apps/gendsa.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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,
  31     OPT_R_ENUM
  32 } OPTION_CHOICE;
  33
  34 const OPTIONS gendsa_options[] = {
  35     {OPT_HELP_STR, 1, '-', "Usage: %s [args] dsaparam-file\n"},
  36     {OPT_HELP_STR, 1, '-', "Valid options are:\n"},
  37     {"help", OPT_HELP, '-', "Display this summary"},
  38     {"out", OPT_OUT, '>', "Output the key to the specified file"},
  39     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  40     OPT_R_OPTIONS,
  41     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  42 # ifndef OPENSSL_NO_ENGINE
  43     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  44 # endif
  45     {NULL}
  46 };
  47
  48 int gendsa_main(int argc, char **argv)
  49 {
  50     ENGINE *e = NULL;
  51     BIO *out = NULL, *in = NULL;
  52     DSA *dsa = NULL;
  53     const EVP_CIPHER *enc = NULL;
  54     char *dsaparams = NULL;
  55     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
  56     OPTION_CHOICE o;
  57     int ret = 1, private = 0;
  58     const BIGNUM *p = NULL;
  59
  60     prog = opt_init(argc, argv, gendsa_options);
  61     while ((o = opt_next()) != OPT_EOF) {
  62         switch (o) {
  63         case OPT_EOF:
  64         case OPT_ERR:
  65  opthelp:
  66             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
  67             goto end;
  68         case OPT_HELP:
  69             ret = 0;
  70             opt_help(gendsa_options);
  71             goto end;
  72         case OPT_OUT:
  73             outfile = opt_arg();
  74             break;
  75         case OPT_PASSOUT:
  76             passoutarg = opt_arg();
  77             break;
  78         case OPT_ENGINE:
  79             e = setup_engine(opt_arg(), 0);
  80             break;
  81         case OPT_R_CASES:
  82             if (!opt_rand(o))
  83                 goto end;
  84             break;
  85         case OPT_CIPHER:
  86             if (!opt_cipher(opt_unknown(), &enc))
  87                 goto end;
  88             break;
  89         }
  90     }
  91     argc = opt_num_rest();
  92     argv = opt_rest();
  93     private = 1;
  94
  95     if (argc != 1)
  96         goto opthelp;
  97     dsaparams = *argv;
  98
  99     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 100         BIO_printf(bio_err, "Error getting password\n");
 101         goto end;
 102     }
 103
 104     in = bio_open_default(dsaparams, 'r', FORMAT_PEM);
 105     if (in == NULL)
 106         goto end2;
 107
 108     if ((dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL)) == NULL) {
 109         BIO_printf(bio_err, "unable to load DSA parameter file\n");
 110         goto end;
 111     }
 112     BIO_free(in);
 113     in = NULL;
 114
 115     out = bio_open_owner(outfile, FORMAT_PEM, private);
 116     if (out == NULL)
 117         goto end2;
 118
 119     DSA_get0_pqg(dsa, &p, NULL, NULL);
 120
 121     if (BN_num_bits(p) > OPENSSL_DSA_MAX_MODULUS_BITS)
 122         BIO_printf(bio_err,
 123                    "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
 124                    "         Your key size is %d! Larger key size may behave not as expected.\n",
 125                    OPENSSL_DSA_MAX_MODULUS_BITS, BN_num_bits(p));
 126
 127     BIO_printf(bio_err, "Generating DSA key, %d bits\n", BN_num_bits(p));
 128     if (!DSA_generate_key(dsa))
 129         goto end;
 130
 131     assert(private);
 132     if (!PEM_write_bio_DSAPrivateKey(out, dsa, enc, NULL, 0, NULL, passout))
 133         goto end;
 134     ret = 0;
 135  end:
 136     if (ret != 0)
 137         ERR_print_errors(bio_err);
 138  end2:
 139     BIO_free(in);
 140     BIO_free_all(out);
 141     DSA_free(dsa);
 142     release_engine(e);
 143     OPENSSL_free(passout);
 144     return ret;
 145 }
 146 #endif