dsa_asn1.c revision 277195 
1/* dsa_asn1.c */
2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2000.
4 */
5/* ====================================================================
6 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 *    software must display the following acknowledgment:
22 *    "This product includes software developed by the OpenSSL Project
23 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 *    endorse or promote products derived from this software without
27 *    prior written permission. For written permission, please contact
28 *    licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 *    nor may "OpenSSL" appear in their names without prior written
32 *    permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 *    acknowledgment:
36 *    "This product includes software developed by the OpenSSL Project
37 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com).  This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/dsa.h>
62#include <openssl/asn1.h>
63#include <openssl/asn1t.h>
64#include <openssl/rand.h>
65
66/* Override the default new methods */
67static int sig_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
68								void *exarg)
69{
70	if(operation == ASN1_OP_NEW_PRE) {
71		DSA_SIG *sig;
72		sig = OPENSSL_malloc(sizeof(DSA_SIG));
73		if (!sig)
74			{
75			DSAerr(DSA_F_SIG_CB, ERR_R_MALLOC_FAILURE);
76			return 0;
77			}
78		sig->r = NULL;
79		sig->s = NULL;
80		*pval = (ASN1_VALUE *)sig;
81		return 2;
82	}
83	return 1;
84}
85
86ASN1_SEQUENCE_cb(DSA_SIG, sig_cb) = {
87	ASN1_SIMPLE(DSA_SIG, r, CBIGNUM),
88	ASN1_SIMPLE(DSA_SIG, s, CBIGNUM)
89} ASN1_SEQUENCE_END_cb(DSA_SIG, DSA_SIG)
90
91IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA_SIG, DSA_SIG, DSA_SIG)
92
93/* Override the default free and new methods */
94static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
95							void *exarg)
96{
97	if(operation == ASN1_OP_NEW_PRE) {
98		*pval = (ASN1_VALUE *)DSA_new();
99		if(*pval) return 2;
100		return 0;
101	} else if(operation == ASN1_OP_FREE_PRE) {
102		DSA_free((DSA *)*pval);
103		*pval = NULL;
104		return 2;
105	}
106	return 1;
107}
108
109ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
110	ASN1_SIMPLE(DSA, version, LONG),
111	ASN1_SIMPLE(DSA, p, BIGNUM),
112	ASN1_SIMPLE(DSA, q, BIGNUM),
113	ASN1_SIMPLE(DSA, g, BIGNUM),
114	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
115	ASN1_SIMPLE(DSA, priv_key, BIGNUM)
116} ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
117
118IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)
119
120ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
121	ASN1_SIMPLE(DSA, p, BIGNUM),
122	ASN1_SIMPLE(DSA, q, BIGNUM),
123	ASN1_SIMPLE(DSA, g, BIGNUM),
124} ASN1_SEQUENCE_END_cb(DSA, DSAparams)
125
126IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)
127
128/* DSA public key is a bit trickier... its effectively a CHOICE type
129 * decided by a field called write_params which can either write out
130 * just the public key as an INTEGER or the parameters and public key
131 * in a SEQUENCE
132 */
133
134ASN1_SEQUENCE(dsa_pub_internal) = {
135	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
136	ASN1_SIMPLE(DSA, p, BIGNUM),
137	ASN1_SIMPLE(DSA, q, BIGNUM),
138	ASN1_SIMPLE(DSA, g, BIGNUM)
139} ASN1_SEQUENCE_END_name(DSA, dsa_pub_internal)
140
141ASN1_CHOICE_cb(DSAPublicKey, dsa_cb) = {
142	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
143	ASN1_EX_COMBINE(0, 0, dsa_pub_internal)
144} ASN1_CHOICE_END_cb(DSA, DSAPublicKey, write_params)
145
146IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)
147
148DSA *DSAparams_dup(DSA *dsa)
149	{
150	return ASN1_item_dup(ASN1_ITEM_rptr(DSAparams), dsa);
151	}
152
153int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
154	     unsigned int *siglen, DSA *dsa)
155	{
156	DSA_SIG *s;
157	RAND_seed(dgst, dlen);
158	s=DSA_do_sign(dgst,dlen,dsa);
159	if (s == NULL)
160		{
161		*siglen=0;
162		return(0);
163		}
164	*siglen=i2d_DSA_SIG(s,&sig);
165	DSA_SIG_free(s);
166	return(1);
167	}
168
169/* data has already been hashed (probably with SHA or SHA-1). */
170/* returns
171 *      1: correct signature
172 *      0: incorrect signature
173 *     -1: error
174 */
175int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
176	     const unsigned char *sigbuf, int siglen, DSA *dsa)
177	{
178	DSA_SIG *s;
179	const unsigned char *p = sigbuf;
180	unsigned char *der = NULL;
181	int derlen = -1;
182	int ret=-1;
183
184	s = DSA_SIG_new();
185	if (s == NULL) return(ret);
186	if (d2i_DSA_SIG(&s,&p,siglen) == NULL) goto err;
187	/* Ensure signature uses DER and doesn't have trailing garbage */
188	derlen = i2d_DSA_SIG(s, &der);
189	if (derlen != siglen || memcmp(sigbuf, der, derlen))
190		goto err;
191	ret=DSA_do_verify(dgst,dgst_len,s,dsa);
192err:
193	if (derlen > 0)
194		{
195		OPENSSL_cleanse(der, derlen);
196		OPENSSL_free(der);
197		}
198	DSA_SIG_free(s);
199	return(ret);
200	}
201