1 /*
2 * Copyright 1995-2021 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 if (sig == NULL)
38 ERR_raise(ERR_LIB_DSA, ERR_R_MALLOC_FAILURE);
39 return sig;
40 }
41
DSA_SIG_free(DSA_SIG * sig)42 void DSA_SIG_free(DSA_SIG *sig)
43 {
44 if (sig == NULL)
45 return;
46 BN_clear_free(sig->r);
47 BN_clear_free(sig->s);
48 OPENSSL_free(sig);
49 }
50
d2i_DSA_SIG(DSA_SIG ** psig,const unsigned char ** ppin,long len)51 DSA_SIG *d2i_DSA_SIG(DSA_SIG **psig, const unsigned char **ppin, long len)
52 {
53 DSA_SIG *sig;
54
55 if (len < 0)
56 return NULL;
57 if (psig != NULL && *psig != NULL) {
58 sig = *psig;
59 } else {
60 sig = DSA_SIG_new();
61 if (sig == NULL)
62 return NULL;
63 }
64 if (sig->r == NULL)
65 sig->r = BN_new();
66 if (sig->s == NULL)
67 sig->s = BN_new();
68 if (sig->r == NULL || sig->s == NULL
69 || ossl_decode_der_dsa_sig(sig->r, sig->s, ppin, (size_t)len) == 0) {
70 if (psig == NULL || *psig == NULL)
71 DSA_SIG_free(sig);
72 return NULL;
73 }
74 if (psig != NULL && *psig == NULL)
75 *psig = sig;
76 return sig;
77 }
78
i2d_DSA_SIG(const DSA_SIG * sig,unsigned char ** ppout)79 int i2d_DSA_SIG(const DSA_SIG *sig, unsigned char **ppout)
80 {
81 BUF_MEM *buf = NULL;
82 size_t encoded_len;
83 WPACKET pkt;
84
85 if (ppout == NULL) {
86 if (!WPACKET_init_null(&pkt, 0))
87 return -1;
88 } else if (*ppout == NULL) {
89 if ((buf = BUF_MEM_new()) == NULL
90 || !WPACKET_init_len(&pkt, buf, 0)) {
91 BUF_MEM_free(buf);
92 return -1;
93 }
94 } else {
95 if (!WPACKET_init_static_len(&pkt, *ppout, SIZE_MAX, 0))
96 return -1;
97 }
98
99 if (!ossl_encode_der_dsa_sig(&pkt, sig->r, sig->s)
100 || !WPACKET_get_total_written(&pkt, &encoded_len)
101 || !WPACKET_finish(&pkt)) {
102 BUF_MEM_free(buf);
103 WPACKET_cleanup(&pkt);
104 return -1;
105 }
106
107 if (ppout != NULL) {
108 if (*ppout == NULL) {
109 *ppout = (unsigned char *)buf->data;
110 buf->data = NULL;
111 BUF_MEM_free(buf);
112 } else {
113 *ppout += encoded_len;
114 }
115 }
116
117 return (int)encoded_len;
118 }
119
DSA_size(const DSA * dsa)120 int DSA_size(const DSA *dsa)
121 {
122 int ret = -1;
123 DSA_SIG sig;
124
125 if (dsa->params.q != NULL) {
126 sig.r = sig.s = dsa->params.q;
127 ret = i2d_DSA_SIG(&sig, NULL);
128
129 if (ret < 0)
130 ret = 0;
131 }
132 return ret;
133 }
134
DSA_SIG_get0(const DSA_SIG * sig,const BIGNUM ** pr,const BIGNUM ** ps)135 void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
136 {
137 if (pr != NULL)
138 *pr = sig->r;
139 if (ps != NULL)
140 *ps = sig->s;
141 }
142
DSA_SIG_set0(DSA_SIG * sig,BIGNUM * r,BIGNUM * s)143 int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
144 {
145 if (r == NULL || s == NULL)
146 return 0;
147 BN_clear_free(sig->r);
148 BN_clear_free(sig->s);
149 sig->r = r;
150 sig->s = s;
151 return 1;
152 }
153
ossl_dsa_sign_int(int type,const unsigned char * dgst,int dlen,unsigned char * sig,unsigned int * siglen,DSA * dsa)154 int ossl_dsa_sign_int(int type, const unsigned char *dgst, int dlen,
155 unsigned char *sig, unsigned int *siglen, DSA *dsa)
156 {
157 DSA_SIG *s;
158
159 /* legacy case uses the method table */
160 if (dsa->libctx == NULL || dsa->meth != DSA_get_default_method())
161 s = DSA_do_sign(dgst, dlen, dsa);
162 else
163 s = ossl_dsa_do_sign_int(dgst, dlen, dsa);
164 if (s == NULL) {
165 *siglen = 0;
166 return 0;
167 }
168 *siglen = i2d_DSA_SIG(s, &sig);
169 DSA_SIG_free(s);
170 return 1;
171 }
172
DSA_sign(int type,const unsigned char * dgst,int dlen,unsigned char * sig,unsigned int * siglen,DSA * dsa)173 int DSA_sign(int type, const unsigned char *dgst, int dlen,
174 unsigned char *sig, unsigned int *siglen, DSA *dsa)
175 {
176 return ossl_dsa_sign_int(type, dgst, dlen, sig, siglen, dsa);
177 }
178
179 /* data has already been hashed (probably with SHA or SHA-1). */
180 /*-
181 * returns
182 * 1: correct signature
183 * 0: incorrect signature
184 * -1: error
185 */
DSA_verify(int type,const unsigned char * dgst,int dgst_len,const unsigned char * sigbuf,int siglen,DSA * dsa)186 int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
187 const unsigned char *sigbuf, int siglen, DSA *dsa)
188 {
189 DSA_SIG *s;
190 const unsigned char *p = sigbuf;
191 unsigned char *der = NULL;
192 int derlen = -1;
193 int ret = -1;
194
195 s = DSA_SIG_new();
196 if (s == NULL)
197 return ret;
198 if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
199 goto err;
200 /* Ensure signature uses DER and doesn't have trailing garbage */
201 derlen = i2d_DSA_SIG(s, &der);
202 if (derlen != siglen || memcmp(sigbuf, der, derlen))
203 goto err;
204 ret = DSA_do_verify(dgst, dgst_len, s, dsa);
205 err:
206 OPENSSL_clear_free(der, derlen);
207 DSA_SIG_free(s);
208 return ret;
209 }
210