/* g13-syshelp.c - Helper for disk key management with GnuPG
* Copyright (C) 2015 Werner Koch
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#ifdef HAVE_PWD_H
# include <pwd.h>
#endif
#include <unistd.h>
#define INCLUDED_BY_MAIN_MODULE 1
#include "g13-syshelp.h"
#include <gcrypt.h>
#include <assuan.h>
#include "../common/i18n.h"
#include "../common/sysutils.h"
#include "../common/asshelp.h"
#include "../common/init.h"
#include "keyblob.h"
enum cmd_and_opt_values {
aNull = 0,
oQuiet = 'q',
oVerbose = 'v',
oRecipient = 'r',
aGPGConfList = 500,
oDebug,
oDebugLevel,
oDebugAll,
oDebugNone,
oDebugWait,
oDebugAllowCoreDump,
oLogFile,
oNoLogFile,
oAuditLog,
oOutput,
oAgentProgram,
oGpgProgram,
oType,
oDisplay,
oTTYname,
oTTYtype,
oLCctype,
oLCmessages,
oXauthority,
oStatusFD,
oLoggerFD,
oNoVerbose,
oNoSecmemWarn,
oHomedir,
oDryRun,
oNoDetach,
oNoRandomSeedFile,
oFakedSystemTime
};
static gpgrt_opt_t opts[] = {
ARGPARSE_s_n (oDryRun, "dry-run", N_("do not make any changes")),
ARGPARSE_s_n (oVerbose, "verbose", N_("verbose")),
ARGPARSE_s_n (oQuiet, "quiet", N_("be somewhat more quiet")),
ARGPARSE_s_s (oDebug, "debug", "@"),
ARGPARSE_s_s (oDebugLevel, "debug-level",
N_("|LEVEL|set the debugging level to LEVEL")),
ARGPARSE_s_n (oDebugAll, "debug-all", "@"),
ARGPARSE_s_n (oDebugNone, "debug-none", "@"),
ARGPARSE_s_i (oDebugWait, "debug-wait", "@"),
ARGPARSE_s_n (oDebugAllowCoreDump, "debug-allow-core-dump", "@"),
ARGPARSE_end ()
};
/* The list of supported debug flags. */
static struct debug_flags_s debug_flags [] =
{
{ DBG_MOUNT_VALUE , "mount" },
{ DBG_CRYPTO_VALUE , "crypto" },
{ DBG_MEMORY_VALUE , "memory" },
{ DBG_MEMSTAT_VALUE, "memstat" },
{ DBG_IPC_VALUE , "ipc" },
{ 0, NULL }
};
/* The timer tick interval used by the idle task. */
#define TIMERTICK_INTERVAL_SEC (1)
/* It is possible that we are currently running under setuid permissions. */
static int maybe_setuid = 1;
/* Helper to implement --debug-level and --debug. */
static const char *debug_level;
static unsigned int debug_value;
/* Local prototypes. */
static void g13_syshelp_deinit_default_ctrl (ctrl_t ctrl);
static void release_tab_items (tab_item_t tab);
static tab_item_t parse_g13tab (const char *username);
static const char *
my_strusage( int level )
{
const char *p;
switch (level)
{
case 9: p = "GPL-3.0-or-later"; break;
case 11: p = "@G13@-syshelp (@GNUPG@)";
break;
case 13: p = VERSION; break;
case 14: p = GNUPG_DEF_COPYRIGHT_LINE; break;
case 17: p = PRINTABLE_OS_NAME; break;
case 19: p = _("Please report bugs to <" PACKAGE_BUGREPORT ">.\n");
break;
case 1:
case 40: p = _("Usage: @G13@-syshelp [options] [files] (-h for help)");
break;
case 41:
p = _("Syntax: @G13@-syshelp [options] [files]\n"
"Helper to perform root-only tasks for g13\n");
break;
case 31: p = "\nHome: "; break;
case 32: p = gnupg_homedir (); break;
default: p = NULL; break;
}
return p;
}
/* Setup the debugging. With a DEBUG_LEVEL of NULL only the active
debug flags are propagated to the subsystems. With DEBUG_LEVEL
set, a specific set of debug flags is set; and individual debugging
flags will be added on top. */
static void
set_debug (void)
{
int numok = (debug_level && digitp (debug_level));
int numlvl = numok? atoi (debug_level) : 0;
if (!debug_level)
;
else if (!strcmp (debug_level, "none") || (numok && numlvl < 1))
opt.debug = 0;
else if (!strcmp (debug_level, "basic") || (numok && numlvl <= 2))
opt.debug = DBG_IPC_VALUE|DBG_MOUNT_VALUE;
else if (!strcmp (debug_level, "advanced") || (numok && numlvl <= 5))
opt.debug = DBG_IPC_VALUE|DBG_MOUNT_VALUE;
else if (!strcmp (debug_level, "expert") || (numok && numlvl <= 8))
opt.debug = (DBG_IPC_VALUE|DBG_MOUNT_VALUE|DBG_CRYPTO_VALUE);
else if (!strcmp (debug_level, "guru") || numok)
{
opt.debug = ~0;
/* if (numok) */
/* opt.debug &= ~(DBG_HASHING_VALUE); */
}
else
{
log_error (_("invalid debug-level '%s' given\n"), debug_level);
g13_exit(2);
}
opt.debug |= debug_value;
if (opt.debug && !opt.verbose)
opt.verbose = 1;
if (opt.debug)
opt.quiet = 0;
if (opt.debug & DBG_CRYPTO_VALUE )
gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 1);
gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
if (opt.debug)
parse_debug_flag (NULL, &opt.debug, debug_flags);
}
int
main (int argc, char **argv)
{
gpgrt_argparse_t pargs;
int orig_argc;
char **orig_argv;
gpg_error_t err = 0;
/* const char *fname; */
int may_coredump;
char *last_configname = NULL;
const char *configname = NULL;
int debug_argparser = 0;
int no_more_options = 0;
char *logfile = NULL;
/* int debug_wait = 0; */
int use_random_seed = 1;
/* int nodetach = 0; */
/* int nokeysetup = 0; */
struct server_control_s ctrl;
/*mtrace();*/
early_system_init ();
gnupg_reopen_std (G13_NAME "-syshelp");
gpgrt_set_strusage (my_strusage);
gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
log_set_prefix (G13_NAME "-syshelp", GPGRT_LOG_WITH_PREFIX);
/* Make sure that our subsystems are ready. */
i18n_init ();
init_common_subsystems (&argc, &argv);
/* Take extra care of the random pool. */
gcry_control (GCRYCTL_USE_SECURE_RNDPOOL);
may_coredump = disable_core_dumps ();
g13_init_signals ();
dotlock_create (NULL, 0); /* Register locking cleanup. */
opt.session_env = session_env_new ();
if (!opt.session_env)
log_fatal ("error allocating session environment block: %s\n",
strerror (errno));
/* First check whether we have a debug option on the commandline. */
orig_argc = argc;
orig_argv = argv;
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags= (ARGPARSE_FLAG_KEEP | ARGPARSE_FLAG_NOVERSION);
while (gpgrt_argparse (NULL, &pargs, opts))
{
switch (pargs.r_opt)
{
case oDebug:
case oDebugAll:
debug_argparser++;
break;
}
}
/* Reset the flags. */
pargs.flags &= ~(ARGPARSE_FLAG_KEEP | ARGPARSE_FLAG_NOVERSION);
/* Initialize the secure memory. */
gcry_control (GCRYCTL_INIT_SECMEM, 16384, 0);
maybe_setuid = 0;
/*
* Now we are working under our real uid
*/
/* Setup malloc hooks. */
{
struct assuan_malloc_hooks malloc_hooks;
malloc_hooks.malloc = gcry_malloc;
malloc_hooks.realloc = gcry_realloc;
malloc_hooks.free = gcry_free;
assuan_set_malloc_hooks (&malloc_hooks);
}
/* Prepare libassuan. */
assuan_set_gpg_err_source (GPG_ERR_SOURCE_DEFAULT);
setup_libassuan_logging (&opt.debug, NULL);
/* Setup a default control structure for command line mode. */
memset (&ctrl, 0, sizeof ctrl);
g13_syshelp_init_default_ctrl (&ctrl);
ctrl.no_server = 1;
ctrl.status_fd = -1; /* No status output. */
/* The configuraton directories for use by gpgrt_argparser. */
gpgrt_set_confdir (GPGRT_CONFDIR_SYS, gnupg_sysconfdir ());
gpgrt_set_confdir (GPGRT_CONFDIR_USER, gnupg_homedir ());
argc = orig_argc;
argv = orig_argv;
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags |= (ARGPARSE_FLAG_RESET
| ARGPARSE_FLAG_KEEP
| ARGPARSE_FLAG_SYS
| ARGPARSE_FLAG_USER);
while (!no_more_options
&& gpgrt_argparser (&pargs, opts, G13_NAME"-syshelp" EXTSEP_S "conf"))
{
switch (pargs.r_opt)
{
case ARGPARSE_CONFFILE:
{
if (debug_argparser)
log_info (_("reading options from '%s'\n"),
pargs.r_type? pargs.r.ret_str: "[cmdline]");
if (pargs.r_type)
{
xfree (last_configname);
last_configname = xstrdup (pargs.r.ret_str);
configname = last_configname;
}
else
configname = NULL;
}
break;
case oQuiet: opt.quiet = 1; break;
case oDryRun: opt.dry_run = 1; break;
case oVerbose:
opt.verbose++;
gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
break;
case oNoVerbose:
opt.verbose = 0;
gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
break;
case oLogFile: logfile = pargs.r.ret_str; break;
case oNoLogFile: logfile = NULL; break;
case oNoDetach: /*nodetach = 1; */break;
case oDebug:
if (parse_debug_flag (pargs.r.ret_str, &opt.debug, debug_flags))
{
pargs.r_opt = ARGPARSE_INVALID_ARG;
pargs.err = ARGPARSE_PRINT_ERROR;
}
break;
case oDebugAll: debug_value = ~0; break;
case oDebugNone: debug_value = 0; break;
case oDebugLevel: debug_level = pargs.r.ret_str; break;
case oDebugWait: /*debug_wait = pargs.r.ret_int; */break;
case oDebugAllowCoreDump:
may_coredump = enable_core_dumps ();
break;
case oStatusFD: ctrl.status_fd = pargs.r.ret_int; break;
case oLoggerFD: log_set_fd (pargs.r.ret_int ); break;
case oHomedir: gnupg_set_homedir (pargs.r.ret_str); break;
case oFakedSystemTime:
{
time_t faked_time = isotime2epoch (pargs.r.ret_str);
if (faked_time == (time_t)(-1))
faked_time = (time_t)strtoul (pargs.r.ret_str, NULL, 10);
gnupg_set_time (faked_time, 0);
}
break;
case oNoSecmemWarn: gcry_control (GCRYCTL_DISABLE_SECMEM_WARN); break;
case oNoRandomSeedFile: use_random_seed = 0; break;
default:
pargs.err = configname? ARGPARSE_PRINT_WARNING:ARGPARSE_PRINT_ERROR;
break;
}
}
gpgrt_argparse (NULL, &pargs, NULL);
if (!last_configname)
opt.config_filename = gpgrt_fnameconcat (gnupg_homedir (),
G13_NAME"-syshelp" EXTSEP_S "conf",
NULL);
else
{
opt.config_filename = last_configname;
last_configname = NULL;
}
if (log_get_errorcount(0))
g13_exit(2);
/* Now that we have the options parsed we need to update the default
control structure. */
g13_syshelp_init_default_ctrl (&ctrl);
if (may_coredump && !opt.quiet)
log_info (_("WARNING: program may create a core file!\n"));
if (logfile)
{
log_set_file (logfile);
log_set_prefix (NULL, GPGRT_LOG_WITH_PREFIX | GPGRT_LOG_WITH_TIME | GPGRT_LOG_WITH_PID);
}
if (gnupg_faked_time_p ())
{
gnupg_isotime_t tbuf;
log_info (_("WARNING: running with faked system time: "));
gnupg_get_isotime (tbuf);
dump_isotime (tbuf);
log_printf ("\n");
}
/* Print any pending secure memory warnings. */
gcry_control (GCRYCTL_RESUME_SECMEM_WARN);
/* Setup the debug flags for all subsystems. */
set_debug ();
/* Install a regular exit handler to make real sure that the secure
memory gets wiped out. */
g13_install_emergency_cleanup ();
/* Terminate if we found any error until now. */
if (log_get_errorcount(0))
g13_exit (2);
/* Set the standard GnuPG random seed file. */
if (use_random_seed)
{
char *p = make_filename (gnupg_homedir (), "random_seed", NULL);
gcry_control (GCRYCTL_SET_RANDOM_SEED_FILE, p);
xfree(p);
}
/* Get the UID of the caller. */
#if defined(HAVE_PWD_H) && defined(HAVE_GETPWUID)
{
const char *uidstr;
struct passwd *pwd = NULL;
uidstr = getenv ("USERV_UID");
/* Print a quick note if we are not started via userv. */
if (!uidstr)
{
if (getuid ())
{
log_info ("WARNING: Not started via userv\n");
ctrl.fail_all_cmds = 1;
}
ctrl.client.uid = getuid ();
}
else
{
unsigned long myuid;
errno = 0;
myuid = strtoul (uidstr, NULL, 10);
if (myuid == ULONG_MAX && errno)
{
log_info ("WARNING: Started via broken userv: %s\n",
strerror (errno));
ctrl.fail_all_cmds = 1;
ctrl.client.uid = getuid ();
}
else
ctrl.client.uid = (uid_t)myuid;
}
pwd = getpwuid (ctrl.client.uid);
if (!pwd || !*pwd->pw_name)
{
log_info ("WARNING: Name for UID not found: %s\n", strerror (errno));
ctrl.fail_all_cmds = 1;
ctrl.client.uname = xstrdup ("?");
}
else
ctrl.client.uname = xstrdup (pwd->pw_name);
/* Check that the user name does not contain a directory
separator. */
if (strchr (ctrl.client.uname, '/'))
{
log_info ("WARNING: Invalid user name passed\n");
ctrl.fail_all_cmds = 1;
}
}
#else /*!HAVE_PWD_H || !HAVE_GETPWUID*/
log_info ("WARNING: System does not support required syscalls\n");
ctrl.fail_all_cmds = 1;
ctrl.client.uid = getuid ();
ctrl.client.uname = xstrdup ("?");
#endif /*!HAVE_PWD_H || !HAVE_GETPWUID*/
/* Read the table entries for this user. */
if (!ctrl.fail_all_cmds
&& !(ctrl.client.tab = parse_g13tab (ctrl.client.uname)))
ctrl.fail_all_cmds = 1;
/* Start the server. */
err = syshelp_server (&ctrl);
if (err)
log_error ("server exited with error: %s <%s>\n",
gpg_strerror (err), gpg_strsource (err));
/* Cleanup. */
g13_syshelp_deinit_default_ctrl (&ctrl);
g13_exit (0);
return 8; /*NOTREACHED*/
}
/* Store defaults into the per-connection CTRL object. */
void
g13_syshelp_init_default_ctrl (ctrl_t ctrl)
{
ctrl->conttype = CONTTYPE_DM_CRYPT;
}
/* Release all resources allocated by default in the CTRl object. */
static void
g13_syshelp_deinit_default_ctrl (ctrl_t ctrl)
{
xfree (ctrl->client.uname);
release_tab_items (ctrl->client.tab);
}
/* Release the list of g13tab itejms at TAB. */
static void
release_tab_items (tab_item_t tab)
{
while (tab)
{
tab_item_t next = tab->next;
xfree (tab->mountpoint);
xfree (tab);
tab = next;
}
}
void
g13_syshelp_i_know_what_i_am_doing (void)
{
const char * const yesfile = "Yes-g13-I-know-what-I-am-doing";
char *fname;
fname = make_filename (gnupg_sysconfdir (), yesfile, NULL);
if (gnupg_access (fname, F_OK))
{
log_info ("*******************************************************\n");
log_info ("* The G13 support for DM-Crypt is new and not matured.\n");
log_info ("* Bugs or improper use may delete all your disks!\n");
log_info ("* To confirm that you are ware of this risk, create\n");
log_info ("* the file '%s'.\n", fname);
log_info ("*******************************************************\n");
exit (1);
}
xfree (fname);
}
/* Parse the /etc/gnupg/g13tab for user USERNAME. Return a table for
the user on success. Return NULL on error and print
diagnostics. */
static tab_item_t
parse_g13tab (const char *username)
{
gpg_error_t err;
int c, n;
char line[512];
char *p;
char *fname;
estream_t fp;
int lnr;
char **words = NULL;
tab_item_t table = NULL;
tab_item_t *tabletail, ti;
fname = make_filename (gnupg_sysconfdir (), G13_NAME"tab", NULL);
fp = es_fopen (fname, "r");
if (!fp)
{
err = gpg_error_from_syserror ();
log_error (_("error opening '%s': %s\n"), fname, gpg_strerror (err));
goto leave;
}
tabletail = &table;
err = 0;
lnr = 0;
while (es_fgets (line, DIM(line)-1, fp))
{
lnr++;
n = strlen (line);
if (!n || line[n-1] != '\n')
{
/* Eat until end of line. */
while ((c=es_getc (fp)) != EOF && c != '\n')
;
err = gpg_error (*line? GPG_ERR_LINE_TOO_LONG
: GPG_ERR_INCOMPLETE_LINE);
log_error (_("file '%s', line %d: %s\n"),
fname, lnr, gpg_strerror (err));
continue;
}
line[--n] = 0; /* Chop the LF. */
if (n && line[n-1] == '\r')
line[--n] = 0; /* Chop an optional CR. */
/* Allow for empty lines and spaces */
for (p=line; spacep (p); p++)
;
if (!*p || *p == '#')
continue;
/* Parse the line. The format is
* <username> <blockdev> [<label>|"-" [<mountpoint>]]
*/
xfree (words);
words = strtokenize (p, " \t");
if (!words)
{
err = gpg_error_from_syserror ();
break;
}
if (!words[0] || !words[1])
{
log_error (_("file '%s', line %d: %s\n"),
fname, lnr, gpg_strerror (GPG_ERR_SYNTAX));
continue;
}
if (!(*words[1] == '/'
|| !strncmp (words[1], "PARTUUID=", 9)
|| !strncmp (words[1], "partuuid=", 9)))
{
log_error (_("file '%s', line %d: %s\n"),
fname, lnr, "Invalid block device syntax");
continue;
}
if (words[2])
{
if (strlen (words[2]) > 16 || strchr (words[2], '/'))
{
log_error (_("file '%s', line %d: %s\n"),
fname, lnr, "Label too long or invalid syntax");
continue;
}
if (words[3] && *words[3] != '/')
{
log_error (_("file '%s', line %d: %s\n"),
fname, lnr, "Invalid mountpoint syntax");
continue;
}
}
if (strcmp (words[0], username))
continue; /* Skip entries for other usernames! */
ti = xtrymalloc (sizeof *ti + strlen (words[1]));
if (!ti)
{
err = gpg_error_from_syserror ();
break;
}
ti->next = NULL;
ti->label = NULL;
ti->mountpoint = NULL;
strcpy (ti->blockdev, *words[1]=='/'? words[1] : words[1]+9);
if (words[2])
{
if (strcmp (words[2], "-")
&& !(ti->label = xtrystrdup (words[2])))
{
err = gpg_error_from_syserror ();
xfree (ti);
break;
}
if (words[3] && !(ti->mountpoint = xtrystrdup (words[3])))
{
err = gpg_error_from_syserror ();
xfree (ti->label);
xfree (ti);
break;
}
}
*tabletail = ti;
tabletail = &ti->next;
}
if (!err && !es_feof (fp))
err = gpg_error_from_syserror ();
if (err)
log_error (_("error reading '%s', line %d: %s\n"),
fname, lnr, gpg_strerror (err));
leave:
xfree (words);
es_fclose (fp);
xfree (fname);
if (err)
{
release_tab_items (table);
return NULL;
}
return table;
}