xref: /openbsd-src/lib/libcrypto/dsa/dsa_lib.c (revision 1fc27e414118cd8922c6b93fbaeb7a5246bfd593)
1 /* crypto/dsa/dsa_lib.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 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
60 
61 #include <stdio.h>
62 #include "cryptlib.h"
63 #include <openssl/bn.h>
64 #include <openssl/dsa.h>
65 #include <openssl/asn1.h>
66 
67 const char *DSA_version="DSA" OPENSSL_VERSION_PTEXT;
68 
69 DSA *DSA_new(void)
70 	{
71 	DSA *ret;
72 
73 	ret=(DSA *)Malloc(sizeof(DSA));
74 	if (ret == NULL)
75 		{
76 		DSAerr(DSA_F_DSA_NEW,ERR_R_MALLOC_FAILURE);
77 		return(NULL);
78 		}
79 	ret->pad=0;
80 	ret->version=0;
81 	ret->write_params=1;
82 	ret->p=NULL;
83 	ret->q=NULL;
84 	ret->g=NULL;
85 	ret->flags=DSA_FLAG_CACHE_MONT_P;
86 
87 	ret->pub_key=NULL;
88 	ret->priv_key=NULL;
89 
90 	ret->kinv=NULL;
91 	ret->r=NULL;
92 	ret->method_mont_p=NULL;
93 
94 	ret->references=1;
95 	return(ret);
96 	}
97 
98 void DSA_free(DSA *r)
99 	{
100 	int i;
101 
102 	if (r == NULL) return;
103 
104 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_DSA);
105 #ifdef REF_PRINT
106 	REF_PRINT("DSA",r);
107 #endif
108 	if (i > 0) return;
109 #ifdef REF_CHECK
110 	if (i < 0)
111 		{
112 		fprintf(stderr,"DSA_free, bad reference count\n");
113 		abort();
114 		}
115 #endif
116 
117 	if (r->p != NULL) BN_clear_free(r->p);
118 	if (r->q != NULL) BN_clear_free(r->q);
119 	if (r->g != NULL) BN_clear_free(r->g);
120 	if (r->pub_key != NULL) BN_clear_free(r->pub_key);
121 	if (r->priv_key != NULL) BN_clear_free(r->priv_key);
122 	if (r->kinv != NULL) BN_clear_free(r->kinv);
123 	if (r->r != NULL) BN_clear_free(r->r);
124 	if (r->method_mont_p != NULL)
125 		BN_MONT_CTX_free((BN_MONT_CTX *)r->method_mont_p);
126 	Free(r);
127 	}
128 
129 int DSA_size(DSA *r)
130 	{
131 	int ret,i;
132 	ASN1_INTEGER bs;
133 	unsigned char buf[4];
134 
135 	i=BN_num_bits(r->q);
136 	bs.length=(i+7)/8;
137 	bs.data=buf;
138 	bs.type=V_ASN1_INTEGER;
139 	/* If the top bit is set the asn1 encoding is 1 larger. */
140 	buf[0]=0xff;
141 
142 	i=i2d_ASN1_INTEGER(&bs,NULL);
143 	i+=i; /* r and s */
144 	ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
145 	return(ret);
146 	}
147 
148 #ifndef NO_DH
149 DH *DSA_dup_DH(DSA *r)
150 	{
151 	/* DSA has p, q, g, optional pub_key, optional priv_key.
152 	 * DH has p, optional length, g, optional pub_key, optional priv_key.
153 	 */
154 
155 	DH *ret = NULL;
156 
157 	if (r == NULL)
158 		goto err;
159 	ret = DH_new();
160 	if (ret == NULL)
161 		goto err;
162 	if (r->p != NULL)
163 		if ((ret->p = BN_dup(r->p)) == NULL)
164 			goto err;
165 	if (r->q != NULL)
166 		ret->length = BN_num_bits(r->q);
167 	if (r->g != NULL)
168 		if ((ret->g = BN_dup(r->g)) == NULL)
169 			goto err;
170 	if (r->pub_key != NULL)
171 		if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
172 			goto err;
173 	if (r->priv_key != NULL)
174 		if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
175 			goto err;
176 
177 	return ret;
178 
179  err:
180 	if (ret != NULL)
181 		DH_free(ret);
182 	return NULL;
183 	}
184 #endif
185