summaryrefslogtreecommitdiff
path: root/src/lib/libcrypto/dsa/dsa_ossl.c
diff options
context:
space:
mode:
authorcvs2svn <admin@example.com>2011-02-12 15:54:19 +0000
committercvs2svn <admin@example.com>2011-02-12 15:54:19 +0000
commitf01f837ce3a9db0dbe6799caba130b35c63a5c32 (patch)
tree26cf8fda7724fe56961aa26b7da50db9634c08a2 /src/lib/libcrypto/dsa/dsa_ossl.c
parent6ed6984480044de43dd93380f4475033ba8cd945 (diff)
downloadopenbsd-OPENBSD_4_9_BASE.tar.gz
openbsd-OPENBSD_4_9_BASE.tar.bz2
openbsd-OPENBSD_4_9_BASE.zip
This commit was manufactured by cvs2git to create tag 'OPENBSD_4_9_BASE'.OPENBSD_4_9_BASE
Diffstat (limited to 'src/lib/libcrypto/dsa/dsa_ossl.c')
-rw-r--r--src/lib/libcrypto/dsa/dsa_ossl.c416
1 files changed, 0 insertions, 416 deletions
diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
deleted file mode 100644
index 4fead07e80..0000000000
--- a/src/lib/libcrypto/dsa/dsa_ossl.c
+++ /dev/null
@@ -1,416 +0,0 @@
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/sha.h>
65#include <openssl/dsa.h>
66#include <openssl/rand.h>
67#include <openssl/asn1.h>
68
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);
75
76static DSA_METHOD openssl_dsa_meth = {
77"OpenSSL DSA method",
78dsa_do_sign,
79dsa_sign_setup,
80dsa_do_verify,
81NULL, /* dsa_mod_exp, */
82NULL, /* dsa_bn_mod_exp, */
83dsa_init,
84dsa_finish,
850,
86NULL,
87NULL,
88NULL
89};
90
91/* These macro wrappers replace attempts to use the dsa_mod_exp() and
92 * bn_mod_exp() handlers in the DSA_METHOD structure. We avoid the problem of
93 * having a the macro work as an expression by bundling an "err_instr". So;
94 *
95 * if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,&k,dsa->p,ctx,
96 * dsa->method_mont_p)) goto err;
97 *
98 * can be replaced by;
99 *
100 * DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, &k, dsa->p, ctx,
101 * dsa->method_mont_p);
102 */
103
104#define DSA_MOD_EXP(err_instr,dsa,rr,a1,p1,a2,p2,m,ctx,in_mont) \
105 do { \
106 int _tmp_res53; \
107 if((dsa)->meth->dsa_mod_exp) \
108 _tmp_res53 = (dsa)->meth->dsa_mod_exp((dsa), (rr), (a1), (p1), \
109 (a2), (p2), (m), (ctx), (in_mont)); \
110 else \
111 _tmp_res53 = BN_mod_exp2_mont((rr), (a1), (p1), (a2), (p2), \
112 (m), (ctx), (in_mont)); \
113 if(!_tmp_res53) err_instr; \
114 } while(0)
115#define DSA_BN_MOD_EXP(err_instr,dsa,r,a,p,m,ctx,m_ctx) \
116 do { \
117 int _tmp_res53; \
118 if((dsa)->meth->bn_mod_exp) \
119 _tmp_res53 = (dsa)->meth->bn_mod_exp((dsa), (r), (a), (p), \
120 (m), (ctx), (m_ctx)); \
121 else \
122 _tmp_res53 = BN_mod_exp_mont((r), (a), (p), (m), (ctx), (m_ctx)); \
123 if(!_tmp_res53) err_instr; \
124 } while(0)
125
126const DSA_METHOD *DSA_OpenSSL(void)
127{
128 return &openssl_dsa_meth;
129}
130
131static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
132 {
133 BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
134 BIGNUM m;
135 BIGNUM xr;
136 BN_CTX *ctx=NULL;
137 int reason=ERR_R_BN_LIB;
138 DSA_SIG *ret=NULL;
139
140 BN_init(&m);
141 BN_init(&xr);
142
143 if (!dsa->p || !dsa->q || !dsa->g)
144 {
145 reason=DSA_R_MISSING_PARAMETERS;
146 goto err;
147 }
148
149 s=BN_new();
150 if (s == NULL) goto err;
151
152 /* reject a excessive digest length (currently at most
153 * dsa-with-SHA256 is supported) */
154 if (dlen > SHA256_DIGEST_LENGTH)
155 {
156 reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
157 goto err;
158 }
159
160 ctx=BN_CTX_new();
161 if (ctx == NULL) goto err;
162
163 if ((dsa->kinv == NULL) || (dsa->r == NULL))
164 {
165 if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
166 }
167 else
168 {
169 kinv=dsa->kinv;
170 dsa->kinv=NULL;
171 r=dsa->r;
172 dsa->r=NULL;
173 }
174
175
176 if (dlen > BN_num_bytes(dsa->q))
177 /* if the digest length is greater than the size of q use the
178 * BN_num_bits(dsa->q) leftmost bits of the digest, see
179 * fips 186-3, 4.2 */
180 dlen = BN_num_bytes(dsa->q);
181 if (BN_bin2bn(dgst,dlen,&m) == NULL)
182 goto err;
183
184 /* Compute s = inv(k) (m + xr) mod q */
185 if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
186 if (!BN_add(s, &xr, &m)) goto err; /* s = m + xr */
187 if (BN_cmp(s,dsa->q) > 0)
188 BN_sub(s,s,dsa->q);
189 if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
190
191 ret=DSA_SIG_new();
192 if (ret == NULL) goto err;
193 ret->r = r;
194 ret->s = s;
195
196err:
197 if (!ret)
198 {
199 DSAerr(DSA_F_DSA_DO_SIGN,reason);
200 BN_free(r);
201 BN_free(s);
202 }
203 if (ctx != NULL) BN_CTX_free(ctx);
204 BN_clear_free(&m);
205 BN_clear_free(&xr);
206 if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
207 BN_clear_free(kinv);
208 return(ret);
209 }
210
211static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
212 {
213 BN_CTX *ctx;
214 BIGNUM k,kq,*K,*kinv=NULL,*r=NULL;
215 int ret=0;
216
217 if (!dsa->p || !dsa->q || !dsa->g)
218 {
219 DSAerr(DSA_F_DSA_SIGN_SETUP,DSA_R_MISSING_PARAMETERS);
220 return 0;
221 }
222
223 BN_init(&k);
224 BN_init(&kq);
225
226 if (ctx_in == NULL)
227 {
228 if ((ctx=BN_CTX_new()) == NULL) goto err;
229 }
230 else
231 ctx=ctx_in;
232
233 if ((r=BN_new()) == NULL) goto err;
234
235 /* Get random k */
236 do
237 if (!BN_rand_range(&k, dsa->q)) goto err;
238 while (BN_is_zero(&k));
239 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
240 {
241 BN_set_flags(&k, BN_FLG_CONSTTIME);
242 }
243
244 if (dsa->flags & DSA_FLAG_CACHE_MONT_P)
245 {
246 if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
247 CRYPTO_LOCK_DSA,
248 dsa->p, ctx))
249 goto err;
250 }
251
252 /* Compute r = (g^k mod p) mod q */
253
254 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
255 {
256 if (!BN_copy(&kq, &k)) goto err;
257
258 /* We do not want timing information to leak the length of k,
259 * so we compute g^k using an equivalent exponent of fixed length.
260 *
261 * (This is a kludge that we need because the BN_mod_exp_mont()
262 * does not let us specify the desired timing behaviour.) */
263
264 if (!BN_add(&kq, &kq, dsa->q)) goto err;
265 if (BN_num_bits(&kq) <= BN_num_bits(dsa->q))
266 {
267 if (!BN_add(&kq, &kq, dsa->q)) goto err;
268 }
269
270 K = &kq;
271 }
272 else
273 {
274 K = &k;
275 }
276 DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, K, dsa->p, ctx,
277 dsa->method_mont_p);
278 if (!BN_mod(r,r,dsa->q,ctx)) goto err;
279
280 /* Compute part of 's = inv(k) (m + xr) mod q' */
281 if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
282
283 if (*kinvp != NULL) BN_clear_free(*kinvp);
284 *kinvp=kinv;
285 kinv=NULL;
286 if (*rp != NULL) BN_clear_free(*rp);
287 *rp=r;
288 ret=1;
289err:
290 if (!ret)
291 {
292 DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
293 if (r != NULL)
294 BN_clear_free(r);
295 }
296 if (ctx_in == NULL) BN_CTX_free(ctx);
297 BN_clear_free(&k);
298 BN_clear_free(&kq);
299 return(ret);
300 }
301
302static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
303 DSA *dsa)
304 {
305 BN_CTX *ctx;
306 BIGNUM u1,u2,t1;
307 BN_MONT_CTX *mont=NULL;
308 int ret = -1, i;
309 if (!dsa->p || !dsa->q || !dsa->g)
310 {
311 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS);
312 return -1;
313 }
314
315 i = BN_num_bits(dsa->q);
316 /* fips 186-3 allows only different sizes for q */
317 if (i != 160 && i != 224 && i != 256)
318 {
319 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_BAD_Q_VALUE);
320 return -1;
321 }
322
323 if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS)
324 {
325 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MODULUS_TOO_LARGE);
326 return -1;
327 }
328
329 /* reject a excessive digest length (currently at most
330 * dsa-with-SHA256 is supported) */
331 if (dgst_len > SHA256_DIGEST_LENGTH)
332 {
333 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
334 return -1;
335 }
336
337 BN_init(&u1);
338 BN_init(&u2);
339 BN_init(&t1);
340
341 if ((ctx=BN_CTX_new()) == NULL) goto err;
342
343 if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
344 BN_ucmp(sig->r, dsa->q) >= 0)
345 {
346 ret = 0;
347 goto err;
348 }
349 if (BN_is_zero(sig->s) || BN_is_negative(sig->s) ||
350 BN_ucmp(sig->s, dsa->q) >= 0)
351 {
352 ret = 0;
353 goto err;
354 }
355
356 /* Calculate W = inv(S) mod Q
357 * save W in u2 */
358 if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
359
360 /* save M in u1 */
361 if (dgst_len > (i >> 3))
362 /* if the digest length is greater than the size of q use the
363 * BN_num_bits(dsa->q) leftmost bits of the digest, see
364 * fips 186-3, 4.2 */
365 dgst_len = (i >> 3);
366 if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
367
368 /* u1 = M * w mod q */
369 if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;
370
371 /* u2 = r * w mod q */
372 if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err;
373
374
375 if (dsa->flags & DSA_FLAG_CACHE_MONT_P)
376 {
377 mont = BN_MONT_CTX_set_locked(&dsa->method_mont_p,
378 CRYPTO_LOCK_DSA, dsa->p, ctx);
379 if (!mont)
380 goto err;
381 }
382
383
384 DSA_MOD_EXP(goto err, dsa, &t1, dsa->g, &u1, dsa->pub_key, &u2, dsa->p, ctx, mont);
385 /* BN_copy(&u1,&t1); */
386 /* let u1 = u1 mod q */
387 if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err;
388
389 /* V is now in u1. If the signature is correct, it will be
390 * equal to R. */
391 ret=(BN_ucmp(&u1, sig->r) == 0);
392
393 err:
394 /* XXX: surely this is wrong - if ret is 0, it just didn't verify;
395 there is no error in BN. Test should be ret == -1 (Ben) */
396 if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
397 if (ctx != NULL) BN_CTX_free(ctx);
398 BN_free(&u1);
399 BN_free(&u2);
400 BN_free(&t1);
401 return(ret);
402 }
403
404static int dsa_init(DSA *dsa)
405{
406 dsa->flags|=DSA_FLAG_CACHE_MONT_P;
407 return(1);
408}
409
410static int dsa_finish(DSA *dsa)
411{
412 if(dsa->method_mont_p)
413 BN_MONT_CTX_free(dsa->method_mont_p);
414 return(1);
415}
416
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-12-25 01:16:40 +0000