xref: /freebsd/crypto/openssl/apps/genrsa.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*
2  * Copyright 1995-2023 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_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 
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     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             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 
251 static 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