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 {
120 BIGNUM *A;
121 BIGNUM *Ai;
122 BIGNUM *e;
123 BIGNUM *mod; /* just a reference */
124 #ifndef OPENSSL_NO_DEPRECATED
125 unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
126 * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
127 #endif
128 CRYPTO_THREADID tid;
129 unsigned int counter;
130 unsigned long flags;
131 BN_MONT_CTX *m_ctx;
132 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
133 const BIGNUM *m, BN_CTX *ctx,
134 BN_MONT_CTX *m_ctx);
135 };
136
BN_BLINDING_new(const BIGNUM * A,const BIGNUM * Ai,BIGNUM * mod)137 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
138 {
139 BN_BLINDING *ret=NULL;
140
141 bn_check_top(mod);
142
143 if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)
144 {
145 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);
146 return(NULL);
147 }
148 memset(ret,0,sizeof(BN_BLINDING));
149 if (A != NULL)
150 {
151 if ((ret->A = BN_dup(A)) == NULL) goto err;
152 }
153 if (Ai != NULL)
154 {
155 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
156 }
157
158 /* save a copy of mod in the BN_BLINDING structure */
159 if ((ret->mod = BN_dup(mod)) == NULL) goto err;
160 if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
161 BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
162
163 ret->counter = BN_BLINDING_COUNTER;
164 CRYPTO_THREADID_current(&ret->tid);
165 return(ret);
166 err:
167 if (ret != NULL) BN_BLINDING_free(ret);
168 return(NULL);
169 }
170
BN_BLINDING_free(BN_BLINDING * r)171 void BN_BLINDING_free(BN_BLINDING *r)
172 {
173 if(r == NULL)
174 return;
175
176 if (r->A != NULL) BN_free(r->A );
177 if (r->Ai != NULL) BN_free(r->Ai);
178 if (r->e != NULL) BN_free(r->e );
179 if (r->mod != NULL) BN_free(r->mod);
180 OPENSSL_free(r);
181 }
182
BN_BLINDING_update(BN_BLINDING * b,BN_CTX * ctx)183 int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
184 {
185 int ret=0;
186
187 if ((b->A == NULL) || (b->Ai == NULL))
188 {
189 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);
190 goto err;
191 }
192
193 if (--(b->counter) == 0 && b->e != NULL &&
194 !(b->flags & BN_BLINDING_NO_RECREATE))
195 {
196 /* re-create blinding parameters */
197 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
198 goto err;
199 }
200 else if (!(b->flags & BN_BLINDING_NO_UPDATE))
201 {
202 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;
203 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;
204 }
205
206 ret=1;
207 err:
208 if (b->counter == 0)
209 b->counter = BN_BLINDING_COUNTER;
210 return(ret);
211 }
212
BN_BLINDING_convert(BIGNUM * n,BN_BLINDING * b,BN_CTX * ctx)213 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
214 {
215 return BN_BLINDING_convert_ex(n, NULL, b, ctx);
216 }
217
BN_BLINDING_convert_ex(BIGNUM * n,BIGNUM * r,BN_BLINDING * b,BN_CTX * ctx)218 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
219 {
220 int ret = 1;
221
222 bn_check_top(n);
223
224 if ((b->A == NULL) || (b->Ai == NULL))
225 {
226 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);
227 return(0);
228 }
229
230 if (r != NULL)
231 {
232 if (!BN_copy(r, b->Ai)) ret=0;
233 }
234
235 if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;
236
237 return ret;
238 }
239
BN_BLINDING_invert(BIGNUM * n,BN_BLINDING * b,BN_CTX * ctx)240 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
241 {
242 return BN_BLINDING_invert_ex(n, NULL, b, ctx);
243 }
244
BN_BLINDING_invert_ex(BIGNUM * n,const BIGNUM * r,BN_BLINDING * b,BN_CTX * ctx)245 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
246 {
247 int ret;
248
249 bn_check_top(n);
250 if ((b->A == NULL) || (b->Ai == NULL))
251 {
252 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
253 return(0);
254 }
255
256 if (r != NULL)
257 ret = BN_mod_mul(n, n, r, b->mod, ctx);
258 else
259 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
260
261 if (ret >= 0)
262 {
263 if (!BN_BLINDING_update(b,ctx))
264 return(0);
265 }
266 bn_check_top(n);
267 return(ret);
268 }
269
270 #ifndef OPENSSL_NO_DEPRECATED
BN_BLINDING_get_thread_id(const BN_BLINDING * b)271 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
272 {
273 return b->thread_id;
274 }
275
BN_BLINDING_set_thread_id(BN_BLINDING * b,unsigned long n)276 void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
277 {
278 b->thread_id = n;
279 }
280 #endif
281
BN_BLINDING_thread_id(BN_BLINDING * b)282 CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b)
283 {
284 return &b->tid;
285 }
286
BN_BLINDING_get_flags(const BN_BLINDING * b)287 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
288 {
289 return b->flags;
290 }
291
BN_BLINDING_set_flags(BN_BLINDING * b,unsigned long flags)292 void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
293 {
294 b->flags = flags;
295 }
296
BN_BLINDING_create_param(BN_BLINDING * b,const BIGNUM * e,BIGNUM * m,BN_CTX * ctx,int (* bn_mod_exp)(BIGNUM * r,const BIGNUM * a,const BIGNUM * p,const BIGNUM * m,BN_CTX * ctx,BN_MONT_CTX * m_ctx),BN_MONT_CTX * m_ctx)297 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
298 const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
299 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
300 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
301 BN_MONT_CTX *m_ctx)
302 {
303 int retry_counter = 32;
304 BN_BLINDING *ret = NULL;
305
306 if (b == NULL)
307 ret = BN_BLINDING_new(NULL, NULL, m);
308 else
309 ret = b;
310
311 if (ret == NULL)
312 goto err;
313
314 if (ret->A == NULL && (ret->A = BN_new()) == NULL)
315 goto err;
316 if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
317 goto err;
318
319 if (e != NULL)
320 {
321 if (ret->e != NULL)
322 BN_free(ret->e);
323 ret->e = BN_dup(e);
324 }
325 if (ret->e == NULL)
326 goto err;
327
328 if (bn_mod_exp != NULL)
329 ret->bn_mod_exp = bn_mod_exp;
330 if (m_ctx != NULL)
331 ret->m_ctx = m_ctx;
332
333 do {
334 if (!BN_rand_range(ret->A, ret->mod)) goto err;
335 if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL)
336 {
337 /* this should almost never happen for good RSA keys */
338 unsigned long error = ERR_peek_last_error();
339 if (ERR_GET_REASON(error) == BN_R_NO_INVERSE)
340 {
341 if (retry_counter-- == 0)
342 {
343 BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
344 BN_R_TOO_MANY_ITERATIONS);
345 goto err;
346 }
347 ERR_clear_error();
348 }
349 else
350 goto err;
351 }
352 else
353 break;
354 } while (1);
355
356 if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)
357 {
358 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
359 goto err;
360 }
361 else
362 {
363 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
364 goto err;
365 }
366
367 return ret;
368 err:
369 if (b == NULL && ret != NULL)
370 {
371 BN_BLINDING_free(ret);
372 ret = NULL;
373 }
374
375 return ret;
376 }
377