xref: /freebsd/crypto/openssl/apps/genrsa.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
1 /*
2  * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 #include <stdio.h>
12 #include <string.h>
13 #include <sys/types.h>
14 #include <sys/stat.h>
15 #include "apps.h"
16 #include "progs.h"
17 #include <openssl/bio.h>
18 #include <openssl/err.h>
19 #include <openssl/bn.h>
20 #include <openssl/rsa.h>
21 #include <openssl/evp.h>
22 #include <openssl/x509.h>
23 #include <openssl/pem.h>
24 #include <openssl/rand.h>
25 
26 #define DEFBITS 2048
27 #define DEFPRIMES 2
28 
29 static int genrsa_cb(int p, int n, BN_GENCB *cb);
30 
31 typedef enum OPTION_choice {
32     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
33     OPT_3, OPT_F4, OPT_ENGINE,
34     OPT_OUT, OPT_PASSOUT, OPT_CIPHER, OPT_PRIMES,
35     OPT_R_ENUM
36 } OPTION_CHOICE;
37 
38 const OPTIONS genrsa_options[] = {
39     {"help", OPT_HELP, '-', "Display this summary"},
40     {"3", OPT_3, '-', "Use 3 for the E value"},
41     {"F4", OPT_F4, '-', "Use F4 (0x10001) for the E value"},
42     {"f4", OPT_F4, '-', "Use F4 (0x10001) for the E value"},
43     {"out", OPT_OUT, '>', "Output the key to specified file"},
44     OPT_R_OPTIONS,
45     {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
46     {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
47 #ifndef OPENSSL_NO_ENGINE
48     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
49 #endif
50     {"primes", OPT_PRIMES, 'p', "Specify number of primes"},
51     {NULL}
52 };
53 
54 int genrsa_main(int argc, char **argv)
55 {
56     BN_GENCB *cb = BN_GENCB_new();
57     PW_CB_DATA cb_data;
58     ENGINE *eng = NULL;
59     BIGNUM *bn = BN_new();
60     BIO *out = NULL;
61     const BIGNUM *e;
62     RSA *rsa = NULL;
63     const EVP_CIPHER *enc = NULL;
64     int ret = 1, num = DEFBITS, private = 0, primes = DEFPRIMES;
65     unsigned long f4 = RSA_F4;
66     char *outfile = NULL, *passoutarg = NULL, *passout = NULL;
67     char *prog, *hexe, *dece;
68     OPTION_CHOICE o;
69 
70     if (bn == NULL || cb == NULL)
71         goto end;
72 
73     BN_GENCB_set(cb, genrsa_cb, bio_err);
74 
75     prog = opt_init(argc, argv, genrsa_options);
76     while ((o = opt_next()) != OPT_EOF) {
77         switch (o) {
78         case OPT_EOF:
79         case OPT_ERR:
80 opthelp:
81             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
82             goto end;
83         case OPT_HELP:
84             ret = 0;
85             opt_help(genrsa_options);
86             goto end;
87         case OPT_3:
88             f4 = 3;
89             break;
90         case OPT_F4:
91             f4 = RSA_F4;
92             break;
93         case OPT_OUT:
94             outfile = opt_arg();
95             break;
96         case OPT_ENGINE:
97             eng = setup_engine(opt_arg(), 0);
98             break;
99         case OPT_R_CASES:
100             if (!opt_rand(o))
101                 goto end;
102             break;
103         case OPT_PASSOUT:
104             passoutarg = opt_arg();
105             break;
106         case OPT_CIPHER:
107             if (!opt_cipher(opt_unknown(), &enc))
108                 goto end;
109             break;
110         case OPT_PRIMES:
111             if (!opt_int(opt_arg(), &primes))
112                 goto end;
113             break;
114         }
115     }
116     argc = opt_num_rest();
117     argv = opt_rest();
118 
119     if (argc == 1) {
120         if (!opt_int(argv[0], &num) || num <= 0)
121             goto end;
122         if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
123             BIO_printf(bio_err,
124                        "Warning: It is not recommended to use more than %d bit for RSA keys.\n"
125                        "         Your key size is %d! Larger key size may behave not as expected.\n",
126                        OPENSSL_RSA_MAX_MODULUS_BITS, num);
127     } else if (argc > 0) {
128         BIO_printf(bio_err, "Extra arguments given.\n");
129         goto opthelp;
130     }
131 
132     private = 1;
133     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
134         BIO_printf(bio_err, "Error getting password\n");
135         goto end;
136     }
137 
138     out = bio_open_owner(outfile, FORMAT_PEM, private);
139     if (out == NULL)
140         goto end;
141 
142     BIO_printf(bio_err, "Generating RSA private key, %d bit long modulus (%d primes)\n",
143                num, primes);
144     rsa = eng ? RSA_new_method(eng) : RSA_new();
145     if (rsa == NULL)
146         goto end;
147 
148     if (!BN_set_word(bn, f4)
149         || !RSA_generate_multi_prime_key(rsa, num, primes, bn, cb))
150         goto end;
151 
152     RSA_get0_key(rsa, NULL, &e, NULL);
153     hexe = BN_bn2hex(e);
154     dece = BN_bn2dec(e);
155     if (hexe && dece) {
156         BIO_printf(bio_err, "e is %s (0x%s)\n", dece, hexe);
157     }
158     OPENSSL_free(hexe);
159     OPENSSL_free(dece);
160     cb_data.password = passout;
161     cb_data.prompt_info = outfile;
162     assert(private);
163     if (!PEM_write_bio_RSAPrivateKey(out, rsa, enc, NULL, 0,
164                                      (pem_password_cb *)password_callback,
165                                      &cb_data))
166         goto end;
167 
168     ret = 0;
169  end:
170     BN_free(bn);
171     BN_GENCB_free(cb);
172     RSA_free(rsa);
173     BIO_free_all(out);
174     release_engine(eng);
175     OPENSSL_free(passout);
176     if (ret != 0)
177         ERR_print_errors(bio_err);
178     return ret;
179 }
180 
181 static int genrsa_cb(int p, int n, BN_GENCB *cb)
182 {
183     char c = '*';
184 
185     if (p == 0)
186         c = '.';
187     if (p == 1)
188         c = '+';
189     if (p == 2)
190         c = '*';
191     if (p == 3)
192         c = '\n';
193     BIO_write(BN_GENCB_get_arg(cb), &c, 1);
194     (void)BIO_flush(BN_GENCB_get_arg(cb));
195     return 1;
196 }
197