diff --git a/agent/command-ssh.c b/agent/command-ssh.c index df63ed713..ff1f0a5bc 100644 --- a/agent/command-ssh.c +++ b/agent/command-ssh.c @@ -1,3899 +1,3901 @@ /* 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 . */ /* 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: https://tools.ietf.org/html/draft-miller-ssh-agent */ #include #include #include #include #include #include #include #include #ifndef HAVE_W32_SYSTEM #include #include #endif /*!HAVE_W32_SYSTEM*/ #ifdef HAVE_SYS_UCRED_H #include #endif #ifdef HAVE_UCRED_H #include #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 SSH_AGENT_RSA_SHA2_256 0x02 #define SSH_AGENT_RSA_SHA2_512 0x04 #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); struct peer_info_s { unsigned long pid; int uid; }; /* 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, 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; 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; /* Flag processing. */ { u32 flags; err = stream_read_uint32 (request, &flags); if (err) goto out; if (spec.algo == GCRY_PK_RSA) { if ((flags & SSH_AGENT_RSA_SHA2_512)) { flags &= ~SSH_AGENT_RSA_SHA2_512; spec.ssh_identifier = "rsa-sha2-512"; spec.hash_algo = GCRY_MD_SHA512; } if ((flags & SSH_AGENT_RSA_SHA2_256)) { /* Note: We prefer SHA256 over SHA512. */ flags &= ~SSH_AGENT_RSA_SHA2_256; spec.ssh_identifier = "rsa-sha2-256"; spec.hash_algo = GCRY_MD_SHA256; } } /* Some flag is present that we do not know about. Note that * processed or known flags have been cleared at this point. */ if (flags) { err = gpg_error (GPG_ERR_UNKNOWN_OPTION); 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. If PASSPHRASE is the empty passphrase, the key is not protected. 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? */ if (*passphrase) err = agent_protect (buffer_new, passphrase, buffer, buffer_n, 0, -1); else { /* The key derivation function does not support zero length * strings. Store key unprotected if the user wishes so. */ *buffer = buffer_new; *buffer_n = buffer_new_n; buffer_new = NULL; err = 0; } 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, 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 (ctrl, 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 void get_client_info (int fd, struct peer_info_s *out) { pid_t client_pid = (pid_t)(-1); - uid_t client_uid = (uid_t)-1; + int client_uid = -1; #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; - client_uid = cr.uid; + client_uid = (int)cr.uid; #elif defined (HAVE_STRUCT_UCRED_CR_PID) client_pid = cr.cr_pid; - client_pid = cr.cr_uid; + client_uid = (int)cr.cr_uid; #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); #if defined (LOCAL_PEERCRED) { struct xucred cr; len = sizeof (struct xucred); if (!getsockopt (fd, SOL_LOCAL, LOCAL_PEERCRED, &cr, &len)) - client_uid = cr.cr_uid; + client_uid = (int)cr.cr_uid; } #endif } #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; - client_uid = unp.unp_euid; + { + client_pid = unp.unp_pid; + client_uid = (int)unp.unp_euid; + } } #elif defined (HAVE_GETPEERUCRED) { ucred_t *ucred = NULL; if (getpeerucred (fd, &ucred) != -1) { client_pid = ucred_getpid (ucred); - client_uid = ucred_geteuid (ucred); + client_uid = (int)ucred_geteuid (ucred); ucred_free (ucred); } } #else (void)fd; #endif out->pid = (client_pid == (pid_t)(-1)? 0 : (unsigned long)client_pid); - out->uid = (int)client_uid; + out->uid = client_uid; } /* 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; struct peer_info_s peer_info; err = agent_copy_startup_env (ctrl); if (err) goto out; get_client_info (FD2INT(sock_client), &peer_info); ctrl->client_pid = peer_info.pid; ctrl->client_uid = peer_info.uid; /* 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; const 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/command.c b/agent/command.c index 925d1f780..087175335 100644 --- a/agent/command.c +++ b/agent/command.c @@ -1,3644 +1,3649 @@ /* command.c - gpg-agent command handler * Copyright (C) 2001-2011 Free Software Foundation, Inc. * Copyright (C) 2001-2013 Werner Koch * 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 . */ /* FIXME: we should not use the default assuan buffering but setup some buffering in secure mempory to protect session keys etc. */ #include #include #include #include #include #include #include #include #include #include #include #include "agent.h" #include #include "../common/i18n.h" #include "cvt-openpgp.h" #include "../common/ssh-utils.h" #include "../common/asshelp.h" #include "../common/server-help.h" /* Maximum allowed size of the inquired ciphertext. */ #define MAXLEN_CIPHERTEXT 4096 /* Maximum allowed size of the key parameters. */ #define MAXLEN_KEYPARAM 1024 /* Maximum allowed size of key data as used in inquiries (bytes). */ #define MAXLEN_KEYDATA 8192 /* Maximum length of a secret to store under one key. */ #define MAXLEN_PUT_SECRET 4096 /* The size of the import/export KEK key (in bytes). */ #define KEYWRAP_KEYSIZE (128/8) /* A shortcut to call assuan_set_error using an gpg_err_code_t and a text string. */ #define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t)) /* Check that the maximum digest length we support has at least the length of the keygrip. */ #if MAX_DIGEST_LEN < 20 #error MAX_DIGEST_LEN shorter than keygrip #endif /* Data used to associate an Assuan context with local server data. This is this modules local part of the server_control_s struct. */ struct server_local_s { /* Our Assuan context. */ assuan_context_t assuan_ctx; /* If this flag is true, the passphrase cache is used for signing operations. It defaults to true but may be set on a per connection base. The global option opt.ignore_cache_for_signing takes precedence over this flag. */ unsigned int use_cache_for_signing : 1; /* Flag to suppress I/O logging during a command. */ unsigned int pause_io_logging : 1; /* Flag indicating that the connection is from ourselves. */ unsigned int connect_from_self : 1; /* Helper flag for io_monitor to allow suppressing of our own * greeting in some cases. See io_monitor for details. */ unsigned int greeting_seen : 1; /* If this flag is set to true the agent will be terminated after the end of the current session. */ unsigned int stopme : 1; /* Flag indicating whether pinentry notifications shall be done. */ unsigned int allow_pinentry_notify : 1; /* An allocated description for the next key operation. This is used if a pinnetry needs to be popped up. */ char *keydesc; /* Malloced KEK (Key-Encryption-Key) for the import_key command. */ void *import_key; /* Malloced KEK for the export_key command. */ void *export_key; /* Client is aware of the error code GPG_ERR_FULLY_CANCELED. */ int allow_fully_canceled; /* Last CACHE_NONCE sent as status (malloced). */ char *last_cache_nonce; /* Last PASSWD_NONCE sent as status (malloced). */ char *last_passwd_nonce; }; /* An entry for the getval/putval commands. */ struct putval_item_s { struct putval_item_s *next; size_t off; /* Offset to the value into DATA. */ size_t len; /* Length of the value. */ char d[1]; /* Key | Nul | value. */ }; /* A list of key value pairs fpr the getval/putval commands. */ static struct putval_item_s *putval_list; /* To help polling clients, we keep track of the number of certain events. This structure keeps those counters. The counters are integers and there should be no problem if they are overflowing as callers need to check only whether a counter changed. The actual values are not meaningful. */ struct { /* Incremented if any of the other counters below changed. */ unsigned int any; /* Incremented if a key is added or removed from the internal privat key database. */ unsigned int key; /* Incremented if a change of the card readers stati has been detected. */ unsigned int card; } eventcounter; /* Local prototypes. */ static int command_has_option (const char *cmd, const char *cmdopt); /* Release the memory buffer MB but first wipe out the used memory. */ static void clear_outbuf (membuf_t *mb) { void *p; size_t n; p = get_membuf (mb, &n); if (p) { wipememory (p, n); xfree (p); } } /* Write the content of memory buffer MB as assuan data to CTX and wipe the buffer out afterwards. */ static gpg_error_t write_and_clear_outbuf (assuan_context_t ctx, membuf_t *mb) { gpg_error_t ae; void *p; size_t n; p = get_membuf (mb, &n); if (!p) return out_of_core (); ae = assuan_send_data (ctx, p, n); memset (p, 0, n); xfree (p); return ae; } /* Clear the nonces used to enable the passphrase cache for certain multi-command command sequences. */ static void clear_nonce_cache (ctrl_t ctrl) { if (ctrl->server_local->last_cache_nonce) { agent_put_cache (ctrl, ctrl->server_local->last_cache_nonce, CACHE_MODE_NONCE, NULL, 0); xfree (ctrl->server_local->last_cache_nonce); ctrl->server_local->last_cache_nonce = NULL; } if (ctrl->server_local->last_passwd_nonce) { agent_put_cache (ctrl, ctrl->server_local->last_passwd_nonce, CACHE_MODE_NONCE, NULL, 0); xfree (ctrl->server_local->last_passwd_nonce); ctrl->server_local->last_passwd_nonce = NULL; } } /* This function is called by Libassuan whenever the client sends a reset. It has been registered similar to the other Assuan commands. */ static gpg_error_t reset_notify (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); (void) line; memset (ctrl->keygrip, 0, 20); ctrl->have_keygrip = 0; ctrl->digest.valuelen = 0; xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; clear_nonce_cache (ctrl); return 0; } /* Replace all '+' by a blank in the string S. */ static void plus_to_blank (char *s) { for (; *s; s++) { if (*s == '+') *s = ' '; } } /* Parse a hex string. Return an Assuan error code or 0 on success and the length of the parsed string in LEN. */ static int parse_hexstring (assuan_context_t ctx, const char *string, size_t *len) { const char *p; size_t n; /* parse the hash value */ for (p=string, n=0; hexdigitp (p); p++, n++) ; if (*p != ' ' && *p != '\t' && *p) return set_error (GPG_ERR_ASS_PARAMETER, "invalid hexstring"); if ((n&1)) return set_error (GPG_ERR_ASS_PARAMETER, "odd number of digits"); *len = n; return 0; } /* Parse the keygrip in STRING into the provided buffer BUF. BUF must provide space for 20 bytes. BUF is not changed if the function returns an error. */ static int parse_keygrip (assuan_context_t ctx, const char *string, unsigned char *buf) { int rc; size_t n = 0; rc = parse_hexstring (ctx, string, &n); if (rc) return rc; n /= 2; if (n != 20) return set_error (GPG_ERR_ASS_PARAMETER, "invalid length of keygrip"); if (hex2bin (string, buf, 20) < 0) return set_error (GPG_ERR_BUG, "hex2bin"); return 0; } /* Parse the TTL from STRING. Leading and trailing spaces are * skipped. The value is constrained to -1 .. MAXINT. On error 0 is * returned, else the number of bytes scanned. */ static size_t parse_ttl (const char *string, int *r_ttl) { const char *string_orig = string; long ttl; char *pend; ttl = strtol (string, &pend, 10); string = pend; if (string == string_orig || !(spacep (string) || !*string) || ttl < -1L || (int)ttl != (long)ttl) { *r_ttl = 0; return 0; } while (spacep (string) || *string== '\n') string++; *r_ttl = (int)ttl; return string - string_orig; } /* Write an Assuan status line. KEYWORD is the first item on the * status line. The following arguments are all separated by a space * in the output. The last argument must be a NULL. Linefeeds and * carriage returns characters (which are not allowed in an Assuan * status line) are silently quoted in C-style. */ gpg_error_t agent_write_status (ctrl_t ctrl, const char *keyword, ...) { gpg_error_t err; va_list arg_ptr; assuan_context_t ctx = ctrl->server_local->assuan_ctx; va_start (arg_ptr, keyword); err = vprint_assuan_status_strings (ctx, keyword, arg_ptr); va_end (arg_ptr); return err; } /* This function is similar to print_assuan_status but takes a CTRL arg instead of an assuan context as first argument. */ gpg_error_t agent_print_status (ctrl_t ctrl, const char *keyword, const char *format, ...) { gpg_error_t err; va_list arg_ptr; assuan_context_t ctx = ctrl->server_local->assuan_ctx; va_start (arg_ptr, format); err = vprint_assuan_status (ctx, keyword, format, arg_ptr); va_end (arg_ptr); return err; } /* Helper to notify the client about a launched Pinentry. Because that might disturb some older clients, this is only done if enabled via an option. Returns an gpg error code. */ gpg_error_t agent_inq_pinentry_launched (ctrl_t ctrl, unsigned long pid, const char *extra) { char line[256]; if (!ctrl || !ctrl->server_local || !ctrl->server_local->allow_pinentry_notify) return 0; snprintf (line, DIM(line), "PINENTRY_LAUNCHED %lu%s%s", pid, extra?" ":"", extra? extra:""); return assuan_inquire (ctrl->server_local->assuan_ctx, line, NULL, NULL, 0); } /* An agent progress callback for Libgcrypt. This has been registered * to be called via the progress dispatcher mechanism from * gpg-agent.c */ static void progress_cb (ctrl_t ctrl, const char *what, int printchar, int current, int total) { if (!ctrl || !ctrl->server_local || !ctrl->server_local->assuan_ctx) ; else if (printchar == '\n' && what && !strcmp (what, "primegen")) agent_print_status (ctrl, "PROGRESS", "%.20s X 100 100", what); else agent_print_status (ctrl, "PROGRESS", "%.20s %c %d %d", what, printchar=='\n'?'X':printchar, current, total); } /* Helper to print a message while leaving a command. Note that this * function does not call assuan_set_error; the caller may do this * prior to calling us. */ static gpg_error_t leave_cmd (assuan_context_t ctx, gpg_error_t err) { if (err) { const char *name = assuan_get_command_name (ctx); if (!name) name = "?"; /* Not all users of gpg-agent know about the fully canceled error code; map it back if needed. */ if (gpg_err_code (err) == GPG_ERR_FULLY_CANCELED) { ctrl_t ctrl = assuan_get_pointer (ctx); if (!ctrl->server_local->allow_fully_canceled) err = gpg_err_make (gpg_err_source (err), GPG_ERR_CANCELED); } /* Most code from common/ does not know the error source, thus we fix this here. */ if (gpg_err_source (err) == GPG_ERR_SOURCE_UNKNOWN) err = gpg_err_make (GPG_ERR_SOURCE_DEFAULT, gpg_err_code (err)); if (gpg_err_source (err) == GPG_ERR_SOURCE_DEFAULT) log_error ("command '%s' failed: %s\n", name, gpg_strerror (err)); else log_error ("command '%s' failed: %s <%s>\n", name, gpg_strerror (err), gpg_strsource (err)); } return err; } static const char hlp_geteventcounter[] = "GETEVENTCOUNTER\n" "\n" "Return a status line named EVENTCOUNTER with the current values\n" "of all event counters. The values are decimal numbers in the range\n" "0 to UINT_MAX and wrapping around to 0. The actual values should\n" "not be relied upon, they shall only be used to detect a change.\n" "\n" "The currently defined counters are:\n" "\n" "ANY - Incremented with any change of any of the other counters.\n" "KEY - Incremented for added or removed private keys.\n" "CARD - Incremented for changes of the card readers stati."; static gpg_error_t cmd_geteventcounter (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); (void)line; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); return agent_print_status (ctrl, "EVENTCOUNTER", "%u %u %u", eventcounter.any, eventcounter.key, eventcounter.card); } /* This function should be called once for all key removals or additions. This function is assured not to do any context switches. */ void bump_key_eventcounter (void) { eventcounter.key++; eventcounter.any++; } /* This function should be called for all card reader status changes. This function is assured not to do any context switches. */ void bump_card_eventcounter (void) { eventcounter.card++; eventcounter.any++; } static const char hlp_istrusted[] = "ISTRUSTED \n" "\n" "Return OK when we have an entry with this fingerprint in our\n" "trustlist"; static gpg_error_t cmd_istrusted (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc, n, i; char *p; char fpr[41]; /* Parse the fingerprint value. */ for (p=line,n=0; hexdigitp (p); p++, n++) ; if (*p || !(n == 40 || n == 32)) return set_error (GPG_ERR_ASS_PARAMETER, "invalid fingerprint"); i = 0; if (n==32) { strcpy (fpr, "00000000"); i += 8; } for (p=line; i < 40; p++, i++) fpr[i] = *p >= 'a'? (*p & 0xdf): *p; fpr[i] = 0; rc = agent_istrusted (ctrl, fpr, NULL); if (!rc || gpg_err_code (rc) == GPG_ERR_NOT_TRUSTED) return rc; else if (rc == -1 || gpg_err_code (rc) == GPG_ERR_EOF ) return gpg_error (GPG_ERR_NOT_TRUSTED); else return leave_cmd (ctx, rc); } static const char hlp_listtrusted[] = "LISTTRUSTED\n" "\n" "List all entries from the trustlist."; static gpg_error_t cmd_listtrusted (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; (void)line; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); rc = agent_listtrusted (ctx); return leave_cmd (ctx, rc); } static const char hlp_martrusted[] = "MARKTRUSTED \n" "\n" "Store a new key in into the trustlist."; static gpg_error_t cmd_marktrusted (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc, n, i; char *p; char fpr[41]; int flag; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); /* parse the fingerprint value */ for (p=line,n=0; hexdigitp (p); p++, n++) ; if (!spacep (p) || !(n == 40 || n == 32)) return set_error (GPG_ERR_ASS_PARAMETER, "invalid fingerprint"); i = 0; if (n==32) { strcpy (fpr, "00000000"); i += 8; } for (p=line; i < 40; p++, i++) fpr[i] = *p >= 'a'? (*p & 0xdf): *p; fpr[i] = 0; while (spacep (p)) p++; flag = *p++; if ( (flag != 'S' && flag != 'P') || !spacep (p) ) return set_error (GPG_ERR_ASS_PARAMETER, "invalid flag - must be P or S"); while (spacep (p)) p++; rc = agent_marktrusted (ctrl, p, fpr, flag); return leave_cmd (ctx, rc); } static const char hlp_havekey[] = "HAVEKEY \n" "\n" "Return success if at least one of the secret keys with the given\n" "keygrips is available."; static gpg_error_t cmd_havekey (assuan_context_t ctx, char *line) { gpg_error_t err; unsigned char buf[20]; do { err = parse_keygrip (ctx, line, buf); if (err) return err; if (!agent_key_available (buf)) return 0; /* Found. */ while (*line && *line != ' ' && *line != '\t') line++; while (*line == ' ' || *line == '\t') line++; } while (*line); /* No leave_cmd() here because errors are expected and would clutter the log. */ return gpg_error (GPG_ERR_NO_SECKEY); } static const char hlp_sigkey[] = "SIGKEY \n" "SETKEY \n" "\n" "Set the key used for a sign or decrypt operation."; static gpg_error_t cmd_sigkey (assuan_context_t ctx, char *line) { int rc; ctrl_t ctrl = assuan_get_pointer (ctx); rc = parse_keygrip (ctx, line, ctrl->keygrip); if (rc) return rc; ctrl->have_keygrip = 1; return 0; } static const char hlp_setkeydesc[] = "SETKEYDESC plus_percent_escaped_string\n" "\n" "Set a description to be used for the next PKSIGN, PKDECRYPT, IMPORT_KEY\n" "or EXPORT_KEY operation if this operation requires a passphrase. If\n" "this command is not used a default text will be used. Note, that\n" "this description implictly selects the label used for the entry\n" "box; if the string contains the string PIN (which in general will\n" "not be translated), \"PIN\" is used, otherwise the translation of\n" "\"passphrase\" is used. The description string should not contain\n" "blanks unless they are percent or '+' escaped.\n" "\n" "The description is only valid for the next PKSIGN, PKDECRYPT,\n" "IMPORT_KEY, EXPORT_KEY, or DELETE_KEY operation."; static gpg_error_t cmd_setkeydesc (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); char *desc, *p; for (p=line; *p == ' '; p++) ; desc = p; p = strchr (desc, ' '); if (p) *p = 0; /* We ignore any garbage; we might late use it for other args. */ if (!*desc) return set_error (GPG_ERR_ASS_PARAMETER, "no description given"); /* Note, that we only need to replace the + characters and should leave the other escaping in place because the escaped string is send verbatim to the pinentry which does the unescaping (but not the + replacing) */ plus_to_blank (desc); xfree (ctrl->server_local->keydesc); if (ctrl->restricted) { ctrl->server_local->keydesc = strconcat ((ctrl->restricted == 2 ? _("Note: Request from the web browser.") : _("Note: Request from a remote site.") ), "%0A%0A", desc, NULL); } else ctrl->server_local->keydesc = xtrystrdup (desc); if (!ctrl->server_local->keydesc) return out_of_core (); return 0; } static const char hlp_sethash[] = "SETHASH (--hash=)|() \n" "\n" "The client can use this command to tell the server about the data\n" "(which usually is a hash) to be signed."; static gpg_error_t cmd_sethash (assuan_context_t ctx, char *line) { int rc; size_t n; char *p; ctrl_t ctrl = assuan_get_pointer (ctx); unsigned char *buf; char *endp; int algo; /* Parse the alternative hash options which may be used instead of the algo number. */ if (has_option_name (line, "--hash")) { if (has_option (line, "--hash=sha1")) algo = GCRY_MD_SHA1; else if (has_option (line, "--hash=sha224")) algo = GCRY_MD_SHA224; else if (has_option (line, "--hash=sha256")) algo = GCRY_MD_SHA256; else if (has_option (line, "--hash=sha384")) algo = GCRY_MD_SHA384; else if (has_option (line, "--hash=sha512")) algo = GCRY_MD_SHA512; else if (has_option (line, "--hash=rmd160")) algo = GCRY_MD_RMD160; else if (has_option (line, "--hash=md5")) algo = GCRY_MD_MD5; else if (has_option (line, "--hash=tls-md5sha1")) algo = MD_USER_TLS_MD5SHA1; else return set_error (GPG_ERR_ASS_PARAMETER, "invalid hash algorithm"); } else algo = 0; line = skip_options (line); if (!algo) { /* No hash option has been given: require an algo number instead */ algo = (int)strtoul (line, &endp, 10); for (line = endp; *line == ' ' || *line == '\t'; line++) ; if (!algo || gcry_md_test_algo (algo)) return set_error (GPG_ERR_UNSUPPORTED_ALGORITHM, NULL); } ctrl->digest.algo = algo; ctrl->digest.raw_value = 0; /* Parse the hash value. */ n = 0; rc = parse_hexstring (ctx, line, &n); if (rc) return rc; n /= 2; if (algo == MD_USER_TLS_MD5SHA1 && n == 36) ; else if (n != 16 && n != 20 && n != 24 && n != 28 && n != 32 && n != 48 && n != 64) return set_error (GPG_ERR_ASS_PARAMETER, "unsupported length of hash"); if (n > MAX_DIGEST_LEN) return set_error (GPG_ERR_ASS_PARAMETER, "hash value to long"); buf = ctrl->digest.value; ctrl->digest.valuelen = n; for (p=line, n=0; n < ctrl->digest.valuelen; p += 2, n++) buf[n] = xtoi_2 (p); for (; n < ctrl->digest.valuelen; n++) buf[n] = 0; return 0; } static const char hlp_pksign[] = "PKSIGN [] []\n" "\n" "Perform the actual sign operation. Neither input nor output are\n" "sensitive to eavesdropping."; static gpg_error_t cmd_pksign (assuan_context_t ctx, char *line) { gpg_error_t err; cache_mode_t cache_mode = CACHE_MODE_NORMAL; ctrl_t ctrl = assuan_get_pointer (ctx); membuf_t outbuf; char *cache_nonce = NULL; char *p; line = skip_options (line); for (p=line; *p && *p != ' ' && *p != '\t'; p++) ; *p = '\0'; if (*line) cache_nonce = xtrystrdup (line); if (opt.ignore_cache_for_signing) cache_mode = CACHE_MODE_IGNORE; else if (!ctrl->server_local->use_cache_for_signing) cache_mode = CACHE_MODE_IGNORE; init_membuf (&outbuf, 512); err = agent_pksign (ctrl, cache_nonce, ctrl->server_local->keydesc, &outbuf, cache_mode); if (err) clear_outbuf (&outbuf); else err = write_and_clear_outbuf (ctx, &outbuf); xfree (cache_nonce); xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; return leave_cmd (ctx, err); } static const char hlp_pkdecrypt[] = "PKDECRYPT []\n" "\n" "Perform the actual decrypt operation. Input is not\n" "sensitive to eavesdropping."; static gpg_error_t cmd_pkdecrypt (assuan_context_t ctx, char *line) { int rc; ctrl_t ctrl = assuan_get_pointer (ctx); unsigned char *value; size_t valuelen; membuf_t outbuf; int padding; (void)line; /* First inquire the data to decrypt */ rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%u", MAXLEN_CIPHERTEXT); if (!rc) rc = assuan_inquire (ctx, "CIPHERTEXT", &value, &valuelen, MAXLEN_CIPHERTEXT); if (rc) return rc; init_membuf (&outbuf, 512); rc = agent_pkdecrypt (ctrl, ctrl->server_local->keydesc, value, valuelen, &outbuf, &padding); xfree (value); if (rc) clear_outbuf (&outbuf); else { if (padding != -1) rc = print_assuan_status (ctx, "PADDING", "%d", padding); else rc = 0; if (!rc) rc = write_and_clear_outbuf (ctx, &outbuf); } xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; return leave_cmd (ctx, rc); } static const char hlp_genkey[] = "GENKEY [--no-protection] [--preset] [--inq-passwd]\n" " [--passwd-nonce=] []\n" "\n" "Generate a new key, store the secret part and return the public\n" "part. Here is an example transaction:\n" "\n" " C: GENKEY\n" " S: INQUIRE KEYPARAM\n" " C: D (genkey (rsa (nbits 3072)))\n" " C: END\n" " S: D (public-key\n" " S: D (rsa (n 326487324683264) (e 10001)))\n" " S: OK key created\n" "\n" "When the --preset option is used the passphrase for the generated\n" "key will be added to the cache. When --inq-passwd is used an inquire\n" "with the keyword NEWPASSWD is used to request the passphrase for the\n" "new key. When a --passwd-nonce is used, the corresponding cached\n" "passphrase is used to protect the new key."; static gpg_error_t cmd_genkey (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; int no_protection; unsigned char *value; size_t valuelen; unsigned char *newpasswd = NULL; membuf_t outbuf; char *cache_nonce = NULL; char *passwd_nonce = NULL; int opt_preset; int opt_inq_passwd; size_t n; char *p, *pend; int c; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); no_protection = has_option (line, "--no-protection"); opt_preset = has_option (line, "--preset"); opt_inq_passwd = has_option (line, "--inq-passwd"); passwd_nonce = option_value (line, "--passwd-nonce"); if (passwd_nonce) { for (pend = passwd_nonce; *pend && !spacep (pend); pend++) ; c = *pend; *pend = '\0'; passwd_nonce = xtrystrdup (passwd_nonce); *pend = c; if (!passwd_nonce) { rc = gpg_error_from_syserror (); goto leave; } } line = skip_options (line); for (p=line; *p && *p != ' ' && *p != '\t'; p++) ; *p = '\0'; if (*line) cache_nonce = xtrystrdup (line); /* First inquire the parameters */ rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%u", MAXLEN_KEYPARAM); if (!rc) rc = assuan_inquire (ctx, "KEYPARAM", &value, &valuelen, MAXLEN_KEYPARAM); if (rc) return rc; init_membuf (&outbuf, 512); /* If requested, ask for the password to be used for the key. If this is not used the regular Pinentry mechanism is used. */ if (opt_inq_passwd && !no_protection) { /* (N is used as a dummy) */ assuan_begin_confidential (ctx); rc = assuan_inquire (ctx, "NEWPASSWD", &newpasswd, &n, 256); assuan_end_confidential (ctx); if (rc) goto leave; if (!*newpasswd) { /* Empty password given - switch to no-protection mode. */ xfree (newpasswd); newpasswd = NULL; no_protection = 1; } } else if (passwd_nonce) newpasswd = agent_get_cache (ctrl, passwd_nonce, CACHE_MODE_NONCE); rc = agent_genkey (ctrl, cache_nonce, (char*)value, valuelen, no_protection, newpasswd, opt_preset, &outbuf); leave: if (newpasswd) { /* Assuan_inquire does not allow us to read into secure memory thus we need to wipe it ourself. */ wipememory (newpasswd, strlen (newpasswd)); xfree (newpasswd); } xfree (value); if (rc) clear_outbuf (&outbuf); else rc = write_and_clear_outbuf (ctx, &outbuf); xfree (cache_nonce); xfree (passwd_nonce); return leave_cmd (ctx, rc); } static const char hlp_readkey[] = "READKEY \n" " --card \n" "\n" "Return the public key for the given keygrip or keyid.\n" "With --card, private key file with card information will be created."; static gpg_error_t cmd_readkey (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char grip[20]; gcry_sexp_t s_pkey = NULL; unsigned char *pkbuf = NULL; char *serialno = NULL; size_t pkbuflen; const char *opt_card; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); opt_card = has_option_name (line, "--card"); line = skip_options (line); if (opt_card) { const char *keyid = opt_card; rc = agent_card_getattr (ctrl, "SERIALNO", &serialno); if (rc) { log_error (_("error getting serial number of card: %s\n"), gpg_strerror (rc)); goto leave; } rc = agent_card_readkey (ctrl, keyid, &pkbuf); if (rc) goto leave; pkbuflen = gcry_sexp_canon_len (pkbuf, 0, NULL, NULL); rc = gcry_sexp_sscan (&s_pkey, NULL, (char*)pkbuf, pkbuflen); if (rc) goto leave; if (!gcry_pk_get_keygrip (s_pkey, grip)) { rc = gcry_pk_testkey (s_pkey); if (rc == 0) rc = gpg_error (GPG_ERR_INTERNAL); goto leave; } rc = agent_write_shadow_key (grip, serialno, keyid, pkbuf, 0); if (rc) goto leave; rc = assuan_send_data (ctx, pkbuf, pkbuflen); } else { rc = parse_keygrip (ctx, line, grip); if (rc) goto leave; rc = agent_public_key_from_file (ctrl, grip, &s_pkey); if (!rc) { pkbuflen = gcry_sexp_sprint (s_pkey, GCRYSEXP_FMT_CANON, NULL, 0); log_assert (pkbuflen); pkbuf = xtrymalloc (pkbuflen); if (!pkbuf) rc = gpg_error_from_syserror (); else { pkbuflen = gcry_sexp_sprint (s_pkey, GCRYSEXP_FMT_CANON, pkbuf, pkbuflen); rc = assuan_send_data (ctx, pkbuf, pkbuflen); } } } leave: xfree (serialno); xfree (pkbuf); gcry_sexp_release (s_pkey); return leave_cmd (ctx, rc); } static const char hlp_keyinfo[] = "KEYINFO [--[ssh-]list] [--data] [--ssh-fpr] [--with-ssh] \n" "\n" "Return information about the key specified by the KEYGRIP. If the\n" "key is not available GPG_ERR_NOT_FOUND is returned. If the option\n" "--list is given the keygrip is ignored and information about all\n" "available keys are returned. If --ssh-list is given information\n" "about all keys listed in the sshcontrol are returned. With --with-ssh\n" "information from sshcontrol is always added to the info. Unless --data\n" "is given, the information is returned as a status line using the format:\n" "\n" " KEYINFO \n" "\n" "KEYGRIP is the keygrip.\n" "\n" "TYPE is describes the type of the key:\n" " 'D' - Regular key stored on disk,\n" " 'T' - Key is stored on a smartcard (token),\n" " 'X' - Unknown type,\n" " '-' - Key is missing.\n" "\n" "SERIALNO is an ASCII string with the serial number of the\n" " smartcard. If the serial number is not known a single\n" " dash '-' is used instead.\n" "\n" "IDSTR is the IDSTR used to distinguish keys on a smartcard. If it\n" " is not known a dash is used instead.\n" "\n" "CACHED is 1 if the passphrase for the key was found in the key cache.\n" " If not, a '-' is used instead.\n" "\n" "PROTECTION describes the key protection type:\n" " 'P' - The key is protected with a passphrase,\n" " 'C' - The key is not protected,\n" " '-' - Unknown protection.\n" "\n" "FPR returns the formatted ssh-style fingerprint of the key. It is only\n" " printed if the option --ssh-fpr has been used. It defaults to '-'.\n" "\n" "TTL is the TTL in seconds for that key or '-' if n/a.\n" "\n" "FLAGS is a word consisting of one-letter flags:\n" " 'D' - The key has been disabled,\n" " 'S' - The key is listed in sshcontrol (requires --with-ssh),\n" " 'c' - Use of the key needs to be confirmed,\n" " '-' - No flags given.\n" "\n" "More information may be added in the future."; static gpg_error_t do_one_keyinfo (ctrl_t ctrl, const unsigned char *grip, assuan_context_t ctx, int data, int with_ssh_fpr, int in_ssh, int ttl, int disabled, int confirm) { gpg_error_t err; char hexgrip[40+1]; char *fpr = NULL; int keytype; unsigned char *shadow_info = NULL; char *serialno = NULL; char *idstr = NULL; const char *keytypestr; const char *cached; const char *protectionstr; char *pw; int missing_key = 0; char ttlbuf[20]; char flagsbuf[5]; err = agent_key_info_from_file (ctrl, grip, &keytype, &shadow_info); if (err) { if (in_ssh && gpg_err_code (err) == GPG_ERR_NOT_FOUND) missing_key = 1; else goto leave; } /* Reformat the grip so that we use uppercase as good style. */ bin2hex (grip, 20, hexgrip); if (ttl > 0) snprintf (ttlbuf, sizeof ttlbuf, "%d", ttl); else strcpy (ttlbuf, "-"); *flagsbuf = 0; if (disabled) strcat (flagsbuf, "D"); if (in_ssh) strcat (flagsbuf, "S"); if (confirm) strcat (flagsbuf, "c"); if (!*flagsbuf) strcpy (flagsbuf, "-"); if (missing_key) { protectionstr = "-"; keytypestr = "-"; } else { switch (keytype) { case PRIVATE_KEY_CLEAR: case PRIVATE_KEY_OPENPGP_NONE: protectionstr = "C"; keytypestr = "D"; break; case PRIVATE_KEY_PROTECTED: protectionstr = "P"; keytypestr = "D"; break; case PRIVATE_KEY_SHADOWED: protectionstr = "-"; keytypestr = "T"; break; default: protectionstr = "-"; keytypestr = "X"; break; } } /* Compute the ssh fingerprint if requested. */ if (with_ssh_fpr) { gcry_sexp_t key; if (!agent_raw_key_from_file (ctrl, grip, &key)) { ssh_get_fingerprint_string (key, GCRY_MD_MD5, &fpr); gcry_sexp_release (key); } } /* Here we have a little race by doing the cache check separately from the retrieval function. Given that the cache flag is only a hint, it should not really matter. */ pw = agent_get_cache (ctrl, hexgrip, CACHE_MODE_NORMAL); cached = pw ? "1" : "-"; xfree (pw); if (shadow_info) { err = parse_shadow_info (shadow_info, &serialno, &idstr, NULL); if (err) goto leave; } if (!data) err = agent_write_status (ctrl, "KEYINFO", hexgrip, keytypestr, serialno? serialno : "-", idstr? idstr : "-", cached, protectionstr, fpr? fpr : "-", ttlbuf, flagsbuf, NULL); else { char *string; string = xtryasprintf ("%s %s %s %s %s %s %s %s %s\n", hexgrip, keytypestr, serialno? serialno : "-", idstr? idstr : "-", cached, protectionstr, fpr? fpr : "-", ttlbuf, flagsbuf); if (!string) err = gpg_error_from_syserror (); else err = assuan_send_data (ctx, string, strlen(string)); xfree (string); } leave: xfree (fpr); xfree (shadow_info); xfree (serialno); xfree (idstr); return err; } /* Entry int for the command KEYINFO. This function handles the command option processing. For details see hlp_keyinfo above. */ static gpg_error_t cmd_keyinfo (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int err; unsigned char grip[20]; DIR *dir = NULL; int list_mode; int opt_data, opt_ssh_fpr, opt_with_ssh; ssh_control_file_t cf = NULL; char hexgrip[41]; int disabled, ttl, confirm, is_ssh; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); if (has_option (line, "--ssh-list")) list_mode = 2; else list_mode = has_option (line, "--list"); opt_data = has_option (line, "--data"); opt_ssh_fpr = has_option (line, "--ssh-fpr"); opt_with_ssh = has_option (line, "--with-ssh"); line = skip_options (line); if (opt_with_ssh || list_mode == 2) cf = ssh_open_control_file (); if (list_mode == 2) { if (cf) { while (!ssh_read_control_file (cf, hexgrip, &disabled, &ttl, &confirm)) { if (hex2bin (hexgrip, grip, 20) < 0 ) continue; /* Bad hex string. */ err = do_one_keyinfo (ctrl, grip, ctx, opt_data, opt_ssh_fpr, 1, ttl, disabled, confirm); if (err) goto leave; } } err = 0; } else if (list_mode) { char *dirname; struct dirent *dir_entry; dirname = make_filename_try (gnupg_homedir (), GNUPG_PRIVATE_KEYS_DIR, NULL); if (!dirname) { err = gpg_error_from_syserror (); goto leave; } dir = opendir (dirname); if (!dir) { err = gpg_error_from_syserror (); xfree (dirname); goto leave; } xfree (dirname); while ( (dir_entry = readdir (dir)) ) { if (strlen (dir_entry->d_name) != 44 || strcmp (dir_entry->d_name + 40, ".key")) continue; strncpy (hexgrip, dir_entry->d_name, 40); hexgrip[40] = 0; if ( hex2bin (hexgrip, grip, 20) < 0 ) continue; /* Bad hex string. */ disabled = ttl = confirm = is_ssh = 0; if (opt_with_ssh) { err = ssh_search_control_file (cf, hexgrip, &disabled, &ttl, &confirm); if (!err) is_ssh = 1; else if (gpg_err_code (err) != GPG_ERR_NOT_FOUND) goto leave; } err = do_one_keyinfo (ctrl, grip, ctx, opt_data, opt_ssh_fpr, is_ssh, ttl, disabled, confirm); if (err) goto leave; } err = 0; } else { err = parse_keygrip (ctx, line, grip); if (err) goto leave; disabled = ttl = confirm = is_ssh = 0; if (opt_with_ssh) { err = ssh_search_control_file (cf, line, &disabled, &ttl, &confirm); if (!err) is_ssh = 1; else if (gpg_err_code (err) != GPG_ERR_NOT_FOUND) goto leave; } err = do_one_keyinfo (ctrl, grip, ctx, opt_data, opt_ssh_fpr, is_ssh, ttl, disabled, confirm); } leave: ssh_close_control_file (cf); if (dir) closedir (dir); if (err && gpg_err_code (err) != GPG_ERR_NOT_FOUND) leave_cmd (ctx, err); return err; } /* Helper for cmd_get_passphrase. */ static int send_back_passphrase (assuan_context_t ctx, int via_data, const char *pw) { size_t n; int rc; assuan_begin_confidential (ctx); n = strlen (pw); if (via_data) rc = assuan_send_data (ctx, pw, n); else { char *p = xtrymalloc_secure (n*2+1); if (!p) rc = gpg_error_from_syserror (); else { bin2hex (pw, n, p); rc = assuan_set_okay_line (ctx, p); xfree (p); } } return rc; } static const char hlp_get_passphrase[] = "GET_PASSPHRASE [--data] [--check] [--no-ask] [--repeat[=N]]\n" " [--qualitybar] \n" " [ ]\n" "\n" "This function is usually used to ask for a passphrase to be used\n" "for conventional encryption, but may also be used by programs which\n" "need specal handling of passphrases. This command uses a syntax\n" "which helps clients to use the agent with minimum effort. The\n" "agent either returns with an error or with a OK followed by the hex\n" "encoded passphrase. Note that the length of the strings is\n" "implicitly limited by the maximum length of a command.\n" "\n" "If the option \"--data\" is used the passphrase is returned by usual\n" "data lines and not on the okay line.\n" "\n" "If the option \"--check\" is used the passphrase constraints checks as\n" "implemented by gpg-agent are applied. A check is not done if the\n" "passphrase has been found in the cache.\n" "\n" "If the option \"--no-ask\" is used and the passphrase is not in the\n" "cache the user will not be asked to enter a passphrase but the error\n" "code GPG_ERR_NO_DATA is returned. \n" "\n" "If the option \"--qualitybar\" is used a visual indication of the\n" "entered passphrase quality is shown. (Unless no minimum passphrase\n" "length has been configured.)"; static gpg_error_t cmd_get_passphrase (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *pw; char *response; char *cacheid = NULL, *desc = NULL, *prompt = NULL, *errtext = NULL; const char *desc2 = _("Please re-enter this passphrase"); char *p; int opt_data, opt_check, opt_no_ask, opt_qualbar; int opt_repeat = 0; char *entry_errtext = NULL; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); opt_data = has_option (line, "--data"); opt_check = has_option (line, "--check"); opt_no_ask = has_option (line, "--no-ask"); if (has_option_name (line, "--repeat")) { p = option_value (line, "--repeat"); if (p) opt_repeat = atoi (p); else opt_repeat = 1; } opt_qualbar = has_option (line, "--qualitybar"); line = skip_options (line); cacheid = line; p = strchr (cacheid, ' '); if (p) { *p++ = 0; while (*p == ' ') p++; errtext = p; p = strchr (errtext, ' '); if (p) { *p++ = 0; while (*p == ' ') p++; prompt = p; p = strchr (prompt, ' '); if (p) { *p++ = 0; while (*p == ' ') p++; desc = p; p = strchr (desc, ' '); if (p) *p = 0; /* Ignore trailing garbage. */ } } } if (!*cacheid || strlen (cacheid) > 50) return set_error (GPG_ERR_ASS_PARAMETER, "invalid length of cacheID"); if (!desc) return set_error (GPG_ERR_ASS_PARAMETER, "no description given"); if (!strcmp (cacheid, "X")) cacheid = NULL; if (!strcmp (errtext, "X")) errtext = NULL; if (!strcmp (prompt, "X")) prompt = NULL; if (!strcmp (desc, "X")) desc = NULL; pw = cacheid ? agent_get_cache (ctrl, cacheid, CACHE_MODE_USER) : NULL; if (pw) { rc = send_back_passphrase (ctx, opt_data, pw); xfree (pw); } else if (opt_no_ask) rc = gpg_error (GPG_ERR_NO_DATA); else { /* Note, that we only need to replace the + characters and should leave the other escaping in place because the escaped string is send verbatim to the pinentry which does the unescaping (but not the + replacing) */ if (errtext) plus_to_blank (errtext); if (prompt) plus_to_blank (prompt); if (desc) plus_to_blank (desc); next_try: rc = agent_get_passphrase (ctrl, &response, desc, prompt, entry_errtext? entry_errtext:errtext, opt_qualbar, cacheid, CACHE_MODE_USER); xfree (entry_errtext); entry_errtext = NULL; if (!rc) { int i; if (opt_check && check_passphrase_constraints (ctrl, response, &entry_errtext)) { xfree (response); goto next_try; } for (i = 0; i < opt_repeat; i++) { char *response2; if (ctrl->pinentry_mode == PINENTRY_MODE_LOOPBACK) break; rc = agent_get_passphrase (ctrl, &response2, desc2, prompt, errtext, 0, cacheid, CACHE_MODE_USER); if (rc) break; if (strcmp (response2, response)) { xfree (response2); xfree (response); entry_errtext = try_percent_escape (_("does not match - try again"), NULL); if (!entry_errtext) { rc = gpg_error_from_syserror (); break; } goto next_try; } xfree (response2); } if (!rc) { if (cacheid) agent_put_cache (ctrl, cacheid, CACHE_MODE_USER, response, 0); rc = send_back_passphrase (ctx, opt_data, response); } xfree (response); } } return leave_cmd (ctx, rc); } static const char hlp_clear_passphrase[] = "CLEAR_PASSPHRASE [--mode=normal] \n" "\n" "may be used to invalidate the cache entry for a passphrase. The\n" "function returns with OK even when there is no cached passphrase.\n" "The --mode=normal option is used to clear an entry for a cacheid\n" "added by the agent.\n"; static gpg_error_t cmd_clear_passphrase (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); char *cacheid = NULL; char *p; int opt_normal; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); opt_normal = has_option (line, "--mode=normal"); line = skip_options (line); /* parse the stuff */ for (p=line; *p == ' '; p++) ; cacheid = p; p = strchr (cacheid, ' '); if (p) *p = 0; /* ignore garbage */ if (!*cacheid || strlen (cacheid) > 50) return set_error (GPG_ERR_ASS_PARAMETER, "invalid length of cacheID"); agent_put_cache (ctrl, cacheid, opt_normal ? CACHE_MODE_NORMAL : CACHE_MODE_USER, NULL, 0); agent_clear_passphrase (ctrl, cacheid, opt_normal ? CACHE_MODE_NORMAL : CACHE_MODE_USER); return 0; } static const char hlp_get_confirmation[] = "GET_CONFIRMATION \n" "\n" "This command may be used to ask for a simple confirmation.\n" "DESCRIPTION is displayed along with a Okay and Cancel button. This\n" "command uses a syntax which helps clients to use the agent with\n" "minimum effort. The agent either returns with an error or with a\n" "OK. Note, that the length of DESCRIPTION is implicitly limited by\n" "the maximum length of a command. DESCRIPTION should not contain\n" "any spaces, those must be encoded either percent escaped or simply\n" "as '+'."; static gpg_error_t cmd_get_confirmation (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *desc = NULL; char *p; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); /* parse the stuff */ for (p=line; *p == ' '; p++) ; desc = p; p = strchr (desc, ' '); if (p) *p = 0; /* We ignore any garbage -may be later used for other args. */ if (!*desc) return set_error (GPG_ERR_ASS_PARAMETER, "no description given"); if (!strcmp (desc, "X")) desc = NULL; /* Note, that we only need to replace the + characters and should leave the other escaping in place because the escaped string is send verbatim to the pinentry which does the unescaping (but not the + replacing) */ if (desc) plus_to_blank (desc); rc = agent_get_confirmation (ctrl, desc, NULL, NULL, 0); return leave_cmd (ctx, rc); } static const char hlp_learn[] = "LEARN [--send] [--sendinfo] [--force]\n" "\n" "Learn something about the currently inserted smartcard. With\n" "--sendinfo information about the card is returned; with --send\n" "the available certificates are returned as D lines; with --force\n" "private key storage will be updated by the result."; static gpg_error_t cmd_learn (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; int send, sendinfo, force; send = has_option (line, "--send"); sendinfo = send? 1 : has_option (line, "--sendinfo"); force = has_option (line, "--force"); if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); err = agent_handle_learn (ctrl, send, sendinfo? ctx : NULL, force); return leave_cmd (ctx, err); } static const char hlp_passwd[] = "PASSWD [--cache-nonce=] [--passwd-nonce=] [--preset]\n" " [--verify] \n" "\n" "Change the passphrase/PIN for the key identified by keygrip in LINE. If\n" "--preset is used then the new passphrase will be added to the cache.\n" "If --verify is used the command asks for the passphrase and verifies\n" "that the passphrase valid.\n"; static gpg_error_t cmd_passwd (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; int c; char *cache_nonce = NULL; char *passwd_nonce = NULL; unsigned char grip[20]; gcry_sexp_t s_skey = NULL; unsigned char *shadow_info = NULL; char *passphrase = NULL; char *pend; int opt_preset, opt_verify; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); opt_preset = has_option (line, "--preset"); cache_nonce = option_value (line, "--cache-nonce"); opt_verify = has_option (line, "--verify"); if (cache_nonce) { for (pend = cache_nonce; *pend && !spacep (pend); pend++) ; c = *pend; *pend = '\0'; cache_nonce = xtrystrdup (cache_nonce); *pend = c; if (!cache_nonce) { err = gpg_error_from_syserror (); goto leave; } } passwd_nonce = option_value (line, "--passwd-nonce"); if (passwd_nonce) { for (pend = passwd_nonce; *pend && !spacep (pend); pend++) ; c = *pend; *pend = '\0'; passwd_nonce = xtrystrdup (passwd_nonce); *pend = c; if (!passwd_nonce) { err = gpg_error_from_syserror (); goto leave; } } line = skip_options (line); err = parse_keygrip (ctx, line, grip); if (err) goto leave; ctrl->in_passwd++; err = agent_key_from_file (ctrl, opt_verify? NULL : cache_nonce, ctrl->server_local->keydesc, grip, &shadow_info, CACHE_MODE_IGNORE, NULL, &s_skey, &passphrase); if (err) ; else if (shadow_info) { log_error ("changing a smartcard PIN is not yet supported\n"); err = gpg_error (GPG_ERR_NOT_IMPLEMENTED); } else if (opt_verify) { /* All done. */ if (passphrase) { if (!passwd_nonce) { char buf[12]; gcry_create_nonce (buf, 12); passwd_nonce = bin2hex (buf, 12, NULL); } if (passwd_nonce && !agent_put_cache (ctrl, passwd_nonce, CACHE_MODE_NONCE, passphrase, CACHE_TTL_NONCE)) { assuan_write_status (ctx, "PASSWD_NONCE", passwd_nonce); xfree (ctrl->server_local->last_passwd_nonce); ctrl->server_local->last_passwd_nonce = passwd_nonce; passwd_nonce = NULL; } } } else { char *newpass = NULL; if (passwd_nonce) newpass = agent_get_cache (ctrl, passwd_nonce, CACHE_MODE_NONCE); err = agent_protect_and_store (ctrl, s_skey, &newpass); if (!err && passphrase) { /* A passphrase existed on the old key and the change was successful. Return a nonce for that old passphrase to let the caller try to unprotect the other subkeys with the same key. */ if (!cache_nonce) { char buf[12]; gcry_create_nonce (buf, 12); cache_nonce = bin2hex (buf, 12, NULL); } if (cache_nonce && !agent_put_cache (ctrl, cache_nonce, CACHE_MODE_NONCE, passphrase, CACHE_TTL_NONCE)) { assuan_write_status (ctx, "CACHE_NONCE", cache_nonce); xfree (ctrl->server_local->last_cache_nonce); ctrl->server_local->last_cache_nonce = cache_nonce; cache_nonce = NULL; } if (newpass) { /* If we have a new passphrase (which might be empty) we store it under a passwd nonce so that the caller may send that nonce again to use it for another key. */ if (!passwd_nonce) { char buf[12]; gcry_create_nonce (buf, 12); passwd_nonce = bin2hex (buf, 12, NULL); } if (passwd_nonce && !agent_put_cache (ctrl, passwd_nonce, CACHE_MODE_NONCE, newpass, CACHE_TTL_NONCE)) { assuan_write_status (ctx, "PASSWD_NONCE", passwd_nonce); xfree (ctrl->server_local->last_passwd_nonce); ctrl->server_local->last_passwd_nonce = passwd_nonce; passwd_nonce = NULL; } } } if (!err && opt_preset) { char hexgrip[40+1]; bin2hex(grip, 20, hexgrip); err = agent_put_cache (ctrl, hexgrip, CACHE_MODE_ANY, newpass, ctrl->cache_ttl_opt_preset); } xfree (newpass); } ctrl->in_passwd--; xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; leave: xfree (passphrase); gcry_sexp_release (s_skey); xfree (shadow_info); xfree (cache_nonce); xfree (passwd_nonce); return leave_cmd (ctx, err); } static const char hlp_preset_passphrase[] = "PRESET_PASSPHRASE [--inquire] []\n" "\n" "Set the cached passphrase/PIN for the key identified by the keygrip\n" "to passwd for the given time, where -1 means infinite and 0 means\n" "the default (currently only a timeout of -1 is allowed, which means\n" "to never expire it). If passwd is not provided, ask for it via the\n" "pinentry module unless --inquire is passed in which case the passphrase\n" "is retrieved from the client via a server inquire.\n"; static gpg_error_t cmd_preset_passphrase (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *grip_clear = NULL; unsigned char *passphrase = NULL; int ttl; size_t len; int opt_inquire; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); if (!opt.allow_preset_passphrase) return set_error (GPG_ERR_NOT_SUPPORTED, "no --allow-preset-passphrase"); opt_inquire = has_option (line, "--inquire"); line = skip_options (line); grip_clear = line; while (*line && (*line != ' ' && *line != '\t')) line++; if (!*line) return gpg_error (GPG_ERR_MISSING_VALUE); *line = '\0'; line++; while (*line && (*line == ' ' || *line == '\t')) line++; /* Currently, only infinite timeouts are allowed. */ ttl = -1; if (line[0] != '-' || line[1] != '1') return gpg_error (GPG_ERR_NOT_IMPLEMENTED); line++; line++; while (!(*line != ' ' && *line != '\t')) line++; /* Syntax check the hexstring. */ len = 0; rc = parse_hexstring (ctx, line, &len); if (rc) return rc; line[len] = '\0'; /* If there is a passphrase, use it. Currently, a passphrase is required. */ if (*line) { if (opt_inquire) { rc = set_error (GPG_ERR_ASS_PARAMETER, "both --inquire and passphrase specified"); goto leave; } /* Do in-place conversion. */ passphrase = line; if (!hex2str (passphrase, passphrase, strlen (passphrase)+1, NULL)) rc = set_error (GPG_ERR_ASS_PARAMETER, "invalid hexstring"); } else if (opt_inquire) { /* Note that the passphrase will be truncated at any null byte and the * limit is 480 characters. */ size_t maxlen = 480; rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%zu", maxlen); if (!rc) rc = assuan_inquire (ctx, "PASSPHRASE", &passphrase, &len, maxlen); } else rc = set_error (GPG_ERR_NOT_IMPLEMENTED, "passphrase is required"); if (!rc) { rc = agent_put_cache (ctrl, grip_clear, CACHE_MODE_ANY, passphrase, ttl); if (opt_inquire) xfree (passphrase); } leave: return leave_cmd (ctx, rc); } static const char hlp_scd[] = "SCD \n" " \n" "This is a general quote command to redirect everything to the\n" "SCdaemon."; static gpg_error_t cmd_scd (assuan_context_t ctx, char *line) { int rc; #ifdef BUILD_WITH_SCDAEMON ctrl_t ctrl = assuan_get_pointer (ctx); if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); rc = divert_generic_cmd (ctrl, line, ctx); #else (void)ctx; (void)line; rc = gpg_error (GPG_ERR_NOT_SUPPORTED); #endif return rc; } static const char hlp_keywrap_key[] = "KEYWRAP_KEY [--clear] \n" "\n" "Return a key to wrap another key. For now the key is returned\n" "verbatim and thus makes not much sense because an eavesdropper on\n" "the gpg-agent connection will see the key as well as the wrapped key.\n" "However, this function may either be equipped with a public key\n" "mechanism or not used at all if the key is a pre-shared key. In any\n" "case wrapping the import and export of keys is a requirement for\n" "certain cryptographic validations and thus useful. The key persists\n" "until a RESET command but may be cleared using the option --clear.\n" "\n" "Supported modes are:\n" " --import - Return a key to import a key into gpg-agent\n" " --export - Return a key to export a key from gpg-agent"; static gpg_error_t cmd_keywrap_key (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err = 0; int clearopt = has_option (line, "--clear"); if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); assuan_begin_confidential (ctx); if (has_option (line, "--import")) { xfree (ctrl->server_local->import_key); if (clearopt) ctrl->server_local->import_key = NULL; else if (!(ctrl->server_local->import_key = gcry_random_bytes (KEYWRAP_KEYSIZE, GCRY_STRONG_RANDOM))) err = gpg_error_from_syserror (); else err = assuan_send_data (ctx, ctrl->server_local->import_key, KEYWRAP_KEYSIZE); } else if (has_option (line, "--export")) { xfree (ctrl->server_local->export_key); if (clearopt) ctrl->server_local->export_key = NULL; else if (!(ctrl->server_local->export_key = gcry_random_bytes (KEYWRAP_KEYSIZE, GCRY_STRONG_RANDOM))) err = gpg_error_from_syserror (); else err = assuan_send_data (ctx, ctrl->server_local->export_key, KEYWRAP_KEYSIZE); } else err = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for MODE"); assuan_end_confidential (ctx); return leave_cmd (ctx, err); } static const char hlp_import_key[] = "IMPORT_KEY [--unattended] [--force] []\n" "\n" "Import a secret key into the key store. The key is expected to be\n" "encrypted using the current session's key wrapping key (cf. command\n" "KEYWRAP_KEY) using the AESWRAP-128 algorithm. This function takes\n" "no arguments but uses the inquiry \"KEYDATA\" to ask for the actual\n" "key data. The unwrapped key must be a canonical S-expression. The\n" "option --unattended tries to import the key as-is without any\n" "re-encryption. Existing key can be overwritten with --force."; static gpg_error_t cmd_import_key (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; int opt_unattended; int force; unsigned char *wrappedkey = NULL; size_t wrappedkeylen; gcry_cipher_hd_t cipherhd = NULL; unsigned char *key = NULL; size_t keylen, realkeylen; char *passphrase = NULL; unsigned char *finalkey = NULL; size_t finalkeylen; unsigned char grip[20]; gcry_sexp_t openpgp_sexp = NULL; char *cache_nonce = NULL; char *p; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); if (!ctrl->server_local->import_key) { err = gpg_error (GPG_ERR_MISSING_KEY); goto leave; } opt_unattended = has_option (line, "--unattended"); force = has_option (line, "--force"); line = skip_options (line); for (p=line; *p && *p != ' ' && *p != '\t'; p++) ; *p = '\0'; if (*line) cache_nonce = xtrystrdup (line); assuan_begin_confidential (ctx); err = assuan_inquire (ctx, "KEYDATA", &wrappedkey, &wrappedkeylen, MAXLEN_KEYDATA); assuan_end_confidential (ctx); if (err) goto leave; if (wrappedkeylen < 24) { err = gpg_error (GPG_ERR_INV_LENGTH); goto leave; } keylen = wrappedkeylen - 8; key = xtrymalloc_secure (keylen); if (!key) { err = gpg_error_from_syserror (); goto leave; } err = gcry_cipher_open (&cipherhd, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_AESWRAP, 0); if (err) goto leave; err = gcry_cipher_setkey (cipherhd, ctrl->server_local->import_key, KEYWRAP_KEYSIZE); if (err) goto leave; err = gcry_cipher_decrypt (cipherhd, key, keylen, wrappedkey, wrappedkeylen); if (err) goto leave; gcry_cipher_close (cipherhd); cipherhd = NULL; xfree (wrappedkey); wrappedkey = NULL; realkeylen = gcry_sexp_canon_len (key, keylen, NULL, &err); if (!realkeylen) goto leave; /* Invalid canonical encoded S-expression. */ err = keygrip_from_canon_sexp (key, realkeylen, grip); if (err) { /* This might be due to an unsupported S-expression format. Check whether this is openpgp-private-key and trigger that import code. */ if (!gcry_sexp_sscan (&openpgp_sexp, NULL, key, realkeylen)) { const char *tag; size_t taglen; tag = gcry_sexp_nth_data (openpgp_sexp, 0, &taglen); if (tag && taglen == 19 && !memcmp (tag, "openpgp-private-key", 19)) ; else { gcry_sexp_release (openpgp_sexp); openpgp_sexp = NULL; } } if (!openpgp_sexp) goto leave; /* Note that ERR is still set. */ } if (openpgp_sexp) { /* In most cases the key is encrypted and thus the conversion function from the OpenPGP format to our internal format will ask for a passphrase. That passphrase will be returned and used to protect the key using the same code as for regular key import. */ xfree (key); key = NULL; err = convert_from_openpgp (ctrl, openpgp_sexp, force, grip, ctrl->server_local->keydesc, cache_nonce, &key, opt_unattended? NULL : &passphrase); if (err) goto leave; realkeylen = gcry_sexp_canon_len (key, 0, NULL, &err); if (!realkeylen) goto leave; /* Invalid canonical encoded S-expression. */ if (passphrase) { assert (!opt_unattended); if (!cache_nonce) { char buf[12]; gcry_create_nonce (buf, 12); cache_nonce = bin2hex (buf, 12, NULL); } if (cache_nonce && !agent_put_cache (ctrl, cache_nonce, CACHE_MODE_NONCE, passphrase, CACHE_TTL_NONCE)) assuan_write_status (ctx, "CACHE_NONCE", cache_nonce); } } else if (opt_unattended) { err = set_error (GPG_ERR_ASS_PARAMETER, "\"--unattended\" may only be used with OpenPGP keys"); goto leave; } else { if (!force && !agent_key_available (grip)) err = gpg_error (GPG_ERR_EEXIST); else { char *prompt = xtryasprintf (_("Please enter the passphrase to protect the " "imported object within the %s system."), GNUPG_NAME); if (!prompt) err = gpg_error_from_syserror (); else err = agent_ask_new_passphrase (ctrl, prompt, &passphrase); xfree (prompt); } if (err) goto leave; } if (passphrase) { err = agent_protect (key, passphrase, &finalkey, &finalkeylen, ctrl->s2k_count, -1); if (!err) err = agent_write_private_key (grip, finalkey, finalkeylen, force); } else err = agent_write_private_key (grip, key, realkeylen, force); leave: gcry_sexp_release (openpgp_sexp); xfree (finalkey); xfree (passphrase); xfree (key); gcry_cipher_close (cipherhd); xfree (wrappedkey); xfree (cache_nonce); xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; return leave_cmd (ctx, err); } static const char hlp_export_key[] = "EXPORT_KEY [--cache-nonce=] [--openpgp] \n" "\n" "Export a secret key from the key store. The key will be encrypted\n" "using the current session's key wrapping key (cf. command KEYWRAP_KEY)\n" "using the AESWRAP-128 algorithm. The caller needs to retrieve that key\n" "prior to using this command. The function takes the keygrip as argument.\n" "\n" "If --openpgp is used, the secret key material will be exported in RFC 4880\n" "compatible passphrase-protected form. Without --openpgp, the secret key\n" "material will be exported in the clear (after prompting the user to unlock\n" "it, if needed).\n"; static gpg_error_t cmd_export_key (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; unsigned char grip[20]; gcry_sexp_t s_skey = NULL; unsigned char *key = NULL; size_t keylen; gcry_cipher_hd_t cipherhd = NULL; unsigned char *wrappedkey = NULL; size_t wrappedkeylen; int openpgp; char *cache_nonce; char *passphrase = NULL; unsigned char *shadow_info = NULL; char *pend; int c; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); openpgp = has_option (line, "--openpgp"); cache_nonce = option_value (line, "--cache-nonce"); if (cache_nonce) { for (pend = cache_nonce; *pend && !spacep (pend); pend++) ; c = *pend; *pend = '\0'; cache_nonce = xtrystrdup (cache_nonce); *pend = c; if (!cache_nonce) { err = gpg_error_from_syserror (); goto leave; } } line = skip_options (line); if (!ctrl->server_local->export_key) { err = set_error (GPG_ERR_MISSING_KEY, "did you run KEYWRAP_KEY ?"); goto leave; } err = parse_keygrip (ctx, line, grip); if (err) goto leave; if (agent_key_available (grip)) { err = gpg_error (GPG_ERR_NO_SECKEY); goto leave; } /* Get the key from the file. With the openpgp flag we also ask for the passphrase so that we can use it to re-encrypt it. */ err = agent_key_from_file (ctrl, cache_nonce, ctrl->server_local->keydesc, grip, &shadow_info, CACHE_MODE_IGNORE, NULL, &s_skey, openpgp ? &passphrase : NULL); if (err) goto leave; if (shadow_info) { /* Key is on a smartcard. */ err = gpg_error (GPG_ERR_UNUSABLE_SECKEY); goto leave; } if (openpgp) { /* The openpgp option changes the key format into the OpenPGP key transfer format. The result is already a padded canonical S-expression. */ if (!passphrase) { err = agent_ask_new_passphrase (ctrl, _("This key (or subkey) is not protected with a passphrase." " Please enter a new passphrase to export it."), &passphrase); if (err) goto leave; } err = convert_to_openpgp (ctrl, s_skey, passphrase, &key, &keylen); if (!err && passphrase) { if (!cache_nonce) { char buf[12]; gcry_create_nonce (buf, 12); cache_nonce = bin2hex (buf, 12, NULL); } if (cache_nonce && !agent_put_cache (ctrl, cache_nonce, CACHE_MODE_NONCE, passphrase, CACHE_TTL_NONCE)) { assuan_write_status (ctx, "CACHE_NONCE", cache_nonce); xfree (ctrl->server_local->last_cache_nonce); ctrl->server_local->last_cache_nonce = cache_nonce; cache_nonce = NULL; } } } else { /* Convert into a canonical S-expression and wrap that. */ err = make_canon_sexp_pad (s_skey, 1, &key, &keylen); } if (err) goto leave; gcry_sexp_release (s_skey); s_skey = NULL; err = gcry_cipher_open (&cipherhd, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_AESWRAP, 0); if (err) goto leave; err = gcry_cipher_setkey (cipherhd, ctrl->server_local->export_key, KEYWRAP_KEYSIZE); if (err) goto leave; wrappedkeylen = keylen + 8; wrappedkey = xtrymalloc (wrappedkeylen); if (!wrappedkey) { err = gpg_error_from_syserror (); goto leave; } err = gcry_cipher_encrypt (cipherhd, wrappedkey, wrappedkeylen, key, keylen); if (err) goto leave; xfree (key); key = NULL; gcry_cipher_close (cipherhd); cipherhd = NULL; assuan_begin_confidential (ctx); err = assuan_send_data (ctx, wrappedkey, wrappedkeylen); assuan_end_confidential (ctx); leave: xfree (cache_nonce); xfree (passphrase); xfree (wrappedkey); gcry_cipher_close (cipherhd); xfree (key); gcry_sexp_release (s_skey); xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; xfree (shadow_info); return leave_cmd (ctx, err); } static const char hlp_delete_key[] = "DELETE_KEY [--force|--stub-only] \n" "\n" "Delete a secret key from the key store. If --force is used\n" "and a loopback pinentry is allowed, the agent will not ask\n" "the user for confirmation. If --stub-only is used the key will\n" "only be deleted if it is a reference to a token."; static gpg_error_t cmd_delete_key (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; int force, stub_only; unsigned char grip[20]; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); force = has_option (line, "--force"); stub_only = has_option (line, "--stub-only"); line = skip_options (line); /* If the use of a loopback pinentry has been disabled, we assume * that a silent deletion of keys shall also not be allowed. */ if (!opt.allow_loopback_pinentry) force = 0; err = parse_keygrip (ctx, line, grip); if (err) goto leave; err = agent_delete_key (ctrl, ctrl->server_local->keydesc, grip, force, stub_only); if (err) goto leave; leave: xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; return leave_cmd (ctx, err); } #if SIZEOF_TIME_T > SIZEOF_UNSIGNED_LONG #define KEYTOCARD_TIMESTAMP_FORMAT "(10:created-at10:%010llu))" #else #define KEYTOCARD_TIMESTAMP_FORMAT "(10:created-at10:%010lu))" #endif static const char hlp_keytocard[] = "KEYTOCARD [--force] \n" "\n"; static gpg_error_t cmd_keytocard (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int force; gpg_error_t err = 0; unsigned char grip[20]; gcry_sexp_t s_skey = NULL; unsigned char *keydata; size_t keydatalen; const char *serialno, *timestamp_str, *id; unsigned char *shadow_info = NULL; time_t timestamp; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); force = has_option (line, "--force"); line = skip_options (line); err = parse_keygrip (ctx, line, grip); if (err) goto leave; if (agent_key_available (grip)) { err =gpg_error (GPG_ERR_NO_SECKEY); goto leave; } /* Fixme: Replace the parsing code by split_fields(). */ line += 40; while (*line && (*line == ' ' || *line == '\t')) line++; serialno = line; while (*line && (*line != ' ' && *line != '\t')) line++; if (!*line) { err = gpg_error (GPG_ERR_MISSING_VALUE); goto leave; } *line = '\0'; line++; while (*line && (*line == ' ' || *line == '\t')) line++; id = line; while (*line && (*line != ' ' && *line != '\t')) line++; if (!*line) { err = gpg_error (GPG_ERR_MISSING_VALUE); goto leave; } *line = '\0'; line++; while (*line && (*line == ' ' || *line == '\t')) line++; timestamp_str = line; while (*line && (*line != ' ' && *line != '\t')) line++; if (*line) *line = '\0'; if ((timestamp = isotime2epoch (timestamp_str)) == (time_t)(-1)) { err = gpg_error (GPG_ERR_INV_TIME); goto leave; } err = agent_key_from_file (ctrl, NULL, ctrl->server_local->keydesc, grip, &shadow_info, CACHE_MODE_IGNORE, NULL, &s_skey, NULL); if (err) { xfree (shadow_info); goto leave; } if (shadow_info) { /* Key is on a smartcard already. */ xfree (shadow_info); gcry_sexp_release (s_skey); err = gpg_error (GPG_ERR_UNUSABLE_SECKEY); goto leave; } keydatalen = gcry_sexp_sprint (s_skey, GCRYSEXP_FMT_CANON, NULL, 0); keydata = xtrymalloc_secure (keydatalen + 30); if (keydata == NULL) { err = gpg_error_from_syserror (); gcry_sexp_release (s_skey); goto leave; } gcry_sexp_sprint (s_skey, GCRYSEXP_FMT_CANON, keydata, keydatalen); gcry_sexp_release (s_skey); keydatalen--; /* Decrement for last '\0'. */ /* Add timestamp "created-at" in the private key */ snprintf (keydata+keydatalen-1, 30, KEYTOCARD_TIMESTAMP_FORMAT, timestamp); keydatalen += 10 + 19 - 1; err = divert_writekey (ctrl, force, serialno, id, keydata, keydatalen); xfree (keydata); leave: return leave_cmd (ctx, err); } static const char hlp_get_secret[] = "GET_SECRET \n" "\n" "Return the secret value stored under KEY\n"; static gpg_error_t cmd_get_secret (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err; char *p, *key; char *value = NULL; size_t valuelen; /* For now we allow this only for local connections. */ if (ctrl->restricted) { err = gpg_error (GPG_ERR_FORBIDDEN); goto leave; } line = skip_options (line); for (p=line; *p == ' '; p++) ; key = p; p = strchr (key, ' '); if (p) { *p++ = 0; for (; *p == ' '; p++) ; if (*p) { err = set_error (GPG_ERR_ASS_PARAMETER, "too many arguments"); goto leave; } } if (!*key) { err = set_error (GPG_ERR_ASS_PARAMETER, "no key given"); goto leave; } value = agent_get_cache (ctrl, key, CACHE_MODE_DATA); if (!value) { err = gpg_error (GPG_ERR_NO_DATA); goto leave; } valuelen = percent_unescape_inplace (value, 0); err = assuan_send_data (ctx, value, valuelen); wipememory (value, valuelen); leave: xfree (value); return leave_cmd (ctx, err); } static const char hlp_put_secret[] = "PUT_SECRET [--clear] []\n" "\n" "This commands stores a secret under KEY in gpg-agent's in-memory\n" "cache. The TTL must be explicitly given by TTL and the options\n" "from the configuration file are not used. The value is either given\n" "percent-escaped as 3rd argument or if not given inquired by gpg-agent\n" "using the keyword \"SECRET\".\n" "The option --clear removes the secret from the cache." ""; static gpg_error_t cmd_put_secret (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err = 0; int opt_clear; unsigned char *value = NULL; size_t valuelen = 0; size_t n; char *p, *key, *ttlstr; unsigned char *valstr; int ttl; char *string = NULL; /* For now we allow this only for local connections. */ if (ctrl->restricted) { err = gpg_error (GPG_ERR_FORBIDDEN); goto leave; } opt_clear = has_option (line, "--clear"); line = skip_options (line); for (p=line; *p == ' '; p++) ; key = p; ttlstr = NULL; valstr = NULL; p = strchr (key, ' '); if (p) { *p++ = 0; for (; *p == ' '; p++) ; if (*p) { ttlstr = p; p = strchr (ttlstr, ' '); if (p) { *p++ = 0; for (; *p == ' '; p++) ; if (*p) valstr = p; } } } if (!*key) { err = set_error (GPG_ERR_ASS_PARAMETER, "no key given"); goto leave; } if (!ttlstr || !*ttlstr || !(n = parse_ttl (ttlstr, &ttl))) { err = set_error (GPG_ERR_ASS_PARAMETER, "no or invalid TTL given"); goto leave; } if (valstr && opt_clear) { err = set_error (GPG_ERR_ASS_PARAMETER, "value not expected with --clear"); goto leave; } if (valstr) { valuelen = percent_unescape_inplace (valstr, 0); value = NULL; } else /* Inquire the value to store */ { err = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%u",MAXLEN_PUT_SECRET); if (!err) err = assuan_inquire (ctx, "SECRET", &value, &valuelen, MAXLEN_PUT_SECRET); if (err) goto leave; } /* Our cache expects strings and thus we need to turn the buffer * into a string. Instead of resorting to base64 encoding we use a * special percent escaping which only quoted the Nul and the * percent character. */ string = percent_data_escape (value? value : valstr, valuelen); if (!string) { err = gpg_error_from_syserror (); goto leave; } err = agent_put_cache (ctrl, key, CACHE_MODE_DATA, string, ttl); leave: if (string) { wipememory (string, strlen (string)); xfree (string); } if (value) { wipememory (value, valuelen); xfree (value); } return leave_cmd (ctx, err); } static const char hlp_getval[] = "GETVAL \n" "\n" "Return the value for KEY from the special environment as created by\n" "PUTVAL."; static gpg_error_t cmd_getval (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; char *key = NULL; char *p; struct putval_item_s *vl; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); for (p=line; *p == ' '; p++) ; key = p; p = strchr (key, ' '); if (p) { *p++ = 0; for (; *p == ' '; p++) ; if (*p) return set_error (GPG_ERR_ASS_PARAMETER, "too many arguments"); } if (!*key) return set_error (GPG_ERR_ASS_PARAMETER, "no key given"); for (vl=putval_list; vl; vl = vl->next) if ( !strcmp (vl->d, key) ) break; if (vl) /* Got an entry. */ rc = assuan_send_data (ctx, vl->d+vl->off, vl->len); else return gpg_error (GPG_ERR_NO_DATA); return leave_cmd (ctx, rc); } static const char hlp_putval[] = "PUTVAL []\n" "\n" "The gpg-agent maintains a kind of environment which may be used to\n" "store key/value pairs in it, so that they can be retrieved later.\n" "This may be used by helper daemons to daemonize themself on\n" "invocation and register them with gpg-agent. Callers of the\n" "daemon's service may now first try connect to get the information\n" "for that service from gpg-agent through the GETVAL command and then\n" "try to connect to that daemon. Only if that fails they may start\n" "an own instance of the service daemon. \n" "\n" "KEY is an arbitrary symbol with the same syntax rules as keys\n" "for shell environment variables. PERCENT_ESCAPED_VALUE is the\n" "corresponding value; they should be similar to the values of\n" "envronment variables but gpg-agent does not enforce any\n" "restrictions. If that value is not given any value under that KEY\n" "is removed from this special environment."; static gpg_error_t cmd_putval (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; char *key = NULL; char *value = NULL; size_t valuelen = 0; char *p; struct putval_item_s *vl, *vlprev; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); for (p=line; *p == ' '; p++) ; key = p; p = strchr (key, ' '); if (p) { *p++ = 0; for (; *p == ' '; p++) ; if (*p) { value = p; p = strchr (value, ' '); if (p) *p = 0; valuelen = percent_plus_unescape_inplace (value, 0); } } if (!*key) return set_error (GPG_ERR_ASS_PARAMETER, "no key given"); for (vl=putval_list,vlprev=NULL; vl; vlprev=vl, vl = vl->next) if ( !strcmp (vl->d, key) ) break; if (vl) /* Delete old entry. */ { if (vlprev) vlprev->next = vl->next; else putval_list = vl->next; xfree (vl); } if (valuelen) /* Add entry. */ { vl = xtrymalloc (sizeof *vl + strlen (key) + valuelen); if (!vl) rc = gpg_error_from_syserror (); else { vl->len = valuelen; vl->off = strlen (key) + 1; strcpy (vl->d, key); memcpy (vl->d + vl->off, value, valuelen); vl->next = putval_list; putval_list = vl; } } return leave_cmd (ctx, rc); } static const char hlp_updatestartuptty[] = "UPDATESTARTUPTTY\n" "\n" "Set startup TTY and X11 DISPLAY variables to the values of this\n" "session. This command is useful to pull future pinentries to\n" "another screen. It is only required because there is no way in the\n" "ssh-agent protocol to convey this information."; static gpg_error_t cmd_updatestartuptty (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err = 0; session_env_t se; char *lc_ctype = NULL; char *lc_messages = NULL; int iterator; const char *name; (void)line; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); se = session_env_new (); if (!se) err = gpg_error_from_syserror (); iterator = 0; while (!err && (name = session_env_list_stdenvnames (&iterator, NULL))) { const char *value = session_env_getenv (ctrl->session_env, name); if (value) err = session_env_setenv (se, name, value); } if (!err && ctrl->lc_ctype) if (!(lc_ctype = xtrystrdup (ctrl->lc_ctype))) err = gpg_error_from_syserror (); if (!err && ctrl->lc_messages) if (!(lc_messages = xtrystrdup (ctrl->lc_messages))) err = gpg_error_from_syserror (); if (err) { session_env_release (se); xfree (lc_ctype); xfree (lc_messages); } else { session_env_release (opt.startup_env); opt.startup_env = se; xfree (opt.startup_lc_ctype); opt.startup_lc_ctype = lc_ctype; xfree (opt.startup_lc_messages); opt.startup_lc_messages = lc_messages; } return err; } static const char hlp_killagent[] = "KILLAGENT\n" "\n" "Stop the agent."; static gpg_error_t cmd_killagent (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); (void)line; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); ctrl->server_local->stopme = 1; assuan_set_flag (ctx, ASSUAN_FORCE_CLOSE, 1); return 0; } static const char hlp_reloadagent[] = "RELOADAGENT\n" "\n" "This command is an alternative to SIGHUP\n" "to reload the configuration."; static gpg_error_t cmd_reloadagent (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); (void)line; if (ctrl->restricted) return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN)); agent_sighup_action (); return 0; } static const char hlp_getinfo[] = "GETINFO \n" "\n" "Multipurpose function to return a variety of information.\n" "Supported values for WHAT are:\n" "\n" " version - Return the version of the program.\n" " pid - Return the process id of the server.\n" " socket_name - Return the name of the socket.\n" " ssh_socket_name - Return the name of the ssh socket.\n" " scd_running - Return OK if the SCdaemon is already running.\n" " s2k_time - Return the time in milliseconds required for S2K.\n" " s2k_count - Return the standard S2K count.\n" " s2k_count_cal - Return the calibrated S2K count.\n" " std_env_names - List the names of the standard environment.\n" " std_session_env - List the standard session environment.\n" " std_startup_env - List the standard startup environment.\n" " getenv NAME - Return value of envvar NAME.\n" " connections - Return number of active connections.\n" " jent_active - Returns OK if Libgcrypt's JENT is active.\n" " restricted - Returns OK if the connection is in restricted mode.\n" " cmd_has_option CMD OPT\n" " - Returns OK if command CMD has option OPT.\n"; static gpg_error_t cmd_getinfo (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; if (!strcmp (line, "version")) { const char *s = VERSION; rc = assuan_send_data (ctx, s, strlen (s)); } else if (!strncmp (line, "cmd_has_option", 14) && (line[14] == ' ' || line[14] == '\t' || !line[14])) { char *cmd, *cmdopt; line += 14; while (*line == ' ' || *line == '\t') line++; if (!*line) rc = gpg_error (GPG_ERR_MISSING_VALUE); else { cmd = line; while (*line && (*line != ' ' && *line != '\t')) line++; if (!*line) rc = gpg_error (GPG_ERR_MISSING_VALUE); else { *line++ = 0; while (*line == ' ' || *line == '\t') line++; if (!*line) rc = gpg_error (GPG_ERR_MISSING_VALUE); else { cmdopt = line; if (!command_has_option (cmd, cmdopt)) rc = gpg_error (GPG_ERR_GENERAL); } } } } else if (!strcmp (line, "s2k_count")) { char numbuf[50]; snprintf (numbuf, sizeof numbuf, "%lu", get_standard_s2k_count ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else if (!strcmp (line, "restricted")) { rc = ctrl->restricted? 0 : gpg_error (GPG_ERR_GENERAL); } else if (ctrl->restricted) { rc = gpg_error (GPG_ERR_FORBIDDEN); } /* All sub-commands below are not allowed in restricted mode. */ else if (!strcmp (line, "pid")) { char numbuf[50]; snprintf (numbuf, sizeof numbuf, "%lu", (unsigned long)getpid ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else if (!strcmp (line, "socket_name")) { const char *s = get_agent_socket_name (); if (s) rc = assuan_send_data (ctx, s, strlen (s)); else rc = gpg_error (GPG_ERR_NO_DATA); } else if (!strcmp (line, "ssh_socket_name")) { const char *s = get_agent_ssh_socket_name (); if (s) rc = assuan_send_data (ctx, s, strlen (s)); else rc = gpg_error (GPG_ERR_NO_DATA); } else if (!strcmp (line, "scd_running")) { rc = agent_scd_check_running ()? 0 : gpg_error (GPG_ERR_GENERAL); } else if (!strcmp (line, "std_env_names")) { int iterator; const char *name; iterator = 0; while ((name = session_env_list_stdenvnames (&iterator, NULL))) { rc = assuan_send_data (ctx, name, strlen (name)+1); if (!rc) rc = assuan_send_data (ctx, NULL, 0); if (rc) break; } } else if (!strcmp (line, "std_session_env") || !strcmp (line, "std_startup_env")) { int iterator; const char *name, *value; char *string; iterator = 0; while ((name = session_env_list_stdenvnames (&iterator, NULL))) { value = session_env_getenv_or_default (line[5] == 't'? opt.startup_env:ctrl->session_env, name, NULL); if (value) { string = xtryasprintf ("%s=%s", name, value); if (!string) rc = gpg_error_from_syserror (); else { rc = assuan_send_data (ctx, string, strlen (string)+1); if (!rc) rc = assuan_send_data (ctx, NULL, 0); } if (rc) break; } } } else if (!strncmp (line, "getenv", 6) && (line[6] == ' ' || line[6] == '\t' || !line[6])) { line += 6; while (*line == ' ' || *line == '\t') line++; if (!*line) rc = gpg_error (GPG_ERR_MISSING_VALUE); else { const char *s = getenv (line); if (!s) rc = set_error (GPG_ERR_NOT_FOUND, "No such envvar"); else rc = assuan_send_data (ctx, s, strlen (s)); } } else if (!strcmp (line, "connections")) { char numbuf[20]; snprintf (numbuf, sizeof numbuf, "%d", get_agent_active_connection_count ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else if (!strcmp (line, "jent_active")) { #if GCRYPT_VERSION_NUMBER >= 0x010800 char *buf; char *fields[5]; buf = gcry_get_config (0, "rng-type"); if (buf && split_fields_colon (buf, fields, DIM (fields)) >= 5 && atoi (fields[4]) > 0) rc = 0; else rc = gpg_error (GPG_ERR_FALSE); gcry_free (buf); #else rc = gpg_error (GPG_ERR_FALSE); #endif } else if (!strcmp (line, "s2k_count_cal")) { char numbuf[50]; snprintf (numbuf, sizeof numbuf, "%lu", get_calibrated_s2k_count ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else if (!strcmp (line, "s2k_time")) { char numbuf[50]; snprintf (numbuf, sizeof numbuf, "%lu", get_standard_s2k_time ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else rc = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for WHAT"); return rc; } /* This function is called by Libassuan to parse the OPTION command. It has been registered similar to the other Assuan commands. */ static gpg_error_t option_handler (assuan_context_t ctx, const char *key, const char *value) { ctrl_t ctrl = assuan_get_pointer (ctx); gpg_error_t err = 0; if (!strcmp (key, "agent-awareness")) { /* The value is a version string telling us of which agent version the caller is aware of. */ ctrl->server_local->allow_fully_canceled = gnupg_compare_version (value, "2.1.0"); } else if (ctrl->restricted) { err = gpg_error (GPG_ERR_FORBIDDEN); } /* All options below are not allowed in restricted mode. */ else if (!strcmp (key, "putenv")) { /* Change the session's environment to be used for the Pinentry. Valid values are: Delete envvar NAME = Set envvar NAME to the empty string = Set envvar NAME to VALUE */ err = session_env_putenv (ctrl->session_env, value); } else if (!strcmp (key, "display")) { err = session_env_setenv (ctrl->session_env, "DISPLAY", value); } else if (!strcmp (key, "ttyname")) { if (!opt.keep_tty) err = session_env_setenv (ctrl->session_env, "GPG_TTY", value); } else if (!strcmp (key, "ttytype")) { if (!opt.keep_tty) err = session_env_setenv (ctrl->session_env, "TERM", value); } else if (!strcmp (key, "lc-ctype")) { if (ctrl->lc_ctype) xfree (ctrl->lc_ctype); ctrl->lc_ctype = xtrystrdup (value); if (!ctrl->lc_ctype) return out_of_core (); } else if (!strcmp (key, "lc-messages")) { if (ctrl->lc_messages) xfree (ctrl->lc_messages); ctrl->lc_messages = xtrystrdup (value); if (!ctrl->lc_messages) return out_of_core (); } else if (!strcmp (key, "xauthority")) { err = session_env_setenv (ctrl->session_env, "XAUTHORITY", value); } else if (!strcmp (key, "pinentry-user-data")) { err = session_env_setenv (ctrl->session_env, "PINENTRY_USER_DATA", value); } else if (!strcmp (key, "use-cache-for-signing")) ctrl->server_local->use_cache_for_signing = *value? !!atoi (value) : 0; else if (!strcmp (key, "allow-pinentry-notify")) ctrl->server_local->allow_pinentry_notify = 1; else if (!strcmp (key, "pinentry-mode")) { int tmp = parse_pinentry_mode (value); if (tmp == -1) err = gpg_error (GPG_ERR_INV_VALUE); else if (tmp == PINENTRY_MODE_LOOPBACK && !opt.allow_loopback_pinentry) err = gpg_error (GPG_ERR_NOT_SUPPORTED); else ctrl->pinentry_mode = tmp; } else if (!strcmp (key, "cache-ttl-opt-preset")) { ctrl->cache_ttl_opt_preset = *value? atoi (value) : 0; } else if (!strcmp (key, "s2k-count")) { ctrl->s2k_count = *value? strtoul(value, NULL, 10) : 0; if (ctrl->s2k_count && ctrl->s2k_count < 65536) { ctrl->s2k_count = 0; } } else if (!strcmp (key, "pretend-request-origin")) { log_assert (!ctrl->restricted); switch (parse_request_origin (value)) { case REQUEST_ORIGIN_LOCAL: ctrl->restricted = 0; break; case REQUEST_ORIGIN_REMOTE: ctrl->restricted = 1; break; case REQUEST_ORIGIN_BROWSER: ctrl->restricted = 2; break; default: err = gpg_error (GPG_ERR_INV_VALUE); /* Better pretend to be remote in case of a bad value. */ ctrl->restricted = 1; break; } } else err = gpg_error (GPG_ERR_UNKNOWN_OPTION); return err; } /* Called by libassuan after all commands. ERR is the error from the last assuan operation and not the one returned from the command. */ static void post_cmd_notify (assuan_context_t ctx, gpg_error_t err) { ctrl_t ctrl = assuan_get_pointer (ctx); (void)err; /* Switch off any I/O monitor controlled logging pausing. */ ctrl->server_local->pause_io_logging = 0; } /* This function is called by libassuan for all I/O. We use it here to disable logging for the GETEVENTCOUNTER commands. This is so that the debug output won't get cluttered by this primitive command. */ static unsigned int io_monitor (assuan_context_t ctx, void *hook, int direction, const char *line, size_t linelen) { ctrl_t ctrl = assuan_get_pointer (ctx); (void) hook; /* We want to suppress all Assuan log messages for connections from * self. However, assuan_get_pid works only after * assuan_accept. Now, assuan_accept already logs a line ending with * the process id. We use this hack here to get the peers pid so * that we can compare it to our pid. We should add an assuan * function to return the pid for a file descriptor and use that to * detect connections to self. */ if (ctx && !ctrl->server_local->greeting_seen && direction == ASSUAN_IO_TO_PEER) { ctrl->server_local->greeting_seen = 1; if (linelen > 32 && !strncmp (line, "OK Pleased to meet you, process ", 32) && strtoul (line+32, NULL, 10) == getpid ()) return ASSUAN_IO_MONITOR_NOLOG; } /* Do not log self-connections. This makes the log cleaner because * we won't see the check-our-own-socket calls. */ if (ctx && ctrl->server_local->connect_from_self) return ASSUAN_IO_MONITOR_NOLOG; /* Note that we only check for the uppercase name. This allows the user to see the logging for debugging if using a non-upercase command name. */ if (ctx && direction == ASSUAN_IO_FROM_PEER && linelen >= 15 && !strncmp (line, "GETEVENTCOUNTER", 15) && (linelen == 15 || spacep (line+15))) { ctrl->server_local->pause_io_logging = 1; } return ctrl->server_local->pause_io_logging? ASSUAN_IO_MONITOR_NOLOG : 0; } /* Return true if the command CMD implements the option OPT. */ static int command_has_option (const char *cmd, const char *cmdopt) { if (!strcmp (cmd, "GET_PASSPHRASE")) { if (!strcmp (cmdopt, "repeat")) return 1; } return 0; } /* Tell Libassuan about our commands. Also register the other Assuan handlers. */ static int register_commands (assuan_context_t ctx) { static struct { const char *name; assuan_handler_t handler; const char * const help; } table[] = { { "GETEVENTCOUNTER",cmd_geteventcounter, hlp_geteventcounter }, { "ISTRUSTED", cmd_istrusted, hlp_istrusted }, { "HAVEKEY", cmd_havekey, hlp_havekey }, { "KEYINFO", cmd_keyinfo, hlp_keyinfo }, { "SIGKEY", cmd_sigkey, hlp_sigkey }, { "SETKEY", cmd_sigkey, hlp_sigkey }, { "SETKEYDESC", cmd_setkeydesc,hlp_setkeydesc }, { "SETHASH", cmd_sethash, hlp_sethash }, { "PKSIGN", cmd_pksign, hlp_pksign }, { "PKDECRYPT", cmd_pkdecrypt, hlp_pkdecrypt }, { "GENKEY", cmd_genkey, hlp_genkey }, { "READKEY", cmd_readkey, hlp_readkey }, { "GET_PASSPHRASE", cmd_get_passphrase, hlp_get_passphrase }, { "PRESET_PASSPHRASE", cmd_preset_passphrase, hlp_preset_passphrase }, { "CLEAR_PASSPHRASE", cmd_clear_passphrase, hlp_clear_passphrase }, { "GET_CONFIRMATION", cmd_get_confirmation, hlp_get_confirmation }, { "LISTTRUSTED", cmd_listtrusted, hlp_listtrusted }, { "MARKTRUSTED", cmd_marktrusted, hlp_martrusted }, { "LEARN", cmd_learn, hlp_learn }, { "PASSWD", cmd_passwd, hlp_passwd }, { "INPUT", NULL }, { "OUTPUT", NULL }, { "SCD", cmd_scd, hlp_scd }, { "KEYWRAP_KEY", cmd_keywrap_key, hlp_keywrap_key }, { "IMPORT_KEY", cmd_import_key, hlp_import_key }, { "EXPORT_KEY", cmd_export_key, hlp_export_key }, { "DELETE_KEY", cmd_delete_key, hlp_delete_key }, { "GET_SECRET", cmd_get_secret, hlp_get_secret }, { "PUT_SECRET", cmd_put_secret, hlp_put_secret }, { "GETVAL", cmd_getval, hlp_getval }, { "PUTVAL", cmd_putval, hlp_putval }, { "UPDATESTARTUPTTY", cmd_updatestartuptty, hlp_updatestartuptty }, { "KILLAGENT", cmd_killagent, hlp_killagent }, { "RELOADAGENT", cmd_reloadagent,hlp_reloadagent }, { "GETINFO", cmd_getinfo, hlp_getinfo }, { "KEYTOCARD", cmd_keytocard, hlp_keytocard }, { NULL } }; int i, rc; for (i=0; table[i].name; i++) { rc = assuan_register_command (ctx, table[i].name, table[i].handler, table[i].help); if (rc) return rc; } assuan_register_post_cmd_notify (ctx, post_cmd_notify); assuan_register_reset_notify (ctx, reset_notify); assuan_register_option_handler (ctx, option_handler); return 0; } /* Startup the server. If LISTEN_FD and FD is given as -1, this is a simple piper server, otherwise it is a regular server. CTRL is the control structure for this connection; it has only the basic initialization. */ void start_command_handler (ctrl_t ctrl, gnupg_fd_t listen_fd, gnupg_fd_t fd) { int rc; assuan_context_t ctx = NULL; if (ctrl->restricted) { if (agent_copy_startup_env (ctrl)) return; } rc = assuan_new (&ctx); if (rc) { log_error ("failed to allocate assuan context: %s\n", gpg_strerror (rc)); agent_exit (2); } if (listen_fd == GNUPG_INVALID_FD && fd == GNUPG_INVALID_FD) { assuan_fd_t filedes[2]; filedes[0] = assuan_fdopen (0); filedes[1] = assuan_fdopen (1); rc = assuan_init_pipe_server (ctx, filedes); } else if (listen_fd != GNUPG_INVALID_FD) { rc = assuan_init_socket_server (ctx, listen_fd, 0); /* FIXME: Need to call assuan_sock_set_nonce for Windows. But this branch is currently not used. */ } else { rc = assuan_init_socket_server (ctx, fd, ASSUAN_SOCKET_SERVER_ACCEPTED); } if (rc) { log_error ("failed to initialize the server: %s\n", gpg_strerror(rc)); agent_exit (2); } rc = register_commands (ctx); if (rc) { log_error ("failed to register commands with Assuan: %s\n", gpg_strerror(rc)); agent_exit (2); } assuan_set_pointer (ctx, ctrl); ctrl->server_local = xcalloc (1, sizeof *ctrl->server_local); ctrl->server_local->assuan_ctx = ctx; ctrl->server_local->use_cache_for_signing = 1; ctrl->digest.raw_value = 0; assuan_set_io_monitor (ctx, io_monitor, NULL); agent_set_progress_cb (progress_cb, ctrl); for (;;) { assuan_peercred_t client_creds; /* Note: Points into CTX. */ pid_t pid; rc = assuan_accept (ctx); if (gpg_err_code (rc) == GPG_ERR_EOF || rc == -1) { break; } else if (rc) { log_info ("Assuan accept problem: %s\n", gpg_strerror (rc)); break; } rc = assuan_get_peercred (ctx, &client_creds); if (rc) { if (listen_fd == GNUPG_INVALID_FD && fd == GNUPG_INVALID_FD) ; else log_info ("Assuan get_peercred failed: %s\n", gpg_strerror (rc)); pid = assuan_get_pid (ctx); ctrl->client_uid = -1; } else { +#ifdef HAVE_W32_SYSTEM + pid = assuan_get_pid (ctx); + ctrl->client_uid = -1; +#else pid = client_creds->pid; ctrl->client_uid = client_creds->uid; +#endif } ctrl->client_pid = (pid == ASSUAN_INVALID_PID)? 0 : (unsigned long)pid; ctrl->server_local->connect_from_self = (pid == getpid ()); rc = assuan_process (ctx); if (rc) { log_info ("Assuan processing failed: %s\n", gpg_strerror (rc)); continue; } } /* Reset the nonce caches. */ clear_nonce_cache (ctrl); /* Reset the SCD if needed. */ agent_reset_scd (ctrl); /* Reset the pinentry (in case of popup messages). */ agent_reset_query (ctrl); /* Cleanup. */ assuan_release (ctx); xfree (ctrl->server_local->keydesc); xfree (ctrl->server_local->import_key); xfree (ctrl->server_local->export_key); if (ctrl->server_local->stopme) agent_exit (0); xfree (ctrl->server_local); ctrl->server_local = NULL; } /* Helper for the pinentry loopback mode. It merely passes the parameters on to the client. */ gpg_error_t pinentry_loopback(ctrl_t ctrl, const char *keyword, unsigned char **buffer, size_t *size, size_t max_length) { gpg_error_t rc; assuan_context_t ctx = ctrl->server_local->assuan_ctx; rc = print_assuan_status (ctx, "INQUIRE_MAXLEN", "%zu", max_length); if (rc) return rc; assuan_begin_confidential (ctx); rc = assuan_inquire (ctx, keyword, buffer, size, max_length); assuan_end_confidential (ctx); return rc; }