apps/genrsa.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/rsa.h>
  22 #include <openssl/evp.h>
  23 #include <openssl/x509.h>
  24 #include <openssl/pem.h>
  25 #include <openssl/rand.h>
  26
  27 #define DEFBITS 2048
  28 #define DEFPRIMES 2
  29
  30 static int verbose = 0;
  31
  32 typedef enum OPTION_choice {
  33     OPT_COMMON,
  34 #ifndef OPENSSL_NO_DEPRECATED_3_0
  35     OPT_3,
  36 #endif
  37     OPT_F4, OPT_ENGINE,
  38     OPT_OUT, OPT_PASSOUT, OPT_CIPHER, OPT_PRIMES, OPT_VERBOSE, OPT_QUIET,
  39     OPT_R_ENUM, OPT_PROV_ENUM, OPT_TRADITIONAL
  40 } OPTION_CHOICE;
  41
  42 const OPTIONS genrsa_options[] = {
  43     {OPT_HELP_STR, 1, '-', "Usage: %s [options] numbits\n"},
  44
  45     OPT_SECTION("General"),
  46     {"help", OPT_HELP, '-', "Display this summary"},
  47 #ifndef OPENSSL_NO_ENGINE
  48     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  49 #endif
  50
  51     OPT_SECTION("Input"),
  52 #ifndef OPENSSL_NO_DEPRECATED_3_0
  53     {"3", OPT_3, '-', "(deprecated) Use 3 for the E value"},
  54 #endif
  55     {"F4", OPT_F4, '-', "Use the Fermat number F4 (0x10001) for the E value"},
  56     {"f4", OPT_F4, '-', "Use the Fermat number F4 (0x10001) for the E value"},
  57
  58     OPT_SECTION("Output"),
  59     {"out", OPT_OUT, '>', "Output the key to specified file"},
  60     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  61     {"primes", OPT_PRIMES, 'p', "Specify number of primes"},
  62     {"verbose", OPT_VERBOSE, '-', "Verbose output"},
  63     {"quiet", OPT_QUIET, '-', "Terse output"},
  64     {"traditional", OPT_TRADITIONAL, '-',
  65      "Use traditional format for private keys"},
  66     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  67
  68     OPT_R_OPTIONS,
  69     OPT_PROV_OPTIONS,
  70
  71     OPT_PARAMETERS(),
  72     {"numbits", 0, 0, "Size of key in bits"},
  73     {NULL}
  74 };
  75
  76 int genrsa_main(int argc, char **argv)
  77 {
  78     BN_GENCB *cb = BN_GENCB_new();
  79     ENGINE *eng = NULL;
  80     BIGNUM *bn = BN_new();
  81     BIO *out = NULL;
  82     EVP_PKEY *pkey = NULL;
  83     EVP_PKEY_CTX *ctx = NULL;
  84     EVP_CIPHER *enc = NULL;
  85     int ret = 1, num = DEFBITS, private = 0, primes = DEFPRIMES;
  86     unsigned long f4 = RSA_F4;
  87     char *outfile = NULL, *passoutarg = NULL, *passout = NULL;
  88     char *prog, *hexe, *dece, *ciphername = NULL;
  89     OPTION_CHOICE o;
  90     int traditional = 0;
  91
  92     if (bn == NULL || cb == NULL)
  93         goto end;
  94
  95     opt_set_unknown_name("cipher");
  96     prog = opt_init(argc, argv, genrsa_options);
  97     while ((o = opt_next()) != OPT_EOF) {
  98         switch (o) {
  99         case OPT_EOF:
 100         case OPT_ERR:
 101 opthelp:
 102             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
 103             goto end;
 104         case OPT_HELP:
 105             ret = 0;
 106             opt_help(genrsa_options);
 107             goto end;
 108 #ifndef OPENSSL_NO_DEPRECATED_3_0
 109         case OPT_3:
 110             f4 = RSA_3;
 111             break;
 112 #endif
 113         case OPT_F4:
 114             f4 = RSA_F4;
 115             break;
 116         case OPT_OUT:
 117             outfile = opt_arg();
 118             break;
 119         case OPT_ENGINE:
 120             eng = setup_engine(opt_arg(), 0);
 121             break;
 122         case OPT_R_CASES:
 123             if (!opt_rand(o))
 124                 goto end;
 125             break;
 126         case OPT_PROV_CASES:
 127             if (!opt_provider(o))
 128                 goto end;
 129             break;
 130         case OPT_PASSOUT:
 131             passoutarg = opt_arg();
 132             break;
 133         case OPT_CIPHER:
 134             ciphername = opt_unknown();
 135             break;
 136         case OPT_PRIMES:
 137             primes = opt_int_arg();
 138             break;
 139         case OPT_VERBOSE:
 140             verbose = 1;
 141             break;
 142         case OPT_QUIET:
 143             verbose = 0;
 144             break;
 145         case OPT_TRADITIONAL:
 146             traditional = 1;
 147             break;
 148         }
 149     }
 150
 151     /* One optional argument, the bitsize. */
 152     argc = opt_num_rest();
 153     argv = opt_rest();
 154
 155     if (argc == 1) {
 156         if (!opt_int(argv[0], &num) || num <= 0)
 157             goto end;
 158         if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
 159             BIO_printf(bio_err,
 160                        "Warning: It is not recommended to use more than %d bit for RSA keys.\n"
 161                        "         Your key size is %d! Larger key size may behave not as expected.\n",
 162                        OPENSSL_RSA_MAX_MODULUS_BITS, num);
 163     } else if (!opt_check_rest_arg(NULL)) {
 164         goto opthelp;
 165     }
 166
 167     if (!app_RAND_load())
 168         goto end;
 169
 170     private = 1;
 171     if (!opt_cipher(ciphername, &enc))
 172         goto end;
 173     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 174         BIO_printf(bio_err, "Error getting password\n");
 175         goto end;
 176     }
 177
 178     out = bio_open_owner(outfile, FORMAT_PEM, private);
 179     if (out == NULL)
 180         goto end;
 181
 182     if (!init_gen_str(&ctx, "RSA", eng, 0, NULL, NULL))
 183         goto end;
 184
 185     if (verbose)
 186         EVP_PKEY_CTX_set_cb(ctx, progress_cb);
 187     EVP_PKEY_CTX_set_app_data(ctx, bio_err);
 188
 189     if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, num) <= 0) {
 190         BIO_printf(bio_err, "Error setting RSA length\n");
 191         goto end;
 192     }
 193     if (!BN_set_word(bn, f4)) {
 194         BIO_printf(bio_err, "Error allocating RSA public exponent\n");
 195         goto end;
 196     }
 197     if (EVP_PKEY_CTX_set1_rsa_keygen_pubexp(ctx, bn) <= 0) {
 198         BIO_printf(bio_err, "Error setting RSA public exponent\n");
 199         goto end;
 200     }
 201     if (EVP_PKEY_CTX_set_rsa_keygen_primes(ctx, primes) <= 0) {
 202         BIO_printf(bio_err, "Error setting number of primes\n");
 203         goto end;
 204     }
 205     pkey = app_keygen(ctx, "RSA", num, verbose);
 206
 207     if (verbose) {
 208         BIGNUM *e = NULL;
 209
 210         /* Every RSA key has an 'e' */
 211         EVP_PKEY_get_bn_param(pkey, "e", &e);
 212         if (e == NULL) {
 213             BIO_printf(bio_err, "Error cannot access RSA e\n");
 214             goto end;
 215         }
 216         hexe = BN_bn2hex(e);
 217         dece = BN_bn2dec(e);
 218         if (hexe && dece) {
 219             BIO_printf(bio_err, "e is %s (0x%s)\n", dece, hexe);
 220         }
 221         OPENSSL_free(hexe);
 222         OPENSSL_free(dece);
 223         BN_free(e);
 224     }
 225     if (traditional) {
 226         if (!PEM_write_bio_PrivateKey_traditional(out, pkey, enc, NULL, 0,
 227                                                   NULL, passout))
 228             goto end;
 229     } else {
 230         if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout))
 231             goto end;
 232     }
 233
 234     ret = 0;
 235  end:
 236     BN_free(bn);
 237     BN_GENCB_free(cb);
 238     EVP_PKEY_CTX_free(ctx);
 239     EVP_PKEY_free(pkey);
 240     EVP_CIPHER_free(enc);
 241     BIO_free_all(out);
 242     release_engine(eng);
 243     OPENSSL_free(passout);
 244     if (ret != 0)
 245         ERR_print_errors(bio_err);
 246     return ret;
 247 }
 248