1 /* $OpenBSD: dsa_key.c,v 1.30 2022/01/07 09:35:36 tb Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59 #include <stdio.h>
60 #include <time.h>
61
62 #include <openssl/opensslconf.h>
63
64 #ifndef OPENSSL_NO_SHA
65
66 #include <openssl/bn.h>
67 #include <openssl/dsa.h>
68
69 #include "bn_lcl.h"
70 #include "dsa_locl.h"
71
72 static int dsa_builtin_keygen(DSA *dsa);
73
74 int
DSA_generate_key(DSA * dsa)75 DSA_generate_key(DSA *dsa)
76 {
77 if (dsa->meth->dsa_keygen)
78 return dsa->meth->dsa_keygen(dsa);
79 return dsa_builtin_keygen(dsa);
80 }
81
82 static int
dsa_builtin_keygen(DSA * dsa)83 dsa_builtin_keygen(DSA *dsa)
84 {
85 int ok = 0;
86 BN_CTX *ctx = NULL;
87 BIGNUM *pub_key = NULL, *priv_key = NULL;
88
89 if ((ctx = BN_CTX_new()) == NULL)
90 goto err;
91
92 if ((priv_key = dsa->priv_key) == NULL) {
93 if ((priv_key = BN_new()) == NULL)
94 goto err;
95 }
96
97 if (!bn_rand_interval(priv_key, BN_value_one(), dsa->q))
98 goto err;
99
100 if ((pub_key = dsa->pub_key) == NULL) {
101 if ((pub_key = BN_new()) == NULL)
102 goto err;
103 }
104
105 if (!BN_mod_exp_ct(pub_key, dsa->g, priv_key, dsa->p, ctx))
106 goto err;
107
108 dsa->priv_key = priv_key;
109 dsa->pub_key = pub_key;
110 ok = 1;
111
112 err:
113 if (dsa->pub_key == NULL)
114 BN_free(pub_key);
115 if (dsa->priv_key == NULL)
116 BN_free(priv_key);
117 BN_CTX_free(ctx);
118 return ok;
119 }
120 #endif
121