinentry_active_p (ctrl, 60))
{
/* We need to give the other thread a chance to actually put
it into the cache. */
npth_sleep (1);
goto retry;
}
/* Timeout - better call pinentry now the plain way. */
}
}
pi = gcry_calloc_secure (1, sizeof (*pi) + MAX_PASSPHRASE_LEN + 1);
if (!pi)
return gpg_error_from_syserror ();
pi->max_length = MAX_PASSPHRASE_LEN + 1;
pi->min_digits = 0; /* we want a real passphrase */
pi->max_digits = 16;
pi->max_tries = 3;
pi->check_cb = try_unprotect_cb;
arg.ctrl = ctrl;
arg.protected_key = *keybuf;
arg.unprotected_key = NULL;
arg.change_required = 0;
pi->check_cb_arg = &arg;
rc = agent_askpin (ctrl, desc_text, NULL, NULL, pi, hexgrip, cache_mode);
if (!rc)
{
assert (arg.unprotected_key);
if (arg.change_required)
{
/* The callback told as that the user should change their
passphrase. Present the dialog to do. */
size_t canlen, erroff;
gcry_sexp_t s_skey;
assert (arg.unprotected_key);
canlen = gcry_sexp_canon_len (arg.unprotected_key, 0, NULL, NULL);
rc = gcry_sexp_sscan (&s_skey, &erroff,
(char*)arg.unprotected_key, canlen);
if (rc)
{
log_error ("failed to build S-Exp (off=%u): %s\n",
(unsigned int)erroff, gpg_strerror (rc));
wipememory (arg.unprotected_key, canlen);
xfree (arg.unprotected_key);
xfree (pi);
return rc;
}
rc = agent_protect_and_store (ctrl, s_skey, NULL);
gcry_sexp_release (s_skey);
if (rc)
{
log_error ("changing the passphrase failed: %s\n",
gpg_strerror (rc));
wipememory (arg.unprotected_key, canlen);
xfree (arg.unprotected_key);
xfree (pi);
return rc;
}
}
else
{
/* Passphrase is fine. */
agent_put_cache (hexgrip, cache_mode, pi->pin,
lookup_ttl? lookup_ttl (hexgrip) : 0);
agent_store_cache_hit (hexgrip);
if (r_passphrase && *pi->pin)
*r_passphrase = xtrystrdup (pi->pin);
}
xfree (*keybuf);
*keybuf = arg.unprotected_key;
}
xfree (pi);
return rc;
}
/* Read the key identified by GRIP from the private key directory and
return it as an gcrypt S-expression object in RESULT. On failure
returns an error code and stores NULL at RESULT. */
static gpg_error_t
read_key_file (const unsigned char *grip, gcry_sexp_t *result)
{
int rc;
char *fname;
estream_t fp;
struct stat st;
unsigned char *buf;
size_t buflen, erroff;
gcry_sexp_t s_skey;
char hexgrip[40+4+1];
char first;
*result = NULL;
bin2hex (grip, 20, hexgrip);
strcpy (hexgrip+40, ".key");
fname = make_filename (gnupg_homedir (), GNUPG_PRIVATE_KEYS_DIR,
hexgrip, NULL);
fp = es_fopen (fname, "rb");
if (!fp)
{
rc = gpg_error_from_syserror ();
if (gpg_err_code (rc) != GPG_ERR_ENOENT)
log_error ("can't open '%s': %s\n", fname, strerror (errno));
xfree (fname);
return rc;
}
if (es_fread (&first, 1, 1, fp) != 1)
{
rc = gpg_error_from_syserror ();
log_error ("error reading first byte from '%s': %s\n",
fname, strerror (errno));
xfree (fname);
es_fclose (fp);
return rc;
}
rc = es_fseek (fp, 0, SEEK_SET);
if (rc)
{
log_error ("error seeking in '%s': %s\n", fname, strerror (errno));
xfree (fname);
es_fclose (fp);
return rc;
}
if (first != '(')
{
/* Key is in extended format. */
nvc_t pk;
int line;
rc = nvc_parse_private_key (&pk, &line, fp);
es_fclose (fp);
if (rc)
log_error ("error parsing '%s' line %d: %s\n",
fname, line, gpg_strerror (rc));
else
{
rc = nvc_get_private_key (pk, result);
nvc_release (pk);
if (rc)
log_error ("error getting private key from '%s': %s\n",
fname, gpg_strerror (rc));
}
xfree (fname);
return rc;
}
if (fstat (es_fileno (fp), &st))
{
rc = gpg_error_from_syserror ();
log_error ("can't stat '%s': %s\n", fname, strerror (errno));
xfree (fname);
es_fclose (fp);
return rc;
}
buflen = st.st_size;
buf = xtrymalloc (buflen+1);
if (!buf)
{
rc = gpg_error_from_syserror ();
log_error ("error allocating %zu bytes for '%s': %s\n",
buflen, fname, strerror (errno));
xfree (fname);
es_fclose (fp);
xfree (buf);
return rc;
}
if (es_fread (buf, buflen, 1, fp) != 1)
{
rc = gpg_error_from_syserror ();
log_error ("error reading %zu bytes from '%s': %s\n",
buflen, fname, strerror (errno));
xfree (fname);
es_fclose (fp);
xfree (buf);
return rc;
}
/* Convert the file into a gcrypt S-expression object. */
rc = gcry_sexp_sscan (&s_skey, &erroff, (char*)buf, buflen);
xfree (fname);
es_fclose (fp);
xfree (buf);
if (rc)
{
log_error ("failed to build S-Exp (off=%u): %s\n",
(unsigned int)erroff, gpg_strerror (rc));
return rc;
}
*result = s_skey;
return 0;
}
/* Remove the key identified by GRIP from the private key directory. */
static gpg_error_t
remove_key_file (const unsigned char *grip)
{
gpg_error_t err = 0;
char *fname;
char hexgrip[40+4+1];
bin2hex (grip, 20, hexgrip);
strcpy (hexgrip+40, ".key");
fname = make_filename (gnupg_homedir (), GNUPG_PRIVATE_KEYS_DIR,
hexgrip, NULL);
if (gnupg_remove (fname))
err = gpg_error_from_syserror ();
xfree (fname);
return err;
}
/* Return the secret key as an S-Exp in RESULT after locating it using
the GRIP. If the operation shall be diverted to a token, an
allocated S-expression with the shadow_info part from the file is
stored at SHADOW_INFO; if not NULL will be stored at SHADOW_INFO.
CACHE_MODE defines now the cache shall be used. DESC_TEXT may be
set to present a custom description for the pinentry. LOOKUP_TTL
is an optional function to convey a TTL to the cache manager; we do
not simply pass the TTL value because the value is only needed if
an unprotect action was needed and looking up the TTL may have some
overhead (e.g. scanning the sshcontrol file). If a CACHE_NONCE is
given that cache item is first tried to get a passphrase. If
R_PASSPHRASE is not NULL, the function succeeded and the key was
protected the used passphrase (entered or from the cache) is stored
there; if not NULL will be stored. The caller needs to free the
returned passphrase. */
gpg_error_t
agent_key_from_file (ctrl_t ctrl, const char *cache_nonce,
const char *desc_text,
const unsigned char *grip, unsigned char **shadow_info,
cache_mode_t cache_mode, lookup_ttl_t lookup_ttl,
gcry_sexp_t *result, char **r_passphrase)
{
int rc;
unsigned char *buf;
size_t len, buflen, erroff;
gcry_sexp_t s_skey;
*result = NULL;
if (shadow_info)
*shadow_info = NULL;
if (r_passphrase)
*r_passphrase = NULL;
rc = read_key_file (grip, &s_skey);
if (rc)
{
if (gpg_err_code (rc) == GPG_ERR_ENOENT)
rc = gpg_error (GPG_ERR_NO_SECKEY);
return rc;
}
/* For use with the protection functions we also need the key as an
canonical encoded S-expression in a buffer. Create this buffer
now. */
rc = make_canon_sexp (s_skey, &buf, &len);
if (rc)
return rc;
switch (agent_private_key_type (buf))
{
case PRIVATE_KEY_CLEAR:
break; /* no unprotection needed */
case PRIVATE_KEY_OPENPGP_NONE:
{
unsigned char *buf_new;
size_t buf_newlen;
rc = agent_unprotect (ctrl, buf, "", NULL, &buf_new, &buf_newlen);
if (rc)
log_error ("failed to convert unprotected openpgp key: %s\n",
gpg_strerror (rc));
else
{
xfree (buf);
buf = buf_new;
}
}
break;
case PRIVATE_KEY_PROTECTED:
{
char *desc_text_final;
char *comment = NULL;
/* Note, that we will take the comment as a C string for
display purposes; i.e. all stuff beyond a Nul character is
ignored. */
{
gcry_sexp_t comment_sexp;
comment_sexp = gcry_sexp_find_token (s_skey, "comment", 0);
if (comment_sexp)
comment = gcry_sexp_nth_string (comment_sexp, 1);
gcry_sexp_release (comment_sexp);
}
desc_text_final = NULL;
if (desc_text)
rc = agent_modify_description (desc_text, comment, s_skey,
&desc_text_final);
gcry_free (comment);
if (!rc)
{
rc = unprotect (ctrl, cache_nonce, desc_text_final, &buf, grip,
cache_mode, lookup_ttl, r_passphrase);
if (rc)
log_error ("failed to unprotect the secret key: %s\n",
gpg_strerror (rc));
}
xfree (desc_text_final);
}
break;
case PRIVATE_KEY_SHADOWED:
if (shadow_info)
{
const unsigned char *s;
size_t n;
rc = agent_get_shadow_info (buf, &s);
if (!rc)
{
n = gcry_sexp_canon_len (s, 0, NULL,NULL);
assert (n);
*shadow_info = xtrymalloc (n);
if (!*shadow_info)
rc = out_of_core ();
else
{
memcpy (*shadow_info, s, n);
rc = 0;
}
}
if (rc)
log_error ("get_shadow_info failed: %s\n", gpg_strerror (rc));
}
else
rc = gpg_error (GPG_ERR_UNUSABLE_SECKEY);
break;
default:
log_error ("invalid private key format\n");
rc = gpg_error (GPG_ERR_BAD_SECKEY);
break;
}
gcry_sexp_release (s_skey);
s_skey = NULL;
if (rc)
{
xfree (buf);
if (r_passphrase)
{
xfree (*r_passphrase);
*r_passphrase = NULL;
}
return rc;
}
buflen = gcry_sexp_canon_len (buf, 0, NULL, NULL);
rc = gcry_sexp_sscan (&s_skey, &erroff, (char*)buf, buflen);
wipememory (buf, buflen);
xfree (buf);
if (rc)
{
log_error ("failed to build S-Exp (off=%u): %s\n",
(unsigned int)erroff, gpg_strerror (rc));
if (r_passphrase)
{
xfree (*r_passphrase);
*r_passphrase = NULL;
}
return rc;
}
*result = s_skey;
return 0;
}
/* Return the string name from the S-expression S_KEY as well as a
string describing the names of the parameters. ALGONAMESIZE and
ELEMSSIZE give the allocated size of the provided buffers. The
buffers may be NULL if not required. If R_LIST is not NULL the top
level list will be stored there; the caller needs to release it in
this case. */
static gpg_error_t
key_parms_from_sexp (gcry_sexp_t s_key, gcry_sexp_t *r_list,
char *r_algoname, size_t algonamesize,
char *r_elems, size_t elemssize)
{
gcry_sexp_t list, l2;
const char *name, *algoname, *elems;
size_t n;
if (r_list)
*r_list = NULL;
list = gcry_sexp_find_token (s_key, "shadowed-private-key", 0 );
if (!list)
list = gcry_sexp_find_token (s_key, "protected-private-key", 0 );
if (!list)
list = gcry_sexp_find_token (s_key, "private-key", 0 );
if (!list)
{
log_error ("invalid private key format\n");
return gpg_error (GPG_ERR_BAD_SECKEY);
}
l2 = gcry_sexp_cadr (list);
gcry_sexp_release (list);
list = l2;
name = gcry_sexp_nth_data (list, 0, &n);
if (n==3 && !memcmp (name, "rsa", 3))
{
algoname = "rsa";
elems = "ne";
}
else if (n==3 && !memcmp (name, "dsa", 3))
{
algoname = "dsa";
elems = "pqgy";
}
else if (n==3 && !memcmp (name, "ecc", 3))
{
algoname = "ecc";
elems = "pabgnq";
}
else if (n==5 && !memcmp (name, "ecdsa", 5))
{
algoname = "ecdsa";
elems = "pabgnq";
}
else if (n==4 && !memcmp (name, "ecdh", 4))
{
algoname = "ecdh";
elems = "pabgnq";
}
else if (n==3 && !memcmp (name, "elg", 3))
{
algoname = "elg";
elems = "pgy";
}
else
{
log_error ("unknown private key algorithm\n");
gcry_sexp_release (list);
return gpg_error (GPG_ERR_BAD_SECKEY);
}
if (r_algoname)
{
if (strlen (algoname) >= algonamesize)
return gpg_error (GPG_ERR_BUFFER_TOO_SHORT);
strcpy (r_algoname, algoname);
}
if (r_elems)
{
if (strlen (elems) >= elemssize)
return gpg_error (GPG_ERR_BUFFER_TOO_SHORT);
strcpy (r_elems, elems);
}
if (r_list)
*r_list = list;
else
gcry_sexp_release (list);
return 0;
}
/* Return true if KEYPARMS holds an EdDSA key. */
static int
is_eddsa (gcry_sexp_t keyparms)
{
int result = 0;
gcry_sexp_t list;
const char *s;
size_t n;
int i;
list = gcry_sexp_find_token (keyparms, "flags", 0);
for (i = list ? gcry_sexp_length (list)-1 : 0; i > 0; i--)
{
s = gcry_sexp_nth_data (list, i, &n);
if (!s)
continue; /* Not a data element. */
if (n == 5 && !memcmp (s, "eddsa", 5))
{
result = 1;
break;
}
}
gcry_sexp_release (list);
return result;
}
/* Return the public key algorithm number if S_KEY is a DSA style key.
If it is not a DSA style key, return 0. */
int
agent_is_dsa_key (gcry_sexp_t s_key)
{
int result;
gcry_sexp_t list;
char algoname[6];
if (!s_key)
return 0;
if (key_parms_from_sexp (s_key, &list, algoname, sizeof algoname, NULL, 0))
return 0; /* Error - assume it is not an DSA key. */
if (!strcmp (algoname, "dsa"))
result = GCRY_PK_DSA;
else if (!strcmp (algoname, "ecc"))
{
if (is_eddsa (list))
result = 0;
else
result = GCRY_PK_ECDSA;
}
else if (!strcmp (algoname, "ecdsa"))
result = GCRY_PK_ECDSA;
else
result = 0;
gcry_sexp_release (list);
return result;
}
/* Return true if S_KEY is an EdDSA key as used with curve Ed25519. */
int
agent_is_eddsa_key (gcry_sexp_t s_key)
{
int result;
gcry_sexp_t list;
char algoname[6];
if (!s_key)
return 0;
if (key_parms_from_sexp (s_key, &list, algoname, sizeof algoname, NULL, 0))
return 0; /* Error - assume it is not an EdDSA key. */
if (!strcmp (algoname, "ecc") && is_eddsa (list))
result = 1;
else if (!strcmp (algoname, "eddsa")) /* backward compatibility. */
result = 1;
else
result = 0;
gcry_sexp_release (list);
return result;
}
/* Return the key for the keygrip GRIP. The result is stored at
RESULT. This function extracts the key from the private key
database and returns it as an S-expression object as it is. On
failure an error code is returned and NULL stored at RESULT. */
gpg_error_t
agent_raw_key_from_file (ctrl_t ctrl, const unsigned char *grip,
gcry_sexp_t *result)
{
gpg_error_t err;
gcry_sexp_t s_skey;
(void)ctrl;
*result = NULL;
err = read_key_file (grip, &s_skey);
if (!err)
*result = s_skey;
return err;
}
/* Return the public key for the keygrip GRIP. The result is stored
at RESULT. This function extracts the public key from the private
key database. On failure an error code is returned and NULL stored
at RESULT. */
gpg_error_t
agent_public_key_from_file (ctrl_t ctrl,
const unsigned char *grip,
gcry_sexp_t *result)
{
gpg_error_t err;
int i, idx;
gcry_sexp_t s_skey;
const char *algoname, *elems;
int npkey;
gcry_mpi_t array[10];
gcry_sexp_t curve = NULL;
gcry_sexp_t flags = NULL;
gcry_sexp_t uri_sexp, comment_sexp;
const char *uri, *comment;
size_t uri_length, comment_length;
char *format, *p;
void *args[2+7+2+2+1]; /* Size is 2 + max. # of elements + 2 for uri + 2
for comment + end-of-list. */
int argidx;
gcry_sexp_t list = NULL;
const char *s;
(void)ctrl;
*result = NULL;
err = read_key_file (grip, &s_skey);
if (err)
return err;
for (i=0; i < DIM (array); i++)
array[i] = NULL;
err = extract_private_key (s_skey, 0, &algoname, &npkey, NULL, &elems,
array, DIM (array), &curve, &flags);
if (err)
{
gcry_sexp_release (s_skey);
return err;
}
uri = NULL;
uri_length = 0;
uri_sexp = gcry_sexp_find_token (s_skey, "uri", 0);
if (uri_sexp)
uri = gcry_sexp_nth_data (uri_sexp, 1, &uri_length);
comment = NULL;
comment_length = 0;
comment_sexp = gcry_sexp_find_token (s_skey, "comment", 0);
if (comment_sexp)
comment = gcry_sexp_nth_data (comment_sexp, 1, &comment_length);
gcry_sexp_release (s_skey);
s_skey = NULL;
/* FIXME: The following thing is pretty ugly code; we should
investigate how to make it cleaner. Probably code to handle
canonical S-expressions in a memory buffer is better suited for
such a task. After all that is what we do in protect.c. Need
to find common patterns and write a straightformward API to use
them. */
assert (sizeof (size_t) <= sizeof (void*));
format = xtrymalloc (15+4+7*npkey+10+15+1+1);
if (!format)
{
err = gpg_error_from_syserror ();
for (i=0; array[i]; i++)
gcry_mpi_release (array[i]);
gcry_sexp_release (curve);
gcry_sexp_release (flags);
gcry_sexp_release (uri_sexp);
gcry_sexp_release (comment_sexp);
return err;
}
argidx = 0;
p = stpcpy (stpcpy (format, "(public-key("), algoname);
p = stpcpy (p, "%S%S"); /* curve name and flags. */
args[argidx++] = &curve;
args[argidx++] = &flags;
for (idx=0, s=elems; idx < npkey; idx++)
{
*p++ = '(';
*p++ = *s++;
p = stpcpy (p, " %m)");
assert (argidx < DIM (args));
args[argidx++] = &array[idx];
}
*p++ = ')';
if (uri)
{
p = stpcpy (p, "(uri %b)");
assert (argidx+1 < DIM (args));
args[argidx++] = (void *)&uri_length;
args[argidx++] = (void *)&uri;
}
if (comment)
{
p = stpcpy (p, "(comment %b)");
assert (argidx+1 < DIM (args));
args[argidx++] = (void *)&comment_length;
args[argidx++] = (void*)&comment;
}
*p++ = ')';
*p = 0;
assert (argidx < DIM (args));
args[argidx] = NULL;
err = gcry_sexp_build_array (&list, NULL, format, args);
xfree (format);
for (i=0; array[i]; i++)
gcry_mpi_release (array[i]);
gcry_sexp_release (curve);
gcry_sexp_release (flags);
gcry_sexp_release (uri_sexp);
gcry_sexp_release (comment_sexp);
if (!err)
*result = list;
return err;
}
/* Check whether the secret key identified by GRIP is available.
Returns 0 is the key is available. */
int
agent_key_available (const unsigned char *grip)
{
int result;
char *fname;
char hexgrip[40+4+1];
bin2hex (grip, 20, hexgrip);
strcpy (hexgrip+40, ".key");
fname = make_filename (gnupg_homedir (), GNUPG_PRIVATE_KEYS_DIR,
hexgrip, NULL);
result = !access (fname, R_OK)? 0 : -1;
xfree (fname);
return result;
}
/* Return the information about the secret key specified by the binary
keygrip GRIP. If the key is a shadowed one the shadow information
will be stored at the address R_SHADOW_INFO as an allocated
S-expression. */
gpg_error_t
agent_key_info_from_file (ctrl_t ctrl, const unsigned char *grip,
int *r_keytype, unsigned char **r_shadow_info)
{
gpg_error_t err;
unsigned char *buf;
size_t len;
int keytype;
(void)ctrl;
if (r_keytype)
*r_keytype = PRIVATE_KEY_UNKNOWN;
if (r_shadow_info)
*r_shadow_info = NULL;
{
gcry_sexp_t sexp;
err = read_key_file (grip, &sexp);
if (err)
{
if (gpg_err_code (err) == GPG_ERR_ENOENT)
return gpg_error (GPG_ERR_NOT_FOUND);
else
return err;
}
err = make_canon_sexp (sexp, &buf, &len);
gcry_sexp_release (sexp);
if (err)
return err;
}
keytype = agent_private_key_type (buf);
switch (keytype)
{
case PRIVATE_KEY_CLEAR:
case PRIVATE_KEY_OPENPGP_NONE:
break;
case PRIVATE_KEY_PROTECTED:
/* If we ever require it we could retrieve the comment fields
from such a key. */
break;
case PRIVATE_KEY_SHADOWED:
if (r_shadow_info)
{
const unsigned char *s;
size_t n;
err = agent_get_shadow_info (buf, &s);
if (!err)
{
n = gcry_sexp_canon_len (s, 0, NULL, NULL);
assert (n);
*r_shadow_info = xtrymalloc (n);
if (!*r_shadow_info)
err = gpg_error_from_syserror ();
else
memcpy (*r_shadow_info, s, n);
}
}
break;
default:
err = gpg_error (GPG_ERR_BAD_SECKEY);
break;
}
if (!err && r_keytype)
*r_keytype = keytype;
xfree (buf);
return err;
}
/* Delete the key with GRIP from the disk after having asked for
* confirmation using DESC_TEXT. If FORCE is set the function won't
* require a confirmation via Pinentry or warns if the key is also
* used by ssh. If ONLY_STUBS is set only stub keys (references to
* smartcards) will be affected.
*
* Common error codes are:
* GPG_ERR_NO_SECKEY
* GPG_ERR_KEY_ON_CARD
* GPG_ERR_NOT_CONFIRMED
* GPG_ERR_FORBIDDEN - Not a stub key and ONLY_STUBS requested.
*/
gpg_error_t
agent_delete_key (ctrl_t ctrl, const char *desc_text,
const unsigned char *grip, int force, int only_stubs)
{
gpg_error_t err;
gcry_sexp_t s_skey = NULL;
unsigned char *buf = NULL;
size_t len;
char *desc_text_final = NULL;
char *comment = NULL;
ssh_control_file_t cf = NULL;
char hexgrip[40+4+1];
char *default_desc = NULL;
int key_type;
err = read_key_file (grip, &s_skey);
if (gpg_err_code (err) == GPG_ERR_ENOENT)
err = gpg_error (GPG_ERR_NO_SECKEY);
if (err)
goto leave;
err = make_canon_sexp (s_skey, &buf, &len);
if (err)
goto leave;
key_type = agent_private_key_type (buf);
if (only_stubs && key_type != PRIVATE_KEY_SHADOWED)
{
err = gpg_error (GPG_ERR_FORBIDDEN);
goto leave;
}
switch (key_type)
{
case PRIVATE_KEY_CLEAR:
case PRIVATE_KEY_OPENPGP_NONE:
case PRIVATE_KEY_PROTECTED:
bin2hex (grip, 20, hexgrip);
if (!force)
{
if (!desc_text)
{
default_desc = xtryasprintf
(L_("Do you really want to delete the key identified by keygrip%%0A"
" %s%%0A %%C%%0A?"), hexgrip);
desc_text = default_desc;
}
/* Note, that we will take the comment as a C string for
display purposes; i.e. all stuff beyond a Nul character is
ignored. */
{
gcry_sexp_t comment_sexp;
comment_sexp = gcry_sexp_find_token (s_skey, "comment", 0);
if (comment_sexp)
comment = gcry_sexp_nth_string (comment_sexp, 1);
gcry_sexp_release (comment_sexp);
}
if (desc_text)
err = agent_modify_description (desc_text, comment, s_skey,
&desc_text_final);
if (err)
goto leave;
err = agent_get_confirmation (ctrl, desc_text_final,
L_("Delete key"), L_("No"), 0);
if (err)
goto leave;
cf = ssh_open_control_file ();
if (cf)
{
if (!ssh_search_control_file (cf, hexgrip, NULL, NULL, NULL))
{
err = agent_get_confirmation
(ctrl,
L_("Warning: This key is also listed for use with SSH!\n"
"Deleting the key might remove your ability to "
"access remote machines."),
L_("Delete key"), L_("No"), 0);
if (err)
goto leave;
}
}
}
err = remove_key_file (grip);
break;
case PRIVATE_KEY_SHADOWED:
err = remove_key_file (grip);
break;
default:
log_error ("invalid private key format\n");
err = gpg_error (GPG_ERR_BAD_SECKEY);
break;
}
leave:
ssh_close_control_file (cf);
gcry_free (comment);
xfree (desc_text_final);
xfree (default_desc);
xfree (buf);
gcry_sexp_release (s_skey);
return err;
}
/* Write an S-expression formatted shadow key to our key storage.
Shadow key is created by an S-expression public key in PKBUF and
card's SERIALNO and the IDSTRING. With FORCE passed as true an
existing key with the given GRIP will get overwritten. */
gpg_error_t
agent_write_shadow_key (const unsigned char *grip,
const char *serialno, const char *keyid,
const unsigned char *pkbuf, int force)
{
gpg_error_t err;
unsigned char *shadow_info;
unsigned char *shdkey;
size_t len;
shadow_info = make_shadow_info (serialno, keyid);
if (!shadow_info)
return gpg_error_from_syserror ();
err = agent_shadow_key (pkbuf, shadow_info, &shdkey);
xfree (shadow_info);
if (err)
{
log_error ("shadowing the key failed: %s\n", gpg_strerror (err));
return err;
}
len = gcry_sexp_canon_len (shdkey, 0, NULL, NULL);
err = agent_write_private_key (grip, shdkey, len, force);
xfree (shdkey);
if (err)
log_error ("error writing key: %s\n", gpg_strerror (err));
return err;
}
diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
index 6ec9b6708..77b811cbb 100644
--- a/agent/gpg-agent.c
+++ b/agent/gpg-agent.c
@@ -1,3124 +1,3133 @@
/* gpg-agent.c - The GnuPG Agent
* Copyright (C) 2000-2007, 2009-2010 Free Software Foundation, Inc.
* Copyright (C) 2000-2016 Werner Koch
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <time.h>
#include <fcntl.h>
#include <sys/stat.h>
#ifdef HAVE_W32_SYSTEM
# ifndef WINVER
# define WINVER 0x0500 /* Same as in common/sysutils.c */
# endif
# ifdef HAVE_WINSOCK2_H
# include <winsock2.h>
# endif
# include <aclapi.h>
# include <sddl.h>
#else /*!HAVE_W32_SYSTEM*/
# include <sys/socket.h>
# include <sys/un.h>
#endif /*!HAVE_W32_SYSTEM*/
#include <unistd.h>
#ifdef HAVE_SIGNAL_H
# include <signal.h>
#endif
#include <npth.h>
#define GNUPG_COMMON_NEED_AFLOCAL
#include "agent.h"
#include <assuan.h> /* Malloc hooks and socket wrappers. */
#include "../common/i18n.h"
#include "../common/sysutils.h"
#include "../common/gc-opt-flags.h"
#include "../common/exechelp.h"
#include "../common/asshelp.h"
#include "../common/init.h"
enum cmd_and_opt_values
{ aNull = 0,
oCsh = 'c',
oQuiet = 'q',
oSh = 's',
oVerbose = 'v',
oNoVerbose = 500,
aGPGConfList,
aGPGConfTest,
aUseStandardSocketP,
oOptions,
oDebug,
oDebugAll,
oDebugLevel,
oDebugWait,
oDebugQuickRandom,
oDebugPinentry,
oNoGreeting,
oNoOptions,
oHomedir,
oNoDetach,
oNoGrab,
oLogFile,
oServer,
oDaemon,
oSupervised,
oBatch,
oPinentryProgram,
oPinentryTouchFile,
oPinentryInvisibleChar,
oPinentryTimeout,
oDisplay,
oTTYname,
oTTYtype,
oLCctype,
oLCmessages,
oXauthority,
oScdaemonProgram,
oDefCacheTTL,
oDefCacheTTLSSH,
oMaxCacheTTL,
oMaxCacheTTLSSH,
oEnforcePassphraseConstraints,
oMinPassphraseLen,
oMinPassphraseNonalpha,
oCheckPassphrasePattern,
oMaxPassphraseDays,
oEnablePassphraseHistory,
oEnableExtendedKeyFormat,
oUseStandardSocket,
oNoUseStandardSocket,
oExtraSocket,
oBrowserSocket,
oFakedSystemTime,
oIgnoreCacheForSigning,
oAllowMarkTrusted,
oNoAllowMarkTrusted,
oAllowPresetPassphrase,
oAllowLoopbackPinentry,
oNoAllowLoopbackPinentry,
oNoAllowExternalCache,
oAllowEmacsPinentry,
oKeepTTY,
oKeepDISPLAY,
oSSHSupport,
+ oSSHFingerprintDigest,
oPuttySupport,
oDisableScdaemon,
oDisableCheckOwnSocket,
oWriteEnvFile
};
#ifndef ENAMETOOLONG
# define ENAMETOOLONG EINVAL
#endif
static ARGPARSE_OPTS opts[] = {
ARGPARSE_c (aGPGConfList, "gpgconf-list", "@"),
ARGPARSE_c (aGPGConfTest, "gpgconf-test", "@"),
ARGPARSE_c (aUseStandardSocketP, "use-standard-socket-p", "@"),
ARGPARSE_group (301, N_("@Options:\n ")),
ARGPARSE_s_n (oDaemon, "daemon", N_("run in daemon mode (background)")),
ARGPARSE_s_n (oServer, "server", N_("run in server mode (foreground)")),
#ifndef HAVE_W32_SYSTEM
ARGPARSE_s_n (oSupervised, "supervised", N_("run in supervised mode")),
#endif
ARGPARSE_s_n (oVerbose, "verbose", N_("verbose")),
ARGPARSE_s_n (oQuiet, "quiet", N_("be somewhat more quiet")),
ARGPARSE_s_n (oSh, "sh", N_("sh-style command output")),
ARGPARSE_s_n (oCsh, "csh", N_("csh-style command output")),
ARGPARSE_s_s (oOptions, "options", N_("|FILE|read options from FILE")),
ARGPARSE_s_s (oDebug, "debug", "@"),
ARGPARSE_s_n (oDebugAll, "debug-all", "@"),
ARGPARSE_s_s (oDebugLevel, "debug-level", "@"),
ARGPARSE_s_i (oDebugWait," debug-wait", "@"),
ARGPARSE_s_n (oDebugQuickRandom, "debug-quick-random", "@"),
ARGPARSE_s_n (oDebugPinentry, "debug-pinentry", "@"),
ARGPARSE_s_n (oNoDetach, "no-detach", N_("do not detach from the console")),
ARGPARSE_s_n (oNoGrab, "no-grab", N_("do not grab keyboard and mouse")),
ARGPARSE_s_s (oLogFile, "log-file", N_("use a log file for the server")),
ARGPARSE_s_s (oPinentryProgram, "pinentry-program",
/* */ N_("|PGM|use PGM as the PIN-Entry program")),
ARGPARSE_s_s (oPinentryTouchFile, "pinentry-touch-file", "@"),
ARGPARSE_s_s (oPinentryInvisibleChar, "pinentry-invisible-char", "@"),
ARGPARSE_s_u (oPinentryTimeout, "pinentry-timeout", "@"),
ARGPARSE_s_s (oScdaemonProgram, "scdaemon-program",
/* */ N_("|PGM|use PGM as the SCdaemon program") ),
ARGPARSE_s_n (oDisableScdaemon, "disable-scdaemon",
/* */ N_("do not use the SCdaemon") ),
ARGPARSE_s_n (oDisableCheckOwnSocket, "disable-check-own-socket", "@"),
ARGPARSE_s_s (oExtraSocket, "extra-socket",
/* */ N_("|NAME|accept some commands via NAME")),
ARGPARSE_s_s (oBrowserSocket, "browser-socket", "@"),
ARGPARSE_s_s (oFakedSystemTime, "faked-system-time", "@"),
ARGPARSE_s_n (oBatch, "batch", "@"),
ARGPARSE_s_s (oHomedir, "homedir", "@"),
ARGPARSE_s_s (oDisplay, "display", "@"),
ARGPARSE_s_s (oTTYname, "ttyname", "@"),
ARGPARSE_s_s (oTTYtype, "ttytype", "@"),
ARGPARSE_s_s (oLCctype, "lc-ctype", "@"),
ARGPARSE_s_s (oLCmessages, "lc-messages", "@"),
ARGPARSE_s_s (oXauthority, "xauthority", "@"),
ARGPARSE_s_n (oKeepTTY, "keep-tty",
/* */ N_("ignore requests to change the TTY")),
ARGPARSE_s_n (oKeepDISPLAY, "keep-display",
/* */ N_("ignore requests to change the X display")),
ARGPARSE_s_u (oDefCacheTTL, "default-cache-ttl",
N_("|N|expire cached PINs after N seconds")),
ARGPARSE_s_u (oDefCacheTTLSSH, "default-cache-ttl-ssh", "@" ),
ARGPARSE_s_u (oMaxCacheTTL, "max-cache-ttl", "@" ),
ARGPARSE_s_u (oMaxCacheTTLSSH, "max-cache-ttl-ssh", "@" ),
ARGPARSE_s_n (oEnforcePassphraseConstraints, "enforce-passphrase-constraints",
/* */ "@"),
ARGPARSE_s_u (oMinPassphraseLen, "min-passphrase-len", "@"),
ARGPARSE_s_u (oMinPassphraseNonalpha, "min-passphrase-nonalpha", "@"),
ARGPARSE_s_s (oCheckPassphrasePattern, "check-passphrase-pattern", "@"),
ARGPARSE_s_u (oMaxPassphraseDays, "max-passphrase-days", "@"),
ARGPARSE_s_n (oEnablePassphraseHistory, "enable-passphrase-history", "@"),
ARGPARSE_s_n (oIgnoreCacheForSigning, "ignore-cache-for-signing",
/* */ N_("do not use the PIN cache when signing")),
ARGPARSE_s_n (oNoAllowExternalCache, "no-allow-external-cache",
/* */ N_("disallow the use of an external password cache")),
ARGPARSE_s_n (oNoAllowMarkTrusted, "no-allow-mark-trusted",
/* */ N_("disallow clients to mark keys as \"trusted\"")),
ARGPARSE_s_n (oAllowMarkTrusted, "allow-mark-trusted", "@"),
ARGPARSE_s_n (oAllowPresetPassphrase, "allow-preset-passphrase",
/* */ N_("allow presetting passphrase")),
ARGPARSE_s_n (oNoAllowLoopbackPinentry, "no-allow-loopback-pinentry",
N_("disallow caller to override the pinentry")),
ARGPARSE_s_n (oAllowLoopbackPinentry, "allow-loopback-pinentry", "@"),
ARGPARSE_s_n (oAllowEmacsPinentry, "allow-emacs-pinentry",
/* */ N_("allow passphrase to be prompted through Emacs")),
ARGPARSE_s_n (oSSHSupport, "enable-ssh-support", N_("enable ssh support")),
+ ARGPARSE_s_s (oSSHFingerprintDigest, "ssh-fingerprint-digest",
+ N_("digest to use when communicating ssh fingerprints")),
ARGPARSE_s_n (oPuttySupport, "enable-putty-support",
#ifdef HAVE_W32_SYSTEM
/* */ N_("enable putty support")
#else
/* */ "@"
#endif
),
ARGPARSE_s_n (oEnableExtendedKeyFormat, "enable-extended-key-format", "@"),
/* Dummy options for backward compatibility. */
ARGPARSE_o_s (oWriteEnvFile, "write-env-file", "@"),
ARGPARSE_s_n (oUseStandardSocket, "use-standard-socket", "@"),
ARGPARSE_s_n (oNoUseStandardSocket, "no-use-standard-socket", "@"),
{0} /* End of list */
};
/* The list of supported debug flags. */
static struct debug_flags_s debug_flags [] =
{
{ DBG_MPI_VALUE , "mpi" },
{ DBG_CRYPTO_VALUE , "crypto" },
{ DBG_MEMORY_VALUE , "memory" },
{ DBG_CACHE_VALUE , "cache" },
{ DBG_MEMSTAT_VALUE, "memstat" },
{ DBG_HASHING_VALUE, "hashing" },
{ DBG_IPC_VALUE , "ipc" },
{ 77, NULL } /* 77 := Do not exit on "help" or "?". */
};
#define DEFAULT_CACHE_TTL (10*60) /* 10 minutes */
#define DEFAULT_CACHE_TTL_SSH (30*60) /* 30 minutes */
#define MAX_CACHE_TTL (120*60) /* 2 hours */
#define MAX_CACHE_TTL_SSH (120*60) /* 2 hours */
#define MIN_PASSPHRASE_LEN (8)
#define MIN_PASSPHRASE_NONALPHA (1)
#define MAX_PASSPHRASE_DAYS (0)
/* The timer tick used for housekeeping stuff. For Windows we use a
longer period as the SetWaitableTimer seems to signal earlier than
the 2 seconds. CHECK_OWN_SOCKET_INTERVAL defines how often we
check our own socket in standard socket mode. If that value is 0
we don't check at all. All values are in seconds. */
#if defined(HAVE_W32CE_SYSTEM)
# define TIMERTICK_INTERVAL (60)
# define CHECK_OWN_SOCKET_INTERVAL (0) /* Never */
#elif defined(HAVE_W32_SYSTEM)
# define TIMERTICK_INTERVAL (4)
# define CHECK_OWN_SOCKET_INTERVAL (60)
#else
# define TIMERTICK_INTERVAL (2)
# define CHECK_OWN_SOCKET_INTERVAL (60)
#endif
/* Flag indicating that the ssh-agent subsystem has been enabled. */
static int ssh_support;
#ifdef HAVE_W32_SYSTEM
/* Flag indicating that support for Putty has been enabled. */
static int putty_support;
/* A magic value used with WM_COPYDATA. */
#define PUTTY_IPC_MAGIC 0x804e50ba
/* To avoid surprises we limit the size of the mapped IPC file to this
value. Putty currently (0.62) uses 8k, thus 16k should be enough
for the foreseeable future. */
#define PUTTY_IPC_MAXLEN 16384
#endif /*HAVE_W32_SYSTEM*/
/* The list of open file descriptors at startup. Note that this list
* has been allocated using the standard malloc. */
#ifndef HAVE_W32_SYSTEM
static int *startup_fd_list;
#endif
/* The signal mask at startup and a flag telling whether it is valid. */
#ifdef HAVE_SIGPROCMASK
static sigset_t startup_signal_mask;
static int startup_signal_mask_valid;
#endif
/* Flag to indicate that a shutdown was requested. */
static int shutdown_pending;
/* Counter for the currently running own socket checks. */
static int check_own_socket_running;
/* Flags to indicate that check_own_socket shall not be called. */
static int disable_check_own_socket;
/* Flag indicating that we are in supervised mode. */
static int is_supervised;
/* Flag to inhibit socket removal in cleanup. */
static int inhibit_socket_removal;
/* It is possible that we are currently running under setuid permissions */
static int maybe_setuid = 1;
/* Name of the communication socket used for native gpg-agent
requests. The second variable is either NULL or a malloced string
with the real socket name in case it has been redirected. */
static char *socket_name;
static char *redir_socket_name;
/* Name of the optional extra socket used for native gpg-agent requests. */
static char *socket_name_extra;
static char *redir_socket_name_extra;
/* Name of the optional browser socket used for native gpg-agent requests. */
static char *socket_name_browser;
static char *redir_socket_name_browser;
/* Name of the communication socket used for ssh-agent protocol. */
static char *socket_name_ssh;
static char *redir_socket_name_ssh;
/* We need to keep track of the server's nonces (these are dummies for
POSIX systems). */
static assuan_sock_nonce_t socket_nonce;
static assuan_sock_nonce_t socket_nonce_extra;
static assuan_sock_nonce_t socket_nonce_browser;
static assuan_sock_nonce_t socket_nonce_ssh;
/* Default values for options passed to the pinentry. */
static char *default_display;
static char *default_ttyname;
static char *default_ttytype;
static char *default_lc_ctype;
static char *default_lc_messages;
static char *default_xauthority;
/* Name of a config file, which will be reread on a HUP if it is not NULL. */
static char *config_filename;
/* Helper to implement --debug-level */
static const char *debug_level;
/* Keep track of the current log file so that we can avoid updating
the log file after a SIGHUP if it didn't changed. Malloced. */
static char *current_logfile;
/* The handle_tick() function may test whether a parent is still
running. We record the PID of the parent here or -1 if it should be
watched. */
static pid_t parent_pid = (pid_t)(-1);
/* Number of active connections. */
static int active_connections;
/* This object is used to dispatch progress messages from Libgcrypt to
* the right thread. Given that we will have at max only a few dozen
* connections at a time, using a linked list is the easiest way to
* handle this. */
struct progress_dispatch_s
{
struct progress_dispatch_s *next;
/* The control object of the connection. If this is NULL no
* connection is associated with this item and it is free for reuse
* by new connections. */
ctrl_t ctrl;
/* The thread id of (npth_self) of the connection. */
npth_t tid;
/* The callback set by the connection. This is similar to the
* Libgcrypt callback but with the control object passed as the
* first argument. */
void (*cb)(ctrl_t ctrl,
const char *what, int printchar,
int current, int total);
};
struct progress_dispatch_s *progress_dispatch_list;
/*
Local prototypes.
*/
static char *create_socket_name (char *standard_name, int with_homedir);
static gnupg_fd_t create_server_socket (char *name, int primary, int cygwin,
char **r_redir_name,
assuan_sock_nonce_t *nonce);
static void create_directories (void);
static void agent_libgcrypt_progress_cb (void *data, const char *what,
int printchar,
int current, int total);
static void agent_init_default_ctrl (ctrl_t ctrl);
static void agent_deinit_default_ctrl (ctrl_t ctrl);
static void handle_connections (gnupg_fd_t listen_fd,
gnupg_fd_t listen_fd_extra,
gnupg_fd_t listen_fd_browser,
gnupg_fd_t listen_fd_ssh);
static void check_own_socket (void);
static int check_for_running_agent (int silent);
/* Pth wrapper function definitions. */
ASSUAN_SYSTEM_NPTH_IMPL;
/*
Functions.
*/
/* Allocate a string describing a library version by calling a GETFNC.
This function is expected to be called only once. GETFNC is
expected to have a semantic like gcry_check_version (). */
static char *
make_libversion (const char *libname, const char *(*getfnc)(const char*))
{
const char *s;
char *result;
if (maybe_setuid)
{
gcry_control (GCRYCTL_INIT_SECMEM, 0, 0); /* Drop setuid. */
maybe_setuid = 0;
}
s = getfnc (NULL);
result = xmalloc (strlen (libname) + 1 + strlen (s) + 1);
strcpy (stpcpy (stpcpy (result, libname), " "), s);
return result;
}
/* Return strings describing this program. The case values are
described in common/argparse.c:strusage. The values here override
the default values given by strusage. */
static const char *
my_strusage (int level)
{
static char *ver_gcry;
const char *p;
switch (level)
{
case 11: p = "@GPG_AGENT@ (@GNUPG@)";
break;
case 13: p = VERSION; break;
case 17: p = PRINTABLE_OS_NAME; break;
/* TRANSLATORS: @EMAIL@ will get replaced by the actual bug
reporting address. This is so that we can change the
reporting address without breaking the translations. */
case 19: p = _("Please report bugs to <@EMAIL@>.\n"); break;
case 20:
if (!ver_gcry)
ver_gcry = make_libversion ("libgcrypt", gcry_check_version);
p = ver_gcry;
break;
case 1:
case 40: p = _("Usage: @GPG_AGENT@ [options] (-h for help)");
break;
case 41: p = _("Syntax: @GPG_AGENT@ [options] [command [args]]\n"
"Secret key management for @GNUPG@\n");
break;
default: p = NULL;
}
return p;
}
/* Setup the debugging. With the global variable DEBUG_LEVEL set to NULL
only the active debug flags are propagated to the subsystems. With
DEBUG_LEVEL set, a specific set of debug flags is set; thus overriding
all flags already set. Note that we don't fail here, because it is
important to keep gpg-agent running even after re-reading the
options due to a SIGHUP. */
static void
set_debug (void)
{
int numok = (debug_level && digitp (debug_level));
int numlvl = numok? atoi (debug_level) : 0;
if (!debug_level)
;
else if (!strcmp (debug_level, "none") || (numok && numlvl < 1))
opt.debug = 0;
else if (!strcmp (debug_level, "basic") || (numok && numlvl <= 2))
opt.debug = DBG_IPC_VALUE;
else if (!strcmp (debug_level, "advanced") || (numok && numlvl <= 5))
opt.debug = DBG_IPC_VALUE;
else if (!strcmp (debug_level, "expert") || (numok && numlvl <= 8))
opt.debug = (DBG_IPC_VALUE | DBG_CACHE_VALUE);
else if (!strcmp (debug_level, "guru") || numok)
{
opt.debug = ~0;
/* Unless the "guru" string has been used we don't want to allow
hashing debugging. The rationale is that people tend to
select the highest debug value and would then clutter their
disk with debug files which may reveal confidential data. */
if (numok)
opt.debug &= ~(DBG_HASHING_VALUE);
}
else
{
log_error (_("invalid debug-level '%s' given\n"), debug_level);
opt.debug = 0; /* Reset debugging, so that prior debug
statements won't have an undesired effect. */
}
if (opt.debug && !opt.verbose)
opt.verbose = 1;
if (opt.debug && opt.quiet)
opt.quiet = 0;
if (opt.debug & DBG_MPI_VALUE)
gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 2);
if (opt.debug & DBG_CRYPTO_VALUE )
gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 1);
gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
if (opt.debug)
parse_debug_flag (NULL, &opt.debug, debug_flags);
}
/* Helper for cleanup to remove one socket with NAME. REDIR_NAME is
the corresponding real name if the socket has been redirected. */
static void
remove_socket (char *name, char *redir_name)
{
if (name && *name)
{
if (redir_name)
name = redir_name;
gnupg_remove (name);
*name = 0;
}
}
/* Discover which inherited file descriptors correspond to which
* services/sockets offered by gpg-agent, using the LISTEN_FDS and
* LISTEN_FDNAMES convention. The understood labels are "ssh",
* "extra", and "browser". "std" or other labels will be interpreted
* as the standard socket.
*
* This function is designed to log errors when the expected file
* descriptors don't make sense, but to do its best to continue to
* work even in the face of minor misconfigurations.
*
* For more information on the LISTEN_FDS convention, see
* sd_listen_fds(3) on certain Linux distributions.
*/
#ifndef HAVE_W32_SYSTEM
static void
map_supervised_sockets (gnupg_fd_t *r_fd,
gnupg_fd_t *r_fd_extra,
gnupg_fd_t *r_fd_browser,
gnupg_fd_t *r_fd_ssh)
{
struct {
const char *label;
int **fdaddr;
char **nameaddr;
} tbl[] = {
{ "ssh", &r_fd_ssh, &socket_name_ssh },
{ "browser", &r_fd_browser, &socket_name_browser },
{ "extra", &r_fd_extra, &socket_name_extra },
{ "std", &r_fd, &socket_name } /* (Must be the last item.) */
};
const char *envvar;
char **fdnames;
int nfdnames;
int fd_count;
*r_fd = *r_fd_extra = *r_fd_browser = *r_fd_ssh = -1;
/* Print a warning if LISTEN_PID does not match outr pid. */
envvar = getenv ("LISTEN_PID");
if (!envvar)
log_error ("no LISTEN_PID environment variable found in "
"--supervised mode (ignoring)\n");
else if (strtoul (envvar, NULL, 10) != (unsigned long)getpid ())
log_error ("environment variable LISTEN_PID (%lu) does not match"
" our pid (%lu) in --supervised mode (ignoring)\n",
(unsigned long)strtoul (envvar, NULL, 10),
(unsigned long)getpid ());
/* Parse LISTEN_FDNAMES into the array FDNAMES. */
envvar = getenv ("LISTEN_FDNAMES");
if (envvar)
{
fdnames = strtokenize (envvar, ":");
if (!fdnames)
{
log_error ("strtokenize failed: %s\n",
gpg_strerror (gpg_error_from_syserror ()));
agent_exit (1);
}
for (nfdnames=0; fdnames[nfdnames]; nfdnames++)
;
}
else
{
fdnames = NULL;
nfdnames = 0;
}
/* Parse LISTEN_FDS into fd_count or provide a replacement. */
envvar = getenv ("LISTEN_FDS");
if (envvar)
fd_count = atoi (envvar);
else if (fdnames)
{
log_error ("no LISTEN_FDS environment variable found in --supervised"
" mode (relying on LISTEN_FDNAMES instead)\n");
fd_count = nfdnames;
}
else
{
log_error ("no LISTEN_FDS or LISTEN_FDNAMES environment variables "
"found in --supervised mode"
" (assuming 1 active descriptor)\n");
fd_count = 1;
}
if (fd_count < 1)
{
log_error ("--supervised mode expects at least one file descriptor"
" (was told %d, carrying on as though it were 1)\n",
fd_count);
fd_count = 1;
}
/* Assign the descriptors to the return values. */
if (!fdnames)
{
struct stat statbuf;
if (fd_count != 1)
log_error ("no LISTEN_FDNAMES and LISTEN_FDS (%d) != 1"
" in --supervised mode."
" (ignoring all sockets but the first one)\n",
fd_count);
if (fstat (3, &statbuf) == -1 && errno ==EBADF)
log_fatal ("file descriptor 3 must be valid in --supervised mode"
" if LISTEN_FDNAMES is not set\n");
*r_fd = 3;
socket_name = gnupg_get_socket_name (3);
}
else if (fd_count != nfdnames)
{
log_fatal ("number of items in LISTEN_FDNAMES (%d) does not match "
"LISTEN_FDS (%d) in --supervised mode\n",
nfdnames, fd_count);
}
else
{
int i, j, fd;
char *name;
for (i = 0; i < nfdnames; i++)
{
for (j = 0; j < DIM (tbl); j++)
{
if (!strcmp (fdnames[i], tbl[j].label) || j == DIM(tbl)-1)
{
fd = 3 + i;
if (**tbl[j].fdaddr == -1)
{
name = gnupg_get_socket_name (fd);
if (name)
{
**tbl[j].fdaddr = fd;
*tbl[j].nameaddr = name;
log_info ("using fd %d for %s socket (%s)\n",
fd, tbl[j].label, name);
}
else
{
log_error ("cannot listen on fd %d for %s socket\n",
fd, tbl[j].label);
close (fd);
}
}
else
{
log_error ("cannot listen on more than one %s socket\n",
tbl[j].label);
close (fd);
}
break;
}
}
}
}
xfree (fdnames);
}
#endif /*!HAVE_W32_SYSTEM*/
/* Cleanup code for this program. This is either called has an atexit
handler or directly. */
static void
cleanup (void)
{
static int done;
if (done)
return;
done = 1;
deinitialize_module_cache ();
if (!is_supervised && !inhibit_socket_removal)
{
remove_socket (socket_name, redir_socket_name);
if (opt.extra_socket > 1)
remove_socket (socket_name_extra, redir_socket_name_extra);
if (opt.browser_socket > 1)
remove_socket (socket_name_browser, redir_socket_name_browser);
remove_socket (socket_name_ssh, redir_socket_name_ssh);
}
}
/* Handle options which are allowed to be reset after program start.
Return true when the current option in PARGS could be handled and
false if not. As a special feature, passing a value of NULL for
PARGS, resets the options to the default. REREAD should be set
true if it is not the initial option parsing. */
static int
parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
{
if (!pargs)
{ /* reset mode */
opt.quiet = 0;
opt.verbose = 0;
opt.debug = 0;
opt.no_grab = 0;
opt.debug_pinentry = 0;
opt.pinentry_program = NULL;
opt.pinentry_touch_file = NULL;
xfree (opt.pinentry_invisible_char);
opt.pinentry_invisible_char = NULL;
opt.pinentry_timeout = 0;
opt.scdaemon_program = NULL;
opt.def_cache_ttl = DEFAULT_CACHE_TTL;
opt.def_cache_ttl_ssh = DEFAULT_CACHE_TTL_SSH;
opt.max_cache_ttl = MAX_CACHE_TTL;
opt.max_cache_ttl_ssh = MAX_CACHE_TTL_SSH;
opt.enforce_passphrase_constraints = 0;
opt.min_passphrase_len = MIN_PASSPHRASE_LEN;
opt.min_passphrase_nonalpha = MIN_PASSPHRASE_NONALPHA;
opt.check_passphrase_pattern = NULL;
opt.max_passphrase_days = MAX_PASSPHRASE_DAYS;
opt.enable_passphrase_history = 0;
opt.enable_extended_key_format = 0;
opt.ignore_cache_for_signing = 0;
opt.allow_mark_trusted = 1;
opt.allow_external_cache = 1;
opt.allow_loopback_pinentry = 1;
opt.allow_emacs_pinentry = 0;
opt.disable_scdaemon = 0;
disable_check_own_socket = 0;
+ opt.ssh_fingerprint_digest = GCRY_MD_MD5;
return 1;
}
switch (pargs->r_opt)
{
case oQuiet: opt.quiet = 1; break;
case oVerbose: opt.verbose++; break;
case oDebug:
parse_debug_flag (pargs->r.ret_str, &opt.debug, debug_flags);
break;
case oDebugAll: opt.debug = ~0; break;
case oDebugLevel: debug_level = pargs->r.ret_str; break;
case oDebugPinentry: opt.debug_pinentry = 1; break;
case oLogFile:
if (!reread)
return 0; /* not handeld */
if (!current_logfile || !pargs->r.ret_str
|| strcmp (current_logfile, pargs->r.ret_str))
{
log_set_file (pargs->r.ret_str);
xfree (current_logfile);
current_logfile = xtrystrdup (pargs->r.ret_str);
}
break;
case oNoGrab: opt.no_grab = 1; break;
case oPinentryProgram: opt.pinentry_program = pargs->r.ret_str; break;
case oPinentryTouchFile: opt.pinentry_touch_file = pargs->r.ret_str; break;
case oPinentryInvisibleChar:
xfree (opt.pinentry_invisible_char);
opt.pinentry_invisible_char = xtrystrdup (pargs->r.ret_str); break;
break;
case oPinentryTimeout: opt.pinentry_timeout = pargs->r.ret_ulong; break;
case oScdaemonProgram: opt.scdaemon_program = pargs->r.ret_str; break;
case oDisableScdaemon: opt.disable_scdaemon = 1; break;
case oDisableCheckOwnSocket: disable_check_own_socket = 1; break;
case oDefCacheTTL: opt.def_cache_ttl = pargs->r.ret_ulong; break;
case oDefCacheTTLSSH: opt.def_cache_ttl_ssh = pargs->r.ret_ulong; break;
case oMaxCacheTTL: opt.max_cache_ttl = pargs->r.ret_ulong; break;
case oMaxCacheTTLSSH: opt.max_cache_ttl_ssh = pargs->r.ret_ulong; break;
case oEnforcePassphraseConstraints:
opt.enforce_passphrase_constraints=1;
break;
case oMinPassphraseLen: opt.min_passphrase_len = pargs->r.ret_ulong; break;
case oMinPassphraseNonalpha:
opt.min_passphrase_nonalpha = pargs->r.ret_ulong;
break;
case oCheckPassphrasePattern:
opt.check_passphrase_pattern = pargs->r.ret_str;
break;
case oMaxPassphraseDays:
opt.max_passphrase_days = pargs->r.ret_ulong;
break;
case oEnablePassphraseHistory:
opt.enable_passphrase_history = 1;
break;
case oEnableExtendedKeyFormat:
opt.enable_extended_key_format = 1;
break;
case oIgnoreCacheForSigning: opt.ignore_cache_for_signing = 1; break;
case oAllowMarkTrusted: opt.allow_mark_trusted = 1; break;
case oNoAllowMarkTrusted: opt.allow_mark_trusted = 0; break;
case oAllowPresetPassphrase: opt.allow_preset_passphrase = 1; break;
case oAllowLoopbackPinentry: opt.allow_loopback_pinentry = 1; break;
case oNoAllowLoopbackPinentry: opt.allow_loopback_pinentry = 0; break;
case oNoAllowExternalCache: opt.allow_external_cache = 0;
break;
case oAllowEmacsPinentry: opt.allow_emacs_pinentry = 1;
break;
default:
return 0; /* not handled */
}
return 1; /* handled */
}
/* Fixup some options after all have been processed. */
static void
finalize_rereadable_options (void)
{
}
static void
thread_init_once (void)
{
static int npth_initialized = 0;
if (!npth_initialized)
{
npth_initialized++;
npth_init ();
}
gpgrt_set_syscall_clamp (npth_unprotect, npth_protect);
/* Now that we have set the syscall clamp we need to tell Libgcrypt
* that it should get them from libgpg-error. Note that Libgcrypt
* has already been initialized but at that point nPth was not
* initialized and thus Libgcrypt could not set its system call
* clamp. */
#if GCRYPT_VERSION_NUMBER >= 0x010800 /* 1.8.0 */
gcry_control (GCRYCTL_REINIT_SYSCALL_CLAMP, 0, 0);
#endif
}
static void
initialize_modules (void)
{
thread_init_once ();
assuan_set_system_hooks (ASSUAN_SYSTEM_NPTH);
initialize_module_cache ();
initialize_module_call_pinentry ();
initialize_module_call_scd ();
initialize_module_trustlist ();
}
/* The main entry point. */
int
main (int argc, char **argv )
{
ARGPARSE_ARGS pargs;
int orig_argc;
char **orig_argv;
FILE *configfp = NULL;
char *configname = NULL;
const char *shell;
unsigned configlineno;
int parse_debug = 0;
int default_config =1;
int pipe_server = 0;
int is_daemon = 0;
int nodetach = 0;
int csh_style = 0;
char *logfile = NULL;
int debug_wait = 0;
int gpgconf_list = 0;
gpg_error_t err;
struct assuan_malloc_hooks malloc_hooks;
early_system_init ();
/* Before we do anything else we save the list of currently open
file descriptors and the signal mask. This info is required to
do the exec call properly. We don't need it on Windows. */
#ifndef HAVE_W32_SYSTEM
startup_fd_list = get_all_open_fds ();
#endif /*!HAVE_W32_SYSTEM*/
#ifdef HAVE_SIGPROCMASK
if (!sigprocmask (SIG_UNBLOCK, NULL, &startup_signal_mask))
startup_signal_mask_valid = 1;
#endif /*HAVE_SIGPROCMASK*/
/* Set program name etc. */
set_strusage (my_strusage);
gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
/* Please note that we may running SUID(ROOT), so be very CAREFUL
when adding any stuff between here and the call to INIT_SECMEM()
somewhere after the option parsing */
log_set_prefix (GPG_AGENT_NAME, GPGRT_LOG_WITH_PREFIX|GPGRT_LOG_WITH_PID);
/* Make sure that our subsystems are ready. */
i18n_init ();
init_common_subsystems (&argc, &argv);
malloc_hooks.malloc = gcry_malloc;
malloc_hooks.realloc = gcry_realloc;
malloc_hooks.free = gcry_free;
assuan_set_malloc_hooks (&malloc_hooks);
assuan_set_gpg_err_source (GPG_ERR_SOURCE_DEFAULT);
assuan_sock_init ();
setup_libassuan_logging (&opt.debug, NULL);
setup_libgcrypt_logging ();
gcry_control (GCRYCTL_USE_SECURE_RNDPOOL);
gcry_set_progress_handler (agent_libgcrypt_progress_cb, NULL);
disable_core_dumps ();
/* Set default options. */
parse_rereadable_options (NULL, 0); /* Reset them to default values. */
shell = getenv ("SHELL");
if (shell && strlen (shell) >= 3 && !strcmp (shell+strlen (shell)-3, "csh") )
csh_style = 1;
/* Record some of the original environment strings. */
{
const char *s;
int idx;
static const char *names[] =
{ "DISPLAY", "TERM", "XAUTHORITY", "PINENTRY_USER_DATA", NULL };
err = 0;
opt.startup_env = session_env_new ();
if (!opt.startup_env)
err = gpg_error_from_syserror ();
for (idx=0; !err && names[idx]; idx++)
{
s = getenv (names[idx]);
if (s)
err = session_env_setenv (opt.startup_env, names[idx], s);
}
if (!err)
{
s = gnupg_ttyname (0);
if (s)
err = session_env_setenv (opt.startup_env, "GPG_TTY", s);
}
if (err)
log_fatal ("error recording startup environment: %s\n",
gpg_strerror (err));
/* Fixme: Better use the locale function here. */
opt.startup_lc_ctype = getenv ("LC_CTYPE");
if (opt.startup_lc_ctype)
opt.startup_lc_ctype = xstrdup (opt.startup_lc_ctype);
opt.startup_lc_messages = getenv ("LC_MESSAGES");
if (opt.startup_lc_messages)
opt.startup_lc_messages = xstrdup (opt.startup_lc_messages);
}
/* Check whether we have a config file on the commandline */
orig_argc = argc;
orig_argv = argv;
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags= 1|(1<<6); /* do not remove the args, ignore version */
while (arg_parse( &pargs, opts))
{
if (pargs.r_opt == oDebug || pargs.r_opt == oDebugAll)
parse_debug++;
else if (pargs.r_opt == oOptions)
{ /* yes there is one, so we do not try the default one, but
read the option file when it is encountered at the
commandline */
default_config = 0;
}
else if (pargs.r_opt == oNoOptions)
default_config = 0; /* --no-options */
else if (pargs.r_opt == oHomedir)
gnupg_set_homedir (pargs.r.ret_str);
else if (pargs.r_opt == oDebugQuickRandom)
{
gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0);
}
}
/* Initialize the secure memory. */
gcry_control (GCRYCTL_INIT_SECMEM, SECMEM_BUFFER_SIZE, 0);
maybe_setuid = 0;
/*
Now we are now working under our real uid
*/
if (default_config)
configname = make_filename (gnupg_homedir (),
GPG_AGENT_NAME EXTSEP_S "conf", NULL);
argc = orig_argc;
argv = orig_argv;
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags= 1; /* do not remove the args */
next_pass:
if (configname)
{
configlineno = 0;
configfp = fopen (configname, "r");
if (!configfp)
{
if (default_config)
{
if( parse_debug )
log_info (_("Note: no default option file '%s'\n"),
configname );
/* Save the default conf file name so that
reread_configuration is able to test whether the
config file has been created in the meantime. */
xfree (config_filename);
config_filename = configname;
configname = NULL;
}
else
{
log_error (_("option file '%s': %s\n"),
configname, strerror(errno) );
exit(2);
}
xfree (configname);
configname = NULL;
}
if (parse_debug && configname )
log_info (_("reading options from '%s'\n"), configname );
default_config = 0;
}
while (optfile_parse( configfp, configname, &configlineno, &pargs, opts) )
{
if (parse_rereadable_options (&pargs, 0))
continue; /* Already handled */
switch (pargs.r_opt)
{
case aGPGConfList: gpgconf_list = 1; break;
case aGPGConfTest: gpgconf_list = 2; break;
case aUseStandardSocketP: gpgconf_list = 3; break;
case oBatch: opt.batch=1; break;
case oDebugWait: debug_wait = pargs.r.ret_int; break;
case oOptions:
/* config files may not be nested (silently ignore them) */
if (!configfp)
{
xfree(configname);
configname = xstrdup(pargs.r.ret_str);
goto next_pass;
}
break;
case oNoGreeting: /* Dummy option. */ break;
case oNoVerbose: opt.verbose = 0; break;
case oNoOptions: break; /* no-options */
case oHomedir: gnupg_set_homedir (pargs.r.ret_str); break;
case oNoDetach: nodetach = 1; break;
case oLogFile: logfile = pargs.r.ret_str; break;
case oCsh: csh_style = 1; break;
case oSh: csh_style = 0; break;
case oServer: pipe_server = 1; break;
case oDaemon: is_daemon = 1; break;
case oSupervised: is_supervised = 1; break;
case oDisplay: default_display = xstrdup (pargs.r.ret_str); break;
case oTTYname: default_ttyname = xstrdup (pargs.r.ret_str); break;
case oTTYtype: default_ttytype = xstrdup (pargs.r.ret_str); break;
case oLCctype: default_lc_ctype = xstrdup (pargs.r.ret_str); break;
case oLCmessages: default_lc_messages = xstrdup (pargs.r.ret_str);
break;
case oXauthority: default_xauthority = xstrdup (pargs.r.ret_str);
break;
case oUseStandardSocket:
case oNoUseStandardSocket:
obsolete_option (configname, configlineno, "use-standard-socket");
break;
case oFakedSystemTime:
{
time_t faked_time = isotime2epoch (pargs.r.ret_str);
if (faked_time == (time_t)(-1))
faked_time = (time_t)strtoul (pargs.r.ret_str, NULL, 10);
gnupg_set_time (faked_time, 0);
}
break;
case oKeepTTY: opt.keep_tty = 1; break;
case oKeepDISPLAY: opt.keep_display = 1; break;
case oSSHSupport:
ssh_support = 1;
break;
+ case oSSHFingerprintDigest:
+ opt.ssh_fingerprint_digest = gcry_md_map_name (pargs.r.ret_str);
+ if (opt.ssh_fingerprint_digest == 0)
+ log_error ("Unknown digest algorithm: %s\n", pargs.r.ret_str);
+ break;
case oPuttySupport:
# ifdef HAVE_W32_SYSTEM
putty_support = 1;
# endif
break;
case oExtraSocket:
opt.extra_socket = 1; /* (1 = points into argv) */
socket_name_extra = pargs.r.ret_str;
break;
case oBrowserSocket:
opt.browser_socket = 1; /* (1 = points into argv) */
socket_name_browser = pargs.r.ret_str;
break;
case oDebugQuickRandom:
/* Only used by the first stage command line parser. */
break;
case oWriteEnvFile:
obsolete_option (configname, configlineno, "write-env-file");
break;
default : pargs.err = configfp? 1:2; break;
}
}
if (configfp)
{
fclose( configfp );
configfp = NULL;
/* Keep a copy of the name so that it can be read on SIGHUP. */
if (config_filename != configname)
{
xfree (config_filename);
config_filename = configname;
}
configname = NULL;
goto next_pass;
}
xfree (configname);
configname = NULL;
if (log_get_errorcount(0))
exit(2);
finalize_rereadable_options ();
/* Print a warning if an argument looks like an option. */
if (!opt.quiet && !(pargs.flags & ARGPARSE_FLAG_STOP_SEEN))
{
int i;
for (i=0; i < argc; i++)
if (argv[i][0] == '-' && argv[i][1] == '-')
log_info (_("Note: '%s' is not considered an option\n"), argv[i]);
}
#ifdef ENABLE_NLS
/* gpg-agent usually does not output any messages because it runs in
the background. For log files it is acceptable to have messages
always encoded in utf-8. We switch here to utf-8, so that
commands like --help still give native messages. It is far
easier to switch only once instead of for every message and it
actually helps when more then one thread is active (avoids an
extra copy step). */
bind_textdomain_codeset (PACKAGE_GT, "UTF-8");
#endif
if (!pipe_server && !is_daemon && !gpgconf_list && !is_supervised)
{
/* We have been called without any command and thus we merely
check whether an agent is already running. We do this right
here so that we don't clobber a logfile with this check but
print the status directly to stderr. */
opt.debug = 0;
set_debug ();
check_for_running_agent (0);
agent_exit (0);
}
if (is_supervised)
;
else if (!opt.extra_socket)
opt.extra_socket = 1;
else if (socket_name_extra
&& (!strcmp (socket_name_extra, "none")
|| !strcmp (socket_name_extra, "/dev/null")))
{
/* User requested not to create this socket. */
opt.extra_socket = 0;
socket_name_extra = NULL;
}
if (is_supervised)
;
else if (!opt.browser_socket)
opt.browser_socket = 1;
else if (socket_name_browser
&& (!strcmp (socket_name_browser, "none")
|| !strcmp (socket_name_browser, "/dev/null")))
{
/* User requested not to create this socket. */
opt.browser_socket = 0;
socket_name_browser = NULL;
}
set_debug ();
if (atexit (cleanup))
{
log_error ("atexit failed\n");
cleanup ();
exit (1);
}
/* Try to create missing directories. */
create_directories ();
if (debug_wait && pipe_server)
{
thread_init_once ();
log_debug ("waiting for debugger - my pid is %u .....\n",
(unsigned int)getpid());
gnupg_sleep (debug_wait);
log_debug ("... okay\n");
}
if (gpgconf_list == 3)
{
/* We now use the standard socket always - return true for
backward compatibility. */
agent_exit (0);
}
else if (gpgconf_list == 2)
agent_exit (0);
else if (gpgconf_list)
{
char *filename;
char *filename_esc;
/* List options and default values in the GPG Conf format. */
filename = make_filename (gnupg_homedir (),
GPG_AGENT_NAME EXTSEP_S "conf", NULL);
filename_esc = percent_escape (filename, NULL);
es_printf ("%s-%s.conf:%lu:\"%s\n",
GPGCONF_NAME, GPG_AGENT_NAME,
GC_OPT_FLAG_DEFAULT, filename_esc);
xfree (filename);
xfree (filename_esc);
es_printf ("verbose:%lu:\n"
"quiet:%lu:\n"
"debug-level:%lu:\"none:\n"
"log-file:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME,
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME,
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME,
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME );
es_printf ("default-cache-ttl:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, DEFAULT_CACHE_TTL );
es_printf ("default-cache-ttl-ssh:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, DEFAULT_CACHE_TTL_SSH );
es_printf ("max-cache-ttl:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, MAX_CACHE_TTL );
es_printf ("max-cache-ttl-ssh:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, MAX_CACHE_TTL_SSH );
es_printf ("enforce-passphrase-constraints:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("min-passphrase-len:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, MIN_PASSPHRASE_LEN );
es_printf ("min-passphrase-nonalpha:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME,
MIN_PASSPHRASE_NONALPHA);
es_printf ("check-passphrase-pattern:%lu:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME);
es_printf ("max-passphrase-days:%lu:%d:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME,
MAX_PASSPHRASE_DAYS);
es_printf ("enable-passphrase-history:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("no-grab:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("ignore-cache-for-signing:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("no-allow-external-cache:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("no-allow-mark-trusted:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("disable-scdaemon:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("enable-ssh-support:%lu:\n", GC_OPT_FLAG_NONE);
#ifdef HAVE_W32_SYSTEM
es_printf ("enable-putty-support:%lu:\n", GC_OPT_FLAG_NONE);
#endif
es_printf ("no-allow-loopback-pinentry:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("allow-emacs-pinentry:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
es_printf ("pinentry-timeout:%lu:0:\n",
GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME);
es_printf ("enable-extended-key-format:%lu:\n",
GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
agent_exit (0);
}
/* Now start with logging to a file if this is desired. */
if (logfile)
{
log_set_file (logfile);
log_set_prefix (NULL, (GPGRT_LOG_WITH_PREFIX
| GPGRT_LOG_WITH_TIME
| GPGRT_LOG_WITH_PID));
current_logfile = xstrdup (logfile);
}
/* Make sure that we have a default ttyname. */
if (!default_ttyname && gnupg_ttyname (1))
default_ttyname = xstrdup (gnupg_ttyname (1));
if (!default_ttytype && getenv ("TERM"))
default_ttytype = xstrdup (getenv ("TERM"));
if (pipe_server)
{
/* This is the simple pipe based server */
ctrl_t ctrl;
initialize_modules ();
ctrl = xtrycalloc (1, sizeof *ctrl);
if (!ctrl)
{
log_error ("error allocating connection control data: %s\n",
strerror (errno) );
agent_exit (1);
}
ctrl->session_env = session_env_new ();
if (!ctrl->session_env)
{
log_error ("error allocating session environment block: %s\n",
strerror (errno) );
xfree (ctrl);
agent_exit (1);
}
agent_init_default_ctrl (ctrl);
start_command_handler (ctrl, GNUPG_INVALID_FD, GNUPG_INVALID_FD);
agent_deinit_default_ctrl (ctrl);
xfree (ctrl);
}
else if (is_supervised)
{
#ifndef HAVE_W32_SYSTEM
gnupg_fd_t fd, fd_extra, fd_browser, fd_ssh;
initialize_modules ();
/* when supervised and sending logs to stderr, the process
supervisor should handle log entry metadata (pid, name,
timestamp) */
if (!logfile)
log_set_prefix (NULL, 0);
log_info ("%s %s starting in supervised mode.\n",
strusage(11), strusage(13) );
/* See below in "regular server mode" on why we remove certain
* envvars. */
if (!opt.keep_display)
gnupg_unsetenv ("DISPLAY");
gnupg_unsetenv ("INSIDE_EMACS");
/* Virtually create the sockets. Note that we use -1 here
* because the whole thing works only on Unix. */
map_supervised_sockets (&fd, &fd_extra, &fd_browser, &fd_ssh);
if (fd == -1)
log_fatal ("no standard socket provided\n");
#ifdef HAVE_SIGPROCMASK
if (startup_signal_mask_valid)
{
if (sigprocmask (SIG_SETMASK, &startup_signal_mask, NULL))
log_error ("error restoring signal mask: %s\n",
strerror (errno));
}
else
log_info ("no saved signal mask\n");
#endif /*HAVE_SIGPROCMASK*/
log_info ("listening on: std=%d extra=%d browser=%d ssh=%d\n",
fd, fd_extra, fd_browser, fd_ssh);
handle_connections (fd, fd_extra, fd_browser, fd_ssh);
#endif /*!HAVE_W32_SYSTEM*/
}
else if (!is_daemon)
; /* NOTREACHED */
else
{ /* Regular server mode */
gnupg_fd_t fd;
gnupg_fd_t fd_extra = GNUPG_INVALID_FD;
gnupg_fd_t fd_browser = GNUPG_INVALID_FD;
gnupg_fd_t fd_ssh = GNUPG_INVALID_FD;
#ifndef HAVE_W32_SYSTEM
pid_t pid;
#endif
/* Remove the DISPLAY variable so that a pinentry does not
default to a specific display. There is still a default
display when gpg-agent was started using --display or a
client requested this using an OPTION command. Note, that we
don't do this when running in reverse daemon mode (i.e. when
exec the program given as arguments). */
#ifndef HAVE_W32_SYSTEM
if (!opt.keep_display && !argc)
gnupg_unsetenv ("DISPLAY");
#endif
/* Remove the INSIDE_EMACS variable so that a pinentry does not
always try to interact with Emacs. The variable is set when
a client requested this using an OPTION command. */
gnupg_unsetenv ("INSIDE_EMACS");
/* Create the sockets. */
socket_name = create_socket_name (GPG_AGENT_SOCK_NAME, 1);
fd = create_server_socket (socket_name, 1, 0,
&redir_socket_name, &socket_nonce);
if (opt.extra_socket)
{
if (socket_name_extra)
socket_name_extra = create_socket_name (socket_name_extra, 0);
else
socket_name_extra = create_socket_name
/**/ (GPG_AGENT_EXTRA_SOCK_NAME, 1);
opt.extra_socket = 2; /* Indicate that it has been malloced. */
fd_extra = create_server_socket (socket_name_extra, 0, 0,
&redir_socket_name_extra,
&socket_nonce_extra);
}
if (opt.browser_socket)
{
if (socket_name_browser)
socket_name_browser = create_socket_name (socket_name_browser, 0);
else
socket_name_browser= create_socket_name
/**/ (GPG_AGENT_BROWSER_SOCK_NAME, 1);
opt.browser_socket = 2; /* Indicate that it has been malloced. */
fd_browser = create_server_socket (socket_name_browser, 0, 0,
&redir_socket_name_browser,
&socket_nonce_browser);
}
socket_name_ssh = create_socket_name (GPG_AGENT_SSH_SOCK_NAME, 1);
fd_ssh = create_server_socket (socket_name_ssh, 0, 1,
&redir_socket_name_ssh,
&socket_nonce_ssh);
/* If we are going to exec a program in the parent, we record
the PID, so that the child may check whether the program is
still alive. */
if (argc)
parent_pid = getpid ();
fflush (NULL);
#ifdef HAVE_W32_SYSTEM
(void)csh_style;
(void)nodetach;
initialize_modules ();
#else /*!HAVE_W32_SYSTEM*/
pid = fork ();
if (pid == (pid_t)-1)
{
log_fatal ("fork failed: %s\n", strerror (errno) );
exit (1);
}
else if (pid)
{ /* We are the parent */
char *infostr_ssh_sock, *infostr_ssh_valid;
/* Close the socket FD. */
close (fd);
/* The signal mask might not be correct right now and thus
we restore it. That is not strictly necessary but some
programs falsely assume a cleared signal mask. */
#ifdef HAVE_SIGPROCMASK
if (startup_signal_mask_valid)
{
if (sigprocmask (SIG_SETMASK, &startup_signal_mask, NULL))
log_error ("error restoring signal mask: %s\n",
strerror (errno));
}
else
log_info ("no saved signal mask\n");
#endif /*HAVE_SIGPROCMASK*/
/* Create the SSH info string if enabled. */
if (ssh_support)
{
if (asprintf (&infostr_ssh_sock, "SSH_AUTH_SOCK=%s",
socket_name_ssh) < 0)
{
log_error ("out of core\n");
kill (pid, SIGTERM);
exit (1);
}
if (asprintf (&infostr_ssh_valid, "gnupg_SSH_AUTH_SOCK_by=%lu",
(unsigned long)getpid()) < 0)
{
log_error ("out of core\n");
kill (pid, SIGTERM);
exit (1);
}
}
*socket_name = 0; /* Don't let cleanup() remove the socket -
the child should do this from now on */
if (opt.extra_socket)
*socket_name_extra = 0;
if (opt.browser_socket)
*socket_name_browser = 0;
*socket_name_ssh = 0;
if (argc)
{ /* Run the program given on the commandline. */
if (ssh_support && (putenv (infostr_ssh_sock)
|| putenv (infostr_ssh_valid)))
{
log_error ("failed to set environment: %s\n",
strerror (errno) );
kill (pid, SIGTERM );
exit (1);
}
/* Close all the file descriptors except the standard
ones and those open at startup. We explicitly don't
close 0,1,2 in case something went wrong collecting
them at startup. */
close_all_fds (3, startup_fd_list);
/* Run the command. */
execvp (argv[0], argv);
log_error ("failed to run the command: %s\n", strerror (errno));
kill (pid, SIGTERM);
exit (1);
}
else
{
/* Print the environment string, so that the caller can use
shell's eval to set it */
if (csh_style)
{
if (ssh_support)
{
*strchr (infostr_ssh_sock, '=') = ' ';
es_printf ("setenv %s;\n", infostr_ssh_sock);
}
}
else
{
if (ssh_support)
{
es_printf ("%s; export SSH_AUTH_SOCK;\n",
infostr_ssh_sock);
}
}
if (ssh_support)
{
xfree (infostr_ssh_sock);
xfree (infostr_ssh_valid);
}
exit (0);
}
/*NOTREACHED*/
} /* End parent */
/*
This is the child
*/
initialize_modules ();
/* Detach from tty and put process into a new session */
if (!nodetach )
{
int i;
unsigned int oldflags;
/* Close stdin, stdout and stderr unless it is the log stream */
for (i=0; i <= 2; i++)
{
if (!log_test_fd (i) && i != fd )
{
if ( ! close (i)
&& open ("/dev/null", i? O_WRONLY : O_RDONLY) == -1)
{
log_error ("failed to open '%s': %s\n",
"/dev/null", strerror (errno));
cleanup ();
exit (1);
}
}
}
if (setsid() == -1)
{
log_error ("setsid() failed: %s\n", strerror(errno) );
cleanup ();
exit (1);
}
log_get_prefix (&oldflags);
log_set_prefix (NULL, oldflags | GPGRT_LOG_RUN_DETACHED);
opt.running_detached = 1;
}
if (chdir("/"))
{
log_error ("chdir to / failed: %s\n", strerror (errno));
exit (1);
}
{
struct sigaction sa;
sa.sa_handler = SIG_IGN;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sigaction (SIGPIPE, &sa, NULL);
}
#endif /*!HAVE_W32_SYSTEM*/
log_info ("%s %s started\n", strusage(11), strusage(13) );
handle_connections (fd, fd_extra, fd_browser, fd_ssh);
assuan_sock_close (fd);
}
return 0;
}
/* Exit entry point. This function should be called instead of a
plain exit. */
void
agent_exit (int rc)
{
/*FIXME: update_random_seed_file();*/
/* We run our cleanup handler because that may close cipher contexts
stored in secure memory and thus this needs to be done before we
explicitly terminate secure memory. */
cleanup ();
#if 1
/* at this time a bit annoying */
if (opt.debug & DBG_MEMSTAT_VALUE)
{
gcry_control( GCRYCTL_DUMP_MEMORY_STATS );
gcry_control( GCRYCTL_DUMP_RANDOM_STATS );
}
if (opt.debug)
gcry_control (GCRYCTL_DUMP_SECMEM_STATS );
#endif
gcry_control (GCRYCTL_TERM_SECMEM );
rc = rc? rc : log_get_errorcount(0)? 2 : 0;
exit (rc);
}
/* This is our callback function for gcrypt progress messages. It is
set once at startup and dispatches progress messages to the
corresponding threads of the agent. */
static void
agent_libgcrypt_progress_cb (void *data, const char *what, int printchar,
int current, int total)
{
struct progress_dispatch_s *dispatch;
npth_t mytid = npth_self ();
(void)data;
for (dispatch = progress_dispatch_list; dispatch; dispatch = dispatch->next)
if (dispatch->ctrl && dispatch->tid == mytid)
break;
if (dispatch && dispatch->cb)
dispatch->cb (dispatch->ctrl, what, printchar, current, total);
/* Libgcrypt < 1.8 does not know about nPth and thus when it reads
* from /dev/random this will block the process. To mitigate this
* problem we yield the thread when Libgcrypt tells us that it needs
* more entropy. This way other threads have chance to run. */
#if GCRYPT_VERSION_NUMBER < 0x010800 /* 1.8.0 */
if (what && !strcmp (what, "need_entropy"))
{
#if GPGRT_VERSION_NUMBER < 0x011900 /* 1.25 */
/* In older gpg-error versions gpgrt_yield is buggy for use with
* nPth and thus we need to resort to a sleep call. */
npth_usleep (1000); /* 1ms */
#else
gpgrt_yield ();
#endif
}
#endif
}
/* If a progress dispatcher callback has been associated with the
* current connection unregister it. */
static void
unregister_progress_cb (void)
{
struct progress_dispatch_s *dispatch;
npth_t mytid = npth_self ();
for (dispatch = progress_dispatch_list; dispatch; dispatch = dispatch->next)
if (dispatch->ctrl && dispatch->tid == mytid)
break;
if (dispatch)
{
dispatch->ctrl = NULL;
dispatch->cb = NULL;
}
}
/* Setup a progress callback CB for the current connection. Using a
* CB of NULL disables the callback. */
void
agent_set_progress_cb (void (*cb)(ctrl_t ctrl, const char *what,
int printchar, int current, int total),
ctrl_t ctrl)
{
struct progress_dispatch_s *dispatch, *firstfree;
npth_t mytid = npth_self ();
firstfree = NULL;
for (dispatch = progress_dispatch_list; dispatch; dispatch = dispatch->next)
{
if (dispatch->ctrl && dispatch->tid == mytid)
break;
if (!dispatch->ctrl && !firstfree)
firstfree = dispatch;
}
if (!dispatch) /* None allocated: Reuse or allocate a new one. */
{
if (firstfree)
{
dispatch = firstfree;
}
else if ((dispatch = xtrycalloc (1, sizeof *dispatch)))
{
dispatch->next = progress_dispatch_list;
progress_dispatch_list = dispatch;
}
else
{
log_error ("error allocating new progress dispatcher slot: %s\n",
gpg_strerror (gpg_error_from_syserror ()));
return;
}
dispatch->ctrl = ctrl;
dispatch->tid = mytid;
}
dispatch->cb = cb;
}
/* Each thread has its own local variables conveyed by a control
structure usually identified by an argument named CTRL. This
function is called immediately after allocating the control
structure. Its purpose is to setup the default values for that
structure. Note that some values may have already been set. */
static void
agent_init_default_ctrl (ctrl_t ctrl)
{
assert (ctrl->session_env);
/* Note we ignore malloc errors because we can't do much about it
and the request will fail anyway shortly after this
initialization. */
session_env_setenv (ctrl->session_env, "DISPLAY", default_display);
session_env_setenv (ctrl->session_env, "GPG_TTY", default_ttyname);
session_env_setenv (ctrl->session_env, "TERM", default_ttytype);
session_env_setenv (ctrl->session_env, "XAUTHORITY", default_xauthority);
session_env_setenv (ctrl->session_env, "PINENTRY_USER_DATA", NULL);
if (ctrl->lc_ctype)
xfree (ctrl->lc_ctype);
ctrl->lc_ctype = default_lc_ctype? xtrystrdup (default_lc_ctype) : NULL;
if (ctrl->lc_messages)
xfree (ctrl->lc_messages);
ctrl->lc_messages = default_lc_messages? xtrystrdup (default_lc_messages)
/**/ : NULL;
ctrl->cache_ttl_opt_preset = CACHE_TTL_OPT_PRESET;
}
/* Release all resources allocated by default in the control
structure. This is the counterpart to agent_init_default_ctrl. */
static void
agent_deinit_default_ctrl (ctrl_t ctrl)
{
unregister_progress_cb ();
session_env_release (ctrl->session_env);
if (ctrl->lc_ctype)
xfree (ctrl->lc_ctype);
if (ctrl->lc_messages)
xfree (ctrl->lc_messages);
}
/* Because the ssh protocol does not send us information about the
current TTY setting, we use this function to use those from startup
or those explicitly set. This is also used for the restricted mode
where we ignore requests to change the environment. */
gpg_error_t
agent_copy_startup_env (ctrl_t ctrl)
{
static const char *names[] =
{"GPG_TTY", "DISPLAY", "TERM", "XAUTHORITY", "PINENTRY_USER_DATA", NULL};
gpg_error_t err = 0;
int idx;
const char *value;
for (idx=0; !err && names[idx]; idx++)
if ((value = session_env_getenv (opt.startup_env, names[idx])))
err = session_env_setenv (ctrl->session_env, names[idx], value);
if (!err && !ctrl->lc_ctype && opt.startup_lc_ctype)
if (!(ctrl->lc_ctype = xtrystrdup (opt.startup_lc_ctype)))
err = gpg_error_from_syserror ();
if (!err && !ctrl->lc_messages && opt.startup_lc_messages)
if (!(ctrl->lc_messages = xtrystrdup (opt.startup_lc_messages)))
err = gpg_error_from_syserror ();
if (err)
log_error ("error setting default session environment: %s\n",
gpg_strerror (err));
return err;
}
/* Reread parts of the configuration. Note, that this function is
obviously not thread-safe and should only be called from the PTH
signal handler.
Fixme: Due to the way the argument parsing works, we create a
memory leak here for all string type arguments. There is currently
no clean way to tell whether the memory for the argument has been
allocated or points into the process' original arguments. Unless
we have a mechanism to tell this, we need to live on with this. */
static void
reread_configuration (void)
{
ARGPARSE_ARGS pargs;
FILE *fp;
unsigned int configlineno = 0;
int dummy;
if (!config_filename)
return; /* No config file. */
fp = fopen (config_filename, "r");
if (!fp)
{
log_info (_("option file '%s': %s\n"),
config_filename, strerror(errno) );
return;
}
parse_rereadable_options (NULL, 1); /* Start from the default values. */
memset (&pargs, 0, sizeof pargs);
dummy = 0;
pargs.argc = &dummy;
pargs.flags = 1; /* do not remove the args */
while (optfile_parse (fp, config_filename, &configlineno, &pargs, opts) )
{
if (pargs.r_opt < -1)
pargs.err = 1; /* Print a warning. */
else /* Try to parse this option - ignore unchangeable ones. */
parse_rereadable_options (&pargs, 1);
}
fclose (fp);
finalize_rereadable_options ();
set_debug ();
}
/* Return the file name of the socket we are using for native
requests. */
const char *
get_agent_socket_name (void)
{
const char *s = socket_name;
return (s && *s)? s : NULL;
}
/* Return the file name of the socket we are using for SSH
requests. */
const char *
get_agent_ssh_socket_name (void)
{
const char *s = socket_name_ssh;
return (s && *s)? s : NULL;
}
/* Return the number of active connections. */
int
get_agent_active_connection_count (void)
{
return active_connections;
}
/* Under W32, this function returns the handle of the scdaemon
notification event. Calling it the first time creates that
event. */
#if defined(HAVE_W32_SYSTEM) && !defined(HAVE_W32CE_SYSTEM)
void *
get_agent_scd_notify_event (void)
{
static HANDLE the_event = INVALID_HANDLE_VALUE;
if (the_event == INVALID_HANDLE_VALUE)
{
HANDLE h, h2;
SECURITY_ATTRIBUTES sa = { sizeof (SECURITY_ATTRIBUTES), NULL, TRUE};
/* We need to use a manual reset event object due to the way our
w32-pth wait function works: If we would use an automatic
reset event we are not able to figure out which handle has
been signaled because at the time we single out the signaled
handles using WFSO the event has already been reset due to
the WFMO. */
h = CreateEvent (&sa, TRUE, FALSE, NULL);
if (!h)
log_error ("can't create scd notify event: %s\n", w32_strerror (-1) );
else if (!DuplicateHandle (GetCurrentProcess(), h,
GetCurrentProcess(), &h2,
EVENT_MODIFY_STATE|SYNCHRONIZE, TRUE, 0))
{
log_error ("setting syncronize for scd notify event failed: %s\n",
w32_strerror (-1) );
CloseHandle (h);
}
else
{
CloseHandle (h);
the_event = h2;
}
}
return the_event;
}
#endif /*HAVE_W32_SYSTEM && !HAVE_W32CE_SYSTEM*/
/* Create a name for the socket in the home directory as using
STANDARD_NAME. We also check for valid characters as well as
against a maximum allowed length for a unix domain socket is done.
The function terminates the process in case of an error. Returns:
Pointer to an allocated string with the absolute name of the socket
used. */
static char *
create_socket_name (char *standard_name, int with_homedir)
{
char *name;
if (with_homedir)
name = make_filename (gnupg_socketdir (), standard_name, NULL);
else
name = make_filename (standard_name, NULL);
if (strchr (name, PATHSEP_C))
{
log_error (("'%s' are not allowed in the socket name\n"), PATHSEP_S);
agent_exit (2);
}
return name;
}
/* Create a Unix domain socket with NAME. Returns the file descriptor
or terminates the process in case of an error. Note that this
function needs to be used for the regular socket first (indicated
by PRIMARY) and only then for the extra and the ssh sockets. If
the socket has been redirected the name of the real socket is
stored as a malloced string at R_REDIR_NAME. If CYGWIN is set a
Cygwin compatible socket is created (Windows only). */
static gnupg_fd_t
create_server_socket (char *name, int primary, int cygwin,
char **r_redir_name, assuan_sock_nonce_t *nonce)
{
struct sockaddr *addr;
struct sockaddr_un *unaddr;
socklen_t len;
gnupg_fd_t fd;
int rc;
xfree (*r_redir_name);
*r_redir_name = NULL;
fd = assuan_sock_new (AF_UNIX, SOCK_STREAM, 0);
if (fd == ASSUAN_INVALID_FD)
{
log_error (_("can't create socket: %s\n"), strerror (errno));
*name = 0; /* Inhibit removal of the socket by cleanup(). */
agent_exit (2);
}
if (cygwin)
assuan_sock_set_flag (fd, "cygwin", 1);
unaddr = xmalloc (sizeof *unaddr);
addr = (struct sockaddr*)unaddr;
{
int redirected;
if (assuan_sock_set_sockaddr_un (name, addr, &redirected))
{
if (errno == ENAMETOOLONG)
log_error (_("socket name '%s' is too long\n"), name);
else
log_error ("error preparing socket '%s': %s\n",
name, gpg_strerror (gpg_error_from_syserror ()));
*name = 0; /* Inhibit removal of the socket by cleanup(). */
agent_exit (2);
}
if (redirected)
{
*r_redir_name = xstrdup (unaddr->sun_path);
if (opt.verbose)
log_info ("redirecting socket '%s' to '%s'\n", name, *r_redir_name);
}
}
len = SUN_LEN (unaddr);
rc = assuan_sock_bind (fd, addr, len);
/* Our error code mapping on W32CE returns EEXIST thus we also test
for this. */
if (rc == -1
&& (errno == EADDRINUSE
#ifdef HAVE_W32_SYSTEM
|| errno == EEXIST
#endif
))
{
/* Check whether a gpg-agent is already running. We do this
test only if this is the primary socket. For secondary
sockets we assume that a test for gpg-agent has already been
done and reuse the requested socket. Testing the ssh-socket
is not possible because at this point, though we know the new
Assuan socket, the Assuan server and thus the ssh-agent
server is not yet operational; this would lead to a hang. */
if (primary && !check_for_running_agent (1))
{
log_set_prefix (NULL, GPGRT_LOG_WITH_PREFIX);
log_set_file (NULL);
log_error (_("a gpg-agent is already running - "
"not starting a new one\n"));
*name = 0; /* Inhibit removal of the socket by cleanup(). */
assuan_sock_close (fd);
agent_exit (2);
}
gnupg_remove (unaddr->sun_path);
rc = assuan_sock_bind (fd, addr, len);
}
if (rc != -1 && (rc=assuan_sock_get_nonce (addr, len, nonce)))
log_error (_("error getting nonce for the socket\n"));
if (rc == -1)
{
/* We use gpg_strerror here because it allows us to get strings
for some W32 socket error codes. */
log_error (_("error binding socket to '%s': %s\n"),
unaddr->sun_path,
gpg_strerror (gpg_error_from_syserror ()));
assuan_sock_close (fd);
*name = 0; /* Inhibit removal of the socket by cleanup(). */
agent_exit (2);
}
if (gnupg_chmod (unaddr->sun_path, "-rwx"))
log_error (_("can't set permissions of '%s': %s\n"),
unaddr->sun_path, strerror (errno));
if (listen (FD2INT(fd), 5 ) == -1)
{
log_error (_("listen() failed: %s\n"), strerror (errno));
*name = 0; /* Inhibit removal of the socket by cleanup(). */
assuan_sock_close (fd);
agent_exit (2);
}
if (opt.verbose)
log_info (_("listening on socket '%s'\n"), unaddr->sun_path);
return fd;
}
/* Check that the directory for storing the private keys exists and
create it if not. This function won't fail as it is only a
convenience function and not strictly necessary. */
static void
create_private_keys_directory (const char *home)
{
char *fname;
struct stat statbuf;
fname = make_filename (home, GNUPG_PRIVATE_KEYS_DIR, NULL);
if (stat (fname, &statbuf) && errno == ENOENT)
{
if (gnupg_mkdir (fname, "-rwx"))
log_error (_("can't create directory '%s': %s\n"),
fname, strerror (errno) );
else if (!opt.quiet)
log_info (_("directory '%s' created\n"), fname);
}
if (gnupg_chmod (fname, "-rwx"))
log_error (_("can't set permissions of '%s': %s\n"),
fname, strerror (errno));
xfree (fname);
}
/* Create the directory only if the supplied directory name is the
same as the default one. This way we avoid to create arbitrary
directories when a non-default home directory is used. To cope
with HOME, we compare only the suffix if we see that the default
homedir does start with a tilde. We don't stop here in case of
problems because other functions will throw an error anyway.*/
static void
create_directories (void)
{
struct stat statbuf;
const char *defhome = standard_homedir ();
char *home;
home = make_filename (gnupg_homedir (), NULL);
if ( stat (home, &statbuf) )
{
if (errno == ENOENT)
{
if (
#ifdef HAVE_W32_SYSTEM
( !compare_filenames (home, defhome) )
#else
(*defhome == '~'
&& (strlen (home) >= strlen (defhome+1)
&& !strcmp (home + strlen(home)
- strlen (defhome+1), defhome+1)))
|| (*defhome != '~' && !strcmp (home, defhome) )
#endif
)
{
if (gnupg_mkdir (home, "-rwx"))
log_error (_("can't create directory '%s': %s\n"),
home, strerror (errno) );
else
{
if (!opt.quiet)
log_info (_("directory '%s' created\n"), home);
create_private_keys_directory (home);
}
}
}
else
log_error (_("stat() failed for '%s': %s\n"), home, strerror (errno));
}
else if ( !S_ISDIR(statbuf.st_mode))
{
log_error (_("can't use '%s' as home directory\n"), home);
}
else /* exists and is a directory. */
{
create_private_keys_directory (home);
}
xfree (home);
}
/* This is the worker for the ticker. It is called every few seconds
and may only do fast operations. */
static void
handle_tick (void)
{
static time_t last_minute;
if (!last_minute)
last_minute = time (NULL);
/* Check whether the scdaemon has died and cleanup in this case. */
agent_scd_check_aliveness ();
/* If we are running as a child of another process, check whether
the parent is still alive and shutdown if not. */
#ifndef HAVE_W32_SYSTEM
if (parent_pid != (pid_t)(-1))
{
if (kill (parent_pid, 0))
{
shutdown_pending = 2;
log_info ("parent process died - shutting down\n");
log_info ("%s %s stopped\n", strusage(11), strusage(13) );
cleanup ();
agent_exit (0);
}
}
#endif /*HAVE_W32_SYSTEM*/
/* Code to be run from time to time. */
#if CHECK_OWN_SOCKET_INTERVAL > 0
if (last_minute + CHECK_OWN_SOCKET_INTERVAL <= time (NULL))
{
check_own_socket ();
last_minute = time (NULL);
}
#endif
}
/* A global function which allows us to call the reload stuff from
other places too. This is only used when build for W32. */
void
agent_sighup_action (void)
{
log_info ("SIGHUP received - "
"re-reading configuration and flushing cache\n");
agent_flush_cache ();
reread_configuration ();
agent_reload_trustlist ();
/* We flush the module name cache so that after installing a
"pinentry" binary that one can be used in case the
"pinentry-basic" fallback was in use. */
gnupg_module_name_flush_some ();
}
/* A helper function to handle SIGUSR2. */
static void
agent_sigusr2_action (void)
{
if (opt.verbose)
log_info ("SIGUSR2 received - updating card event counter\n");
/* Nothing to check right now. We only increment a counter. */
bump_card_eventcounter ();
}
#ifndef HAVE_W32_SYSTEM
/* The signal handler for this program. It is expected to be run in
its own trhead and not in the context of a signal handler. */
static void
handle_signal (int signo)
{
switch (signo)
{
#ifndef HAVE_W32_SYSTEM
case SIGHUP:
agent_sighup_action ();
break;
case SIGUSR1:
log_info ("SIGUSR1 received - printing internal information:\n");
/* Fixme: We need to see how to integrate pth dumping into our
logging system. */
/* pth_ctrl (PTH_CTRL_DUMPSTATE, log_get_stream ()); */
agent_query_dump_state ();
agent_scd_dump_state ();
break;
case SIGUSR2:
agent_sigusr2_action ();
break;
case SIGTERM:
if (!shutdown_pending)
log_info ("SIGTERM received - shutting down ...\n");
else
log_info ("SIGTERM received - still %i open connections\n",
active_connections);
shutdown_pending++;
if (shutdown_pending > 2)
{
log_info ("shutdown forced\n");
log_info ("%s %s stopped\n", strusage(11), strusage(13) );
cleanup ();
agent_exit (0);
}
break;
case SIGINT:
log_info ("SIGINT received - immediate shutdown\n");
log_info( "%s %s stopped\n", strusage(11), strusage(13));
cleanup ();
agent_exit (0);
break;
#endif
default:
log_info ("signal %d received - no action defined\n", signo);
}
}
#endif
/* Check the nonce on a new connection. This is a NOP unless we
are using our Unix domain socket emulation under Windows. */
static int
check_nonce (ctrl_t ctrl, assuan_sock_nonce_t *nonce)
{
if (assuan_sock_check_nonce (ctrl->thread_startup.fd, nonce))
{
log_info (_("error reading nonce on fd %d: %s\n"),
FD2INT(ctrl->thread_startup.fd), strerror (errno));
assuan_sock_close (ctrl->thread_startup.fd);
xfree (ctrl);
return -1;
}
else
return 0;
}
#ifdef HAVE_W32_SYSTEM
/* The window message processing function for Putty. Warning: This
code runs as a native Windows thread. Use of our own functions
needs to be bracket with pth_leave/pth_enter. */
static LRESULT CALLBACK
putty_message_proc (HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
int ret = 0;
int w32rc;
COPYDATASTRUCT *cds;
const char *mapfile;
HANDLE maphd;
PSID mysid = NULL;
PSID mapsid = NULL;
void *data = NULL;
PSECURITY_DESCRIPTOR psd = NULL;
ctrl_t ctrl = NULL;
if (msg != WM_COPYDATA)
{
return DefWindowProc (hwnd, msg, wparam, lparam);
}
cds = (COPYDATASTRUCT*)lparam;
if (cds->dwData != PUTTY_IPC_MAGIC)
return 0; /* Ignore data with the wrong magic. */
mapfile = cds->lpData;
if (!cds->cbData || mapfile[cds->cbData - 1])
return 0; /* Ignore empty and non-properly terminated strings. */
if (DBG_IPC)
{
npth_protect ();
log_debug ("ssh map file '%s'", mapfile);
npth_unprotect ();
}
maphd = OpenFileMapping (FILE_MAP_ALL_ACCESS, FALSE, mapfile);
if (DBG_IPC)
{
npth_protect ();
log_debug ("ssh map handle %p\n", maphd);
npth_unprotect ();
}
if (!maphd || maphd == INVALID_HANDLE_VALUE)
return 0;
npth_protect ();
mysid = w32_get_user_sid ();
if (!mysid)
{
log_error ("error getting my sid\n");
goto leave;
}
w32rc = GetSecurityInfo (maphd, SE_KERNEL_OBJECT,
OWNER_SECURITY_INFORMATION,
&mapsid, NULL, NULL, NULL,
&psd);
if (w32rc)
{
log_error ("error getting sid of ssh map file: rc=%d", w32rc);
goto leave;
}
if (DBG_IPC)
{
char *sidstr;
if (!ConvertSidToStringSid (mysid, &sidstr))
sidstr = NULL;
log_debug (" my sid: '%s'", sidstr? sidstr: "[error]");
LocalFree (sidstr);
if (!ConvertSidToStringSid (mapsid, &sidstr))
sidstr = NULL;
log_debug ("ssh map file sid: '%s'", sidstr? sidstr: "[error]");
LocalFree (sidstr);
}
if (!EqualSid (mysid, mapsid))
{
log_error ("ssh map file has a non-matching sid\n");
goto leave;
}
data = MapViewOfFile (maphd, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (DBG_IPC)
log_debug ("ssh IPC buffer at %p\n", data);
if (!data)
goto leave;
/* log_printhex ("request:", data, 20); */
ctrl = xtrycalloc (1, sizeof *ctrl);
if (!ctrl)
{
log_error ("error allocating connection control data: %s\n",
strerror (errno) );
goto leave;
}
ctrl->session_env = session_env_new ();
if (!ctrl->session_env)
{
log_error ("error allocating session environment block: %s\n",
strerror (errno) );
goto leave;
}
agent_init_default_ctrl (ctrl);
if (!serve_mmapped_ssh_request (ctrl, data, PUTTY_IPC_MAXLEN))
ret = 1; /* Valid ssh message has been constructed. */
agent_deinit_default_ctrl (ctrl);
/* log_printhex (" reply:", data, 20); */
leave:
xfree (ctrl);
if (data)
UnmapViewOfFile (data);
xfree (mapsid);
if (psd)
LocalFree (psd);
xfree (mysid);
CloseHandle (maphd);
npth_unprotect ();
return ret;
}
#endif /*HAVE_W32_SYSTEM*/
#ifdef HAVE_W32_SYSTEM
/* The thread handling Putty's IPC requests. */
static void *
putty_message_thread (void *arg)
{
WNDCLASS wndwclass = {0, putty_message_proc, 0, 0,
NULL, NULL, NULL, NULL, NULL, "Pageant"};
HWND hwnd;
MSG msg;
(void)arg;
if (opt.verbose)
log_info ("putty message loop thread started\n");
/* The message loop runs as thread independent from our nPth system.
This also means that we need to make sure that we switch back to
our system before calling any no-windows function. */
npth_unprotect ();
/* First create a window to make sure that a message queue exists
for this thread. */
if (!RegisterClass (&wndwclass))
{
npth_protect ();
log_error ("error registering Pageant window class");
return NULL;
}
hwnd = CreateWindowEx (0, "Pageant", "Pageant", 0,
0, 0, 0, 0,
HWND_MESSAGE, /* hWndParent */
NULL, /* hWndMenu */
NULL, /* hInstance */
NULL); /* lpParm */
if (!hwnd)
{
npth_protect ();
log_error ("error creating Pageant window");
return NULL;
}
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
/* Back to nPth. */
npth_protect ();
if (opt.verbose)
log_info ("putty message loop thread stopped\n");
return NULL;
}
#endif /*HAVE_W32_SYSTEM*/
static void *
do_start_connection_thread (ctrl_t ctrl)
{
active_connections++;
agent_init_default_ctrl (ctrl);
if (opt.verbose && !DBG_IPC)
log_info (_("handler 0x%lx for fd %d started\n"),
(unsigned long) npth_self(), FD2INT(ctrl->thread_startup.fd));
start_command_handler (ctrl, GNUPG_INVALID_FD, ctrl->thread_startup.fd);
if (opt.verbose && !DBG_IPC)
log_info (_("handler 0x%lx for fd %d terminated\n"),
(unsigned long) npth_self(), FD2INT(ctrl->thread_startup.fd));
agent_deinit_default_ctrl (ctrl);
xfree (ctrl);
active_connections--;
return NULL;
}
/* This is the standard connection thread's main function. */
static void *
start_connection_thread_std (void *arg)
{
ctrl_t ctrl = arg;
if (check_nonce (ctrl, &socket_nonce))
{
log_error ("handler 0x%lx nonce check FAILED\n",
(unsigned long) npth_self());
return NULL;
}
return do_start_connection_thread (ctrl);
}
/* This is the extra socket connection thread's main function. */
static void *
start_connection_thread_extra (void *arg)
{
ctrl_t ctrl = arg;
if (check_nonce (ctrl, &socket_nonce_extra))
{
log_error ("handler 0x%lx nonce check FAILED\n",
(unsigned long) npth_self());
return NULL;
}
ctrl->restricted = 1;
return do_start_connection_thread (ctrl);
}
/* This is the browser socket connection thread's main function. */
static void *
start_connection_thread_browser (void *arg)
{
ctrl_t ctrl = arg;
if (check_nonce (ctrl, &socket_nonce_browser))
{
log_error ("handler 0x%lx nonce check FAILED\n",
(unsigned long) npth_self());
return NULL;
}
ctrl->restricted = 2;
return do_start_connection_thread (ctrl);
}
/* This is the ssh connection thread's main function. */
static void *
start_connection_thread_ssh (void *arg)
{
ctrl_t ctrl = arg;
if (check_nonce (ctrl, &socket_nonce_ssh))
return NULL;
active_connections++;
agent_init_default_ctrl (ctrl);
if (opt.verbose)
log_info (_("ssh handler 0x%lx for fd %d started\n"),
(unsigned long) npth_self(), FD2INT(ctrl->thread_startup.fd));
start_command_handler_ssh (ctrl, ctrl->thread_startup.fd);
if (opt.verbose)
log_info (_("ssh handler 0x%lx for fd %d terminated\n"),
(unsigned long) npth_self(), FD2INT(ctrl->thread_startup.fd));
agent_deinit_default_ctrl (ctrl);
xfree (ctrl);
active_connections--;
return NULL;
}
/* Connection handler loop. Wait for connection requests and spawn a
thread after accepting a connection. */
static void
handle_connections (gnupg_fd_t listen_fd,
gnupg_fd_t listen_fd_extra,
gnupg_fd_t listen_fd_browser,
gnupg_fd_t listen_fd_ssh)
{
gpg_error_t err;
npth_attr_t tattr;
struct sockaddr_un paddr;
socklen_t plen;
fd_set fdset, read_fdset;
int ret;
gnupg_fd_t fd;
int nfd;
int saved_errno;
struct timespec abstime;
struct timespec curtime;
struct timespec timeout;
#ifdef HAVE_W32_SYSTEM
HANDLE events[2];
unsigned int events_set;
#endif
int my_inotify_fd = -1;
struct {
const char *name;
void *(*func) (void *arg);
gnupg_fd_t l_fd;
} listentbl[] = {
{ "std", start_connection_thread_std },
{ "extra", start_connection_thread_extra },
{ "browser", start_connection_thread_browser },
{ "ssh", start_connection_thread_ssh }
};
ret = npth_attr_init(&tattr);
if (ret)
log_fatal ("error allocating thread attributes: %s\n",
strerror (ret));
npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
#ifndef HAVE_W32_SYSTEM
npth_sigev_init ();
npth_sigev_add (SIGHUP);
npth_sigev_add (SIGUSR1);
npth_sigev_add (SIGUSR2);
npth_sigev_add (SIGINT);
npth_sigev_add (SIGTERM);
npth_sigev_fini ();
#else
# ifdef HAVE_W32CE_SYSTEM
/* Use a dummy event. */
sigs = 0;
ev = pth_event (PTH_EVENT_SIGS, &sigs, &signo);
# else
events[0] = get_agent_scd_notify_event ();
events[1] = INVALID_HANDLE_VALUE;
# endif
#endif
if (disable_check_own_socket)
my_inotify_fd = -1;
else if ((err = gnupg_inotify_watch_socket (&my_inotify_fd, socket_name)))
{
if (gpg_err_code (err) != GPG_ERR_NOT_SUPPORTED)
log_info ("error enabling fast daemon termination: %s\n",
gpg_strerror (err));
}
/* On Windows we need to fire up a separate thread to listen for
requests from Putty (an SSH client), so we can replace Putty's
Pageant (its ssh-agent implementation). */
#ifdef HAVE_W32_SYSTEM
if (putty_support)
{
npth_t thread;
ret = npth_create (&thread, &tattr, putty_message_thread, NULL);
if (ret)
{
log_error ("error spawning putty message loop: %s\n", strerror (ret));
}
}
#endif /*HAVE_W32_SYSTEM*/
/* Set a flag to tell call-scd.c that it may enable event
notifications. */
opt.sigusr2_enabled = 1;
FD_ZERO (&fdset);
FD_SET (FD2INT (listen_fd), &fdset);
nfd = FD2INT (listen_fd);
if (listen_fd_extra != GNUPG_INVALID_FD)
{
FD_SET ( FD2INT(listen_fd_extra), &fdset);
if (FD2INT (listen_fd_extra) > nfd)
nfd = FD2INT (listen_fd_extra);
}
if (listen_fd_browser != GNUPG_INVALID_FD)
{
FD_SET ( FD2INT(listen_fd_browser), &fdset);
if (FD2INT (listen_fd_browser) > nfd)
nfd = FD2INT (listen_fd_browser);
}
if (listen_fd_ssh != GNUPG_INVALID_FD)
{
FD_SET ( FD2INT(listen_fd_ssh), &fdset);
if (FD2INT (listen_fd_ssh) > nfd)
nfd = FD2INT (listen_fd_ssh);
}
if (my_inotify_fd != -1)
{
FD_SET (my_inotify_fd, &fdset);
if (my_inotify_fd > nfd)
nfd = my_inotify_fd;
}
listentbl[0].l_fd = listen_fd;
listentbl[1].l_fd = listen_fd_extra;
listentbl[2].l_fd = listen_fd_browser;
listentbl[3].l_fd = listen_fd_ssh;
npth_clock_gettime (&abstime);
abstime.tv_sec += TIMERTICK_INTERVAL;
for (;;)
{
/* Shutdown test. */
if (shutdown_pending)
{
if (active_connections == 0)
break; /* ready */
/* Do not accept new connections but keep on running the
* loop to cope with the timer events.
*
* Note that we do not close the listening socket because a
* client trying to connect to that socket would instead
* restart a new dirmngr instance - which is unlikely the
* intention of a shutdown. */
FD_ZERO (&fdset);
nfd = -1;
if (my_inotify_fd != -1)
{
FD_SET (my_inotify_fd, &fdset);
nfd = my_inotify_fd;
}
}
/* POSIX says that fd_set should be implemented as a structure,
thus a simple assignment is fine to copy the entire set. */
read_fdset = fdset;
npth_clock_gettime (&curtime);
if (!(npth_timercmp (&curtime, &abstime, <)))
{
/* Timeout. */
handle_tick ();
npth_clock_gettime (&abstime);
abstime.tv_sec += TIMERTICK_INTERVAL;
}
npth_timersub (&abstime, &curtime, &timeout);
#ifndef HAVE_W32_SYSTEM
ret = npth_pselect (nfd+1, &read_fdset, NULL, NULL, &timeout,
npth_sigev_sigmask ());
saved_errno = errno;
{
int signo;
while (npth_sigev_get_pending (&signo))
handle_signal (signo);
}
#else
ret = npth_eselect (nfd+1, &read_fdset, NULL, NULL, &timeout,
events, &events_set);
saved_errno = errno;
/* This is valid even if npth_eselect returns an error. */
if (events_set & 1)
agent_sigusr2_action ();
#endif
if (ret == -1 && saved_errno != EINTR)
{
log_error (_("npth_pselect failed: %s - waiting 1s\n"),
strerror (saved_errno));
npth_sleep (1);
continue;
}
if (ret <= 0)
/* Interrupt or timeout. Will be handled when calculating the
next timeout. */
continue;
if (!shutdown_pending)
{
int idx;
ctrl_t ctrl;
npth_t thread;
if (my_inotify_fd != -1
&& FD_ISSET (my_inotify_fd, &read_fdset)
&& gnupg_inotify_has_name (my_inotify_fd, GPG_AGENT_SOCK_NAME))
{
shutdown_pending = 1;
log_info ("socket file has been removed - shutting down\n");
}
for (idx=0; idx < DIM(listentbl); idx++)
{
if (listentbl[idx].l_fd == GNUPG_INVALID_FD)
continue;
if (!FD_ISSET (FD2INT (listentbl[idx].l_fd), &read_fdset))
continue;
plen = sizeof paddr;
fd = INT2FD (npth_accept (FD2INT(listentbl[idx].l_fd),
(struct sockaddr *)&paddr, &plen));
if (fd == GNUPG_INVALID_FD)
{
log_error ("accept failed for %s: %s\n",
listentbl[idx].name, strerror (errno));
}
else if ( !(ctrl = xtrycalloc (1, sizeof *ctrl)))
{
log_error ("error allocating connection data for %s: %s\n",
listentbl[idx].name, strerror (errno) );
assuan_sock_close (fd);
}
else if ( !(ctrl->session_env = session_env_new ()))
{
log_error ("error allocating session env block for %s: %s\n",
listentbl[idx].name, strerror (errno) );
xfree (ctrl);
assuan_sock_close (fd);
}
else
{
ctrl->thread_startup.fd = fd;
ret = npth_create (&thread, &tattr,
listentbl[idx].func, ctrl);
if (ret)
{
log_error ("error spawning connection handler for %s:"
" %s\n", listentbl[idx].name, strerror (ret));
assuan_sock_close (fd);
xfree (ctrl);
}
}
}
}
}
if (my_inotify_fd != -1)
close (my_inotify_fd);
cleanup ();
log_info (_("%s %s stopped\n"), strusage(11), strusage(13));
npth_attr_destroy (&tattr);
}
/* Helper for check_own_socket. */
static gpg_error_t
check_own_socket_pid_cb (void *opaque, const void *buffer, size_t length)
{
membuf_t *mb = opaque;
put_membuf (mb, buffer, length);
return 0;
}
/* The thread running the actual check. We need to run this in a
separate thread so that check_own_thread can be called from the
timer tick. */
static void *
check_own_socket_thread (void *arg)
{
int rc;
char *sockname = arg;
assuan_context_t ctx = NULL;
membuf_t mb;
char *buffer;
check_own_socket_running++;
rc = assuan_new (&ctx);
if (rc)
{
log_error ("can't allocate assuan context: %s\n", gpg_strerror (rc));
goto leave;
}
assuan_set_flag (ctx, ASSUAN_NO_LOGGING, 1);
rc = assuan_socket_connect (ctx, sockname, (pid_t)(-1), 0);
if (rc)
{
log_error ("can't connect my own socket: %s\n", gpg_strerror (rc));
goto leave;
}
init_membuf (&mb, 100);
rc = assuan_transact (ctx, "GETINFO pid", check_own_socket_pid_cb, &mb,
NULL, NULL, NULL, NULL);
put_membuf (&mb, "", 1);
buffer = get_membuf (&mb, NULL);
if (rc || !buffer)
{
log_error ("sending command \"%s\" to my own socket failed: %s\n",
"GETINFO pid", gpg_strerror (rc));
rc = 1;
}
else if ( (pid_t)strtoul (buffer, NULL, 10) != getpid ())
{
log_error ("socket is now serviced by another server\n");
rc = 1;
}
else if (opt.verbose > 1)
log_error ("socket is still served by this server\n");
xfree (buffer);
leave:
xfree (sockname);
if (ctx)
assuan_release (ctx);
if (rc)
{
/* We may not remove the socket as it is now in use by another
server. */
inhibit_socket_removal = 1;
shutdown_pending = 2;
log_info ("this process is useless - shutting down\n");
}
check_own_socket_running--;
return NULL;
}
/* Check whether we are still listening on our own socket. In case
another gpg-agent process started after us has taken ownership of
our socket, we would linger around without any real task. Thus we
better check once in a while whether we are really needed. */
static void
check_own_socket (void)
{
char *sockname;
npth_t thread;
npth_attr_t tattr;
int err;
if (disable_check_own_socket)
return;
if (check_own_socket_running || shutdown_pending)
return; /* Still running or already shutting down. */
sockname = make_filename_try (gnupg_socketdir (), GPG_AGENT_SOCK_NAME, NULL);
if (!sockname)
return; /* Out of memory. */
err = npth_attr_init (&tattr);
if (err)
return;
npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
err = npth_create (&thread, &tattr, check_own_socket_thread, sockname);
if (err)
log_error ("error spawning check_own_socket_thread: %s\n", strerror (err));
npth_attr_destroy (&tattr);
}
/* Figure out whether an agent is available and running. Prints an
error if not. If SILENT is true, no messages are printed.
Returns 0 if the agent is running. */
static int
check_for_running_agent (int silent)
{
gpg_error_t err;
char *sockname;
assuan_context_t ctx = NULL;
sockname = make_filename_try (gnupg_socketdir (), GPG_AGENT_SOCK_NAME, NULL);
if (!sockname)
return gpg_error_from_syserror ();
err = assuan_new (&ctx);
if (!err)
err = assuan_socket_connect (ctx, sockname, (pid_t)(-1), 0);
xfree (sockname);
if (err)
{
if (!silent)
log_error (_("no gpg-agent running in this session\n"));
if (ctx)
assuan_release (ctx);
return -1;
}
if (!opt.quiet && !silent)
log_info ("gpg-agent running and available\n");
assuan_release (ctx);
return 0;
}
diff --git a/doc/gpg-agent.texi b/doc/gpg-agent.texi
index 6ed0ff87e..d61dc85ae 100644
--- a/doc/gpg-agent.texi
+++ b/doc/gpg-agent.texi
@@ -1,1543 +1,1550 @@
@c Copyright (C) 2002 Free Software Foundation, Inc.
@c This is part of the GnuPG manual.
@c For copying conditions, see the file gnupg.texi.
@include defs.inc
@node Invoking GPG-AGENT
@chapter Invoking GPG-AGENT
@cindex GPG-AGENT command options
@cindex command options
@cindex options, GPG-AGENT command
@manpage gpg-agent.1
@ifset manverb
.B gpg-agent
\- Secret key management for GnuPG
@end ifset
@mansect synopsis
@ifset manverb
.B gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.br
.B gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.B \-\-server
.br
.B gpg-agent
.RB [ \-\-homedir
.IR dir ]
.RB [ \-\-options
.IR file ]
.RI [ options ]
.B \-\-daemon
.RI [ command_line ]
@end ifset
@mansect description
@command{gpg-agent} is a daemon to manage secret (private) keys
independently from any protocol. It is used as a backend for
@command{gpg} and @command{gpgsm} as well as for a couple of other
utilities.
The agent is automatically started on demand by @command{gpg},
@command{gpgsm}, @command{gpgconf}, or @command{gpg-connect-agent}.
Thus there is no reason to start it manually. In case you want to use
the included Secure Shell Agent you may start the agent using:
@c From dkg on gnupg-devel on 2016-04-21:
@c
@c Here's an attempt at writing a short description of the goals of an
@c isolated cryptographic agent:
@c
@c A cryptographic agent should control access to secret key material.
@c The agent permits use of the secret key material by a supplicant
@c without providing a copy of the secret key material to the supplicant.
@c
@c An isolated cryptographic agent separates the request for use of
@c secret key material from permission for use of secret key material.
@c That is, the system or process requesting use of the key (the
@c "supplicant") can be denied use of the key by the owner/operator of
@c the agent (the "owner"), which the supplicant has no control over.
@c
@c One way of enforcing this split is a per-key or per-session
@c passphrase, known only by the owner, which must be supplied to the
@c agent to permit the use of the secret key material. Another way is
@c with an out-of-band permission mechanism (e.g. a button or GUI
@c interface that the owner has access to, but the supplicant does not).
@c
@c The rationale for this separation is that it allows access to the
@c secret key to be tightly controlled and audited, and it doesn't permit
@c the supplicant to either copy the key or to override the owner's
@c intentions.
@example
gpg-connect-agent /bye
@end example
@noindent
If you want to manually terminate the currently-running agent, you can
safely do so with:
@example
gpgconf --kill gpg-agent
@end example
@noindent
@efindex GPG_TTY
You should always add the following lines to your @code{.bashrc} or
whatever initialization file is used for all shell invocations:
@smallexample
GPG_TTY=$(tty)
export GPG_TTY
@end smallexample
@noindent
It is important that this environment variable always reflects the
output of the @code{tty} command. For W32 systems this option is not
required.
Please make sure that a proper pinentry program has been installed
under the default filename (which is system dependent) or use the
option @option{pinentry-program} to specify the full name of that program.
It is often useful to install a symbolic link from the actual used
pinentry (e.g. @file{@value{BINDIR}/pinentry-gtk}) to the expected
one (e.g. @file{@value{BINDIR}/pinentry}).
@manpause
@noindent
@xref{Option Index}, for an index to @command{GPG-AGENT}'s commands and options.
@mancont
@menu
* Agent Commands:: List of all commands.
* Agent Options:: List of all options.
* Agent Configuration:: Configuration files.
* Agent Signals:: Use of some signals.
* Agent Examples:: Some usage examples.
* Agent Protocol:: The protocol the agent uses.
@end menu
@mansect commands
@node Agent Commands
@section Commands
Commands are not distinguished from options except for the fact that
only one command is allowed.
@table @gnupgtabopt
@item --version
@opindex version
Print the program version and licensing information. Note that you cannot
abbreviate this command.
@item --help
@itemx -h
@opindex help
Print a usage message summarizing the most useful command-line options.
Note that you cannot abbreviate this command.
@item --dump-options
@opindex dump-options
Print a list of all available options and commands. Note that you cannot
abbreviate this command.
@item --server
@opindex server
Run in server mode and wait for commands on the @code{stdin}. The
default mode is to create a socket and listen for commands there.
@item --daemon [@var{command line}]
@opindex daemon
Start the gpg-agent as a daemon; that is, detach it from the console
and run it in the background.
As an alternative you may create a new process as a child of
gpg-agent: @code{gpg-agent --daemon /bin/sh}. This way you get a new
shell with the environment setup properly; after you exit from this
shell, gpg-agent terminates within a few seconds.
@item --supervised
@opindex supervised
Run in the foreground, sending logs by default to stderr, and
listening on provided file descriptors, which must already be bound to
listening sockets. This command is useful when running under systemd
or other similar process supervision schemes. This option is not
supported on Windows.
In --supervised mode, different file descriptors can be provided for
use as different socket types (e.g. ssh, extra) as long as they are
identified in the environment variable @code{LISTEN_FDNAMES} (see
sd_listen_fds(3) on some Linux distributions for more information on
this convention).
@end table
@mansect options
@node Agent Options
@section Option Summary
@table @gnupgtabopt
@anchor{option --options}
@item --options @var{file}
@opindex options
Reads configuration from @var{file} instead of from the default
per-user configuration file. The default configuration file is named
@file{gpg-agent.conf} and expected in the @file{.gnupg} directory directly
below the home directory of the user.
@anchor{option --homedir}
@include opt-homedir.texi
@item -v
@item --verbose
@opindex verbose
Outputs additional information while running.
You can increase the verbosity by giving several
verbose commands to @command{gpg-agent}, such as @samp{-vv}.
@item -q
@item --quiet
@opindex quiet
Try to be as quiet as possible.
@item --batch
@opindex batch
Don't invoke a pinentry or do any other thing requiring human interaction.
@item --faked-system-time @var{epoch}
@opindex faked-system-time
This option is only useful for testing; it sets the system time back or
forth to @var{epoch} which is the number of seconds elapsed since the year
1970.
@item --debug-level @var{level}
@opindex debug-level
Select the debug level for investigating problems. @var{level} may be
a numeric value or a keyword:
@table @code
@item none
No debugging at all. A value of less than 1 may be used instead of
the keyword.
@item basic
Some basic debug messages. A value between 1 and 2 may be used
instead of the keyword.
@item advanced
More verbose debug messages. A value between 3 and 5 may be used
instead of the keyword.
@item expert
Even more detailed messages. A value between 6 and 8 may be used
instead of the keyword.
@item guru
All of the debug messages you can get. A value greater than 8 may be
used instead of the keyword. The creation of hash tracing files is
only enabled if the keyword is used.
@end table
How these messages are mapped to the actual debugging flags is not
specified and may change with newer releases of this program. They are
however carefully selected to best aid in debugging.
@item --debug @var{flags}
@opindex debug
This option is only useful for debugging and the behavior may change at
any time without notice. FLAGS are bit encoded and may be given in
usual C-Syntax. The currently defined bits are:
@table @code
@item 0 (1)
X.509 or OpenPGP protocol related data
@item 1 (2)
values of big number integers
@item 2 (4)
low level crypto operations
@item 5 (32)
memory allocation
@item 6 (64)
caching
@item 7 (128)
show memory statistics
@item 9 (512)
write hashed data to files named @code{dbgmd-000*}
@item 10 (1024)
trace Assuan protocol
@item 12 (4096)
bypass all certificate validation
@end table
@item --debug-all
@opindex debug-all
Same as @code{--debug=0xffffffff}
@item --debug-wait @var{n}
@opindex debug-wait
When running in server mode, wait @var{n} seconds before entering the
actual processing loop and print the pid. This gives time to attach a
debugger.
@item --debug-quick-random
@opindex debug-quick-random
This option inhibits the use of the very secure random quality level
(Libgcrypt’s @code{GCRY_VERY_STRONG_RANDOM}) and degrades all request
down to standard random quality. It is only used for testing and
should not be used for any production quality keys. This option is
only effective when given on the command line.
On GNU/Linux, another way to quickly generate insecure keys is to use
@command{rngd} to fill the kernel's entropy pool with lower quality
random data. @command{rngd} is typically provided by the
@command{rng-tools} package. It can be run as follows: @samp{sudo
rngd -f -r /dev/urandom}.
@item --debug-pinentry
@opindex debug-pinentry
This option enables extra debug information pertaining to the
Pinentry. As of now it is only useful when used along with
@code{--debug 1024}.
@item --no-detach
@opindex no-detach
Don't detach the process from the console. This is mainly useful for
debugging.
@item -s
@itemx --sh
@itemx -c
@itemx --csh
@opindex sh
@opindex csh
@efindex SHELL
Format the info output in daemon mode for use with the standard Bourne
shell or the C-shell respectively. The default is to guess it based on
the environment variable @code{SHELL} which is correct in almost all
cases.
@item --no-grab
@opindex no-grab
Tell the pinentry not to grab the keyboard and mouse. This option
should in general not be used to avoid X-sniffing attacks.
@anchor{option --log-file}
@item --log-file @var{file}
@opindex log-file
@efindex HKCU\Software\GNU\GnuPG:DefaultLogFile
Append all logging output to @var{file}. This is very helpful in
seeing what the agent actually does. Use @file{socket://} to log to
socket. If neither a log file nor a log file descriptor has been set
on a Windows platform, the Registry entry
@code{HKCU\Software\GNU\GnuPG:DefaultLogFile}, if set, is used to
specify the logging output.
@anchor{option --no-allow-mark-trusted}
@item --no-allow-mark-trusted
@opindex no-allow-mark-trusted
Do not allow clients to mark keys as trusted, i.e. put them into the
@file{trustlist.txt} file. This makes it harder for users to inadvertently
accept Root-CA keys.
@anchor{option --allow-preset-passphrase}
@item --allow-preset-passphrase
@opindex allow-preset-passphrase
This option allows the use of @command{gpg-preset-passphrase} to seed the
internal cache of @command{gpg-agent} with passphrases.
@anchor{option --no-allow-loopback-pinentry}
@item --no-allow-loopback-pinentry
@item --allow-loopback-pinentry
@opindex no-allow-loopback-pinentry
@opindex allow-loopback-pinentry
Disallow or allow clients to use the loopback pinentry features; see
the option @option{pinentry-mode} for details. Allow is the default.
The @option{--force} option of the Assuan command @command{DELETE_KEY}
is also controlled by this option: The option is ignored if a loopback
pinentry is disallowed.
@item --no-allow-external-cache
@opindex no-allow-external-cache
Tell Pinentry not to enable features which use an external cache for
passphrases.
Some desktop environments prefer to unlock all
credentials with one master password and may have installed a Pinentry
which employs an additional external cache to implement such a policy.
By using this option the Pinentry is advised not to make use of such a
cache and instead always ask the user for the requested passphrase.
@item --allow-emacs-pinentry
@opindex allow-emacs-pinentry
Tell Pinentry to allow features to divert the passphrase entry to a
running Emacs instance. How this is exactly handled depends on the
version of the used Pinentry.
@item --ignore-cache-for-signing
@opindex ignore-cache-for-signing
This option will let @command{gpg-agent} bypass the passphrase cache for all
signing operation. Note that there is also a per-session option to
control this behavior but this command line option takes precedence.
@item --default-cache-ttl @var{n}
@opindex default-cache-ttl
Set the time a cache entry is valid to @var{n} seconds. The default
is 600 seconds. Each time a cache entry is accessed, the entry's
timer is reset. To set an entry's maximum lifetime, use
@command{max-cache-ttl}.
@item --default-cache-ttl-ssh @var{n}
@opindex default-cache-ttl
Set the time a cache entry used for SSH keys is valid to @var{n}
seconds. The default is 1800 seconds. Each time a cache entry is
accessed, the entry's timer is reset. To set an entry's maximum
lifetime, use @command{max-cache-ttl-ssh}.
@item --max-cache-ttl @var{n}
@opindex max-cache-ttl
Set the maximum time a cache entry is valid to @var{n} seconds. After
this time a cache entry will be expired even if it has been accessed
recently or has been set using @command{gpg-preset-passphrase}. The
default is 2 hours (7200 seconds).
@item --max-cache-ttl-ssh @var{n}
@opindex max-cache-ttl-ssh
Set the maximum time a cache entry used for SSH keys is valid to
@var{n} seconds. After this time a cache entry will be expired even
if it has been accessed recently or has been set using
@command{gpg-preset-passphrase}. The default is 2 hours (7200
seconds).
@item --enforce-passphrase-constraints
@opindex enforce-passphrase-constraints
Enforce the passphrase constraints by not allowing the user to bypass
them using the ``Take it anyway'' button.
@item --min-passphrase-len @var{n}
@opindex min-passphrase-len
Set the minimal length of a passphrase. When entering a new passphrase
shorter than this value a warning will be displayed. Defaults to 8.
@item --min-passphrase-nonalpha @var{n}
@opindex min-passphrase-nonalpha
Set the minimal number of digits or special characters required in a
passphrase. When entering a new passphrase with less than this number
of digits or special characters a warning will be displayed. Defaults
to 1.
@item --check-passphrase-pattern @var{file}
@opindex check-passphrase-pattern
Check the passphrase against the pattern given in @var{file}. When
entering a new passphrase matching one of these pattern a warning will
be displayed. @var{file} should be an absolute filename. The default is
not to use any pattern file.
Security note: It is known that checking a passphrase against a list of
pattern or even against a complete dictionary is not very effective to
enforce good passphrases. Users will soon figure up ways to bypass such
a policy. A better policy is to educate users on good security
behavior and optionally to run a passphrase cracker regularly on all
users passphrases to catch the very simple ones.
@item --max-passphrase-days @var{n}
@opindex max-passphrase-days
Ask the user to change the passphrase if @var{n} days have passed since
the last change. With @option{--enforce-passphrase-constraints} set the
user may not bypass this check.
@item --enable-passphrase-history
@opindex enable-passphrase-history
This option does nothing yet.
@item --pinentry-invisible-char @var{char}
@opindex pinentry-invisible-char
This option asks the Pinentry to use @var{char} for displaying hidden
characters. @var{char} must be one character UTF-8 string. A
Pinentry may or may not honor this request.
@item --pinentry-timeout @var{n}
@opindex pinentry-timeout
This option asks the Pinentry to timeout after @var{n} seconds with no
user input. The default value of 0 does not ask the pinentry to
timeout, however a Pinentry may use its own default timeout value in
this case. A Pinentry may or may not honor this request.
@item --pinentry-program @var{filename}
@opindex pinentry-program
Use program @var{filename} as the PIN entry. The default is
installation dependent. With the default configuration the name of
the default pinentry is @file{pinentry}; if that file does not exist
but a @file{pinentry-basic} exist the latter is used.
On a Windows platform the default is to use the first existing program
from this list:
@file{bin\pinentry.exe},
@file{..\Gpg4win\bin\pinentry.exe},
@file{..\Gpg4win\pinentry.exe},
@file{..\GNU\GnuPG\pinentry.exe},
@file{..\GNU\bin\pinentry.exe},
@file{bin\pinentry-basic.exe}
where the file names are relative to the GnuPG installation directory.
@item --pinentry-touch-file @var{filename}
@opindex pinentry-touch-file
By default the filename of the socket gpg-agent is listening for
requests is passed to Pinentry, so that it can touch that file before
exiting (it does this only in curses mode). This option changes the
file passed to Pinentry to @var{filename}. The special name
@code{/dev/null} may be used to completely disable this feature. Note
that Pinentry will not create that file, it will only change the
modification and access time.
@item --scdaemon-program @var{filename}
@opindex scdaemon-program
Use program @var{filename} as the Smartcard daemon. The default is
installation dependent and can be shown with the @command{gpgconf}
command.
@item --disable-scdaemon
@opindex disable-scdaemon
Do not make use of the scdaemon tool. This option has the effect of
disabling the ability to do smartcard operations. Note, that enabling
this option at runtime does not kill an already forked scdaemon.
@item --disable-check-own-socket
@opindex disable-check-own-socket
@command{gpg-agent} employs a periodic self-test to detect a stolen
socket. This usually means a second instance of @command{gpg-agent}
has taken over the socket and @command{gpg-agent} will then terminate
itself. This option may be used to disable this self-test for
debugging purposes.
@item --use-standard-socket
@itemx --no-use-standard-socket
@itemx --use-standard-socket-p
@opindex use-standard-socket
@opindex no-use-standard-socket
@opindex use-standard-socket-p
Since GnuPG 2.1 the standard socket is always used. These options
have no more effect. The command @code{gpg-agent
--use-standard-socket-p} will thus always return success.
@item --display @var{string}
@itemx --ttyname @var{string}
@itemx --ttytype @var{string}
@itemx --lc-ctype @var{string}
@itemx --lc-messages @var{string}
@itemx --xauthority @var{string}
@opindex display
@opindex ttyname
@opindex ttytype
@opindex lc-ctype
@opindex lc-messages
@opindex xauthority
These options are used with the server mode to pass localization
information.
@item --keep-tty
@itemx --keep-display
@opindex keep-tty
@opindex keep-display
Ignore requests to change the current @code{tty} or X window system's
@code{DISPLAY} variable respectively. This is useful to lock the
pinentry to pop up at the @code{tty} or display you started the agent.
@anchor{option --extra-socket}
@item --extra-socket @var{name}
@opindex extra-socket
The extra socket is created by default, you may use this option to
change the name of the socket. To disable the creation of the socket
use ``none'' or ``/dev/null'' for @var{name}.
Also listen on native gpg-agent connections on the given socket. The
intended use for this extra socket is to setup a Unix domain socket
forwarding from a remote machine to this socket on the local machine.
A @command{gpg} running on the remote machine may then connect to the
local gpg-agent and use its private keys. This enables decrypting or
signing data on a remote machine without exposing the private keys to the
remote machine.
@anchor{option --enable-extended-key-format}
@item --enable-extended-key-format
@opindex enable-extended-key-format
This option creates keys in the extended private key format. Changing
the passphrase of a key will also convert the key to that new format.
Using this option makes the private keys unreadable for gpg-agent
versions before 2.1.12. The advantage of the extended private key
format is that it is text based and can carry additional meta data.
Note that this option also changes the key protection format to use
OCB mode.
@anchor{option --enable-ssh-support}
@item --enable-ssh-support
@itemx --enable-putty-support
@opindex enable-ssh-support
@opindex enable-putty-support
The OpenSSH Agent protocol is always enabled, but @command{gpg-agent}
will only set the @code{SSH_AUTH_SOCK} variable if this flag is given.
In this mode of operation, the agent does not only implement the
gpg-agent protocol, but also the agent protocol used by OpenSSH
(through a separate socket). Consequently, it should be possible to use
the gpg-agent as a drop-in replacement for the well known ssh-agent.
SSH Keys, which are to be used through the agent, need to be added to
the gpg-agent initially through the ssh-add utility. When a key is
added, ssh-add will ask for the password of the provided key file and
send the unprotected key material to the agent; this causes the
gpg-agent to ask for a passphrase, which is to be used for encrypting
the newly received key and storing it in a gpg-agent specific
directory.
Once a key has been added to the gpg-agent this way, the gpg-agent
will be ready to use the key.
Note: in case the gpg-agent receives a signature request, the user might
need to be prompted for a passphrase, which is necessary for decrypting
the stored key. Since the ssh-agent protocol does not contain a
mechanism for telling the agent on which display/terminal it is running,
gpg-agent's ssh-support will use the TTY or X display where gpg-agent
has been started. To switch this display to the current one, the
following command may be used:
@smallexample
gpg-connect-agent updatestartuptty /bye
@end smallexample
Although all GnuPG components try to start the gpg-agent as needed, this
is not possible for the ssh support because ssh does not know about it.
Thus if no GnuPG tool which accesses the agent has been run, there is no
guarantee that ssh is able to use gpg-agent for authentication. To fix
this you may start gpg-agent if needed using this simple command:
@smallexample
gpg-connect-agent /bye
@end smallexample
Adding the @option{--verbose} shows the progress of starting the agent.
The @option{--enable-putty-support} is only available under Windows
and allows the use of gpg-agent with the ssh implementation
@command{putty}. This is similar to the regular ssh-agent support but
makes use of Windows message queue as required by @command{putty}.
+@anchor{option --ssh-fingerprint-digest}
+@item --ssh-fingerprint-digest
+@opindex ssh-fingerprint-digest
+
+Select the digest algorithm used to compute ssh fingerprints that are
+communicated to the user, e.g. in pinentry dialogs. OpenSSH has
+transitioned from using MD5 to the more secure SHA256.
@end table
All the long options may also be given in the configuration file after
stripping off the two leading dashes.
@mansect files
@node Agent Configuration
@section Configuration
There are a few configuration files needed for the operation of the
agent. By default they may all be found in the current home directory
(@pxref{option --homedir}).
@table @file
@item gpg-agent.conf
@efindex gpg-agent.conf
This is the standard configuration file read by @command{gpg-agent} on
startup. It may contain any valid long option; the leading
two dashes may not be entered and the option may not be abbreviated.
This file is also read after a @code{SIGHUP} however only a few
options will actually have an effect. This default name may be
changed on the command line (@pxref{option --options}).
You should backup this file.
@item trustlist.txt
@efindex trustlist.txt
This is the list of trusted keys. You should backup this file.
Comment lines, indicated by a leading hash mark, as well as empty
lines are ignored. To mark a key as trusted you need to enter its
fingerprint followed by a space and a capital letter @code{S}. Colons
may optionally be used to separate the bytes of a fingerprint; this
enables cutting and pasting the fingerprint from a key listing output. If
the line is prefixed with a @code{!} the key is explicitly marked as
not trusted.
Here is an example where two keys are marked as ultimately trusted
and one as not trusted:
@cartouche
@smallexample
# CN=Wurzel ZS 3,O=Intevation GmbH,C=DE
A6935DD34EF3087973C706FC311AA2CCF733765B S
# CN=PCA-1-Verwaltung-02/O=PKI-1-Verwaltung/C=DE
DC:BD:69:25:48:BD:BB:7E:31:6E:BB:80:D3:00:80:35:D4:F8:A6:CD S
# CN=Root-CA/O=Schlapphuete/L=Pullach/C=DE
!14:56:98:D3:FE:9C:CA:5A:31:6E:BC:81:D3:11:4E:00:90:A3:44:C2 S
@end smallexample
@end cartouche
Before entering a key into this file, you need to ensure its
authenticity. How to do this depends on your organisation; your
administrator might have already entered those keys which are deemed
trustworthy enough into this file. Places where to look for the
fingerprint of a root certificate are letters received from the CA or
the website of the CA (after making 100% sure that this is indeed the
website of that CA). You may want to consider disallowing interactive
updates of this file by using the @ref{option --no-allow-mark-trusted}.
It might even be advisable to change the permissions to read-only so
that this file can't be changed inadvertently.
As a special feature a line @code{include-default} will include a global
list of trusted certificates (e.g. @file{@value{SYSCONFDIR}/trustlist.txt}).
This global list is also used if the local list is not available.
It is possible to add further flags after the @code{S} for use by the
caller:
@table @code
@item relax
@cindex relax
Relax checking of some root certificate requirements. As of now this
flag allows the use of root certificates with a missing basicConstraints
attribute (despite that it is a MUST for CA certificates) and disables
CRL checking for the root certificate.
@item cm
If validation of a certificate finally issued by a CA with this flag set
fails, try again using the chain validation model.
@end table
@item sshcontrol
@efindex sshcontrol
This file is used when support for the secure shell agent protocol has
been enabled (@pxref{option --enable-ssh-support}). Only keys present in
this file are used in the SSH protocol. You should backup this file.
The @command{ssh-add} tool may be used to add new entries to this file;
you may also add them manually. Comment lines, indicated by a leading
hash mark, as well as empty lines are ignored. An entry starts with
optional whitespace, followed by the keygrip of the key given as 40 hex
digits, optionally followed by the caching TTL in seconds and another
optional field for arbitrary flags. A non-zero TTL overrides the global
default as set by @option{--default-cache-ttl-ssh}.
The only flag support is @code{confirm}. If this flag is found for a
key, each use of the key will pop up a pinentry to confirm the use of
that key. The flag is automatically set if a new key was loaded into
@code{gpg-agent} using the option @option{-c} of the @code{ssh-add}
command.
The keygrip may be prefixed with a @code{!} to disable an entry.
The following example lists exactly one key. Note that keys available
through a OpenPGP smartcard in the active smartcard reader are
implicitly added to this list; i.e. there is no need to list them.
@cartouche
@smallexample
# Key added on: 2011-07-20 20:38:46
# Fingerprint: 5e:8d:c4:ad:e7:af:6e:27:8a:d6:13:e4:79:ad:0b:81
34B62F25E277CF13D3C6BCEBFD3F85D08F0A864B 0 confirm
@end smallexample
@end cartouche
@item private-keys-v1.d/
@efindex private-keys-v1.d
This is the directory where gpg-agent stores the private keys. Each
key is stored in a file with the name made up of the keygrip and the
suffix @file{key}. You should backup all files in this directory
and take great care to keep this backup closed away.
@end table
Note that on larger installations, it is useful to put predefined
files into the directory @file{@value{SYSCONFSKELDIR}} so that newly created
users start up with a working configuration. For existing users the
a small helper script is provided to create these files (@pxref{addgnupghome}).
@c
@c Agent Signals
@c
@mansect signals
@node Agent Signals
@section Use of some signals
A running @command{gpg-agent} may be controlled by signals, i.e. using
the @command{kill} command to send a signal to the process.
Here is a list of supported signals:
@table @gnupgtabopt
@item SIGHUP
@cpindex SIGHUP
This signal flushes all cached passphrases and if the program has been
started with a configuration file, the configuration file is read
again. Only certain options are honored: @code{quiet},
@code{verbose}, @code{debug}, @code{debug-all}, @code{debug-level},
@code{debug-pinentry},
@code{no-grab},
@code{pinentry-program},
@code{pinentry-invisible-char},
@code{default-cache-ttl},
@code{max-cache-ttl}, @code{ignore-cache-for-signing},
@code{no-allow-external-cache}, @code{allow-emacs-pinentry},
@code{no-allow-mark-trusted}, @code{disable-scdaemon}, and
@code{disable-check-own-socket}. @code{scdaemon-program} is also
supported but due to the current implementation, which calls the
scdaemon only once, it is not of much use unless you manually kill the
scdaemon.
@item SIGTERM
@cpindex SIGTERM
Shuts down the process but waits until all current requests are
fulfilled. If the process has received 3 of these signals and requests
are still pending, a shutdown is forced.
@item SIGINT
@cpindex SIGINT
Shuts down the process immediately.
@item SIGUSR1
@cpindex SIGUSR1
Dump internal information to the log file.
@item SIGUSR2
@cpindex SIGUSR2
This signal is used for internal purposes.
@end table
@c
@c Examples
@c
@mansect examples
@node Agent Examples
@section Examples
It is important to set the environment variable @code{GPG_TTY} in
your login shell, for example in the @file{~/.bashrc} init script:
@cartouche
@example
export GPG_TTY=$(tty)
@end example
@end cartouche
If you enabled the Ssh Agent Support, you also need to tell ssh about
it by adding this to your init script:
@cartouche
@example
unset SSH_AGENT_PID
if [ "$@{gnupg_SSH_AUTH_SOCK_by:-0@}" -ne $$ ]; then
export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)"
fi
@end example
@end cartouche
@c
@c Assuan Protocol
@c
@manpause
@node Agent Protocol
@section Agent's Assuan Protocol
Note: this section does only document the protocol, which is used by
GnuPG components; it does not deal with the ssh-agent protocol. To
see the full specification of each command, use
@example
gpg-connect-agent 'help COMMAND' /bye
@end example
@noindent
or just 'help' to list all available commands.
@noindent
The @command{gpg-agent} daemon is started on demand by the GnuPG
components.
To identify a key we use a thing called keygrip which is the SHA-1 hash
of an canonical encoded S-Expression of the public key as used in
Libgcrypt. For the purpose of this interface the keygrip is given as a
hex string. The advantage of using this and not the hash of a
certificate is that it will be possible to use the same keypair for
different protocols, thereby saving space on the token used to keep the
secret keys.
The @command{gpg-agent} may send status messages during a command or when
returning from a command to inform a client about the progress or result of an
operation. For example, the @var{INQUIRE_MAXLEN} status message may be sent
during a server inquire to inform the client of the maximum usable length of
the inquired data (which should not be exceeded).
@menu
* Agent PKDECRYPT:: Decrypting a session key
* Agent PKSIGN:: Signing a Hash
* Agent GENKEY:: Generating a Key
* Agent IMPORT:: Importing a Secret Key
* Agent EXPORT:: Exporting a Secret Key
* Agent ISTRUSTED:: Importing a Root Certificate
* Agent GET_PASSPHRASE:: Ask for a passphrase
* Agent CLEAR_PASSPHRASE:: Expire a cached passphrase
* Agent PRESET_PASSPHRASE:: Set a passphrase for a keygrip
* Agent GET_CONFIRMATION:: Ask for confirmation
* Agent HAVEKEY:: Check whether a key is available
* Agent LEARN:: Register a smartcard
* Agent PASSWD:: Change a Passphrase
* Agent UPDATESTARTUPTTY:: Change the Standard Display
* Agent GETEVENTCOUNTER:: Get the Event Counters
* Agent GETINFO:: Return information about the process
* Agent OPTION:: Set options for the session
@end menu
@node Agent PKDECRYPT
@subsection Decrypting a session key
The client asks the server to decrypt a session key. The encrypted
session key should have all information needed to select the
appropriate secret key or to delegate it to a smartcard.
@example
SETKEY <keyGrip>
@end example
Tell the server about the key to be used for decryption. If this is
not used, @command{gpg-agent} may try to figure out the key by trying to
decrypt the message with each key available.
@example
PKDECRYPT
@end example
The agent checks whether this command is allowed and then does an
INQUIRY to get the ciphertext the client should then send the cipher
text.
@example
S: INQUIRE CIPHERTEXT
C: D (xxxxxx
C: D xxxx)
C: END
@end example
Please note that the server may send status info lines while reading the
data lines from the client. The data send is a SPKI like S-Exp with
this structure:
@example
(enc-val
(<algo>
(<param_name1> <mpi>)
...
(<param_namen> <mpi>)))
@end example
Where algo is a string with the name of the algorithm; see the libgcrypt
documentation for a list of valid algorithms. The number and names of
the parameters depend on the algorithm. The agent does return an error
if there is an inconsistency.
If the decryption was successful the decrypted data is returned by
means of "D" lines.
Here is an example session:
@cartouche
@smallexample
C: PKDECRYPT
S: INQUIRE CIPHERTEXT
C: D (enc-val elg (a 349324324)
C: D (b 3F444677CA)))
C: END
S: # session key follows
S: S PADDING 0
S: D (value 1234567890ABCDEF0)
S: OK decryption successful
@end smallexample
@end cartouche
The “PADDING” status line is only send if gpg-agent can tell what kind
of padding is used. As of now only the value 0 is used to indicate
that the padding has been removed.
@node Agent PKSIGN
@subsection Signing a Hash
The client asks the agent to sign a given hash value. A default key
will be chosen if no key has been set. To set a key a client first
uses:
@example
SIGKEY <keyGrip>
@end example
This can be used multiple times to create multiple signature, the list
of keys is reset with the next PKSIGN command or a RESET. The server
tests whether the key is a valid key to sign something and responds with
okay.
@example
SETHASH --hash=<name>|<algo> <hexstring>
@end example
The client can use this command to tell the server about the data <hexstring>
(which usually is a hash) to be signed. <algo> is the decimal encoded hash
algorithm number as used by Libgcrypt. Either <algo> or --hash=<name>
must be given. Valid names for <name> are:
@table @code
@item sha1
The SHA-1 hash algorithm
@item sha256
The SHA-256 hash algorithm
@item rmd160
The RIPE-MD160 hash algorithm
@item md5
The old and broken MD5 hash algorithm
@item tls-md5sha1
A combined hash algorithm as used by the TLS protocol.
@end table
@noindent
The actual signing is done using
@example
PKSIGN <options>
@end example
Options are not yet defined, but may later be used to choose among
different algorithms. The agent does then some checks, asks for the
passphrase and as a result the server returns the signature as an SPKI
like S-expression in "D" lines:
@example
(sig-val
(<algo>
(<param_name1> <mpi>)
...
(<param_namen> <mpi>)))
@end example
The operation is affected by the option
@example
OPTION use-cache-for-signing=0|1
@end example
The default of @code{1} uses the cache. Setting this option to @code{0}
will lead @command{gpg-agent} to ignore the passphrase cache. Note, that there is
also a global command line option for @command{gpg-agent} to globally disable the
caching.
Here is an example session:
@cartouche
@smallexample
C: SIGKEY <keyGrip>
S: OK key available
C: SIGKEY <keyGrip>
S: OK key available
C: PKSIGN
S: # I did ask the user whether he really wants to sign
S: # I did ask the user for the passphrase
S: INQUIRE HASHVAL
C: D ABCDEF012345678901234
C: END
S: # signature follows
S: D (sig-val rsa (s 45435453654612121212))
S: OK
@end smallexample
@end cartouche
@node Agent GENKEY
@subsection Generating a Key
This is used to create a new keypair and store the secret key inside the
active PSE --- which is in most cases a Soft-PSE. A not-yet-defined
option allows choosing the storage location. To get the secret key out
of the PSE, a special export tool has to be used.
@example
GENKEY [--no-protection] [--preset] [<cache_nonce>]
@end example
Invokes the key generation process and the server will then inquire
on the generation parameters, like:
@example
S: INQUIRE KEYPARM
C: D (genkey (rsa (nbits 1024)))
C: END
@end example
The format of the key parameters which depends on the algorithm is of
the form:
@example
(genkey
(algo
(parameter_name_1 ....)
....
(parameter_name_n ....)))
@end example
If everything succeeds, the server returns the *public key* in a SPKI
like S-Expression like this:
@example
(public-key
(rsa
(n <mpi>)
(e <mpi>)))
@end example
Here is an example session:
@cartouche
@smallexample
C: GENKEY
S: INQUIRE KEYPARM
C: D (genkey (rsa (nbits 1024)))
C: END
S: D (public-key
S: D (rsa (n 326487324683264) (e 10001)))
S OK key created
@end smallexample
@end cartouche
The @option{--no-protection} option may be used to prevent prompting for a
passphrase to protect the secret key while leaving the secret key unprotected.
The @option{--preset} option may be used to add the passphrase to the cache
using the default cache parameters.
The @option{--inq-passwd} option may be used to create the key with a
supplied passphrase. When used the agent does an inquiry with the
keyword @code{NEWPASSWD} to retrieve that passphrase. This option
takes precedence over @option{--no-protection}; however if the client
sends a empty (zero-length) passphrase, this is identical to
@option{--no-protection}.
@node Agent IMPORT
@subsection Importing a Secret Key
This operation is not yet supported by GpgAgent. Specialized tools
are to be used for this.
There is no actual need because we can expect that secret keys
created by a 3rd party are stored on a smartcard. If we have
generated the key ourselves, we do not need to import it.
@node Agent EXPORT
@subsection Export a Secret Key
Not implemented.
Should be done by an extra tool.
@node Agent ISTRUSTED
@subsection Importing a Root Certificate
Actually we do not import a Root Cert but provide a way to validate
any piece of data by storing its Hash along with a description and
an identifier in the PSE. Here is the interface description:
@example
ISTRUSTED <fingerprint>
@end example
Check whether the OpenPGP primary key or the X.509 certificate with the
given fingerprint is an ultimately trusted key or a trusted Root CA
certificate. The fingerprint should be given as a hexstring (without
any blanks or colons or whatever in between) and may be left padded with
00 in case of an MD5 fingerprint. GPGAgent will answer with:
@example
OK
@end example
The key is in the table of trusted keys.
@example
ERR 304 (Not Trusted)
@end example
The key is not in this table.
Gpg needs the entire list of trusted keys to maintain the web of
trust; the following command is therefore quite helpful:
@example
LISTTRUSTED
@end example
GpgAgent returns a list of trusted keys line by line:
@example
S: D 000000001234454556565656677878AF2F1ECCFF P
S: D 340387563485634856435645634856438576457A P
S: D FEDC6532453745367FD83474357495743757435D S
S: OK
@end example
The first item on a line is the hexified fingerprint where MD5
fingerprints are @code{00} padded to the left and the second item is a
flag to indicate the type of key (so that gpg is able to only take care
of PGP keys). P = OpenPGP, S = S/MIME. A client should ignore the rest
of the line, so that we can extend the format in the future.
Finally a client should be able to mark a key as trusted:
@example
MARKTRUSTED @var{fingerprint} "P"|"S"
@end example
The server will then pop up a window to ask the user whether she
really trusts this key. For this it will probably ask for a text to
be displayed like this:
@example
S: INQUIRE TRUSTDESC
C: D Do you trust the key with the fingerprint @@FPR@@
C: D bla fasel blurb.
C: END
S: OK
@end example
Known sequences with the pattern @@foo@@ are replaced according to this
table:
@table @code
@item @@FPR16@@
Format the fingerprint according to gpg rules for a v3 keys.
@item @@FPR20@@
Format the fingerprint according to gpg rules for a v4 keys.
@item @@FPR@@
Choose an appropriate format to format the fingerprint.
@item @@@@
Replaced by a single @code{@@}.
@end table
@node Agent GET_PASSPHRASE
@subsection Ask for a passphrase
This function is usually used to ask for a passphrase to be used for
symmetric encryption, but may also be used by programs which need
special handling of passphrases. This command uses a syntax which helps
clients to use the agent with minimum effort.
@example
GET_PASSPHRASE [--data] [--check] [--no-ask] [--repeat[=N]] \
[--qualitybar] @var{cache_id} \
[@var{error_message} @var{prompt} @var{description}]
@end example
@var{cache_id} is expected to be a string used to identify a cached
passphrase. Use a @code{X} to bypass the cache. With no other
arguments the agent returns a cached passphrase or an error. By
convention either the hexified fingerprint of the key shall be used for
@var{cache_id} or an arbitrary string prefixed with the name of the
calling application and a colon: Like @code{gpg:somestring}.
@var{error_message} is either a single @code{X} for no error message or
a string to be shown as an error message like (e.g. "invalid
passphrase"). Blanks must be percent escaped or replaced by @code{+}'.
@var{prompt} is either a single @code{X} for a default prompt or the
text to be shown as the prompt. Blanks must be percent escaped or
replaced by @code{+}.
@var{description} is a text shown above the entry field. Blanks must be
percent escaped or replaced by @code{+}.
The agent either returns with an error or with a OK followed by the hex
encoded passphrase. Note that the length of the strings is implicitly
limited by the maximum length of a command. If the option
@option{--data} is used, the passphrase is not returned on the OK line
but by regular data lines; this is the preferred method.
If the option @option{--check} is used, the standard passphrase
constraints checks are applied. A check is not done if the passphrase
has been found in the cache.
If the option @option{--no-ask} is used and the passphrase is not in the
cache the user will not be asked to enter a passphrase but the error
code @code{GPG_ERR_NO_DATA} is returned.
If the option @option{--qualitybar} is used and a minimum passphrase
length has been configured, a visual indication of the entered
passphrase quality is shown.
@example
CLEAR_PASSPHRASE @var{cache_id}
@end example
may be used to invalidate the cache entry for a passphrase. The
function returns with OK even when there is no cached passphrase.
@node Agent CLEAR_PASSPHRASE
@subsection Remove a cached passphrase
Use this command to remove a cached passphrase.
@example
CLEAR_PASSPHRASE [--mode=normal] <cache_id>
@end example
The @option{--mode=normal} option can be used to clear a @var{cache_id} that
was set by gpg-agent.
@node Agent PRESET_PASSPHRASE
@subsection Set a passphrase for a keygrip
This command adds a passphrase to the cache for the specified @var{keygrip}.
@example
PRESET_PASSPHRASE [--inquire] <string_or_keygrip> <timeout> [<hexstring>]
@end example
The passphrase is a hexadecimal string when specified. When not specified, the
passphrase will be retrieved from the pinentry module unless the
@option{--inquire} option was specified in which case the passphrase will be
retrieved from the client.
The @var{timeout} parameter keeps the passphrase cached for the specified
number of seconds. A value of @code{-1} means infinite while @code{0} means
the default (currently only a timeout of -1 is allowed, which means to never
expire it).
@node Agent GET_CONFIRMATION
@subsection Ask for confirmation
This command may be used to ask for a simple confirmation by
presenting a text and 2 buttons: Okay and Cancel.
@example
GET_CONFIRMATION @var{description}
@end example
@var{description}is displayed along with a Okay and Cancel
button. Blanks must be percent escaped or replaced by @code{+}. A
@code{X} may be used to display confirmation dialog with a default
text.
The agent either returns with an error or with a OK. Note, that the
length of @var{description} is implicitly limited by the maximum
length of a command.
@node Agent HAVEKEY
@subsection Check whether a key is available
This can be used to see whether a secret key is available. It does
not return any information on whether the key is somehow protected.
@example
HAVEKEY @var{keygrips}
@end example
The agent answers either with OK or @code{No_Secret_Key} (208). The
caller may want to check for other error codes as well. More than one
keygrip may be given. In this case the command returns success if at
least one of the keygrips corresponds to an available secret key.
@node Agent LEARN
@subsection Register a smartcard
@example
LEARN [--send]
@end example
This command is used to register a smartcard. With the @option{--send}
option given the certificates are sent back.
@node Agent PASSWD
@subsection Change a Passphrase
@example
PASSWD [--cache-nonce=<c>] [--passwd-nonce=<s>] [--preset] @var{keygrip}
@end example
This command is used to interactively change the passphrase of the key
identified by the hex string @var{keygrip}. The @option{--preset}
option may be used to add the new passphrase to the cache using the
default cache parameters.
@node Agent UPDATESTARTUPTTY
@subsection Change the standard display
@example
UPDATESTARTUPTTY
@end example
Set the startup TTY and X-DISPLAY variables to the values of this
session. This command is useful to direct future pinentry invocations
to another screen. It is only required because there is no way in the
ssh-agent protocol to convey this information.
@node Agent GETEVENTCOUNTER
@subsection Get the Event Counters
@example
GETEVENTCOUNTER
@end example
This function return one status line with the current values of the
event counters. The event counters are useful to avoid polling by
delaying a poll until something has changed. The values are decimal
numbers in the range @code{0} to @code{UINT_MAX} and wrapping around to
0. The actual values should not be relied upon; they shall only be used
to detect a change.
The currently defined counters are:
@table @code
@item ANY
Incremented with any change of any of the other counters.
@item KEY
Incremented for added or removed private keys.
@item CARD
Incremented for changes of the card readers stati.
@end table
@node Agent GETINFO
@subsection Return information about the process
This is a multipurpose function to return a variety of information.
@example
GETINFO @var{what}
@end example
The value of @var{what} specifies the kind of information returned:
@table @code
@item version
Return the version of the program.
@item pid
Return the process id of the process.
@item socket_name
Return the name of the socket used to connect the agent.
@item ssh_socket_name
Return the name of the socket used for SSH connections. If SSH support
has not been enabled the error @code{GPG_ERR_NO_DATA} will be returned.
@end table
@node Agent OPTION
@subsection Set options for the session
Here is a list of session options which are not yet described with
other commands. The general syntax for an Assuan option is:
@smallexample
OPTION @var{key}=@var{value}
@end smallexample
@noindent
Supported @var{key}s are:
@table @code
@item agent-awareness
This may be used to tell gpg-agent of which gpg-agent version the
client is aware of. gpg-agent uses this information to enable
features which might break older clients.
@item putenv
Change the session's environment to be used for the
Pinentry. Valid values are:
@table @code
@item @var{name}
Delete envvar @var{name}
@item @var{name}=
Set envvar @var{name} to the empty string
@item @var{name}=@var{value}
Set envvar @var{name} to the string @var{value}.
@end table
@item use-cache-for-signing
See Assuan command @code{PKSIGN}.
@item allow-pinentry-notify
This does not need any value. It is used to enable the
PINENTRY_LAUNCHED inquiry.
@item pinentry-mode
This option is used to change the operation mode of the pinentry. The
following values are defined:
@table @code
@item ask
This is the default mode which pops up a pinentry as needed.
@item cancel
Instead of popping up a pinentry, return the error code
@code{GPG_ERR_CANCELED}.
@item error
Instead of popping up a pinentry, return the error code
@code{GPG_ERR_NO_PIN_ENTRY}.
@item loopback
Use a loopback pinentry. This fakes a pinentry by using inquiries
back to the caller to ask for a passphrase. This option may only be
set if the agent has been configured for that.
To disable this feature use @ref{option --no-allow-loopback-pinentry}.
@end table
@item cache-ttl-opt-preset
This option sets the cache TTL for new entries created by GENKEY and
PASSWD commands when using the @option{--preset} option. It is not
used a default value is used.
@item s2k-count
Instead of using the standard S2K count (which is computed on the
fly), the given S2K count is used for new keys or when changing the
passphrase of a key. Values below 65536 are considered to be 0. This
option is valid for the entire session or until reset to 0. This
option is useful if the key is later used on boxes which are either
much slower or faster than the actual box.
@end table
@mansect see also
@ifset isman
@command{@gpgname}(1),
@command{gpgsm}(1),
@command{gpgconf}(1),
@command{gpg-connect-agent}(1),
@command{scdaemon}(1)
@end ifset
@include see-also-note.texi

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