apps/gendsa.c

   1 /*
   2  * Copyright 1995-2021 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
  12 #include <stdio.h>
  13 #include <string.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include "apps.h"
  17 #include "progs.h"
  18 #include <openssl/bio.h>
  19 #include <openssl/err.h>
  20 #include <openssl/bn.h>
  21 #include <openssl/dsa.h>
  22 #include <openssl/x509.h>
  23 #include <openssl/pem.h>
  24
  25 typedef enum OPTION_choice {
  26     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
  27     OPT_OUT, OPT_PASSOUT, OPT_ENGINE, OPT_CIPHER, OPT_VERBOSE,
  28     OPT_R_ENUM, OPT_PROV_ENUM
  29 } OPTION_CHOICE;
  30
  31 const OPTIONS gendsa_options[] = {
  32     {OPT_HELP_STR, 1, '-', "Usage: %s [options] dsaparam-file\n"},
  33
  34     OPT_SECTION("General"),
  35     {"help", OPT_HELP, '-', "Display this summary"},
  36 #ifndef OPENSSL_NO_ENGINE
  37     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  38 #endif
  39
  40     OPT_SECTION("Output"),
  41     {"out", OPT_OUT, '>', "Output the key to the specified file"},
  42     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  43     OPT_R_OPTIONS,
  44     OPT_PROV_OPTIONS,
  45     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  46     {"verbose", OPT_VERBOSE, '-', "Verbose output"},
  47
  48     OPT_PARAMETERS(),
  49     {"dsaparam-file", 0, 0, "File containing DSA parameters"},
  50     {NULL}
  51 };
  52
  53 int gendsa_main(int argc, char **argv)
  54 {
  55     ENGINE *e = NULL;
  56     BIO *out = NULL, *in = NULL;
  57     EVP_PKEY *pkey = NULL;
  58     EVP_PKEY_CTX *ctx = NULL;
  59     const EVP_CIPHER *enc = NULL;
  60     char *dsaparams = NULL, *ciphername = NULL;
  61     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
  62     OPTION_CHOICE o;
  63     int ret = 1, private = 0, verbose = 0;
  64     const BIGNUM *p = NULL;
  65
  66     prog = opt_init(argc, argv, gendsa_options);
  67     while ((o = opt_next()) != OPT_EOF) {
  68         switch (o) {
  69         case OPT_EOF:
  70         case OPT_ERR:
  71  opthelp:
  72             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
  73             goto end;
  74         case OPT_HELP:
  75             ret = 0;
  76             opt_help(gendsa_options);
  77             goto end;
  78         case OPT_OUT:
  79             outfile = opt_arg();
  80             break;
  81         case OPT_PASSOUT:
  82             passoutarg = opt_arg();
  83             break;
  84         case OPT_ENGINE:
  85             e = setup_engine(opt_arg(), 0);
  86             break;
  87         case OPT_R_CASES:
  88             if (!opt_rand(o))
  89                 goto end;
  90             break;
  91         case OPT_PROV_CASES:
  92             if (!opt_provider(o))
  93                 goto end;
  94             break;
  95         case OPT_CIPHER:
  96             ciphername = opt_unknown();
  97             break;
  98         case OPT_VERBOSE:
  99             verbose = 1;
 100             break;
 101         }
 102     }
 103
 104     /* One argument, the params file. */
 105     argc = opt_num_rest();
 106     argv = opt_rest();
 107     if (argc != 1)
 108         goto opthelp;
 109     dsaparams = argv[0];
 110
 111     app_RAND_load();
 112     if (ciphername != NULL) {
 113         if (!opt_cipher(ciphername, &enc))
 114             goto end;
 115     }
 116     private = 1;
 117
 118     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 119         BIO_printf(bio_err, "Error getting password\n");
 120         goto end;
 121     }
 122
 123     pkey = load_keyparams(dsaparams, 1, "DSA", "DSA parameters");
 124
 125     out = bio_open_owner(outfile, FORMAT_PEM, private);
 126     if (out == NULL)
 127         goto end2;
 128
 129     if (EVP_PKEY_bits(pkey) > OPENSSL_DSA_MAX_MODULUS_BITS)
 130         BIO_printf(bio_err,
 131                    "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
 132                    "         Your key size is %d! Larger key size may behave not as expected.\n",
 133                    OPENSSL_DSA_MAX_MODULUS_BITS, EVP_PKEY_bits(pkey));
 134
 135     ctx = EVP_PKEY_CTX_new(pkey, NULL);
 136     if (ctx == NULL) {
 137         BIO_printf(bio_err, "unable to create PKEY context\n");
 138         goto end;
 139     }
 140     EVP_PKEY_free(pkey);
 141     pkey = NULL;
 142     if (EVP_PKEY_keygen_init(ctx) <= 0) {
 143         BIO_printf(bio_err, "unable to set up for key generation\n");
 144         goto end;
 145     }
 146     if (verbose)
 147         BIO_printf(bio_err, "Generating DSA key, %d bits\n", BN_num_bits(p));
 148     if (EVP_PKEY_keygen(ctx, &pkey) <= 0) {
 149         BIO_printf(bio_err, "unable to generate key\n");
 150         goto end;
 151     }
 152
 153     assert(private);
 154     if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout)) {
 155         BIO_printf(bio_err, "unable to output generated key\n");
 156         goto end;
 157     }
 158     ret = 0;
 159  end:
 160     if (ret != 0)
 161         ERR_print_errors(bio_err);
 162  end2:
 163     BIO_free(in);
 164     BIO_free_all(out);
 165     EVP_PKEY_free(pkey);
 166     EVP_PKEY_CTX_free(ctx);
 167     release_engine(e);
 168     OPENSSL_free(passout);
 169     return ret;
 170 }