release/src/router/nettle/examples/rsa-keygen.c

   1 /* rsa-keygen.c
   2  *
   3  */
   4
   5 /* nettle, low-level cryptographics library
   6  *
   7  * Copyright (C) 2002 Niels Möller
   8  *
   9  * The nettle library is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or (at your
  12  * option) any later version.
  13  *
  14  * The nettle library is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  17  * License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  21  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  22  * MA 02111-1301, USA.
  23  */
  24
  25 #if HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34
  35 #include "buffer.h"
  36 #include "rsa.h"
  37 #include "sexp.h"
  38 #include "yarrow.h"
  39
  40 #include "io.h"
  41
  42 #include "getopt.h"
  43
  44 #define DEFAULT_KEYSIZE 2048
  45 #define ESIZE 30
  46
  47 static void
  48 progress(void *ctx, int c)
  49 {
  50   (void) ctx;
  51   fputc(c, stderr);
  52 }
  53
  54 static unsigned long
  55 uint_arg (char c, const char *arg)
  56 {
  57   unsigned long val;
  58   char *end;
  59
  60   val = strtoul(arg, &end, 0);
  61   if (*arg == '\0' || *end != '\0')
  62     {
  63       werror ("Invalid integer argument for -%c option.\n", c);
  64       exit (EXIT_FAILURE);
  65     }
  66
  67   return val;
  68 }
  69
  70 int
  71 main(int argc, char **argv)
  72 {
  73   struct yarrow256_ctx yarrow;
  74   struct rsa_public_key pub;
  75   struct rsa_private_key priv;
  76
  77   int c;
  78   char *pub_name = NULL;
  79   const char *priv_name = NULL;
  80   const char *random_name = NULL;
  81
  82   struct nettle_buffer pub_buffer;
  83   struct nettle_buffer priv_buffer;
  84
  85   unsigned long key_size = DEFAULT_KEYSIZE;
  86   unsigned long key_e = 0;
  87
  88   enum { OPT_HELP = 300 };
  89   static const struct option options[] =
  90     {
  91       /* Name, args, flag, val */
  92       { "help", no_argument, NULL, OPT_HELP },
  93       { "random", required_argument, NULL, 'r' },
  94       { NULL, 0, NULL, 0}
  95     };
  96
  97   while ( (c = getopt_long(argc, argv, "o:r:e:s:", options, NULL)) != -1)
  98     switch (c)
  99       {
 100       case 'o':
 101         priv_name = optarg;
 102         break;
 103
 104       case 'r':
 105         random_name = optarg;
 106         break;
 107
 108       case 's':
 109         key_size = uint_arg ('s', optarg);
 110         break;
 111
 112       case 'e':
 113         key_e = uint_arg ('e', optarg);
 114         break;
 115
 116       case OPT_HELP:
 117         printf("FIXME: Usage information.\n");
 118         return EXIT_SUCCESS;
 119
 120       case '?':
 121         return EXIT_FAILURE;
 122
 123       default:
 124         abort();
 125       }
 126
 127   if (!priv_name)
 128     {
 129       werror("No filename provided.\n");
 130       return EXIT_FAILURE;
 131     }
 132
 133   pub_name = xalloc(strlen(priv_name) + 5);
 134   sprintf(pub_name, "%s.pub", priv_name);
 135
 136   /* NOTE: No sources */
 137   yarrow256_init(&yarrow, 0, NULL);
 138
 139   /* Read some data to seed the generator */
 140   if (!simple_random(&yarrow, random_name))
 141     {
 142       werror("Initialization of randomness generator failed.\n");
 143       return EXIT_FAILURE;
 144     }
 145
 146   rsa_public_key_init(&pub);
 147   rsa_private_key_init(&priv);
 148
 149   if (key_e)
 150     mpz_set_ui (pub.e, key_e);
 151
 152   if (!rsa_generate_keypair
 153       (&pub, &priv,
 154        (void *) &yarrow, (nettle_random_func *) yarrow256_random,
 155        NULL, progress,
 156        key_size, key_e == 0 ? ESIZE : 0))
 157     {
 158       werror("Key generation failed.\n");
 159       return EXIT_FAILURE;
 160     }
 161
 162   nettle_buffer_init(&priv_buffer);
 163   nettle_buffer_init(&pub_buffer);
 164
 165   if (!rsa_keypair_to_sexp(&pub_buffer, "rsa-pkcs1-sha1", &pub, NULL))
 166     {
 167       werror("Formatting public key failed.\n");
 168       return EXIT_FAILURE;
 169     }
 170
 171   if (!rsa_keypair_to_sexp(&priv_buffer, "rsa-pkcs1-sha1", &pub, &priv))
 172     {
 173       werror("Formatting private key failed.\n");
 174       return EXIT_FAILURE;
 175     }
 176
 177   if (!write_file(pub_name, pub_buffer.size, pub_buffer.contents))
 178     {
 179       werror("Failed to write public key: %s\n",
 180               strerror(errno));
 181       return EXIT_FAILURE;
 182     }
 183
 184   /* NOTE: This doesn't set up paranoid access restrictions on the
 185    * private key file, like a serious key generation tool would do. */
 186   if (!write_file(priv_name, priv_buffer.size, priv_buffer.contents))
 187     {
 188       werror("Failed to write private key: %s\n",
 189               strerror(errno));
 190       return EXIT_FAILURE;
 191     }
 192
 193   nettle_buffer_clear(&priv_buffer);
 194   nettle_buffer_clear(&pub_buffer);
 195   rsa_public_key_clear(&pub);
 196   rsa_private_key_clear(&priv);
 197   free (pub_name);
 198
 199   return EXIT_SUCCESS;
 200 }