agent/genkey.c

   1 /* pksign.c - Generate a keypair
   2  *      Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19  * USA.
  20  */
  21
  22 #include <config.h>
  23 #include <errno.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <assert.h>
  29
  30 #include "agent.h"
  31 #include "i18n.h"
  32
  33 static int
  34 store_key (gcry_sexp_t private, const char *passphrase, int force)
  35 {
  36   int rc;
  37   unsigned char *buf;
  38   size_t len;
  39   unsigned char grip[20];
  40
  41   if ( !gcry_pk_get_keygrip (private, grip) )
  42     {
  43       log_error ("can't calculate keygrip\n");
  44       return gpg_error (GPG_ERR_GENERAL);
  45     }
  46
  47   len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, NULL, 0);
  48   assert (len);
  49   buf = gcry_malloc_secure (len);
  50   if (!buf)
  51       return out_of_core ();
  52   len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, buf, len);
  53   assert (len);
  54
  55   if (passphrase)
  56     {
  57       unsigned char *p;
  58
  59       rc = agent_protect (buf, passphrase, &p, &len);
  60       if (rc)
  61         {
  62           xfree (buf);
  63           return rc;
  64         }
  65       xfree (buf);
  66       buf = p;
  67     }
  68
  69   rc = agent_write_private_key (grip, buf, len, force);
  70   xfree (buf);
  71   return rc;
  72 }
  73
  74 /* Callback function to compare the first entered PIN with the one
  75    currently being entered. */
  76 static int
  77 reenter_compare_cb (struct pin_entry_info_s *pi)
  78 {
  79   const char *pin1 = pi->check_cb_arg;
  80
  81   if (!strcmp (pin1, pi->pin))
  82     return 0; /* okay */
  83   return -1;
  84 }
  85
  86
  87
  88 /* Generate a new keypair according to the parameters given in
  89    KEYPARAM */
  90 int
  91 agent_genkey (ctrl_t ctrl, const char *keyparam, size_t keyparamlen,
  92               membuf_t *outbuf)
  93 {
  94   gcry_sexp_t s_keyparam, s_key, s_private, s_public;
  95   struct pin_entry_info_s *pi, *pi2;
  96   int rc;
  97   size_t len;
  98   char *buf;
  99
 100   rc = gcry_sexp_sscan (&s_keyparam, NULL, keyparam, keyparamlen);
 101   if (rc)
 102     {
 103       log_error ("failed to convert keyparam: %s\n", gpg_strerror (rc));
 104       return gpg_error (GPG_ERR_INV_DATA);
 105     }
 106
 107   /* Get the passphrase now, cause key generation may take a while. */
 108   {
 109     const char *text1 = _("Please enter the passphrase to%0A"
 110                                "to protect your new key");
 111     const char *text2 = _("Please re-enter this passphrase");
 112     const char *initial_errtext = NULL;
 113
 114     pi = gcry_calloc_secure (2, sizeof (*pi) + 100);
 115     pi2 = pi + (sizeof *pi + 100);
 116     pi->max_length = 100;
 117     pi->max_tries = 3;
 118     pi2->max_length = 100;
 119     pi2->max_tries = 3;
 120     pi2->check_cb = reenter_compare_cb;
 121     pi2->check_cb_arg = pi->pin;
 122
 123   next_try:
 124     rc = agent_askpin (ctrl, text1, NULL, initial_errtext, pi);
 125     initial_errtext = NULL;
 126     if (!rc)
 127       {
 128         rc = agent_askpin (ctrl, text2, NULL, NULL, pi2);
 129         if (rc == -1)
 130           { /* The re-entered one did not match and the user did not
 131                hit cancel. */
 132             initial_errtext = _("does not match - try again");
 133             goto next_try;
 134           }
 135       }
 136     if (rc)
 137       return rc;
 138     if (!*pi->pin)
 139       {
 140         xfree (pi);
 141         pi = NULL; /* User does not want a passphrase. */
 142       }
 143   }
 144
 145   rc = gcry_pk_genkey (&s_key, s_keyparam );
 146   gcry_sexp_release (s_keyparam);
 147   if (rc)
 148     {
 149       log_error ("key generation failed: %s\n", gpg_strerror (rc));
 150       xfree (pi);
 151       return rc;
 152     }
 153
 154   /* break out the parts */
 155   s_private = gcry_sexp_find_token (s_key, "private-key", 0);
 156   if (!s_private)
 157     {
 158       log_error ("key generation failed: invalid return value\n");
 159       gcry_sexp_release (s_key);
 160       xfree (pi);
 161       return gpg_error (GPG_ERR_INV_DATA);
 162     }
 163   s_public = gcry_sexp_find_token (s_key, "public-key", 0);
 164   if (!s_public)
 165     {
 166       log_error ("key generation failed: invalid return value\n");
 167       gcry_sexp_release (s_private);
 168       gcry_sexp_release (s_key);
 169       xfree (pi);
 170       return gpg_error (GPG_ERR_INV_DATA);
 171     }
 172   gcry_sexp_release (s_key); s_key = NULL;
 173
 174   /* store the secret key */
 175   if (DBG_CRYPTO)
 176     log_debug ("storing private key\n");
 177   rc = store_key (s_private, pi? pi->pin:NULL, 0);
 178   xfree (pi); pi = NULL;
 179   gcry_sexp_release (s_private);
 180   if (rc)
 181     {
 182       gcry_sexp_release (s_public);
 183       return rc;
 184     }
 185
 186   /* return the public key */
 187   if (DBG_CRYPTO)
 188     log_debug ("returning public key\n");
 189   len = gcry_sexp_sprint (s_public, GCRYSEXP_FMT_CANON, NULL, 0);
 190   assert (len);
 191   buf = xtrymalloc (len);
 192   if (!buf)
 193     {
 194       gpg_error_t tmperr = out_of_core ();
 195       gcry_sexp_release (s_private);
 196       gcry_sexp_release (s_public);
 197       return tmperr;
 198     }
 199   len = gcry_sexp_sprint (s_public, GCRYSEXP_FMT_CANON, buf, len);
 200   assert (len);
 201   put_membuf (outbuf, buf, len);
 202   gcry_sexp_release (s_public);
 203   xfree (buf);
 204
 205   return 0;
 206 }
 207
 208
 209 \f
 210 /* Apply a new passpahrse to the key S_SKEY and store it. */
 211 int
 212 agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey)
 213 {
 214   struct pin_entry_info_s *pi, *pi2;
 215   int rc;
 216
 217   {
 218     const char *text1 = _("Please enter the new passphrase");
 219     const char *text2 = _("Please re-enter this passphrase");
 220     const char *initial_errtext = NULL;
 221
 222     pi = gcry_calloc_secure (2, sizeof (*pi) + 100);
 223     pi2 = pi + (sizeof *pi + 100);
 224     pi->max_length = 100;
 225     pi->max_tries = 3;
 226     pi2->max_length = 100;
 227     pi2->max_tries = 3;
 228     pi2->check_cb = reenter_compare_cb;
 229     pi2->check_cb_arg = pi->pin;
 230
 231   next_try:
 232     rc = agent_askpin (ctrl, text1, NULL, initial_errtext, pi);
 233     if (!rc)
 234       {
 235         rc = agent_askpin (ctrl, text2, NULL, NULL, pi2);
 236         if (rc == -1)
 237           { /* The re-entered one did not match and the user did not
 238                hit cancel. */
 239             initial_errtext = _("does not match - try again");
 240             goto next_try;
 241           }
 242       }
 243     if (rc)
 244       return rc;
 245     if (!*pi->pin)
 246       {
 247         xfree (pi);
 248         pi = NULL; /* User does not want a passphrase. */
 249       }
 250   }
 251
 252   rc = store_key (s_skey, pi? pi->pin:NULL, 1);
 253   xfree (pi);
 254   return 0;
 255 }