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get-passphrase.c
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/* get-passphrase.c - Ask for a passphrase via the agent
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either
*
* - the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* or
*
* - the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* or both in parallel, as here.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <assuan.h>
#include "util.h"
#include "i18n.h"
#include "asshelp.h"
#include "membuf.h"
#include "sysutils.h"
#include "get-passphrase.h"
/* The context used by this process to ask for the passphrase. */
static assuan_context_t agent_ctx;
static struct
{
gpg_err_source_t errsource;
int verbosity;
const char *agent_program;
const char *lc_ctype;
const char *lc_messages;
session_env_t session_env;
const char *pinentry_user_data;
} agentargs;
/* Set local variable to be used for a possible agent startup. Note
that the strings are just pointers and should not anymore be
modified by the caller. */
void
gnupg_prepare_get_passphrase (gpg_err_source_t errsource,
int verbosity,
const char *agent_program,
const char *opt_lc_ctype,
const char *opt_lc_messages,
session_env_t session_env)
{
agentargs.errsource = errsource;
agentargs.verbosity = verbosity;
agentargs.agent_program = agent_program;
agentargs.lc_ctype = opt_lc_ctype;
agentargs.lc_messages = opt_lc_messages;
agentargs.session_env = session_env;
}
/* Try to connect to the agent via socket or fork it off and work by
pipes. Handle the server's initial greeting. */
static gpg_error_t
start_agent (void)
{
gpg_error_t err;
/* Fixme: This code is not thread safe, thus we don't build it with
pth. We will need a context for each thread or serialize the
access to the agent. */
if (agent_ctx)
return 0;
err = start_new_gpg_agent (&agent_ctx,
agentargs.errsource,
agentargs.agent_program,
agentargs.lc_ctype,
agentargs.lc_messages,
agentargs.session_env,
1, agentargs.verbosity, 0, NULL, NULL);
if (!err)
{
/* Tell the agent that we support Pinentry notifications. No
error checking so that it will work with older agents. */
assuan_transact (agent_ctx, "OPTION allow-pinentry-notify",
NULL, NULL, NULL, NULL, NULL, NULL);
}
return err;
}
/* This is the default inquiry callback. It merely handles the
Pinentry notification. */
static gpg_error_t
default_inq_cb (void *opaque, const char *line)
{
(void)opaque;
if (!strncmp (line, "PINENTRY_LAUNCHED", 17) && (line[17]==' '||!line[17]))
{
gnupg_allow_set_foregound_window ((pid_t)strtoul (line+17, NULL, 10));
/* We do not return errors to avoid breaking other code. */
}
else
log_debug ("ignoring gpg-agent inquiry '%s'\n", line);
return 0;
}
/* Ask for a passphrase via gpg-agent. On success the caller needs to
free the string stored at R_PASSPHRASE. On error NULL will be
stored at R_PASSPHRASE and an appropriate gpg error code is
returned. With REPEAT set to 1, gpg-agent will ask the user to
repeat the just entered passphrase. CACHE_ID is a gpg-agent style
passphrase cache id or NULL. ERR_MSG is a error message to be
presented to the user (e.g. "bad passphrase - try again") or NULL.
PROMPT is the prompt string to label the entry box, it may be NULL
for a default one. DESC_MSG is a longer description to be
displayed above the entry box, if may be NULL for a default one.
If USE_SECMEM is true, the returned passphrase is returned in
secure memory. The length of all these strings is limited; they
need to fit in their encoded form into a standard Assuan line (i.e
less then about 950 characters). All strings shall be UTF-8. */
gpg_error_t
gnupg_get_passphrase (const char *cache_id,
const char *err_msg,
const char *prompt,
const char *desc_msg,
int repeat,
int check_quality,
int use_secmem,
char **r_passphrase)
{
gpg_error_t err;
char line[ASSUAN_LINELENGTH];
const char *arg1 = NULL;
char *arg2 = NULL;
char *arg3 = NULL;
char *arg4 = NULL;
membuf_t data;
*r_passphrase = NULL;
err = start_agent ();
if (err)
return err;
/* Check that the gpg-agent understands the repeat option. */
if (assuan_transact (agent_ctx,
"GETINFO cmd_has_option GET_PASSPHRASE repeat",
NULL, NULL, NULL, NULL, NULL, NULL))
return gpg_error (GPG_ERR_NOT_SUPPORTED);
arg1 = cache_id && *cache_id? cache_id:NULL;
if (err_msg && *err_msg)
if (!(arg2 = percent_plus_escape (err_msg)))
goto no_mem;
if (prompt && *prompt)
if (!(arg3 = percent_plus_escape (prompt)))
goto no_mem;
if (desc_msg && *desc_msg)
if (!(arg4 = percent_plus_escape (desc_msg)))
goto no_mem;
snprintf (line, DIM(line),
"GET_PASSPHRASE --data %s--repeat=%d -- %s %s %s %s",
check_quality? "--check ":"",
repeat,
arg1? arg1:"X",
arg2? arg2:"X",
arg3? arg3:"X",
arg4? arg4:"X");
xfree (arg2);
xfree (arg3);
xfree (arg4);
if (use_secmem)
init_membuf_secure (&data, 64);
else
init_membuf (&data, 64);
err = assuan_transact (agent_ctx, line,
put_membuf_cb, &data,
default_inq_cb, NULL, NULL, NULL);
/* Older Pinentries return the old assuan error code for canceled
which gets translated by libassuan to GPG_ERR_ASS_CANCELED and
not to the code for a user cancel. Fix this here. */
if (err && gpg_err_source (err)
&& gpg_err_code (err) == GPG_ERR_ASS_CANCELED)
err = gpg_err_make (gpg_err_source (err), GPG_ERR_CANCELED);
if (err)
{
void *p;
size_t n;
p = get_membuf (&data, &n);
if (p)
wipememory (p, n);
xfree (p);
}
else
{
put_membuf (&data, "", 1);
*r_passphrase = get_membuf (&data, NULL);
if (!*r_passphrase)
err = gpg_error_from_syserror ();
}
return err;
no_mem:
err = gpg_error_from_syserror ();
xfree (arg2);
xfree (arg3);
xfree (arg4);
return err;
}
/* Flush the passphrase cache with Id CACHE_ID. */
gpg_error_t
gnupg_clear_passphrase (const char *cache_id)
{
gpg_error_t err;
char line[ASSUAN_LINELENGTH];
if (!cache_id || !*cache_id)
return 0;
err = start_agent ();
if (err)
return err;
snprintf (line, DIM(line), "CLEAR_PASSPHRASE %s", cache_id);
return assuan_transact (agent_ctx, line, NULL, NULL,
default_inq_cb, NULL, NULL, NULL);
}

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Tue, Oct 7, 3:51 AM (1 d, 10 h)
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Storage Format
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Storage Handle
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