dsa_asn1.c revision 194206 
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 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/bn.h>
65#ifdef OPENSSL_FIPS
66#include <openssl/fips.h>
67#endif
68
69
70/* Override the default new methods */
71static int sig_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it)
72{
73	if(operation == ASN1_OP_NEW_PRE) {
74		DSA_SIG *sig;
75		sig = OPENSSL_malloc(sizeof(DSA_SIG));
76		sig->r = NULL;
77		sig->s = NULL;
78		*pval = (ASN1_VALUE *)sig;
79		if(sig) return 2;
80		DSAerr(DSA_F_SIG_CB, ERR_R_MALLOC_FAILURE);
81		return 0;
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{
96	if(operation == ASN1_OP_NEW_PRE) {
97		*pval = (ASN1_VALUE *)DSA_new();
98		if(*pval) return 2;
99		return 0;
100	} else if(operation == ASN1_OP_FREE_PRE) {
101		DSA_free((DSA *)*pval);
102		*pval = NULL;
103		return 2;
104	}
105	return 1;
106}
107
108ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
109	ASN1_SIMPLE(DSA, version, LONG),
110	ASN1_SIMPLE(DSA, p, BIGNUM),
111	ASN1_SIMPLE(DSA, q, BIGNUM),
112	ASN1_SIMPLE(DSA, g, BIGNUM),
113	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
114	ASN1_SIMPLE(DSA, priv_key, BIGNUM)
115} ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
116
117IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)
118
119ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
120	ASN1_SIMPLE(DSA, p, BIGNUM),
121	ASN1_SIMPLE(DSA, q, BIGNUM),
122	ASN1_SIMPLE(DSA, g, BIGNUM),
123} ASN1_SEQUENCE_END_cb(DSA, DSAparams)
124
125IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)
126
127/* DSA public key is a bit trickier... its effectively a CHOICE type
128 * decided by a field called write_params which can either write out
129 * just the public key as an INTEGER or the parameters and public key
130 * in a SEQUENCE
131 */
132
133ASN1_SEQUENCE(dsa_pub_internal) = {
134	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
135	ASN1_SIMPLE(DSA, p, BIGNUM),
136	ASN1_SIMPLE(DSA, q, BIGNUM),
137	ASN1_SIMPLE(DSA, g, BIGNUM)
138} ASN1_SEQUENCE_END_name(DSA, dsa_pub_internal)
139
140ASN1_CHOICE_cb(DSAPublicKey, dsa_cb) = {
141	ASN1_SIMPLE(DSA, pub_key, BIGNUM),
142	ASN1_EX_COMBINE(0, 0, dsa_pub_internal)
143} ASN1_CHOICE_END_cb(DSA, DSAPublicKey, write_params)
144
145IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)
146
147int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
148	     unsigned int *siglen, DSA *dsa)
149	{
150	DSA_SIG *s;
151#ifdef OPENSSL_FIPS
152	if(FIPS_mode() && !(dsa->flags & DSA_FLAG_NON_FIPS_ALLOW))
153		{
154		DSAerr(DSA_F_DSA_SIGN, DSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE);
155		return 0;
156		}
157#endif
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
169int DSA_size(const DSA *r)
170	{
171	int ret,i;
172	ASN1_INTEGER bs;
173	unsigned char buf[4];	/* 4 bytes looks really small.
174				   However, i2d_ASN1_INTEGER() will not look
175				   beyond the first byte, as long as the second
176				   parameter is NULL. */
177
178	i=BN_num_bits(r->q);
179	bs.length=(i+7)/8;
180	bs.data=buf;
181	bs.type=V_ASN1_INTEGER;
182	/* If the top bit is set the asn1 encoding is 1 larger. */
183	buf[0]=0xff;
184
185	i=i2d_ASN1_INTEGER(&bs,NULL);
186	i+=i; /* r and s */
187	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
188	return(ret);
189	}
190
191/* data has already been hashed (probably with SHA or SHA-1). */
192/* returns
193 *      1: correct signature
194 *      0: incorrect signature
195 *     -1: error
196 */
197int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
198	     const unsigned char *sigbuf, int siglen, DSA *dsa)
199	{
200	DSA_SIG *s;
201	int ret=-1;
202#ifdef OPENSSL_FIPS
203	if(FIPS_mode() && !(dsa->flags & DSA_FLAG_NON_FIPS_ALLOW))
204		{
205		DSAerr(DSA_F_DSA_VERIFY, DSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE);
206		return 0;
207		}
208#endif
209
210	s = DSA_SIG_new();
211	if (s == NULL) return(ret);
212	if (d2i_DSA_SIG(&s,&sigbuf,siglen) == NULL) goto err;
213	ret=DSA_do_verify(dgst,dgst_len,s,dsa);
214err:
215	DSA_SIG_free(s);
216	return(ret);
217	}
218
219