fips_dsa_key.c revision 296465 
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#ifndef OPENSSL_NO_SHA
62# include <openssl/bn.h>
63# include <openssl/dsa.h>
64# include <openssl/rand.h>
65# include <openssl/err.h>
66# include <openssl/evp.h>
67# include <openssl/fips.h>
68# include "fips_locl.h"
69
70# ifdef OPENSSL_FIPS
71
72static int fips_dsa_pairwise_fail = 0;
73
74void FIPS_corrupt_dsa_keygen(void)
75{
76    fips_dsa_pairwise_fail = 1;
77}
78
79static int dsa_builtin_keygen(DSA *dsa);
80
81static int fips_check_dsa(DSA *dsa)
82{
83    EVP_PKEY pk;
84    unsigned char tbs[] = "DSA Pairwise Check Data";
85    pk.type = EVP_PKEY_DSA;
86    pk.pkey.dsa = dsa;
87
88    if (!fips_pkey_signature_test(&pk, tbs, -1, NULL, 0, EVP_dss1(), 0, NULL)) {
89        FIPSerr(FIPS_F_FIPS_CHECK_DSA, FIPS_R_PAIRWISE_TEST_FAILED);
90        fips_set_selftest_fail();
91        return 0;
92    }
93    return 1;
94}
95
96int DSA_generate_key(DSA *dsa)
97{
98    if (dsa->meth->dsa_keygen)
99        return dsa->meth->dsa_keygen(dsa);
100    return dsa_builtin_keygen(dsa);
101}
102
103static int dsa_builtin_keygen(DSA *dsa)
104{
105    int ok = 0;
106    BN_CTX *ctx = NULL;
107    BIGNUM *pub_key = NULL, *priv_key = NULL;
108
109    if (FIPS_mode()
110        && (BN_num_bits(dsa->p) < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS)) {
111        DSAerr(DSA_F_DSA_BUILTIN_KEYGEN, DSA_R_KEY_SIZE_TOO_SMALL);
112        goto err;
113    }
114
115    if ((ctx = BN_CTX_new()) == NULL)
116        goto err;
117
118    if (dsa->priv_key == NULL) {
119        if ((priv_key = BN_new()) == NULL)
120            goto err;
121    } else
122        priv_key = dsa->priv_key;
123
124    do
125        if (!BN_rand_range(priv_key, dsa->q))
126            goto err;
127    while (BN_is_zero(priv_key)) ;
128
129    if (dsa->pub_key == NULL) {
130        if ((pub_key = BN_new()) == NULL)
131            goto err;
132    } else
133        pub_key = dsa->pub_key;
134
135    {
136        BIGNUM local_prk;
137        BIGNUM *prk;
138
139        if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
140            BN_init(&local_prk);
141            prk = &local_prk;
142            BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
143        } else
144            prk = priv_key;
145
146        if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx))
147            goto err;
148    }
149
150    dsa->priv_key = priv_key;
151    dsa->pub_key = pub_key;
152    if (fips_dsa_pairwise_fail)
153        BN_add_word(dsa->pub_key, 1);
154    if (!fips_check_dsa(dsa))
155        goto err;
156    ok = 1;
157
158 err:
159    if ((pub_key != NULL) && (dsa->pub_key == NULL))
160        BN_free(pub_key);
161    if ((priv_key != NULL) && (dsa->priv_key == NULL))
162        BN_free(priv_key);
163    if (ctx != NULL)
164        BN_CTX_free(ctx);
165    return (ok);
166}
167# endif
168
169#endif
170