xref: /third_party/openssl/apps/genrsa.c (revision e1051a39)
1/*
2 * Copyright 1995-2022 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
30static int verbose = 0;
31
32static int genrsa_cb(EVP_PKEY_CTX *ctx);
33
34typedef enum OPTION_choice {
35    OPT_COMMON,
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
44const 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
77int 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    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:
101opthelp:
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_TRADITIONAL:
143            traditional = 1;
144            break;
145        }
146    }
147
148    /* One optional argument, the bitsize. */
149    argc = opt_num_rest();
150    argv = opt_rest();
151
152    if (argc == 1) {
153        if (!opt_int(argv[0], &num) || num <= 0)
154            goto end;
155        if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
156            BIO_printf(bio_err,
157                       "Warning: It is not recommended to use more than %d bit for RSA keys.\n"
158                       "         Your key size is %d! Larger key size may behave not as expected.\n",
159                       OPENSSL_RSA_MAX_MODULUS_BITS, num);
160    } else if (argc > 0) {
161        BIO_printf(bio_err, "Extra arguments given.\n");
162        goto opthelp;
163    }
164
165    if (!app_RAND_load())
166        goto end;
167
168    private = 1;
169    if (ciphername != NULL) {
170        if (!opt_cipher(ciphername, &enc))
171            goto end;
172    }
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, app_get0_libctx(),
183                      app_get0_propq()))
184        goto end;
185
186    EVP_PKEY_CTX_set_cb(ctx, genrsa_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    if (pkey == NULL)
207        goto end;
208
209    if (verbose) {
210        BIGNUM *e = NULL;
211
212        /* Every RSA key has an 'e' */
213        EVP_PKEY_get_bn_param(pkey, "e", &e);
214        if (e == NULL) {
215            BIO_printf(bio_err, "Error cannot access RSA e\n");
216            goto end;
217        }
218        hexe = BN_bn2hex(e);
219        dece = BN_bn2dec(e);
220        if (hexe && dece) {
221            BIO_printf(bio_err, "e is %s (0x%s)\n", dece, hexe);
222        }
223        OPENSSL_free(hexe);
224        OPENSSL_free(dece);
225        BN_free(e);
226    }
227    if (traditional) {
228        if (!PEM_write_bio_PrivateKey_traditional(out, pkey, enc, NULL, 0,
229                                                  NULL, passout))
230            goto end;
231    } else {
232        if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout))
233            goto end;
234    }
235
236    ret = 0;
237 end:
238    BN_free(bn);
239    BN_GENCB_free(cb);
240    EVP_PKEY_CTX_free(ctx);
241    EVP_PKEY_free(pkey);
242    EVP_CIPHER_free(enc);
243    BIO_free_all(out);
244    release_engine(eng);
245    OPENSSL_free(passout);
246    if (ret != 0)
247        ERR_print_errors(bio_err);
248    return ret;
249}
250
251static int genrsa_cb(EVP_PKEY_CTX *ctx)
252{
253    char c = '*';
254    BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
255    int p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
256
257    if (!verbose)
258        return 1;
259
260    if (p == 0)
261        c = '.';
262    if (p == 1)
263        c = '+';
264    if (p == 2)
265        c = '*';
266    if (p == 3)
267        c = '\n';
268    BIO_write(b, &c, 1);
269    (void)BIO_flush(b);
270    return 1;
271}
272