Line data Source code
1 : /* crypto/dsa/dsa_key.c */
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 : #include "cryptlib.h"
62 : #ifndef OPENSSL_NO_SHA
63 : # include <openssl/bn.h>
64 : # include <openssl/dsa.h>
65 : # include <openssl/rand.h>
66 :
67 : # ifdef OPENSSL_FIPS
68 : # include <openssl/fips.h>
69 : # endif
70 :
71 : static int dsa_builtin_keygen(DSA *dsa);
72 :
73 0 : int DSA_generate_key(DSA *dsa)
74 : {
75 : # ifdef OPENSSL_FIPS
76 : if (FIPS_mode() && !(dsa->meth->flags & DSA_FLAG_FIPS_METHOD)
77 : && !(dsa->flags & DSA_FLAG_NON_FIPS_ALLOW)) {
78 : DSAerr(DSA_F_DSA_GENERATE_KEY, DSA_R_NON_FIPS_DSA_METHOD);
79 : return 0;
80 : }
81 : # endif
82 0 : if (dsa->meth->dsa_keygen)
83 0 : return dsa->meth->dsa_keygen(dsa);
84 : # ifdef OPENSSL_FIPS
85 : if (FIPS_mode())
86 : return FIPS_dsa_generate_key(dsa);
87 : # endif
88 0 : return dsa_builtin_keygen(dsa);
89 : }
90 :
91 0 : static int dsa_builtin_keygen(DSA *dsa)
92 : {
93 : int ok = 0;
94 : BN_CTX *ctx = NULL;
95 : BIGNUM *pub_key = NULL, *priv_key = NULL;
96 :
97 0 : if ((ctx = BN_CTX_new()) == NULL)
98 : goto err;
99 :
100 0 : if (dsa->priv_key == NULL) {
101 0 : if ((priv_key = BN_new()) == NULL)
102 : goto err;
103 : } else
104 : priv_key = dsa->priv_key;
105 :
106 : do
107 0 : if (!BN_rand_range(priv_key, dsa->q))
108 : goto err;
109 0 : while (BN_is_zero(priv_key)) ;
110 :
111 0 : if (dsa->pub_key == NULL) {
112 0 : if ((pub_key = BN_new()) == NULL)
113 : goto err;
114 : } else
115 : pub_key = dsa->pub_key;
116 :
117 : {
118 : BIGNUM local_prk;
119 : BIGNUM *prk;
120 :
121 0 : if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
122 0 : BN_init(&local_prk);
123 : prk = &local_prk;
124 0 : BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
125 : } else
126 : prk = priv_key;
127 :
128 0 : if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx))
129 : goto err;
130 : }
131 :
132 0 : dsa->priv_key = priv_key;
133 0 : dsa->pub_key = pub_key;
134 : ok = 1;
135 :
136 : err:
137 0 : if ((pub_key != NULL) && (dsa->pub_key == NULL))
138 0 : BN_free(pub_key);
139 0 : if ((priv_key != NULL) && (dsa->priv_key == NULL))
140 0 : BN_free(priv_key);
141 0 : if (ctx != NULL)
142 0 : BN_CTX_free(ctx);
143 0 : return (ok);
144 : }
145 : #endif
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