summaryrefslogtreecommitdiff
path: root/src/lib/libcrypto/dsa/dsa_ossl.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libcrypto/dsa/dsa_ossl.c')
-rw-r--r--src/lib/libcrypto/dsa/dsa_ossl.c350
1 files changed, 350 insertions, 0 deletions
diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
new file mode 100644
index 0000000000..f1a85afcde
--- /dev/null
+++ b/src/lib/libcrypto/dsa/dsa_ossl.c
@@ -0,0 +1,350 @@
1/* crypto/dsa/dsa_ossl.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/rand.h>
66#include <openssl/asn1.h>
67
68#ifndef OPENSSL_FIPS
69static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
70static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
71static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
72 DSA *dsa);
73static int dsa_init(DSA *dsa);
74static int dsa_finish(DSA *dsa);
75static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
76 BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
77 BN_MONT_CTX *in_mont);
78static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
79 const BIGNUM *m, BN_CTX *ctx,
80 BN_MONT_CTX *m_ctx);
81
82static DSA_METHOD openssl_dsa_meth = {
83"OpenSSL DSA method",
84dsa_do_sign,
85dsa_sign_setup,
86dsa_do_verify,
87dsa_mod_exp,
88dsa_bn_mod_exp,
89dsa_init,
90dsa_finish,
910,
92NULL
93};
94
95const DSA_METHOD *DSA_OpenSSL(void)
96{
97 return &openssl_dsa_meth;
98}
99
100static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
101 {
102 BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
103 BIGNUM m;
104 BIGNUM xr;
105 BN_CTX *ctx=NULL;
106 int i,reason=ERR_R_BN_LIB;
107 DSA_SIG *ret=NULL;
108
109 BN_init(&m);
110 BN_init(&xr);
111
112 if (!dsa->p || !dsa->q || !dsa->g)
113 {
114 reason=DSA_R_MISSING_PARAMETERS;
115 goto err;
116 }
117
118 s=BN_new();
119 if (s == NULL) goto err;
120
121 i=BN_num_bytes(dsa->q); /* should be 20 */
122 if ((dlen > i) || (dlen > 50))
123 {
124 reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
125 goto err;
126 }
127
128 ctx=BN_CTX_new();
129 if (ctx == NULL) goto err;
130
131 if ((dsa->kinv == NULL) || (dsa->r == NULL))
132 {
133 if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
134 }
135 else
136 {
137 kinv=dsa->kinv;
138 dsa->kinv=NULL;
139 r=dsa->r;
140 dsa->r=NULL;
141 }
142
143 if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
144
145 /* Compute s = inv(k) (m + xr) mod q */
146 if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
147 if (!BN_add(s, &xr, &m)) goto err; /* s = m + xr */
148 if (BN_cmp(s,dsa->q) > 0)
149 BN_sub(s,s,dsa->q);
150 if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
151
152 ret=DSA_SIG_new();
153 if (ret == NULL) goto err;
154 ret->r = r;
155 ret->s = s;
156
157err:
158 if (!ret)
159 {
160 DSAerr(DSA_F_DSA_DO_SIGN,reason);
161 BN_free(r);
162 BN_free(s);
163 }
164 if (ctx != NULL) BN_CTX_free(ctx);
165 BN_clear_free(&m);
166 BN_clear_free(&xr);
167 if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
168 BN_clear_free(kinv);
169 return(ret);
170 }
171
172static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
173 {
174 BN_CTX *ctx;
175 BIGNUM k,*kinv=NULL,*r=NULL;
176 int ret=0;
177
178 if (!dsa->p || !dsa->q || !dsa->g)
179 {
180 DSAerr(DSA_F_DSA_SIGN_SETUP,DSA_R_MISSING_PARAMETERS);
181 return 0;
182 }
183
184 BN_init(&k);
185
186 if (ctx_in == NULL)
187 {
188 if ((ctx=BN_CTX_new()) == NULL) goto err;
189 }
190 else
191 ctx=ctx_in;
192
193 if ((r=BN_new()) == NULL) goto err;
194 kinv=NULL;
195
196 /* Get random k */
197 do
198 if (!BN_rand_range(&k, dsa->q)) goto err;
199 while (BN_is_zero(&k));
200
201 if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
202 {
203 if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
204 if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
205 dsa->p,ctx)) goto err;
206 }
207
208 /* Compute r = (g^k mod p) mod q */
209 if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
210 (BN_MONT_CTX *)dsa->method_mont_p)) goto err;
211 if (!BN_mod(r,r,dsa->q,ctx)) goto err;
212
213 /* Compute part of 's = inv(k) (m + xr) mod q' */
214 if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
215
216 if (*kinvp != NULL) BN_clear_free(*kinvp);
217 *kinvp=kinv;
218 kinv=NULL;
219 if (*rp != NULL) BN_clear_free(*rp);
220 *rp=r;
221 ret=1;
222err:
223 if (!ret)
224 {
225 DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
226 if (kinv != NULL) BN_clear_free(kinv);
227 if (r != NULL) BN_clear_free(r);
228 }
229 if (ctx_in == NULL) BN_CTX_free(ctx);
230 if (kinv != NULL) BN_clear_free(kinv);
231 BN_clear_free(&k);
232 return(ret);
233 }
234
235static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
236 DSA *dsa)
237 {
238 BN_CTX *ctx;
239 BIGNUM u1,u2,t1;
240 BN_MONT_CTX *mont=NULL;
241 int ret = -1;
242 if (!dsa->p || !dsa->q || !dsa->g)
243 {
244 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS);
245 return -1;
246 }
247
248 BN_init(&u1);
249 BN_init(&u2);
250 BN_init(&t1);
251
252 if ((ctx=BN_CTX_new()) == NULL) goto err;
253
254 if (BN_is_zero(sig->r) || sig->r->neg || BN_ucmp(sig->r, dsa->q) >= 0)
255 {
256 ret = 0;
257 goto err;
258 }
259 if (BN_is_zero(sig->s) || sig->s->neg || BN_ucmp(sig->s, dsa->q) >= 0)
260 {
261 ret = 0;
262 goto err;
263 }
264
265 /* Calculate W = inv(S) mod Q
266 * save W in u2 */
267 if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
268
269 /* save M in u1 */
270 if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
271
272 /* u1 = M * w mod q */
273 if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;
274
275 /* u2 = r * w mod q */
276 if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err;
277
278 if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
279 {
280 if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
281 if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
282 dsa->p,ctx)) goto err;
283 }
284 mont=(BN_MONT_CTX *)dsa->method_mont_p;
285
286#if 0
287 {
288 BIGNUM t2;
289
290 BN_init(&t2);
291 /* v = ( g^u1 * y^u2 mod p ) mod q */
292 /* let t1 = g ^ u1 mod p */
293 if (!BN_mod_exp_mont(&t1,dsa->g,&u1,dsa->p,ctx,mont)) goto err;
294 /* let t2 = y ^ u2 mod p */
295 if (!BN_mod_exp_mont(&t2,dsa->pub_key,&u2,dsa->p,ctx,mont)) goto err;
296 /* let u1 = t1 * t2 mod p */
297 if (!BN_mod_mul(&u1,&t1,&t2,dsa->p,ctx)) goto err_bn;
298 BN_free(&t2);
299 }
300 /* let u1 = u1 mod q */
301 if (!BN_mod(&u1,&u1,dsa->q,ctx)) goto err;
302#else
303 {
304 if (!dsa->meth->dsa_mod_exp(dsa, &t1,dsa->g,&u1,dsa->pub_key,&u2,
305 dsa->p,ctx,mont)) goto err;
306 /* BN_copy(&u1,&t1); */
307 /* let u1 = u1 mod q */
308 if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err;
309 }
310#endif
311 /* V is now in u1. If the signature is correct, it will be
312 * equal to R. */
313 ret=(BN_ucmp(&u1, sig->r) == 0);
314
315 err:
316 if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
317 if (ctx != NULL) BN_CTX_free(ctx);
318 BN_free(&u1);
319 BN_free(&u2);
320 BN_free(&t1);
321 return(ret);
322 }
323
324static int dsa_init(DSA *dsa)
325{
326 dsa->flags|=DSA_FLAG_CACHE_MONT_P;
327 return(1);
328}
329
330static int dsa_finish(DSA *dsa)
331{
332 if(dsa->method_mont_p)
333 BN_MONT_CTX_free((BN_MONT_CTX *)dsa->method_mont_p);
334 return(1);
335}
336
337static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
338 BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
339 BN_MONT_CTX *in_mont)
340{
341 return BN_mod_exp2_mont(rr, a1, p1, a2, p2, m, ctx, in_mont);
342}
343
344static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
345 const BIGNUM *m, BN_CTX *ctx,
346 BN_MONT_CTX *m_ctx)
347{
348 return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
349}
350#endif