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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 <openssl/bn.h> | |
63 #include <openssl/dsa.h> | |
64 #include <openssl/rand.h> | |
65 #include <openssl/asn1.h> | |
66 #include <openssl/err.h> | |
67 #ifndef OPENSSL_NO_ENGINE | |
68 #include <openssl/engine.h> | |
69 #endif | |
70 #include <openssl/fips.h> | |
71 | |
72 #ifdef OPENSSL_FIPS | |
73 | |
74 static DSA_SIG *dsa_do_sign(const unsigned char *dgst, FIPS_DSA_SIZE_T dlen, DSA
*dsa); | |
75 static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
; | |
76 static int dsa_do_verify(const unsigned char *dgst, FIPS_DSA_SIZE_T dgst_len, DS
A_SIG *sig, | |
77 DSA *dsa); | |
78 static int dsa_init(DSA *dsa); | |
79 static int dsa_finish(DSA *dsa); | |
80 static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, | |
81 BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx, | |
82 BN_MONT_CTX *in_mont); | |
83 static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p, | |
84 const BIGNUM *m, BN_CTX *ctx, | |
85 BN_MONT_CTX *m_ctx); | |
86 | |
87 static const DSA_METHOD openssl_dsa_meth = { | |
88 "OpenSSL FIPS DSA method", | |
89 dsa_do_sign, | |
90 dsa_sign_setup, | |
91 dsa_do_verify, | |
92 dsa_mod_exp, | |
93 dsa_bn_mod_exp, | |
94 dsa_init, | |
95 dsa_finish, | |
96 DSA_FLAG_FIPS_METHOD, | |
97 NULL | |
98 }; | |
99 #if 0 | |
100 int FIPS_dsa_check(struct dsa_st *dsa) | |
101 { | |
102 if(dsa->meth != &openssl_dsa_meth || dsa->meth->dsa_do_sign != dsa_do_sign | |
103 || dsa->meth->dsa_sign_setup != dsa_sign_setup | |
104 || dsa->meth->dsa_mod_exp != dsa_mod_exp | |
105 || dsa->meth->bn_mod_exp != dsa_bn_mod_exp | |
106 || dsa->meth->init != dsa_init | |
107 || dsa->meth->finish != dsa_finish) | |
108 { | |
109 FIPSerr(FIPS_F_FIPS_DSA_CHECK,FIPS_R_NON_FIPS_METHOD); | |
110 return 0; | |
111 } | |
112 return 1; | |
113 } | |
114 #endif | |
115 | |
116 const DSA_METHOD *DSA_OpenSSL(void) | |
117 { | |
118 return &openssl_dsa_meth; | |
119 } | |
120 | |
121 static DSA_SIG *dsa_do_sign(const unsigned char *dgst, FIPS_DSA_SIZE_T dlen, DSA
*dsa) | |
122 { | |
123 BIGNUM *kinv=NULL,*r=NULL,*s=NULL; | |
124 BIGNUM m; | |
125 BIGNUM xr; | |
126 BN_CTX *ctx=NULL; | |
127 int i,reason=ERR_R_BN_LIB; | |
128 DSA_SIG *ret=NULL; | |
129 | |
130 if(FIPS_selftest_failed()) | |
131 { | |
132 FIPSerr(FIPS_F_DSA_DO_SIGN,FIPS_R_FIPS_SELFTEST_FAILED); | |
133 return NULL; | |
134 } | |
135 | |
136 if (FIPS_mode() && (BN_num_bits(dsa->p) < OPENSSL_DSA_FIPS_MIN_MODULUS_B
ITS)) | |
137 { | |
138 DSAerr(DSA_F_DSA_DO_SIGN, DSA_R_KEY_SIZE_TOO_SMALL); | |
139 return NULL; | |
140 } | |
141 | |
142 BN_init(&m); | |
143 BN_init(&xr); | |
144 | |
145 if (!dsa->p || !dsa->q || !dsa->g) | |
146 { | |
147 reason=DSA_R_MISSING_PARAMETERS; | |
148 goto err; | |
149 } | |
150 | |
151 s=BN_new(); | |
152 if (s == NULL) goto err; | |
153 | |
154 i=BN_num_bytes(dsa->q); /* should be 20 */ | |
155 if ((dlen > i) || (dlen > 50)) | |
156 { | |
157 reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE; | |
158 goto err; | |
159 } | |
160 | |
161 ctx=BN_CTX_new(); | |
162 if (ctx == NULL) goto err; | |
163 | |
164 if (!dsa->meth->dsa_sign_setup(dsa,ctx,&kinv,&r)) goto err; | |
165 | |
166 if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err; | |
167 | |
168 /* Compute s = inv(k) (m + xr) mod q */ | |
169 if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */ | |
170 if (!BN_add(s, &xr, &m)) goto err; /* s = m + xr */ | |
171 if (BN_cmp(s,dsa->q) > 0) | |
172 BN_sub(s,s,dsa->q); | |
173 if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err; | |
174 | |
175 ret= DSA_SIG_new(); | |
176 if (ret == NULL) goto err; | |
177 ret->r = r; | |
178 ret->s = s; | |
179 | |
180 err: | |
181 if (!ret) | |
182 { | |
183 DSAerr(DSA_F_DSA_DO_SIGN,reason); | |
184 BN_free(r); | |
185 BN_free(s); | |
186 } | |
187 if (ctx != NULL) BN_CTX_free(ctx); | |
188 BN_clear_free(&m); | |
189 BN_clear_free(&xr); | |
190 if (kinv != NULL) /* dsa->kinv is NULL now if we used it */ | |
191 BN_clear_free(kinv); | |
192 return(ret); | |
193 } | |
194 | |
195 static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp) | |
196 { | |
197 BN_CTX *ctx; | |
198 BIGNUM k,kq,*K,*kinv=NULL,*r=NULL; | |
199 int ret=0; | |
200 | |
201 if (!dsa->p || !dsa->q || !dsa->g) | |
202 { | |
203 DSAerr(DSA_F_DSA_SIGN_SETUP,DSA_R_MISSING_PARAMETERS); | |
204 return 0; | |
205 } | |
206 | |
207 BN_init(&k); | |
208 BN_init(&kq); | |
209 | |
210 if (ctx_in == NULL) | |
211 { | |
212 if ((ctx=BN_CTX_new()) == NULL) goto err; | |
213 } | |
214 else | |
215 ctx=ctx_in; | |
216 | |
217 if ((r=BN_new()) == NULL) goto err; | |
218 | |
219 /* Get random k */ | |
220 do | |
221 if (!BN_rand_range(&k, dsa->q)) goto err; | |
222 while (BN_is_zero(&k)); | |
223 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) | |
224 { | |
225 BN_set_flags(&k, BN_FLG_CONSTTIME); | |
226 } | |
227 | |
228 if (dsa->flags & DSA_FLAG_CACHE_MONT_P) | |
229 { | |
230 if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p, | |
231 CRYPTO_LOCK_DSA, | |
232 dsa->p, ctx)) | |
233 goto err; | |
234 } | |
235 | |
236 /* Compute r = (g^k mod p) mod q */ | |
237 | |
238 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) | |
239 { | |
240 if (!BN_copy(&kq, &k)) goto err; | |
241 | |
242 /* We do not want timing information to leak the length of k, | |
243 * so we compute g^k using an equivalent exponent of fixed lengt
h. | |
244 * | |
245 * (This is a kludge that we need because the BN_mod_exp_mont() | |
246 * does not let us specify the desired timing behaviour.) */ | |
247 | |
248 if (!BN_add(&kq, &kq, dsa->q)) goto err; | |
249 if (BN_num_bits(&kq) <= BN_num_bits(dsa->q)) | |
250 { | |
251 if (!BN_add(&kq, &kq, dsa->q)) goto err; | |
252 } | |
253 | |
254 K = &kq; | |
255 } | |
256 else | |
257 { | |
258 K = &k; | |
259 } | |
260 if (!dsa->meth->bn_mod_exp(dsa, r,dsa->g,K,dsa->p,ctx, | |
261 (BN_MONT_CTX *)dsa->method_mont_p)) goto err; | |
262 if (!BN_mod(r,r,dsa->q,ctx)) goto err; | |
263 | |
264 /* Compute part of 's = inv(k) (m + xr) mod q' */ | |
265 if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err; | |
266 | |
267 if (*kinvp != NULL) BN_clear_free(*kinvp); | |
268 *kinvp=kinv; | |
269 kinv=NULL; | |
270 if (*rp != NULL) BN_clear_free(*rp); | |
271 *rp=r; | |
272 ret=1; | |
273 err: | |
274 if (!ret) | |
275 { | |
276 DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB); | |
277 if (kinv != NULL) BN_clear_free(kinv); | |
278 if (r != NULL) BN_clear_free(r); | |
279 } | |
280 if (ctx_in == NULL) BN_CTX_free(ctx); | |
281 if (kinv != NULL) BN_clear_free(kinv); | |
282 BN_clear_free(&k); | |
283 BN_clear_free(&kq); | |
284 return(ret); | |
285 } | |
286 | |
287 static int dsa_do_verify(const unsigned char *dgst, FIPS_DSA_SIZE_T dgst_len, DS
A_SIG *sig, | |
288 DSA *dsa) | |
289 { | |
290 BN_CTX *ctx; | |
291 BIGNUM u1,u2,t1; | |
292 BN_MONT_CTX *mont=NULL; | |
293 int ret = -1; | |
294 | |
295 if (!dsa->p || !dsa->q || !dsa->g) | |
296 { | |
297 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS); | |
298 return -1; | |
299 } | |
300 | |
301 if(FIPS_selftest_failed()) | |
302 { | |
303 FIPSerr(FIPS_F_DSA_DO_VERIFY,FIPS_R_FIPS_SELFTEST_FAILED); | |
304 return -1; | |
305 } | |
306 | |
307 if (BN_num_bits(dsa->q) != 160) | |
308 { | |
309 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_BAD_Q_VALUE); | |
310 return -1; | |
311 } | |
312 | |
313 if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) | |
314 { | |
315 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MODULUS_TOO_LARGE); | |
316 return -1; | |
317 } | |
318 | |
319 if (FIPS_mode() && (BN_num_bits(dsa->p) < OPENSSL_DSA_FIPS_MIN_MODULUS_B
ITS)) | |
320 { | |
321 DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_KEY_SIZE_TOO_SMALL); | |
322 return -1; | |
323 } | |
324 | |
325 BN_init(&u1); | |
326 BN_init(&u2); | |
327 BN_init(&t1); | |
328 | |
329 if ((ctx=BN_CTX_new()) == NULL) goto err; | |
330 | |
331 if (BN_is_zero(sig->r) || sig->r->neg || BN_ucmp(sig->r, dsa->q) >= 0) | |
332 { | |
333 ret = 0; | |
334 goto err; | |
335 } | |
336 if (BN_is_zero(sig->s) || sig->s->neg || BN_ucmp(sig->s, dsa->q) >= 0) | |
337 { | |
338 ret = 0; | |
339 goto err; | |
340 } | |
341 | |
342 /* Calculate W = inv(S) mod Q | |
343 * save W in u2 */ | |
344 if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err; | |
345 | |
346 /* save M in u1 */ | |
347 if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err; | |
348 | |
349 /* u1 = M * w mod q */ | |
350 if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err; | |
351 | |
352 /* u2 = r * w mod q */ | |
353 if (!BN_mod_mul(&u2,sig->r,&u2,dsa->q,ctx)) goto err; | |
354 | |
355 | |
356 if (dsa->flags & DSA_FLAG_CACHE_MONT_P) | |
357 { | |
358 mont = BN_MONT_CTX_set_locked( | |
359 (BN_MONT_CTX **)&dsa->method_mont_p, | |
360 CRYPTO_LOCK_DSA, dsa->p, ctx); | |
361 if (!mont) | |
362 goto err; | |
363 } | |
364 | |
365 #if 0 | |
366 { | |
367 BIGNUM t2; | |
368 | |
369 BN_init(&t2); | |
370 /* v = ( g^u1 * y^u2 mod p ) mod q */ | |
371 /* let t1 = g ^ u1 mod p */ | |
372 if (!BN_mod_exp_mont(&t1,dsa->g,&u1,dsa->p,ctx,mont)) goto err; | |
373 /* let t2 = y ^ u2 mod p */ | |
374 if (!BN_mod_exp_mont(&t2,dsa->pub_key,&u2,dsa->p,ctx,mont)) goto err; | |
375 /* let u1 = t1 * t2 mod p */ | |
376 if (!BN_mod_mul(&u1,&t1,&t2,dsa->p,ctx)) goto err_bn; | |
377 BN_free(&t2); | |
378 } | |
379 /* let u1 = u1 mod q */ | |
380 if (!BN_mod(&u1,&u1,dsa->q,ctx)) goto err; | |
381 #else | |
382 { | |
383 if (!dsa->meth->dsa_mod_exp(dsa, &t1,dsa->g,&u1,dsa->pub_key,&u2, | |
384 dsa->p,ctx,mont)) goto err; | |
385 /* BN_copy(&u1,&t1); */ | |
386 /* let u1 = u1 mod q */ | |
387 if (!BN_mod(&u1,&t1,dsa->q,ctx)) goto err; | |
388 } | |
389 #endif | |
390 /* V is now in u1. If the signature is correct, it will be | |
391 * equal to R. */ | |
392 ret=(BN_ucmp(&u1, sig->r) == 0); | |
393 | |
394 err: | |
395 if (ret != 1) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB); | |
396 if (ctx != NULL) BN_CTX_free(ctx); | |
397 BN_free(&u1); | |
398 BN_free(&u2); | |
399 BN_free(&t1); | |
400 return(ret); | |
401 } | |
402 | |
403 static int dsa_init(DSA *dsa) | |
404 { | |
405 FIPS_selftest_check(); | |
406 dsa->flags|=DSA_FLAG_CACHE_MONT_P; | |
407 return(1); | |
408 } | |
409 | |
410 static int dsa_finish(DSA *dsa) | |
411 { | |
412 if(dsa->method_mont_p) | |
413 BN_MONT_CTX_free((BN_MONT_CTX *)dsa->method_mont_p); | |
414 return(1); | |
415 } | |
416 | |
417 static int dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, | |
418 BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx, | |
419 BN_MONT_CTX *in_mont) | |
420 { | |
421 return BN_mod_exp2_mont(rr, a1, p1, a2, p2, m, ctx, in_mont); | |
422 } | |
423 | |
424 static int dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p, | |
425 const BIGNUM *m, BN_CTX *ctx, | |
426 BN_MONT_CTX *m_ctx) | |
427 { | |
428 return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx); | |
429 } | |
430 | |
431 #else /* ndef OPENSSL_FIPS */ | |
432 | |
433 static void *dummy=&dummy; | |
434 | |
435 #endif /* ndef OPENSSL_FIPS */ | |
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