apps/gendsa.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <openssl/opensslconf.h>
  11 #ifdef OPENSSL_NO_DSA
  12 NON_EMPTY_TRANSLATION_UNIT
  13 #else
  14
  15 # include <stdio.h>
  16 # include <string.h>
  17 # include <sys/types.h>
  18 # include <sys/stat.h>
  19 # include "apps.h"
  20 # include "progs.h"
  21 # include <openssl/bio.h>
  22 # include <openssl/err.h>
  23 # include <openssl/bn.h>
  24 # include <openssl/dsa.h>
  25 # include <openssl/x509.h>
  26 # include <openssl/pem.h>
  27
  28 typedef enum OPTION_choice {
  29     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
  30     OPT_OUT, OPT_PASSOUT, OPT_ENGINE, OPT_CIPHER, OPT_VERBOSE,
  31     OPT_R_ENUM
  32 } OPTION_CHOICE;
  33
  34 const OPTIONS gendsa_options[] = {
  35     {OPT_HELP_STR, 1, '-', "Usage: %s [options] dsaparam-file\n"},
  36
  37     OPT_SECTION("General"),
  38     {"help", OPT_HELP, '-', "Display this summary"},
  39 # ifndef OPENSSL_NO_ENGINE
  40     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  41 # endif
  42
  43     OPT_SECTION("Output"),
  44     {"out", OPT_OUT, '>', "Output the key to the specified file"},
  45     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  46     OPT_R_OPTIONS,
  47     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  48     {"verbose", OPT_VERBOSE, '-', "Verbose output"},
  49
  50     OPT_PARAMETERS(),
  51     {"dsaparam-file", 0, 0, "File containing DSA parameters"},
  52     {NULL}
  53 };
  54
  55 int gendsa_main(int argc, char **argv)
  56 {
  57     ENGINE *e = NULL;
  58     BIO *out = NULL, *in = NULL;
  59     DSA *dsa = NULL;
  60     const EVP_CIPHER *enc = NULL;
  61     char *dsaparams = NULL;
  62     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
  63     OPTION_CHOICE o;
  64     int ret = 1, private = 0, verbose = 0;
  65     const BIGNUM *p = NULL;
  66
  67     prog = opt_init(argc, argv, gendsa_options);
  68     while ((o = opt_next()) != OPT_EOF) {
  69         switch (o) {
  70         case OPT_EOF:
  71         case OPT_ERR:
  72  opthelp:
  73             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
  74             goto end;
  75         case OPT_HELP:
  76             ret = 0;
  77             opt_help(gendsa_options);
  78             goto end;
  79         case OPT_OUT:
  80             outfile = opt_arg();
  81             break;
  82         case OPT_PASSOUT:
  83             passoutarg = opt_arg();
  84             break;
  85         case OPT_ENGINE:
  86             e = setup_engine(opt_arg(), 0);
  87             break;
  88         case OPT_R_CASES:
  89             if (!opt_rand(o))
  90                 goto end;
  91             break;
  92         case OPT_CIPHER:
  93             if (!opt_cipher(opt_unknown(), &enc))
  94                 goto end;
  95             break;
  96         case OPT_VERBOSE:
  97             verbose = 1;
  98             break;
  99         }
 100     }
 101     argc = opt_num_rest();
 102     argv = opt_rest();
 103     private = 1;
 104
 105     if (argc != 1)
 106         goto opthelp;
 107     dsaparams = *argv;
 108
 109     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 110         BIO_printf(bio_err, "Error getting password\n");
 111         goto end;
 112     }
 113
 114     in = bio_open_default(dsaparams, 'r', FORMAT_PEM);
 115     if (in == NULL)
 116         goto end2;
 117
 118     if ((dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL)) == NULL) {
 119         BIO_printf(bio_err, "unable to load DSA parameter file\n");
 120         goto end;
 121     }
 122     BIO_free(in);
 123     in = NULL;
 124
 125     out = bio_open_owner(outfile, FORMAT_PEM, private);
 126     if (out == NULL)
 127         goto end2;
 128
 129     DSA_get0_pqg(dsa, &p, NULL, NULL);
 130
 131     if (BN_num_bits(p) > OPENSSL_DSA_MAX_MODULUS_BITS)
 132         BIO_printf(bio_err,
 133                    "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
 134                    "         Your key size is %d! Larger key size may behave not as expected.\n",
 135                    OPENSSL_DSA_MAX_MODULUS_BITS, BN_num_bits(p));
 136
 137     if (verbose)
 138         BIO_printf(bio_err, "Generating DSA key, %d bits\n", BN_num_bits(p));
 139     if (!DSA_generate_key(dsa))
 140         goto end;
 141
 142     assert(private);
 143     if (!PEM_write_bio_DSAPrivateKey(out, dsa, enc, NULL, 0, NULL, passout))
 144         goto end;
 145     ret = 0;
 146  end:
 147     if (ret != 0)
 148         ERR_print_errors(bio_err);
 149  end2:
 150     BIO_free(in);
 151     BIO_free_all(out);
 152     DSA_free(dsa);
 153     release_engine(e);
 154     OPENSSL_free(passout);
 155     return ret;
 156 }
 157 #endif