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 static int genrsa_cb(EVP_PKEY_CTX *ctx);
  33
  34 typedef enum OPTION_choice {
  35     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
  36 #ifndef OPENSSL_NO_DEPRECATED_3_0
  37     OPT_3,
  38 #endif
  39     OPT_F4, OPT_ENGINE,
  40     OPT_OUT, OPT_PASSOUT, OPT_CIPHER, OPT_PRIMES, OPT_VERBOSE,
  41     OPT_R_ENUM, OPT_PROV_ENUM, OPT_TRADITIONAL
  42 } OPTION_CHOICE;
  43
  44 const OPTIONS genrsa_options[] = {
  45     {OPT_HELP_STR, 1, '-', "Usage: %s [options] numbits\n"},
  46
  47     OPT_SECTION("General"),
  48     {"help", OPT_HELP, '-', "Display this summary"},
  49 #ifndef OPENSSL_NO_ENGINE
  50     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  51 #endif
  52
  53     OPT_SECTION("Input"),
  54 #ifndef OPENSSL_NO_DEPRECATED_3_0
  55     {"3", OPT_3, '-', "(deprecated) Use 3 for the E value"},
  56 #endif
  57     {"F4", OPT_F4, '-', "Use the Fermat number F4 (0x10001) for the E value"},
  58     {"f4", OPT_F4, '-', "Use the Fermat number F4 (0x10001) for the E value"},
  59
  60     OPT_SECTION("Output"),
  61     {"out", OPT_OUT, '>', "Output the key to specified file"},
  62     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
  63     {"primes", OPT_PRIMES, 'p', "Specify number of primes"},
  64     {"verbose", OPT_VERBOSE, '-', "Verbose output"},
  65     {"traditional", OPT_TRADITIONAL, '-',
  66      "Use traditional format for private keys"},
  67     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
  68
  69     OPT_R_OPTIONS,
  70     OPT_PROV_OPTIONS,
  71
  72     OPT_PARAMETERS(),
  73     {"numbits", 0, 0, "Size of key in bits"},
  74     {NULL}
  75 };
  76
  77 int genrsa_main(int argc, char **argv)
  78 {
  79     BN_GENCB *cb = BN_GENCB_new();
  80     ENGINE *eng = NULL;
  81     BIGNUM *bn = BN_new();
  82     BIO *out = NULL;
  83     EVP_PKEY *pkey = NULL;
  84     EVP_PKEY_CTX *ctx = NULL;
  85     const EVP_CIPHER *enc = NULL;
  86     int ret = 1, num = DEFBITS, private = 0, primes = DEFPRIMES;
  87     unsigned long f4 = RSA_F4;
  88     char *outfile = NULL, *passoutarg = NULL, *passout = NULL;
  89     char *prog, *hexe, *dece, *ciphername = NULL;
  90     OPTION_CHOICE o;
  91     int traditional = 0;
  92
  93     if (bn == NULL || cb == NULL)
  94         goto end;
  95
  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             if (!opt_int(opt_arg(), &primes))
 138                 goto end;
 139             break;
 140         case OPT_VERBOSE:
 141             verbose = 1;
 142             break;
 143         case OPT_TRADITIONAL:
 144             traditional = 1;
 145             break;
 146         }
 147     }
 148
 149     /* One optional argument, the bitsize. */
 150     argc = opt_num_rest();
 151     argv = opt_rest();
 152
 153     if (argc == 1) {
 154         if (!opt_int(argv[0], &num) || num <= 0)
 155             goto end;
 156         if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
 157             BIO_printf(bio_err,
 158                        "Warning: It is not recommended to use more than %d bit for RSA keys.\n"
 159                        "         Your key size is %d! Larger key size may behave not as expected.\n",
 160                        OPENSSL_RSA_MAX_MODULUS_BITS, num);
 161     } else if (argc > 0) {
 162         BIO_printf(bio_err, "Extra arguments given.\n");
 163         goto opthelp;
 164     }
 165
 166     app_RAND_load();
 167     private = 1;
 168     if (ciphername != NULL) {
 169         if (!opt_cipher(ciphername, &enc))
 170             goto end;
 171     }
 172     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
 173         BIO_printf(bio_err, "Error getting password\n");
 174         goto end;
 175     }
 176
 177     out = bio_open_owner(outfile, FORMAT_PEM, private);
 178     if (out == NULL)
 179         goto end;
 180
 181     if (!init_gen_str(&ctx, "RSA", eng, 0, NULL, NULL))
 182         goto end;
 183
 184     EVP_PKEY_CTX_set_cb(ctx, genrsa_cb);
 185     EVP_PKEY_CTX_set_app_data(ctx, bio_err);
 186
 187     if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, num) <= 0) {
 188         BIO_printf(bio_err, "Error setting RSA length\n");
 189         goto end;
 190     }
 191     if (!BN_set_word(bn, f4)) {
 192         BIO_printf(bio_err, "Error allocating RSA public exponent\n");
 193         goto end;
 194     }
 195     if (EVP_PKEY_CTX_set1_rsa_keygen_pubexp(ctx, bn) <= 0) {
 196         BIO_printf(bio_err, "Error setting RSA public exponent\n");
 197         goto end;
 198     }
 199     if (EVP_PKEY_CTX_set_rsa_keygen_primes(ctx, primes) <= 0) {
 200         BIO_printf(bio_err, "Error setting number of primes\n");
 201         goto end;
 202     }
 203     if (verbose)
 204         BIO_printf(bio_err, "Generating RSA private key, %d bit long modulus (%d primes)\n",
 205                    num, primes);
 206     if (!EVP_PKEY_keygen(ctx, &pkey)) {
 207         BIO_printf(bio_err, "Error generating RSA key\n");
 208         goto end;
 209     }
 210
 211     if (verbose) {
 212         BIGNUM *e = NULL;
 213
 214         /* Every RSA key has an 'e' */
 215         EVP_PKEY_get_bn_param(pkey, "e", &e);
 216         if (e == NULL) {
 217             BIO_printf(bio_err, "Error cannot access RSA e\n");
 218             goto end;
 219         }
 220         hexe = BN_bn2hex(e);
 221         dece = BN_bn2dec(e);
 222         if (hexe && dece) {
 223             BIO_printf(bio_err, "e is %s (0x%s)\n", dece, hexe);
 224         }
 225         OPENSSL_free(hexe);
 226         OPENSSL_free(dece);
 227         BN_free(e);
 228     }
 229     if (traditional) {
 230         if (!PEM_write_bio_PrivateKey_traditional(out, pkey, enc, NULL, 0,
 231                                                   NULL, passout))
 232             goto end;
 233     } else {
 234         if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout))
 235             goto end;
 236     }
 237
 238     ret = 0;
 239  end:
 240     BN_free(bn);
 241     BN_GENCB_free(cb);
 242     EVP_PKEY_CTX_free(ctx);
 243     EVP_PKEY_free(pkey);
 244     BIO_free_all(out);
 245     release_engine(eng);
 246     OPENSSL_free(passout);
 247     if (ret != 0)
 248         ERR_print_errors(bio_err);
 249     return ret;
 250 }
 251
 252 static int genrsa_cb(EVP_PKEY_CTX *ctx)
 253 {
 254     char c = '*';
 255     BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
 256     int p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
 257
 258     if (!verbose)
 259         return 1;
 260
 261     if (p == 0)
 262         c = '.';
 263     if (p == 1)
 264         c = '+';
 265     if (p == 2)
 266         c = '*';
 267     if (p == 3)
 268         c = '\n';
 269     BIO_write(b, &c, 1);
 270     (void)BIO_flush(b);
 271     return 1;
 272 }