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gnupg/common/asshelp.c

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/* asshelp.c - Helper functions for Assuan
* Copyright (C) 2002, 2004, 2007, 2009, 2010 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 <unistd.h>
#include <errno.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include "i18n.h"
#include "util.h"
#include "exechelp.h"
#include "sysutils.h"
#include "status.h"
#include "membuf.h"
#include "asshelp.h"
/* The type we use for lock_agent_spawning. */
#ifdef HAVE_W32_SYSTEM
# define lock_spawn_t HANDLE
#else
# define lock_spawn_t dotlock_t
#endif
/* The time we wait until the agent or the dirmngr are ready for
operation after we started them before giving up. */
#ifdef HAVE_W32CE_SYSTEM
# define SECS_TO_WAIT_FOR_AGENT 30
# define SECS_TO_WAIT_FOR_DIRMNGR 30
#else
# define SECS_TO_WAIT_FOR_AGENT 5
# define SECS_TO_WAIT_FOR_DIRMNGR 5
#endif
/* A bitfield that specifies the assuan categories to log. This is
identical to the default log handler of libassuan. We need to do
it ourselves because we use a custom log handler and want to use
the same assuan variables to select the categories to log. */
static int log_cats;
#define TEST_LOG_CAT(x) (!! (log_cats & (1 << (x - 1))))
/* The assuan log monitor used to temporary inhibit log messages from
* assuan. */
static int (*my_log_monitor) (assuan_context_t ctx,
unsigned int cat,
const char *msg);
static int
my_libassuan_log_handler (assuan_context_t ctx, void *hook,
unsigned int cat, const char *msg)
{
unsigned int dbgval;
if (! TEST_LOG_CAT (cat))
return 0;
dbgval = hook? *(unsigned int*)hook : 0;
if (!(dbgval & 1024))
return 0; /* Assuan debugging is not enabled. */
if (ctx && my_log_monitor && !my_log_monitor (ctx, cat, msg))
return 0; /* Temporary disabled. */
if (msg)
log_string (GPGRT_LOG_DEBUG, msg);
return 1;
}
/* Setup libassuan to use our own logging functions. Should be used
early at startup. */
void
setup_libassuan_logging (unsigned int *debug_var_address,
int (*log_monitor)(assuan_context_t ctx,
unsigned int cat,
const char *msg))
{
char *flagstr;
flagstr = getenv ("ASSUAN_DEBUG");
if (flagstr)
log_cats = atoi (flagstr);
else /* Default to log the control channel. */
log_cats = (1 << (ASSUAN_LOG_CONTROL - 1));
my_log_monitor = log_monitor;
assuan_set_log_cb (my_libassuan_log_handler, debug_var_address);
}
/* Change the Libassuan log categories to those given by NEWCATS.
NEWCATS is 0 the default category of ASSUAN_LOG_CONTROL is
selected. Note, that setup_libassuan_logging overrides the values
given here. */
void
set_libassuan_log_cats (unsigned int newcats)
{
if (newcats)
log_cats = newcats;
else /* Default to log the control channel. */
log_cats = (1 << (ASSUAN_LOG_CONTROL - 1));
}
static gpg_error_t
send_one_option (assuan_context_t ctx, gpg_err_source_t errsource,
const char *name, const char *value, int use_putenv)
{
gpg_error_t err;
char *optstr;
(void)errsource;
if (!value || !*value)
err = 0; /* Avoid sending empty strings. */
else if (asprintf (&optstr, "OPTION %s%s=%s",
use_putenv? "putenv=":"", name, value) < 0)
err = gpg_error_from_syserror ();
else
{
err = assuan_transact (ctx, optstr, NULL, NULL, NULL, NULL, NULL, NULL);
xfree (optstr);
}
return err;
}
/* Send the assuan commands pertaining to the pinentry environment. The
OPT_* arguments are optional and may be used to override the
defaults taken from the current locale. */
gpg_error_t
send_pinentry_environment (assuan_context_t ctx,
gpg_err_source_t errsource,
const char *opt_lc_ctype,
const char *opt_lc_messages,
session_env_t session_env)
{
gpg_error_t err = 0;
#if defined(HAVE_SETLOCALE)
char *old_lc = NULL;
#endif
char *dft_lc = NULL;
const char *dft_ttyname;
int iterator;
const char *name, *assname, *value;
int is_default;
iterator = 0;
while ((name = session_env_list_stdenvnames (&iterator, &assname)))
{
value = session_env_getenv_or_default (session_env, name, NULL);
if (!value)
continue;
if (assname)
err = send_one_option (ctx, errsource, assname, value, 0);
else
{
err = send_one_option (ctx, errsource, name, value, 1);
if (gpg_err_code (err) == GPG_ERR_UNKNOWN_OPTION)
err = 0; /* Server too old; can't pass the new envvars. */
}
if (err)
return err;
}
dft_ttyname = session_env_getenv_or_default (session_env, "GPG_TTY",
&is_default);
if (dft_ttyname && !is_default)
dft_ttyname = NULL; /* We need the default value. */
/* Send the value for LC_CTYPE. */
#if defined(HAVE_SETLOCALE) && defined(LC_CTYPE)
old_lc = setlocale (LC_CTYPE, NULL);
if (old_lc)
{
old_lc = xtrystrdup (old_lc);
if (!old_lc)
return gpg_error_from_syserror ();
}
dft_lc = setlocale (LC_CTYPE, "");
#endif
if (opt_lc_ctype || (dft_ttyname && dft_lc))
{
err = send_one_option (ctx, errsource, "lc-ctype",
opt_lc_ctype ? opt_lc_ctype : dft_lc, 0);
}
#if defined(HAVE_SETLOCALE) && defined(LC_CTYPE)
if (old_lc)
{
setlocale (LC_CTYPE, old_lc);
xfree (old_lc);
}
#endif
if (err)
return err;
/* Send the value for LC_MESSAGES. */
#if defined(HAVE_SETLOCALE) && defined(LC_MESSAGES)
old_lc = setlocale (LC_MESSAGES, NULL);
if (old_lc)
{
old_lc = xtrystrdup (old_lc);
if (!old_lc)
return gpg_error_from_syserror ();
}
dft_lc = setlocale (LC_MESSAGES, "");
#endif
if (opt_lc_messages || (dft_ttyname && dft_lc))
{
err = send_one_option (ctx, errsource, "lc-messages",
opt_lc_messages ? opt_lc_messages : dft_lc, 0);
}
#if defined(HAVE_SETLOCALE) && defined(LC_MESSAGES)
if (old_lc)
{
setlocale (LC_MESSAGES, old_lc);
xfree (old_lc);
}
#endif
if (err)
return err;
return 0;
}
/* Lock a spawning process. The caller needs to provide the address
of a variable to store the lock information and the name or the
process. */
static gpg_error_t
lock_spawning (lock_spawn_t *lock, const char *homedir, const char *name,
int verbose)
{
#ifdef HAVE_W32_SYSTEM
int waitrc;
int timeout = (!strcmp (name, "agent")
? SECS_TO_WAIT_FOR_AGENT
: SECS_TO_WAIT_FOR_DIRMNGR);
(void)homedir; /* Not required. */
*lock = CreateMutexW
(NULL, FALSE,
!strcmp (name, "agent")? L"spawn_"GNUPG_NAME"_agent_sentinel":
!strcmp (name, "dirmngr")? L"spawn_"GNUPG_NAME"_dirmngr_sentinel":
/* */ L"spawn_"GNUPG_NAME"_unknown_sentinel");
if (!*lock)
{
log_error ("failed to create the spawn_%s mutex: %s\n",
name, w32_strerror (-1));
return gpg_error (GPG_ERR_GENERAL);
}
retry:
waitrc = WaitForSingleObject (*lock, 1000);
if (waitrc == WAIT_OBJECT_0)
return 0;
if (waitrc == WAIT_TIMEOUT && timeout)
{
timeout--;
if (verbose)
log_info ("another process is trying to start the %s ... (%ds)\n",
name, timeout);
goto retry;
}
if (waitrc == WAIT_TIMEOUT)
log_info ("error waiting for the spawn_%s mutex: timeout\n", name);
else
log_info ("error waiting for the spawn_%s mutex: (code=%d) %s\n",
name, waitrc, w32_strerror (-1));
return gpg_error (GPG_ERR_GENERAL);
#else /*!HAVE_W32_SYSTEM*/
char *fname;
(void)verbose;
*lock = NULL;
fname = make_absfilename_try
(homedir,
!strcmp (name, "agent")? "gnupg_spawn_agent_sentinel":
!strcmp (name, "dirmngr")? "gnupg_spawn_dirmngr_sentinel":
/* */ "gnupg_spawn_unknown_sentinel",
NULL);
if (!fname)
return gpg_error_from_syserror ();
*lock = dotlock_create (fname, 0);
xfree (fname);
if (!*lock)
return gpg_error_from_syserror ();
/* FIXME: We should use a timeout of 5000 here - however
make_dotlock does not yet support values other than -1 and 0. */
if (dotlock_take (*lock, -1))
return gpg_error_from_syserror ();
return 0;
#endif /*!HAVE_W32_SYSTEM*/
}
/* Unlock the spawning process. */
static void
unlock_spawning (lock_spawn_t *lock, const char *name)
{
if (*lock)
{
#ifdef HAVE_W32_SYSTEM
if (!ReleaseMutex (*lock))
log_error ("failed to release the spawn_%s mutex: %s\n",
name, w32_strerror (-1));
CloseHandle (*lock);
#else /*!HAVE_W32_SYSTEM*/
(void)name;
dotlock_destroy (*lock);
#endif /*!HAVE_W32_SYSTEM*/
*lock = NULL;
}
}
/* Try to connect to the agent via socket or start it if it is not
running and AUTOSTART is set. Handle the server's initial
greeting. Returns a new assuan context at R_CTX or an error
code. */
gpg_error_t
start_new_gpg_agent (assuan_context_t *r_ctx,
gpg_err_source_t errsource,
const char *agent_program,
const char *opt_lc_ctype,
const char *opt_lc_messages,
session_env_t session_env,
int autostart, int verbose, int debug,
gpg_error_t (*status_cb)(ctrl_t, int, ...),
ctrl_t status_cb_arg)
{
gpg_error_t err;
assuan_context_t ctx;
int did_success_msg = 0;
char *sockname;
const char *argv[6];
*r_ctx = NULL;
err = assuan_new (&ctx);
if (err)
{
log_error ("error allocating assuan context: %s\n", gpg_strerror (err));
return err;
}
sockname = make_filename_try (gnupg_socketdir (), GPG_AGENT_SOCK_NAME, NULL);
if (!sockname)
{
err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
assuan_release (ctx);
return err;
}
err = assuan_socket_connect (ctx, sockname, 0, 0);
if (err && autostart)
{
char *abs_homedir;
lock_spawn_t lock;
char *program = NULL;
const char *program_arg = NULL;
char *p;
const char *s;
int i;
/* With no success start a new server. */
if (!agent_program || !*agent_program)
agent_program = gnupg_module_name (GNUPG_MODULE_NAME_AGENT);
else if ((s=strchr (agent_program, '|')) && s[1] == '-' && s[2]=='-')
{
/* Hack to insert an additional option on the command line. */
program = xtrystrdup (agent_program);
if (!program)
{
gpg_error_t tmperr = gpg_err_make (errsource,
gpg_err_code_from_syserror ());
xfree (sockname);
assuan_release (ctx);
return tmperr;
}
p = strchr (program, '|');
*p++ = 0;
program_arg = p;
}
if (verbose)
log_info (_("no running gpg-agent - starting '%s'\n"),
agent_program);
if (status_cb)
status_cb (status_cb_arg, STATUS_PROGRESS,
"starting_agent ? 0 0", NULL);
/* We better pass an absolute home directory to the agent just
in case gpg-agent does not convert the passed name to an
absolute one (which it should do). */
abs_homedir = make_absfilename_try (gnupg_homedir (), NULL);
if (!abs_homedir)
{
gpg_error_t tmperr = gpg_err_make (errsource,
gpg_err_code_from_syserror ());
log_error ("error building filename: %s\n",gpg_strerror (tmperr));
xfree (sockname);
assuan_release (ctx);
xfree (program);
return tmperr;
}
if (fflush (NULL))
{
gpg_error_t tmperr = gpg_err_make (errsource,
gpg_err_code_from_syserror ());
log_error ("error flushing pending output: %s\n",
strerror (errno));
xfree (sockname);
assuan_release (ctx);
xfree (abs_homedir);
xfree (program);
return tmperr;
}
/* If the agent has been configured for use with a standard
socket, an environment variable is not required and thus
we we can savely start the agent here. */
i = 0;
argv[i++] = "--homedir";
argv[i++] = abs_homedir;
argv[i++] = "--use-standard-socket";
if (program_arg)
argv[i++] = program_arg;
argv[i++] = "--daemon";
argv[i++] = NULL;
if (!(err = lock_spawning (&lock, gnupg_homedir (), "agent", verbose))
&& assuan_socket_connect (ctx, sockname, 0, 0))
{
err = gnupg_spawn_process_detached (program? program : agent_program,
argv, NULL);
if (err)
log_error ("failed to start agent '%s': %s\n",
agent_program, gpg_strerror (err));
else
{
for (i=0; i < SECS_TO_WAIT_FOR_AGENT; i++)
{
if (verbose)
log_info (_("waiting for the agent to come up ... (%ds)\n"),
SECS_TO_WAIT_FOR_AGENT - i);
gnupg_sleep (1);
err = assuan_socket_connect (ctx, sockname, 0, 0);
if (!err)
{
if (verbose)
{
log_info (_("connection to agent established\n"));
did_success_msg = 1;
}
break;
}
}
}
}
unlock_spawning (&lock, "agent");
xfree (abs_homedir);
xfree (program);
}
xfree (sockname);
if (err)
{
if (autostart || gpg_err_code (err) != GPG_ERR_ASS_CONNECT_FAILED)
log_error ("can't connect to the agent: %s\n", gpg_strerror (err));
assuan_release (ctx);
return gpg_err_make (errsource, GPG_ERR_NO_AGENT);
}
if (debug && !did_success_msg)
log_debug ("connection to agent established\n");
err = assuan_transact (ctx, "RESET",
NULL, NULL, NULL, NULL, NULL, NULL);
if (!err)
{
err = send_pinentry_environment (ctx, errsource,
opt_lc_ctype, opt_lc_messages,
session_env);
if (gpg_err_code (err) == GPG_ERR_FORBIDDEN
&& gpg_err_source (err) == GPG_ERR_SOURCE_GPGAGENT)
{
/* Check whether we are in restricted mode. */
if (!assuan_transact (ctx, "GETINFO restricted",
NULL, NULL, NULL, NULL, NULL, NULL))
{
if (verbose)
log_info (_("connection to agent is in restricted mode\n"));
err = 0;
}
}
}
if (err)
{
assuan_release (ctx);
return err;
}
*r_ctx = ctx;
return 0;
}
/* Try to connect to the dirmngr via a socket. On platforms
supporting it, start it up if needed and if AUTOSTART is true.
Returns a new assuan context at R_CTX or an error code. */
gpg_error_t
start_new_dirmngr (assuan_context_t *r_ctx,
gpg_err_source_t errsource,
const char *dirmngr_program,
int autostart,
int verbose, int debug,
gpg_error_t (*status_cb)(ctrl_t, int, ...),
ctrl_t status_cb_arg)
{
gpg_error_t err;
assuan_context_t ctx;
const char *sockname;
int did_success_msg = 0;
*r_ctx = NULL;
err = assuan_new (&ctx);
if (err)
{
log_error ("error allocating assuan context: %s\n", gpg_strerror (err));
return err;
}
sockname = dirmngr_socket_name ();
err = assuan_socket_connect (ctx, sockname, 0, 0);
#ifdef USE_DIRMNGR_AUTO_START
if (err && autostart)
{
lock_spawn_t lock;
const char *argv[4];
char *abs_homedir;
/* No connection: Try start a new Dirmngr. */
if (!dirmngr_program || !*dirmngr_program)
dirmngr_program = gnupg_module_name (GNUPG_MODULE_NAME_DIRMNGR);
if (verbose)
log_info (_("no running Dirmngr - starting '%s'\n"),
dirmngr_program);
if (status_cb)
status_cb (status_cb_arg, STATUS_PROGRESS,
"starting_dirmngr ? 0 0", NULL);
abs_homedir = make_absfilename (gnupg_homedir (), NULL);
if (!abs_homedir)
{
gpg_error_t tmperr = gpg_err_make (errsource,
gpg_err_code_from_syserror ());
log_error ("error building filename: %s\n",gpg_strerror (tmperr));
assuan_release (ctx);
return tmperr;
}
if (fflush (NULL))
{
gpg_error_t tmperr = gpg_err_make (errsource,
gpg_err_code_from_syserror ());
log_error ("error flushing pending output: %s\n",
strerror (errno));
assuan_release (ctx);
return tmperr;
}
argv[0] = "--daemon";
/* Try starting the daemon. Versions of dirmngr < 2.1.15 do
* this only if the home directory is given on the command line. */
argv[1] = "--homedir";
argv[2] = abs_homedir;
argv[3] = NULL;
if (!(err = lock_spawning (&lock, gnupg_homedir (), "dirmngr", verbose))
&& assuan_socket_connect (ctx, sockname, 0, 0))
{
err = gnupg_spawn_process_detached (dirmngr_program, argv, NULL);
if (err)
log_error ("failed to start the dirmngr '%s': %s\n",
dirmngr_program, gpg_strerror (err));
else
{
int i;
for (i=0; i < SECS_TO_WAIT_FOR_DIRMNGR; i++)
{
if (verbose)
log_info (_("waiting for the dirmngr "
"to come up ... (%ds)\n"),
SECS_TO_WAIT_FOR_DIRMNGR - i);
gnupg_sleep (1);
err = assuan_socket_connect (ctx, sockname, 0, 0);
if (!err)
{
if (verbose)
{
log_info (_("connection to the dirmngr"
" established\n"));
did_success_msg = 1;
}
break;
}
}
}
}
unlock_spawning (&lock, "dirmngr");
xfree (abs_homedir);
}
#else
(void)dirmngr_program;
(void)verbose;
(void)status_cb;
(void)status_cb_arg;
#endif /*USE_DIRMNGR_AUTO_START*/
if (err)
{
if (autostart || gpg_err_code (err) != GPG_ERR_ASS_CONNECT_FAILED)
log_error ("connecting dirmngr at '%s' failed: %s\n",
sockname, gpg_strerror (err));
assuan_release (ctx);
return gpg_err_make (errsource, GPG_ERR_NO_DIRMNGR);
}
if (debug && !did_success_msg)
log_debug ("connection to the dirmngr established\n");
*r_ctx = ctx;
return 0;
}
/* Return the version of a server using "GETINFO version". On success
0 is returned and R_VERSION receives a malloced string with the
version which must be freed by the caller. On error NULL is stored
at R_VERSION and an error code returned. Mode is in general 0 but
certain values may be used to modify the used version command:
MODE == 0 = Use "GETINFO version"
MODE == 2 - Use "SCD GETINFO version"
*/
gpg_error_t
get_assuan_server_version (assuan_context_t ctx, int mode, char **r_version)
{
gpg_error_t err;
membuf_t data;
init_membuf (&data, 64);
err = assuan_transact (ctx,
mode == 2? "SCD GETINFO version"
/**/ : "GETINFO version",
put_membuf_cb, &data,
NULL, NULL, NULL, NULL);
if (err)
{
xfree (get_membuf (&data, NULL));
*r_version = NULL;
}
else
{
put_membuf (&data, "", 1);
*r_version = get_membuf (&data, NULL);
if (!*r_version)
err = gpg_error_from_syserror ();
}
return err;
}
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