/* protect-tool.c - A tool to test the secret key protection
* Copyright (C) 2002 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/stat.h>
#include <unistd.h>
#include <gcrypt.h>
#define JNLIB_NEED_LOG_LOGV
#include "agent.h"
#include "minip12.h"
#include "simple-pwquery.h"
#include "i18n.h"
enum cmd_and_opt_values
{ aNull = 0,
oVerbose = 'v',
oArmor = 'a',
oPassphrase = 'P',
oProtect = 'p',
oUnprotect = 'u',
oNoVerbose = 500,
oShadow,
oShowShadowInfo,
oShowKeygrip,
oP12Import,
oP12Export,
oStore,
oForce,
aTest };
struct rsa_secret_key_s
{
MPI n; /* public modulus */
MPI e; /* public exponent */
MPI d; /* exponent */
MPI p; /* prime p. */
MPI q; /* prime q. */
MPI u; /* inverse of p mod q. */
};
static int opt_armor;
static int opt_store;
static int opt_force;
static const char *passphrase;
static const char *get_passphrase (void);
static int store_private_key (const unsigned char *grip,
const void *buffer, size_t length, int force);
static ARGPARSE_OPTS opts[] = {
{ 301, NULL, 0, N_("@Options:\n ") },
{ oVerbose, "verbose", 0, "verbose" },
{ oArmor, "armor", 0, "write output in advanced format" },
{ oPassphrase, "passphrase", 2, "|STRING|use passphrase STRING" },
{ oProtect, "protect", 256, "protect a private key"},
{ oUnprotect, "unprotect", 256, "unprotect a private key"},
{ oShadow, "shadow", 256, "create a shadow entry for a priblic key"},
{ oShowShadowInfo, "show-shadow-info", 256, "return the shadow info"},
{ oShowKeygrip, "show-keygrip", 256, "show the \"keygrip\""},
{ oP12Import, "p12-import", 256, "import a PKCS-12 encoded private key"},
{ oP12Export, "p12-export", 256, "export a private key PKCS-12 encoded"},
{ oStore, "store", 0, "store the created key in the appropriate place"},
{ oForce, "force", 0, "force overwriting"},
{0}
};
static const char *
my_strusage (int level)
{
const char *p;
switch (level)
{
case 11: p = "gpg-protect-tool (GnuPG)";
break;
case 13: p = VERSION; 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: 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
i18n_init (void)
{
#ifdef USE_SIMPLE_GETTEXT
set_gettext_file( PACKAGE );
#else
#ifdef ENABLE_NLS
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
#endif
#endif
}
/* Used by gcry for logging */
static void
my_gcry_logger (void *dummy, int level, const char *fmt, va_list arg_ptr)
{
/* translate the log levels */
switch (level)
{
case GCRY_LOG_CONT: level = JNLIB_LOG_CONT; break;
case GCRY_LOG_INFO: level = JNLIB_LOG_INFO; break;
case GCRY_LOG_WARN: level = JNLIB_LOG_WARN; break;
case GCRY_LOG_ERROR:level = JNLIB_LOG_ERROR; break;
case GCRY_LOG_FATAL:level = JNLIB_LOG_FATAL; break;
case GCRY_LOG_BUG: level = JNLIB_LOG_BUG; break;
case GCRY_LOG_DEBUG:level = JNLIB_LOG_DEBUG; break;
default: level = JNLIB_LOG_ERROR; break; }
log_logv (level, fmt, arg_ptr);
}
/* static void */
/* print_mpi (const char *text, GcryMPI 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, gcry_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 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, gcry_strerror (rc));
return NULL;
}
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_CANON, NULL, 0);
assert (len);
result = xmalloc (len);
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_CANON, result, len);
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 sexp;
unsigned char *result;
rc = gcry_sexp_sscan (&sexp, &erroff, buf, buflen);
if (rc)
{
log_error ("invalid canonical S-Expression (off=%u): %s\n",
(unsigned int)erroff, gcry_strerror (rc));
return NULL;
}
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, NULL, 0);
assert (len);
result = xmalloc (len);
len = gcry_sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, result, len);
assert (len);
gcry_sexp_release (sexp);
return result;
}
static char *
read_file (const char *fname, size_t *r_length)
{
FILE *fp;
struct stat st;
char *buf;
size_t buflen;
fp = fopen (fname, "rb");
if (!fp)
{
log_error ("can't open `%s': %s\n", fname, strerror (errno));
return NULL;
}
if (fstat (fileno(fp), &st))
{
log_error ("can't stat `%s': %s\n", fname, strerror (errno));
fclose (fp);
return NULL;
}
buflen = st.st_size;
buf = xmalloc (buflen+1);
if (fread (buf, buflen, 1, fp) != 1)
{
log_error ("error reading `%s': %s\n", fname, strerror (errno));
fclose (fp);
xfree (buf);
return NULL;
}
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);
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;
key = read_key (fname);
if (!key)
return;
rc = agent_protect (key, get_passphrase (), &result, &resultlen);
xfree (key);
if (rc)
{
log_error ("protecting the key failed: %s\n", gnupg_strerror (rc));
return;
}
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = p;
resultlen = strlen (p);
}
fwrite (result, resultlen, 1, stdout);
xfree (result);
}
static void
read_and_unprotect (const char *fname)
{
int rc;
unsigned char *key;
unsigned char *result;
size_t resultlen;
key = read_key (fname);
if (!key)
return;
rc = agent_unprotect (key, get_passphrase (), &result, &resultlen);
xfree (key);
if (rc)
{
log_error ("unprotecting the key failed: %s\n", gnupg_strerror (rc));
return;
}
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = 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;
key = read_key (fname);
if (!key)
return;
rc = agent_shadow_key (key, "(8:313233342:43)", &result);
xfree (key);
if (rc)
{
log_error ("shadowing the key failed: %s\n", gnupg_strerror (rc));
return;
}
resultlen = gcry_sexp_canon_len (result, 0, NULL,NULL);
assert (resultlen);
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = 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", gnupg_strerror (rc));
return;
}
infolen = gcry_sexp_canon_len (info, 0, NULL,NULL);
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);
assert (keylen);
p = make_advanced (key, keylen);
xfree (key);
if (p)
{
fwrite (p, strlen (p), 1, stdout);
xfree (p);
}
}
static void
show_keygrip (const char *fname)
{
unsigned char *key;
GcrySexp 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');
}
static int
rsa_key_check (struct rsa_secret_key_s *skey)
{
int err = 0;
MPI t = gcry_mpi_snew (0);
MPI t1 = gcry_mpi_snew (0);
MPI t2 = gcry_mpi_snew (0);
MPI phi = gcry_mpi_snew (0);
/* check that n == p * q */
gcry_mpi_mul (t, skey->p, skey->q);
if (gcry_mpi_cmp( t, skey->n) )
{
log_error ("RSA oops: n != p * q\n");
err++;
}
/* check that p is less than q */
if (gcry_mpi_cmp (skey->p, skey->q) > 0)
{
GcryMPI tmp;
log_info ("swapping secret primes\n");
tmp = gcry_mpi_copy (skey->p);
gcry_mpi_set (skey->p, skey->q);
gcry_mpi_set (skey->q, tmp);
gcry_mpi_release (tmp);
/* and must recompute u of course */
gcry_mpi_invm (skey->u, skey->p, skey->q);
}
/* check that e divides neither p-1 nor q-1 */
gcry_mpi_sub_ui (t, skey->p, 1 );
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0) )
{
log_error ("RSA oops: e divides p-1\n");
err++;
}
gcry_mpi_sub_ui (t, skey->q, 1);
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0))
{
log_info ( "RSA oops: e divides q-1\n" );
err++;
}
/* check that d is correct. */
gcry_mpi_sub_ui (t1, skey->p, 1);
gcry_mpi_sub_ui (t2, skey->q, 1);
gcry_mpi_mul (phi, t1, t2);
gcry_mpi_invm (t, skey->e, phi);
if (gcry_mpi_cmp (t, skey->d))
{ /* no: try universal exponent. */
gcry_mpi_gcd (t, t1, t2);
gcry_mpi_div (t, NULL, phi, t, 0);
gcry_mpi_invm (t, skey->e, t);
if (gcry_mpi_cmp (t, skey->d))
{
log_error ("RSA oops: bad secret exponent\n");
err++;
}
}
/* check for correctness of u */
gcry_mpi_invm (t, skey->p, skey->q);
if (gcry_mpi_cmp (t, skey->u))
{
log_info ( "RSA oops: bad u parameter\n");
err++;
}
if (err)
log_info ("RSA secret key check failed\n");
gcry_mpi_release (t);
gcry_mpi_release (t1);
gcry_mpi_release (t2);
gcry_mpi_release (phi);
return err? -1:0;
}
static void
import_p12_file (const char *fname)
{
char *buf;
unsigned char *result;
size_t buflen, resultlen;
int i;
int rc;
GcryMPI *kparms;
struct rsa_secret_key_s sk;
GcrySexp s_key;
unsigned char *key;
unsigned char grip[20];
/* fixme: we should release some stuff on error */
buf = read_file (fname, &buflen);
if (!buf)
return;
kparms = p12_parse (buf, buflen, get_passphrase ());
xfree (buf);
if (!kparms)
{
log_error ("error parsing or decrypting the PKCS-1 file\n");
return;
}
for (i=0; kparms[i]; i++)
;
if (i != 8)
{
log_error ("invalid structure of private key\n");
return;
}
/* print_mpi (" n", kparms[0]); */
/* print_mpi (" e", kparms[1]); */
/* print_mpi (" d", kparms[2]); */
/* print_mpi (" p", kparms[3]); */
/* print_mpi (" q", kparms[4]); */
/* print_mpi ("dmp1", kparms[5]); */
/* print_mpi ("dmq1", kparms[6]); */
/* print_mpi (" u", kparms[7]); */
sk.n = kparms[0];
sk.e = kparms[1];
sk.d = kparms[2];
sk.q = kparms[3];
sk.p = kparms[4];
sk.u = kparms[7];
if (rsa_key_check (&sk))
return;
/* print_mpi (" n", sk.n); */
/* print_mpi (" e", sk.e); */
/* print_mpi (" d", sk.d); */
/* print_mpi (" p", sk.p); */
/* print_mpi (" q", sk.q); */
/* print_mpi (" u", sk.u); */
/* Create an S-expresion from the parameters. */
rc = gcry_sexp_build (&s_key, NULL,
"(private-key(rsa(n%m)(e%m)(d%m)(p%m)(q%m)(u%m)))",
sk.n, sk.e, sk.d, sk.p, sk.q, sk.u, NULL);
for (i=0; i < 8; i++)
gcry_mpi_release (kparms[i]);
gcry_free (kparms);
if (rc)
{
log_error ("failed to created S-expression from key: %s\n",
gcry_strerror (rc));
return;
}
/* Compute the keygrip. */
if (!gcry_pk_get_keygrip (s_key, grip))
{
log_error ("can't calculate keygrip\n");
return;
}
log_info ("keygrip: ");
for (i=0; i < 20; i++)
log_printf ("%02X", grip[i]);
log_printf ("\n");
/* convert to canonical encoding */
buflen = gcry_sexp_sprint (s_key, GCRYSEXP_FMT_CANON, NULL, 0);
assert (buflen);
key = gcry_xmalloc_secure (buflen);
buflen = gcry_sexp_sprint (s_key, GCRYSEXP_FMT_CANON, key, buflen);
assert (buflen);
gcry_sexp_release (s_key);
rc = agent_protect (key, get_passphrase (), &result, &resultlen);
xfree (key);
if (rc)
{
log_error ("protecting the key failed: %s\n", gnupg_strerror (rc));
return;
}
if (opt_armor)
{
char *p = make_advanced (result, resultlen);
xfree (result);
if (!p)
return;
result = p;
resultlen = strlen (p);
}
if (opt_store)
store_private_key (grip, result, resultlen, opt_force);
else
fwrite (result, resultlen, 1, stdout);
xfree (result);
}
static GcryMPI *
sexp_to_kparms (GCRY_SEXP sexp)
{
GcrySexp list, l2;
const char *name;
const char *s;
size_t n;
int i, idx;
const char *elems;
GcryMPI *array;
list = gcry_sexp_find_token (sexp, "private-key", 0 );
if(!list)
return NULL;
l2 = gcry_sexp_cadr (list);
gcry_sexp_release (list);
list = l2;
name = gcry_sexp_nth_data (list, 0, &n);
if(!name || n != 3 || memcmp (name, "rsa", 3))
{
gcry_sexp_release (list);
return NULL;
}
/* Paramter names used with RSA. */
elems = "nedpqu";
array = xcalloc (strlen(elems) + 1, sizeof *array);
for (idx=0, s=elems; *s; s++, idx++ )
{
l2 = gcry_sexp_find_token (list, s, 1);
if (!l2)
{
for (i=0; i<idx; i++)
gcry_mpi_release (array[i]);
xfree (array);
gcry_sexp_release (list);
return NULL; /* required parameter not found */
}
array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
gcry_sexp_release (l2);
if (!array[idx])
{
for (i=0; i<idx; i++)
gcry_mpi_release (array[i]);
xfree (array);
gcry_sexp_release (list);
return NULL; /* required parameter is invalid */
}
}
gcry_sexp_release (list);
return array;
}
static void
export_p12_file (const char *fname)
{
GcryMPI kparms[9], *kp;
unsigned char *key;
size_t keylen;
GcrySexp private;
struct rsa_secret_key_s sk;
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);
kp = sexp_to_kparms (private);
gcry_sexp_release (private);
if (!kp)
{
log_error ("error converting key parameters\n");
return;
}
sk.n = kp[0];
sk.e = kp[1];
sk.d = kp[2];
sk.p = kp[3];
sk.q = kp[4];
sk.u = kp[5];
xfree (kp);
kparms[0] = sk.n;
kparms[1] = sk.e;
kparms[2] = sk.d;
kparms[3] = sk.q;
kparms[4] = sk.p;
kparms[5] = gcry_mpi_snew (0); /* compute d mod (p-1) */
gcry_mpi_sub_ui (kparms[5], kparms[3], 1);
gcry_mpi_mod (kparms[5], sk.d, kparms[5]);
kparms[6] = gcry_mpi_snew (0); /* compute d mod (q-1) */
gcry_mpi_sub_ui (kparms[6], kparms[4], 1);
gcry_mpi_mod (kparms[6], sk.d, kparms[6]);
kparms[7] = sk.u;
kparms[8] = NULL;
key = p12_build (kparms, get_passphrase (), &keylen);
for (i=0; i < 8; i++)
gcry_mpi_release (kparms[i]);
if (!key)
return;
fwrite (key, keylen, 1, stdout);
xfree (key);
}
int
main (int argc, char **argv )
{
ARGPARSE_ARGS pargs;
int cmd = 0;
set_strusage (my_strusage);
gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
log_set_prefix ("gpg-protect-tool", 1);
i18n_init ();
if (!gcry_check_version (NEED_LIBGCRYPT_VERSION) )
{
log_fatal( _("libgcrypt is too old (need %s, have %s)\n"),
NEED_LIBGCRYPT_VERSION, gcry_check_version (NULL) );
}
gcry_set_log_handler (my_gcry_logger, NULL);
gcry_control (GCRYCTL_INIT_SECMEM, 16384, 0);
pargs.argc = &argc;
pargs.argv = &argv;
pargs.flags= 1; /* do not remove the args */
while (arg_parse (&pargs, opts) )
{
switch (pargs.r_opt)
{
case oVerbose: opt.verbose++; break;
case oArmor: opt_armor=1; 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 oP12Import: cmd = oP12Import; break;
case oP12Export: cmd = oP12Export; break;
case oPassphrase: passphrase = pargs.r.ret_str; break;
case oStore: opt_store = 1; break;
case oForce: opt_force = 1; break;
default : pargs.err = 2; break;
}
}
if (log_get_errorcount(0))
exit(2);
if (argc != 1)
usage (1);
if (cmd == oProtect)
read_and_protect (*argv);
else if (cmd == oUnprotect)
read_and_unprotect (*argv);
else if (cmd == oShadow)
read_and_shadow (*argv);
else if (cmd == oShowShadowInfo)
show_shadow_info (*argv);
else if (cmd == oShowKeygrip)
show_keygrip (*argv);
else if (cmd == oP12Import)
import_p12_file (*argv);
else if (cmd == oP12Export)
export_p12_file (*argv);
else
show_file (*argv);
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. */
static const char *
get_passphrase (void)
{
char *pw;
int err;
if (passphrase)
return passphrase;
pw = simple_pwquery (NULL,NULL,
_("Enter passphrase:"),
_("Please enter the passphrase or the PIN\n"
"needed to complete this operation."),
&err);
if (!pw)
{
if (err)
log_error ("error while asking for the passphrase\n");
else
log_info ("cancelled\n");
agent_exit (0);
}
passphrase = pw;
return passphrase;
}
static int
store_private_key (const unsigned char *grip,
const void *buffer, size_t length, int force)
{
int i;
const char *homedir;
char *fname;
FILE *fp;
char hexgrip[40+4+1];
for (i=0; i < 20; i++)
sprintf (hexgrip+2*i, "%02X", grip[i]);
strcpy (hexgrip+40, ".key");
homedir = getenv("GNUPGHOME");
if (!homedir || !*homedir)
homedir = GNUPG_DEFAULT_HOMEDIR;
fname = make_filename (homedir, GNUPG_PRIVATE_KEYS_DIR, hexgrip, NULL);
if (force)
fp = fopen (fname, "wb");
else
{
if (!access (fname, F_OK))
{
log_error ("secret key file `%s' already exists\n", fname);
xfree (fname);
return -1;
}
fp = fopen (fname, "wbx"); /* FIXME: the x is a GNU extension - let
configure check whether this actually
works */
}
if (!fp)
{
log_error ("can't create `%s': %s\n", fname, strerror (errno));
xfree (fname);
return -1;
}
if (fwrite (buffer, length, 1, fp) != 1)
{
log_error ("error writing `%s': %s\n", fname, strerror (errno));
fclose (fp);
remove (fname);
xfree (fname);
return -1;
}
if ( fclose (fp) )
{
log_error ("error closing `%s': %s\n", fname, strerror (errno));
remove (fname);
xfree (fname);
return -1;
}
log_info ("secret key stored as `%s'\n", fname);
xfree (fname);
return 0;
}