Line data Source code
1 : /* crypto/bn/bn_blind.c */
2 : /* ====================================================================
3 : * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
4 : *
5 : * Redistribution and use in source and binary forms, with or without
6 : * modification, are permitted provided that the following conditions
7 : * are met:
8 : *
9 : * 1. Redistributions of source code must retain the above copyright
10 : * notice, this list of conditions and the following disclaimer.
11 : *
12 : * 2. Redistributions in binary form must reproduce the above copyright
13 : * notice, this list of conditions and the following disclaimer in
14 : * the documentation and/or other materials provided with the
15 : * distribution.
16 : *
17 : * 3. All advertising materials mentioning features or use of this
18 : * software must display the following acknowledgment:
19 : * "This product includes software developed by the OpenSSL Project
20 : * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 : *
22 : * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 : * endorse or promote products derived from this software without
24 : * prior written permission. For written permission, please contact
25 : * openssl-core@openssl.org.
26 : *
27 : * 5. Products derived from this software may not be called "OpenSSL"
28 : * nor may "OpenSSL" appear in their names without prior written
29 : * permission of the OpenSSL Project.
30 : *
31 : * 6. Redistributions of any form whatsoever must retain the following
32 : * acknowledgment:
33 : * "This product includes software developed by the OpenSSL Project
34 : * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 : *
36 : * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 : * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 : * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 : * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 : * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 : * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 : * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 : * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 : * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 : * OF THE POSSIBILITY OF SUCH DAMAGE.
48 : * ====================================================================
49 : *
50 : * This product includes cryptographic software written by Eric Young
51 : * (eay@cryptsoft.com). This product includes software written by Tim
52 : * Hudson (tjh@cryptsoft.com).
53 : *
54 : */
55 : /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
56 : * All rights reserved.
57 : *
58 : * This package is an SSL implementation written
59 : * by Eric Young (eay@cryptsoft.com).
60 : * The implementation was written so as to conform with Netscapes SSL.
61 : *
62 : * This library is free for commercial and non-commercial use as long as
63 : * the following conditions are aheared to. The following conditions
64 : * apply to all code found in this distribution, be it the RC4, RSA,
65 : * lhash, DES, etc., code; not just the SSL code. The SSL documentation
66 : * included with this distribution is covered by the same copyright terms
67 : * except that the holder is Tim Hudson (tjh@cryptsoft.com).
68 : *
69 : * Copyright remains Eric Young's, and as such any Copyright notices in
70 : * the code are not to be removed.
71 : * If this package is used in a product, Eric Young should be given attribution
72 : * as the author of the parts of the library used.
73 : * This can be in the form of a textual message at program startup or
74 : * in documentation (online or textual) provided with the package.
75 : *
76 : * Redistribution and use in source and binary forms, with or without
77 : * modification, are permitted provided that the following conditions
78 : * are met:
79 : * 1. Redistributions of source code must retain the copyright
80 : * notice, this list of conditions and the following disclaimer.
81 : * 2. Redistributions in binary form must reproduce the above copyright
82 : * notice, this list of conditions and the following disclaimer in the
83 : * documentation and/or other materials provided with the distribution.
84 : * 3. All advertising materials mentioning features or use of this software
85 : * must display the following acknowledgement:
86 : * "This product includes cryptographic software written by
87 : * Eric Young (eay@cryptsoft.com)"
88 : * The word 'cryptographic' can be left out if the rouines from the library
89 : * being used are not cryptographic related :-).
90 : * 4. If you include any Windows specific code (or a derivative thereof) from
91 : * the apps directory (application code) you must include an acknowledgement:
92 : * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
93 : *
94 : * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
95 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
96 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
97 : * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
98 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
99 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
100 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
101 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
102 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
103 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
104 : * SUCH DAMAGE.
105 : *
106 : * The licence and distribution terms for any publically available version or
107 : * derivative of this code cannot be changed. i.e. this code cannot simply be
108 : * copied and put under another distribution licence
109 : * [including the GNU Public Licence.]
110 : */
111 :
112 : #include <stdio.h>
113 : #include "cryptlib.h"
114 : #include "bn_lcl.h"
115 :
116 : #define BN_BLINDING_COUNTER 32
117 :
118 : struct bn_blinding_st {
119 : BIGNUM *A;
120 : BIGNUM *Ai;
121 : BIGNUM *e;
122 : BIGNUM *mod; /* just a reference */
123 : #ifndef OPENSSL_NO_DEPRECATED
124 : unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b; used
125 : * only by crypto/rsa/rsa_eay.c, rsa_lib.c */
126 : #endif
127 : CRYPTO_THREADID tid;
128 : int counter;
129 : unsigned long flags;
130 : BN_MONT_CTX *m_ctx;
131 : int (*bn_mod_exp) (BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
132 : const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
133 : };
134 :
135 345 : BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
136 : {
137 : BN_BLINDING *ret = NULL;
138 :
139 : bn_check_top(mod);
140 :
141 345 : if ((ret = (BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL) {
142 0 : BNerr(BN_F_BN_BLINDING_NEW, ERR_R_MALLOC_FAILURE);
143 0 : return (NULL);
144 : }
145 : memset(ret, 0, sizeof(BN_BLINDING));
146 345 : if (A != NULL) {
147 0 : if ((ret->A = BN_dup(A)) == NULL)
148 : goto err;
149 : }
150 345 : if (Ai != NULL) {
151 0 : if ((ret->Ai = BN_dup(Ai)) == NULL)
152 : goto err;
153 : }
154 :
155 : /* save a copy of mod in the BN_BLINDING structure */
156 345 : if ((ret->mod = BN_dup(mod)) == NULL)
157 : goto err;
158 345 : if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
159 345 : BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
160 :
161 : /*
162 : * Set the counter to the special value -1 to indicate that this is
163 : * never-used fresh blinding that does not need updating before first
164 : * use.
165 : */
166 345 : ret->counter = -1;
167 345 : CRYPTO_THREADID_current(&ret->tid);
168 345 : return (ret);
169 : err:
170 0 : if (ret != NULL)
171 0 : BN_BLINDING_free(ret);
172 : return (NULL);
173 : }
174 :
175 345 : void BN_BLINDING_free(BN_BLINDING *r)
176 : {
177 345 : if (r == NULL)
178 345 : return;
179 :
180 345 : if (r->A != NULL)
181 345 : BN_free(r->A);
182 345 : if (r->Ai != NULL)
183 345 : BN_free(r->Ai);
184 345 : if (r->e != NULL)
185 345 : BN_free(r->e);
186 345 : if (r->mod != NULL)
187 345 : BN_free(r->mod);
188 345 : OPENSSL_free(r);
189 : }
190 :
191 36 : int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
192 : {
193 : int ret = 0;
194 :
195 36 : if ((b->A == NULL) || (b->Ai == NULL)) {
196 0 : BNerr(BN_F_BN_BLINDING_UPDATE, BN_R_NOT_INITIALIZED);
197 0 : goto err;
198 : }
199 :
200 36 : if (b->counter == -1)
201 0 : b->counter = 0;
202 :
203 36 : if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
204 0 : !(b->flags & BN_BLINDING_NO_RECREATE)) {
205 : /* re-create blinding parameters */
206 0 : if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
207 : goto err;
208 36 : } else if (!(b->flags & BN_BLINDING_NO_UPDATE)) {
209 36 : if (!BN_mod_mul(b->A, b->A, b->A, b->mod, ctx))
210 : goto err;
211 36 : if (!BN_mod_mul(b->Ai, b->Ai, b->Ai, b->mod, ctx))
212 : goto err;
213 : }
214 :
215 : ret = 1;
216 : err:
217 36 : if (b->counter == BN_BLINDING_COUNTER)
218 0 : b->counter = 0;
219 36 : return (ret);
220 : }
221 :
222 0 : int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
223 : {
224 0 : return BN_BLINDING_convert_ex(n, NULL, b, ctx);
225 : }
226 :
227 381 : int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
228 : {
229 : int ret = 1;
230 :
231 : bn_check_top(n);
232 :
233 381 : if ((b->A == NULL) || (b->Ai == NULL)) {
234 0 : BNerr(BN_F_BN_BLINDING_CONVERT_EX, BN_R_NOT_INITIALIZED);
235 0 : return (0);
236 : }
237 :
238 381 : if (b->counter == -1)
239 : /* Fresh blinding, doesn't need updating. */
240 345 : b->counter = 0;
241 36 : else if (!BN_BLINDING_update(b, ctx))
242 : return (0);
243 :
244 381 : if (r != NULL) {
245 0 : if (!BN_copy(r, b->Ai))
246 : ret = 0;
247 : }
248 :
249 381 : if (!BN_mod_mul(n, n, b->A, b->mod, ctx))
250 : ret = 0;
251 :
252 381 : return ret;
253 : }
254 :
255 0 : int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
256 : {
257 0 : return BN_BLINDING_invert_ex(n, NULL, b, ctx);
258 : }
259 :
260 381 : int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b,
261 : BN_CTX *ctx)
262 : {
263 : int ret;
264 :
265 : bn_check_top(n);
266 :
267 381 : if (r != NULL)
268 0 : ret = BN_mod_mul(n, n, r, b->mod, ctx);
269 : else {
270 381 : if (b->Ai == NULL) {
271 0 : BNerr(BN_F_BN_BLINDING_INVERT_EX, BN_R_NOT_INITIALIZED);
272 0 : return (0);
273 : }
274 381 : ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
275 : }
276 :
277 : bn_check_top(n);
278 381 : return (ret);
279 : }
280 :
281 : #ifndef OPENSSL_NO_DEPRECATED
282 0 : unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
283 : {
284 0 : return b->thread_id;
285 : }
286 :
287 0 : void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
288 : {
289 0 : b->thread_id = n;
290 0 : }
291 : #endif
292 :
293 726 : CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b)
294 : {
295 726 : return &b->tid;
296 : }
297 :
298 0 : unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
299 : {
300 0 : return b->flags;
301 : }
302 :
303 0 : void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
304 : {
305 0 : b->flags = flags;
306 0 : }
307 :
308 345 : BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
309 : const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
310 : int (*bn_mod_exp) (BIGNUM *r,
311 : const BIGNUM *a,
312 : const BIGNUM *p,
313 : const BIGNUM *m,
314 : BN_CTX *ctx,
315 : BN_MONT_CTX *m_ctx),
316 : BN_MONT_CTX *m_ctx)
317 : {
318 : int retry_counter = 32;
319 : BN_BLINDING *ret = NULL;
320 :
321 345 : if (b == NULL)
322 345 : ret = BN_BLINDING_new(NULL, NULL, m);
323 : else
324 : ret = b;
325 :
326 345 : if (ret == NULL)
327 : goto err;
328 :
329 345 : if (ret->A == NULL && (ret->A = BN_new()) == NULL)
330 : goto err;
331 345 : if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
332 : goto err;
333 :
334 345 : if (e != NULL) {
335 345 : if (ret->e != NULL)
336 0 : BN_free(ret->e);
337 345 : ret->e = BN_dup(e);
338 : }
339 345 : if (ret->e == NULL)
340 : goto err;
341 :
342 345 : if (bn_mod_exp != NULL)
343 345 : ret->bn_mod_exp = bn_mod_exp;
344 345 : if (m_ctx != NULL)
345 0 : ret->m_ctx = m_ctx;
346 :
347 : do {
348 345 : if (!BN_rand_range(ret->A, ret->mod))
349 : goto err;
350 345 : if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL) {
351 : /*
352 : * this should almost never happen for good RSA keys
353 : */
354 0 : unsigned long error = ERR_peek_last_error();
355 0 : if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) {
356 0 : if (retry_counter-- == 0) {
357 0 : BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
358 : BN_R_TOO_MANY_ITERATIONS);
359 0 : goto err;
360 : }
361 0 : ERR_clear_error();
362 : } else
363 : goto err;
364 : } else
365 : break;
366 0 : } while (1);
367 :
368 345 : if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) {
369 0 : if (!ret->bn_mod_exp
370 0 : (ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
371 : goto err;
372 : } else {
373 345 : if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
374 : goto err;
375 : }
376 :
377 345 : return ret;
378 : err:
379 0 : if (b == NULL && ret != NULL) {
380 0 : BN_BLINDING_free(ret);
381 : ret = NULL;
382 : }
383 :
384 0 : return ret;
385 : }
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