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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-25 10:49:57 +01:00
gnupg/common/get-passphrase.c
Werner Koch b008274afd Nuked almost all trailing white space.
We better do this once and for all instead of cluttering all future
commits with diffs of trailing white spaces.  In the majority of cases
blank or single lines are affected and thus this change won't disturb
a git blame too much.  For future commits the pre-commit scripts
checks that this won't happen again.
2011-02-04 12:57:53 +01:00

263 lines
7.8 KiB
C

/* get-passphrase.c - Ask for a passphrase via the agent
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* 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 <http://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 *homedir;
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 *homedir,
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.homedir = homedir;
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.homedir,
agentargs.agent_program,
agentargs.lc_ctype,
agentargs.lc_messages,
agentargs.session_env,
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;
}
static gpg_error_t
membuf_data_cb (void *opaque, const void *buffer, size_t length)
{
membuf_t *data = opaque;
if (buffer)
put_membuf (data, buffer, length);
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 retruned 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)-1,
"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");
line[DIM(line)-1] = 0;
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,
membuf_data_cb, &data,
default_inq_cb, NULL, NULL, NULL);
/* Older Pinentries return the old assuan error code for canceled
which gets translated bt 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)-1, "CLEAR_PASSPHRASE %s", cache_id);
line[DIM(line)-1] = 0;
return assuan_transact (agent_ctx, line, NULL, NULL,
default_inq_cb, NULL, NULL, NULL);
}