1 /*
2 * Copyright 1995-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * DSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/bn.h>
17 #include "internal/cryptlib.h"
18 #include "dsa_local.h"
19 #include "crypto/asn1_dsa.h"
20 #include "crypto/dsa.h"
21
DSA_do_sign(const unsigned char * dgst,int dlen,DSA * dsa)22 DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
23 {
24 return dsa->meth->dsa_do_sign(dgst, dlen, dsa);
25 }
26
27 #ifndef OPENSSL_NO_DEPRECATED_3_0
DSA_sign_setup(DSA * dsa,BN_CTX * ctx_in,BIGNUM ** kinvp,BIGNUM ** rp)28 int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
29 {
30 return dsa->meth->dsa_sign_setup(dsa, ctx_in, kinvp, rp);
31 }
32 #endif
33
DSA_SIG_new(void)34 DSA_SIG *DSA_SIG_new(void)
35 {
36 DSA_SIG *sig = OPENSSL_zalloc(sizeof(*sig));
37
38 return sig;
39 }
40
DSA_SIG_free(DSA_SIG * sig)41 void DSA_SIG_free(DSA_SIG *sig)
42 {
43 if (sig == NULL)
44 return;
45 BN_clear_free(sig->r);
46 BN_clear_free(sig->s);
47 OPENSSL_free(sig);
48 }
49
d2i_DSA_SIG(DSA_SIG ** psig,const unsigned char ** ppin,long len)50 DSA_SIG *d2i_DSA_SIG(DSA_SIG **psig, const unsigned char **ppin, long len)
51 {
52 DSA_SIG *sig;
53
54 if (len < 0)
55 return NULL;
56 if (psig != NULL && *psig != NULL) {
57 sig = *psig;
58 } else {
59 sig = DSA_SIG_new();
60 if (sig == NULL)
61 return NULL;
62 }
63 if (sig->r == NULL)
64 sig->r = BN_new();
65 if (sig->s == NULL)
66 sig->s = BN_new();
67 if (sig->r == NULL || sig->s == NULL
68 || ossl_decode_der_dsa_sig(sig->r, sig->s, ppin, (size_t)len) == 0) {
69 if (psig == NULL || *psig == NULL)
70 DSA_SIG_free(sig);
71 return NULL;
72 }
73 if (psig != NULL && *psig == NULL)
74 *psig = sig;
75 return sig;
76 }
77
i2d_DSA_SIG(const DSA_SIG * sig,unsigned char ** ppout)78 int i2d_DSA_SIG(const DSA_SIG *sig, unsigned char **ppout)
79 {
80 BUF_MEM *buf = NULL;
81 size_t encoded_len;
82 WPACKET pkt;
83
84 if (ppout == NULL) {
85 if (!WPACKET_init_null(&pkt, 0))
86 return -1;
87 } else if (*ppout == NULL) {
88 if ((buf = BUF_MEM_new()) == NULL
89 || !WPACKET_init_len(&pkt, buf, 0)) {
90 BUF_MEM_free(buf);
91 return -1;
92 }
93 } else {
94 if (!WPACKET_init_static_len(&pkt, *ppout, SIZE_MAX, 0))
95 return -1;
96 }
97
98 if (!ossl_encode_der_dsa_sig(&pkt, sig->r, sig->s)
99 || !WPACKET_get_total_written(&pkt, &encoded_len)
100 || !WPACKET_finish(&pkt)) {
101 BUF_MEM_free(buf);
102 WPACKET_cleanup(&pkt);
103 return -1;
104 }
105
106 if (ppout != NULL) {
107 if (*ppout == NULL) {
108 *ppout = (unsigned char *)buf->data;
109 buf->data = NULL;
110 BUF_MEM_free(buf);
111 } else {
112 *ppout += encoded_len;
113 }
114 }
115
116 return (int)encoded_len;
117 }
118
DSA_size(const DSA * dsa)119 int DSA_size(const DSA *dsa)
120 {
121 int ret = -1;
122 DSA_SIG sig;
123
124 if (dsa->params.q != NULL) {
125 sig.r = sig.s = dsa->params.q;
126 ret = i2d_DSA_SIG(&sig, NULL);
127
128 if (ret < 0)
129 ret = 0;
130 }
131 return ret;
132 }
133
DSA_SIG_get0(const DSA_SIG * sig,const BIGNUM ** pr,const BIGNUM ** ps)134 void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
135 {
136 if (pr != NULL)
137 *pr = sig->r;
138 if (ps != NULL)
139 *ps = sig->s;
140 }
141
DSA_SIG_set0(DSA_SIG * sig,BIGNUM * r,BIGNUM * s)142 int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
143 {
144 if (r == NULL || s == NULL)
145 return 0;
146 BN_clear_free(sig->r);
147 BN_clear_free(sig->s);
148 sig->r = r;
149 sig->s = s;
150 return 1;
151 }
152
ossl_dsa_sign_int(int type,const unsigned char * dgst,int dlen,unsigned char * sig,unsigned int * siglen,DSA * dsa,unsigned int nonce_type,const char * digestname,OSSL_LIB_CTX * libctx,const char * propq)153 int ossl_dsa_sign_int(int type, const unsigned char *dgst, int dlen,
154 unsigned char *sig, unsigned int *siglen, DSA *dsa,
155 unsigned int nonce_type, const char *digestname,
156 OSSL_LIB_CTX *libctx, const char *propq)
157 {
158 DSA_SIG *s;
159
160 if (sig == NULL) {
161 *siglen = DSA_size(dsa);
162 return 1;
163 }
164
165 /* legacy case uses the method table */
166 if (dsa->libctx == NULL || dsa->meth != DSA_get_default_method())
167 s = DSA_do_sign(dgst, dlen, dsa);
168 else
169 s = ossl_dsa_do_sign_int(dgst, dlen, dsa,
170 nonce_type, digestname, libctx, propq);
171 if (s == NULL) {
172 *siglen = 0;
173 return 0;
174 }
175 *siglen = i2d_DSA_SIG(s, &sig);
176 DSA_SIG_free(s);
177 return 1;
178 }
179
DSA_sign(int type,const unsigned char * dgst,int dlen,unsigned char * sig,unsigned int * siglen,DSA * dsa)180 int DSA_sign(int type, const unsigned char *dgst, int dlen,
181 unsigned char *sig, unsigned int *siglen, DSA *dsa)
182 {
183 return ossl_dsa_sign_int(type, dgst, dlen, sig, siglen, dsa,
184 0, NULL, NULL, NULL);
185 }
186
187 /* data has already been hashed (probably with SHA or SHA-1). */
188 /*-
189 * returns
190 * 1: correct signature
191 * 0: incorrect signature
192 * -1: error
193 */
DSA_verify(int type,const unsigned char * dgst,int dgst_len,const unsigned char * sigbuf,int siglen,DSA * dsa)194 int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
195 const unsigned char *sigbuf, int siglen, DSA *dsa)
196 {
197 DSA_SIG *s;
198 const unsigned char *p = sigbuf;
199 unsigned char *der = NULL;
200 int derlen = -1;
201 int ret = -1;
202
203 s = DSA_SIG_new();
204 if (s == NULL)
205 return ret;
206 if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
207 goto err;
208 /* Ensure signature uses DER and doesn't have trailing garbage */
209 derlen = i2d_DSA_SIG(s, &der);
210 if (derlen != siglen || memcmp(sigbuf, der, derlen))
211 goto err;
212 ret = DSA_do_verify(dgst, dgst_len, s, dsa);
213 err:
214 OPENSSL_clear_free(der, derlen);
215 DSA_SIG_free(s);
216 return ret;
217 }
218
