gnupg/agent/protect-tool.c

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/* protect-tool.c - A tool to test the secret key protection
* Copyright (C) 2002, 2003, 2004, 2006 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 <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#ifdef HAVE_LANGINFO_CODESET
#include <langinfo.h>
#endif
#ifdef HAVE_DOSISH_SYSTEM
#include <fcntl.h> /* for setmode() */
#endif
#define INCLUDED_BY_MAIN_MODULE 1
#include "agent.h"
#include "../common/i18n.h"
#include "../common/get-passphrase.h"
#include "../common/sysutils.h"
#include "../common/init.h"
enum cmd_and_opt_values
{
aNull = 0,
oVerbose = 'v',
oArmor = 'a',
oPassphrase = 'P',
oProtect = 'p',
oUnprotect = 'u',
oNoVerbose = 500,
oShadow,
oShowShadowInfo,
oShowKeygrip,
oS2Kcalibration,
oCanonical,
oStore,
oForce,
oHaveCert,
oNoFailOnExist,
oHomedir,
oPrompt,
oStatusMsg,
oDebugUseOCB,
oAgentProgram
};
struct rsa_secret_key_s
{
gcry_mpi_t n; /* public modulus */
gcry_mpi_t e; /* public exponent */
gcry_mpi_t d; /* exponent */
gcry_mpi_t p; /* prime p. */
gcry_mpi_t q; /* prime q. */
gcry_mpi_t u; /* inverse of p mod q. */
};
static int opt_armor;
static int opt_canonical;
static int opt_store;
static int opt_force;
static int opt_no_fail_on_exist;
static int opt_have_cert;
static const char *opt_passphrase;
static char *opt_prompt;
static int opt_status_msg;
static const char *opt_agent_program;
static char *get_passphrase (int promptno);
static void release_passphrase (char *pw);
static gpgrt_opt_t opts[] = {
ARGPARSE_group (300, N_("@Commands:\n ")),
ARGPARSE_c (oProtect, "protect", "protect a private key"),
ARGPARSE_c (oUnprotect, "unprotect", "unprotect a private key"),
ARGPARSE_c (oShadow, "shadow", "create a shadow entry for a public key"),
ARGPARSE_c (oShowShadowInfo, "show-shadow-info", "return the shadow info"),
ARGPARSE_c (oShowKeygrip, "show-keygrip", "show the \"keygrip\""),
ARGPARSE_c (oS2Kcalibration, "s2k-calibration", "@"),
ARGPARSE_group (301, N_("@\nOptions:\n ")),
ARGPARSE_s_n (oVerbose, "verbose", "verbose"),
ARGPARSE_s_n (oArmor, "armor", "write output in advanced format"),
ARGPARSE_s_n (oCanonical, "canonical", "write output in canonical format"),
ARGPARSE_s_s (oPassphrase, "passphrase", "|STRING|use passphrase STRING"),
ARGPARSE_s_n (oHaveCert, "have-cert",
"certificate to export provided on STDIN"),
ARGPARSE_s_n (oStore, "store",
"store the created key in the appropriate place"),
ARGPARSE_s_n (oForce, "force",
"force overwriting"),
ARGPARSE_s_n (oNoFailOnExist, "no-fail-on-exist", "@"),
ARGPARSE_s_s (oHomedir, "homedir", "@"),
ARGPARSE_s_s (oPrompt, "prompt",
"|ESCSTRING|use ESCSTRING as prompt in pinentry"),
ARGPARSE_s_n (oStatusMsg, "enable-status-msg", "@"),
ARGPARSE_s_s (oAgentProgram, "agent-program", "@"),
ARGPARSE_s_n (oDebugUseOCB, "debug-use-ocb", "@"), /* For hacking only. */
ARGPARSE_end ()
};
static const char *
my_strusage (int level)
{
const char *p;
switch (level)
{
case 9: p = "GPL-3.0-or-later"; break;
case 11: p = "gpg-protect-tool (" GNUPG_NAME ")";
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 <@EMAIL@>.\n"); break;
case 1:
case 40: p = _("Usage: gpg-protect-tool [options] (-h for help)\n");
break;
case 41: p = _("Syntax: gpg-protect-tool [options] [args]\n"
"Secret key maintenance tool\n");
break;
default: p = NULL;
}
return p;
}
/* static void */
/* print_mpi (const char *text, gcry_mpi_t a) */
/* { */
/* char *buf; */
/* void *bufaddr = &buf; */
/* int rc; */
/* rc = gcry_mpi_aprint (GCRYMPI_FMT_HEX, bufaddr, NULL, a); */
/* if (rc) */
/* log_info ("%s: [error printing number: %s]\n", text, gpg_strerror (rc)); */
/* else */
/* { */
/* log_info ("%s: %s\n", text, buf); */
/* gcry_free (buf); */
/* } */
/* } */
static unsigned char *
make_canonical (const char *fname, const char *buf, size_t buflen)
{
int rc;
size_t erroff, len;
gcry_sexp_t sexp;
unsigned char *result;
rc = gcry_sexp_sscan (&sexp, &erroff, buf, buflen);
if (rc)
{
log_error ("invalid S-Expression in '%s' (off=%u): %s\n",
fname, (unsigned int)erroff, gpg_strerror (rc));
return NULL;
}
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_CANON, NULL, 0);
log_assert (len);
result = xmalloc (len);
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_CANON, result, len);
log_assert (len);
gcry_sexp_release (sexp);
return result;
}
static char *
make_advanced (const unsigned char *buf, size_t buflen)
{
int rc;
size_t erroff, len;
gcry_sexp_t sexp;
char *result;
rc = gcry_sexp_sscan (&sexp, &erroff, (const char*)buf, buflen);
if (rc)
{
log_error ("invalid canonical S-Expression (off=%u): %s\n",
(unsigned int)erroff, gpg_strerror (rc));
return NULL;
}
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, NULL, 0);
log_assert (len);
result = xmalloc (len);
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, result, len);
log_assert (len);
gcry_sexp_release (sexp);
return result;
}
static char *
read_file (const char *fname, size_t *r_length)
{
estream_t fp;
char *buf;
size_t buflen;
if (!strcmp (fname, "-"))
{
size_t nread, bufsize = 0;
fp = es_stdin;
es_set_binary (fp);
buf = NULL;
buflen = 0;
#define NCHUNK 8192
do
{
bufsize += NCHUNK;
if (!buf)
buf = xmalloc (bufsize);
else
buf = xrealloc (buf, bufsize);
nread = es_fread (buf+buflen, 1, NCHUNK, fp);
if (nread < NCHUNK && es_ferror (fp))
{
log_error ("error reading '[stdin]': %s\n", strerror (errno));
xfree (buf);
return NULL;
}
buflen += nread;
}
while (nread == NCHUNK);
#undef NCHUNK
}
else
{
struct stat st;
fp = es_fopen (fname, "rb");
if (!fp)
{
log_error ("can't open '%s': %s\n", fname, strerror (errno));
return NULL;
}
if (fstat (es_fileno (fp), &st))
{
log_error ("can't stat '%s': %s\n", fname, strerror (errno));
es_fclose (fp);
return NULL;
}
buflen = st.st_size;
buf = xmalloc (buflen+1);
if (es_fread (buf, buflen, 1, fp) != 1)
{
log_error ("error reading '%s': %s\n", fname, strerror (errno));
es_fclose (fp);
xfree (buf);
return NULL;
}
es_fclose (fp);
}
*r_length = buflen;
return buf;
}
static unsigned char *
read_key (const char *fname)
{
char *buf;
size_t buflen;
unsigned char *key;
buf = read_file (fname, &buflen);
if (!buf)
return NULL;
if (buflen >= 4 && !memcmp (buf, "Key:", 4))
{
log_error ("Extended key format is not supported by this tool\n");
xfree (buf);
return NULL;
}
key = make_canonical (fname, buf, buflen);
xfree (buf);
return key;
}
static void
read_and_protect (const char *fname)
{
int rc;
unsigned char *key;
unsigned char *result;
size_t resultlen;
char *pw;
key = read_key (fname);
if (!key)
return;
pw = get_passphrase (1);
rc = agent_protect (key, pw, &result, &resultlen, 0);
release_passphrase (pw);
xfree (key);
if (rc)
{
log_error ("protecting the key failed: %s\n", gpg_strerror (rc));
return;
}
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = (unsigned char*)p;
resultlen = strlen (p);
}
fwrite (result, resultlen, 1, stdout);
xfree (result);
}
static void
read_and_unprotect (ctrl_t ctrl, const char *fname)
{
gpg_error_t err;
unsigned char *key;
unsigned char *result;
size_t resultlen;
char *pw;
gnupg_isotime_t protected_at;
key = read_key (fname);
if (!key)
return;
err = agent_unprotect (ctrl, key, (pw=get_passphrase (1)),
protected_at, &result, &resultlen);
release_passphrase (pw);
xfree (key);
if (err)
{
if (opt_status_msg)
log_info ("[PROTECT-TOOL:] bad-passphrase\n");
log_error ("unprotecting the key failed: %s\n", gpg_strerror (err));
return;
}
if (opt.verbose)
{
if (*protected_at)
log_info ("key protection done at %.4s-%.2s-%.2s %.2s:%.2s:%s\n",
protected_at, protected_at+4, protected_at+6,
protected_at+9, protected_at+11, protected_at+13);
else
log_info ("key protection done at [unknown]\n");
}
err = fixup_when_ecc_private_key (result, &resultlen);
if (err)
{
log_error ("malformed key: %s\n", gpg_strerror (err));
return;
}
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = (unsigned char*)p;
resultlen = strlen (p);
}
fwrite (result, resultlen, 1, stdout);
xfree (result);
}
static void
read_and_shadow (const char *fname)
{
int rc;
unsigned char *key;
unsigned char *result;
size_t resultlen;
unsigned char dummy_info[] = "(8:313233342:43)";
key = read_key (fname);
if (!key)
return;
rc = agent_shadow_key (key, dummy_info, &result);
xfree (key);
if (rc)
{
log_error ("shadowing the key failed: %s\n", gpg_strerror (rc));
return;
}
resultlen = gcry_sexp_canon_len (result, 0, NULL,NULL);
log_assert (resultlen);
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = (unsigned char*)p;
resultlen = strlen (p);
}
fwrite (result, resultlen, 1, stdout);
xfree (result);
}
static void
show_shadow_info (const char *fname)
{
int rc;
unsigned char *key;
const unsigned char *info;
size_t infolen;
key = read_key (fname);
if (!key)
return;
rc = agent_get_shadow_info (key, &info);
xfree (key);
if (rc)
{
log_error ("get_shadow_info failed: %s\n", gpg_strerror (rc));
return;
}
infolen = gcry_sexp_canon_len (info, 0, NULL,NULL);
log_assert (infolen);
if (opt_armor)
{
char *p = make_advanced (info, infolen);
if (!p)
return;
fwrite (p, strlen (p), 1, stdout);
xfree (p);
}
else
fwrite (info, infolen, 1, stdout);
}
static void
show_file (const char *fname)
{
unsigned char *key;
size_t keylen;
char *p;
key = read_key (fname);
if (!key)
return;
keylen = gcry_sexp_canon_len (key, 0, NULL,NULL);
log_assert (keylen);
if (opt_canonical)
{
fwrite (key, keylen, 1, stdout);
}
else
{
p = make_advanced (key, keylen);
if (p)
{
fwrite (p, strlen (p), 1, stdout);
xfree (p);
}
}
xfree (key);
}
static void
show_keygrip (const char *fname)
{
unsigned char *key;
gcry_sexp_t private;
unsigned char grip[20];
int i;
key = read_key (fname);
if (!key)
return;
if (gcry_sexp_new (&private, key, 0, 0))
{
log_error ("gcry_sexp_new failed\n");
return;
}
xfree (key);
if (!gcry_pk_get_keygrip (private, grip))
{
log_error ("can't calculate keygrip\n");
return;
}
gcry_sexp_release (private);
for (i=0; i < 20; i++)
printf ("%02X", grip[i]);
putchar ('\n');
}
int
main (int argc, char **argv )
{
gpgrt_argparse_t pargs;
int cmd = 0;
const char *fname;
ctrl_t ctrl;
early_system_init ();
gpgrt_set_strusage (my_strusage);
gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
log_set_prefix ("gpg-protect-tool", GPGRT_LOG_WITH_PREFIX);
/* Make sure that our subsystems are ready. */
i18n_init ();
init_common_subsystems (&argc, &argv);
setup_libgcrypt_logging ();
gcry_control (GCRYCTL_INIT_SECMEM, 16384, 0);
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags= ARGPARSE_FLAG_KEEP;
while (gpgrt_argparse (NULL, &pargs, opts))
{
switch (pargs.r_opt)
{
case oVerbose: opt.verbose++; break;
case oArmor: opt_armor=1; break;
case oCanonical: opt_canonical=1; break;
case oHomedir: gnupg_set_homedir (pargs.r.ret_str); break;
case oAgentProgram: opt_agent_program = pargs.r.ret_str; break;
case oProtect: cmd = oProtect; break;
case oUnprotect: cmd = oUnprotect; break;
case oShadow: cmd = oShadow; break;
case oShowShadowInfo: cmd = oShowShadowInfo; break;
case oShowKeygrip: cmd = oShowKeygrip; break;
case oS2Kcalibration: cmd = oS2Kcalibration; break;
case oPassphrase: opt_passphrase = pargs.r.ret_str; break;
case oStore: opt_store = 1; break;
case oForce: opt_force = 1; break;
case oNoFailOnExist: opt_no_fail_on_exist = 1; break;
case oHaveCert: opt_have_cert = 1; break;
case oPrompt: opt_prompt = pargs.r.ret_str; break;
case oStatusMsg: opt_status_msg = 1; break;
case oDebugUseOCB: /* dummy */; break;
default: pargs.err = ARGPARSE_PRINT_ERROR; break;
}
}
gpgrt_argparse (NULL, &pargs, NULL); /* Release internal state. */
if (log_get_errorcount (0))
exit (2);
fname = "-";
if (argc == 1)
fname = *argv;
else if (argc > 1)
gpgrt_usage (1);
/* Allocate an CTRL object. An empty object should be sufficient. */
ctrl = xtrycalloc (1, sizeof *ctrl);
if (!ctrl)
{
log_error ("error allocating connection control data: %s\n",
strerror (errno));
agent_exit (1);
}
/* Set the information which can't be taken from envvars. */
gnupg_prepare_get_passphrase (GPG_ERR_SOURCE_DEFAULT,
opt.verbose,
opt_agent_program,
NULL, NULL, NULL);
if (opt_prompt)
opt_prompt = percent_plus_unescape (opt_prompt, 0);
if (cmd == oProtect)
read_and_protect (fname);
else if (cmd == oUnprotect)
read_and_unprotect (ctrl, fname);
else if (cmd == oShadow)
read_and_shadow (fname);
else if (cmd == oShowShadowInfo)
show_shadow_info (fname);
else if (cmd == oShowKeygrip)
show_keygrip (fname);
else if (cmd == oS2Kcalibration)
{
if (!opt.verbose)
opt.verbose++; /* We need to see something. */
get_standard_s2k_count ();
}
else
show_file (fname);
xfree (ctrl);
agent_exit (0);
return 8; /*NOTREACHED*/
}
void
agent_exit (int rc)
{
rc = rc? rc : log_get_errorcount(0)? 2 : 0;
exit (rc);
}
/* Return the passphrase string and ask the agent if it has not been
set from the command line PROMPTNO select the prompt to display:
0 = default
1 = taken from the option --prompt
2 = for unprotecting a pkcs#12 object
3 = for protecting a new pkcs#12 object
4 = for protecting an imported pkcs#12 in our system
*/
static char *
get_passphrase (int promptno)
{
char *pw;
int err;
const char *desc;
char *orig_codeset;
int repeat = 0;
if (opt_passphrase)
return xstrdup (opt_passphrase);
orig_codeset = i18n_switchto_utf8 ();
if (promptno == 1 && opt_prompt)
{
desc = opt_prompt;
}
else if (promptno == 2)
{
desc = _("Please enter the passphrase to unprotect the "
"PKCS#12 object.");
}
else if (promptno == 3)
{
desc = _("Please enter the passphrase to protect the "
"new PKCS#12 object.");
repeat = 1;
}
else if (promptno == 4)
{
desc = _("Please enter the passphrase to protect the "
"imported object within the GnuPG system.");
repeat = 1;
}
else
desc = _("Please enter the passphrase or the PIN\n"
"needed to complete this operation.");
i18n_switchback (orig_codeset);
err = gnupg_get_passphrase (NULL, NULL, _("Passphrase:"), desc,
repeat, repeat, 1, &pw);
if (err)
{
if (gpg_err_code (err) == GPG_ERR_CANCELED
|| gpg_err_code (err) == GPG_ERR_FULLY_CANCELED)
log_info (_("cancelled\n"));
else
log_error (_("error while asking for the passphrase: %s\n"),
gpg_strerror (err));
agent_exit (0);
}
log_assert (pw);
return pw;
}
static void
release_passphrase (char *pw)
{
if (pw)
{
wipememory (pw, strlen (pw));
xfree (pw);
}
}
/* Stub function. */
int
agent_key_available (ctrl_t ctrl, const unsigned char *grip)
{
(void)ctrl;
(void)grip;
return -1; /* Not available. */
}
char *
agent_get_cache (ctrl_t ctrl, const char *key, cache_mode_t cache_mode)
{
(void)ctrl;
(void)key;
(void)cache_mode;
return NULL;
}
gpg_error_t
agent_askpin (ctrl_t ctrl,
const char *desc_text, const char *prompt_text,
const char *initial_errtext,
struct pin_entry_info_s *pininfo,
const char *keyinfo, cache_mode_t cache_mode)
{
gpg_error_t err;
unsigned char *passphrase;
size_t size;
(void)ctrl;
(void)desc_text;
(void)prompt_text;
(void)initial_errtext;
(void)keyinfo;
(void)cache_mode;
*pininfo->pin = 0; /* Reset the PIN. */
passphrase = get_passphrase (0);
size = strlen (passphrase);
if (size >= pininfo->max_length)
{
xfree (passphrase);
return gpg_error (GPG_ERR_TOO_LARGE);
}
memcpy (&pininfo->pin, passphrase, size);
xfree (passphrase);
pininfo->pin[size] = 0;
if (pininfo->check_cb)
{
/* More checks by utilizing the optional callback. */
pininfo->cb_errtext = NULL;
err = pininfo->check_cb (pininfo);
}
else
err = 0;
return err;
}
/* Replacement for the function in findkey.c. Here we write the key
* to stdout. */
gpg_error_t
agent_write_private_key (ctrl_t ctrl, const unsigned char *grip,
const void *buffer, size_t length, int force,
const char *serialno, const char *keyref,
const char *dispserialno, time_t timestamp)
{
char hexgrip[40+4+1];
char *p;
(void)ctrl;
(void)force;
(void)serialno;
(void)keyref;
(void)timestamp;
(void)dispserialno;
bin2hex (grip, 20, hexgrip);
strcpy (hexgrip+40, ".key");
p = make_advanced (buffer, length);
if (p)
{
printf ("# Begin dump of %s\n%s%s# End dump of %s\n",
hexgrip, p, (*p && p[strlen(p)-1] == '\n')? "":"\n", hexgrip);
xfree (p);
}
return 0;
}