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 /* We need to use some deprecated APIs */
  11 #define OPENSSL_SUPPRESS_DEPRECATED
  12
  13 #include <openssl/opensslconf.h>
  14 #ifdef OPENSSL_NO_DSA
  15 NON_EMPTY_TRANSLATION_UNIT
  16 #else
  17
  18 # include <stdio.h>
  19 # include <string.h>
  20 # include <sys/types.h>
  21 # include <sys/stat.h>
  22 # include "apps.h"
  23 # include "progs.h"
  24 # include <openssl/bio.h>
  25 # include <openssl/err.h>
  26 # include <openssl/bn.h>
  27 # include <openssl/dsa.h>
  28 # include <openssl/x509.h>
  29 # include <openssl/pem.h>
  30
  31 typedef enum OPTION_choice {
  32     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
  33     OPT_OUT, OPT_PASSOUT, OPT_ENGINE, OPT_CIPHER, OPT_VERBOSE,
  34     OPT_R_ENUM
  35 } OPTION_CHOICE;
  36
  37 const OPTIONS gendsa_options[] = {
  38     {OPT_HELP_STR, 1, '-', "Usage: %s [options] dsaparam-file\n"},
  39
  40     OPT_SECTION("General"),
  41     {"help", OPT_HELP, '-', "Display this summary"},
  42 # ifndef OPENSSL_NO_ENGINE
  43     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  44 # endif
  45
  46     OPT_SECTION("Output"),
  47     {"out", OPT_OUT, '>', "Output the key to the specified file"},
  48     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  49     OPT_R_OPTIONS,
  50     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  51     {"verbose", OPT_VERBOSE, '-', "Verbose output"},
  52
  53     OPT_PARAMETERS(),
  54     {"dsaparam-file", 0, 0, "File containing DSA parameters"},
  55     {NULL}
  56 };
  57
  58 int gendsa_main(int argc, char **argv)
  59 {
  60     ENGINE *e = NULL;
  61     BIO *out = NULL, *in = NULL;
  62     DSA *dsa = NULL;
  63     const EVP_CIPHER *enc = NULL;
  64     char *dsaparams = NULL;
  65     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
  66     OPTION_CHOICE o;
  67     int ret = 1, private = 0, verbose = 0;
  68     const BIGNUM *p = NULL;
  69
  70     prog = opt_init(argc, argv, gendsa_options);
  71     while ((o = opt_next()) != OPT_EOF) {
  72         switch (o) {
  73         case OPT_EOF:
  74         case OPT_ERR:
  75  opthelp:
  76             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
  77             goto end;
  78         case OPT_HELP:
  79             ret = 0;
  80             opt_help(gendsa_options);
  81             goto end;
  82         case OPT_OUT:
  83             outfile = opt_arg();
  84             break;
  85         case OPT_PASSOUT:
  86             passoutarg = opt_arg();
  87             break;
  88         case OPT_ENGINE:
  89             e = setup_engine(opt_arg(), 0);
  90             break;
  91         case OPT_R_CASES:
  92             if (!opt_rand(o))
  93                 goto end;
  94             break;
  95         case OPT_CIPHER:
  96             if (!opt_cipher(opt_unknown(), &enc))
  97                 goto end;
  98             break;
  99         case OPT_VERBOSE:
 100             verbose = 1;
 101             break;
 102         }
 103     }
 104     argc = opt_num_rest();
 105     argv = opt_rest();
 106     private = 1;
 107
 108     if (argc != 1)
 109         goto opthelp;
 110     dsaparams = *argv;
 111
 112     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 113         BIO_printf(bio_err, "Error getting password\n");
 114         goto end;
 115     }
 116
 117     in = bio_open_default(dsaparams, 'r', FORMAT_PEM);
 118     if (in == NULL)
 119         goto end2;
 120
 121     if ((dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL)) == NULL) {
 122         BIO_printf(bio_err, "unable to load DSA parameter file\n");
 123         goto end;
 124     }
 125     BIO_free(in);
 126     in = NULL;
 127
 128     out = bio_open_owner(outfile, FORMAT_PEM, private);
 129     if (out == NULL)
 130         goto end2;
 131
 132     DSA_get0_pqg(dsa, &p, NULL, NULL);
 133
 134     if (BN_num_bits(p) > OPENSSL_DSA_MAX_MODULUS_BITS)
 135         BIO_printf(bio_err,
 136                    "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
 137                    "         Your key size is %d! Larger key size may behave not as expected.\n",
 138                    OPENSSL_DSA_MAX_MODULUS_BITS, BN_num_bits(p));
 139
 140     if (verbose)
 141         BIO_printf(bio_err, "Generating DSA key, %d bits\n", BN_num_bits(p));
 142     if (!DSA_generate_key(dsa))
 143         goto end;
 144
 145     assert(private);
 146     if (!PEM_write_bio_DSAPrivateKey(out, dsa, enc, NULL, 0, NULL, passout))
 147         goto end;
 148     ret = 0;
 149  end:
 150     if (ret != 0)
 151         ERR_print_errors(bio_err);
 152  end2:
 153     BIO_free(in);
 154     BIO_free_all(out);
 155     DSA_free(dsa);
 156     release_engine(e);
 157     OPENSSL_free(passout);
 158     return ret;
 159 }
 160 #endif