1 /* crypto/bn/bn_blind.c */
2 /* ====================================================================
3 * Copyright (c) 1998-2005 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 unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
125 * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
126 unsigned int counter;
127 unsigned long flags;
128 BN_MONT_CTX *m_ctx;
129 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
130 const BIGNUM *m, BN_CTX *ctx,
131 BN_MONT_CTX *m_ctx);
132 };
133
BN_BLINDING_new(const BIGNUM * A,const BIGNUM * Ai,BIGNUM * mod)134 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
135 {
136 BN_BLINDING *ret=NULL;
137
138 bn_check_top(mod);
139
140 if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL)
141 {
142 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE);
143 return(NULL);
144 }
145 memset(ret,0,sizeof(BN_BLINDING));
146 if (A != NULL)
147 {
148 if ((ret->A = BN_dup(A)) == NULL) goto err;
149 }
150 if (Ai != NULL)
151 {
152 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
153 }
154 ret->mod = mod;
155 ret->counter = BN_BLINDING_COUNTER;
156 return(ret);
157 err:
158 if (ret != NULL) BN_BLINDING_free(ret);
159 return(NULL);
160 }
161
BN_BLINDING_free(BN_BLINDING * r)162 void BN_BLINDING_free(BN_BLINDING *r)
163 {
164 if(r == NULL)
165 return;
166
167 if (r->A != NULL) BN_free(r->A );
168 if (r->Ai != NULL) BN_free(r->Ai);
169 if (r->e != NULL) BN_free(r->e );
170 OPENSSL_free(r);
171 }
172
BN_BLINDING_update(BN_BLINDING * b,BN_CTX * ctx)173 int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
174 {
175 int ret=0;
176
177 if ((b->A == NULL) || (b->Ai == NULL))
178 {
179 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED);
180 goto err;
181 }
182
183 if (--(b->counter) == 0 && b->e != NULL &&
184 !(b->flags & BN_BLINDING_NO_RECREATE))
185 {
186 /* re-create blinding parameters */
187 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
188 goto err;
189 }
190 else if (!(b->flags & BN_BLINDING_NO_UPDATE))
191 {
192 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err;
193 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err;
194 }
195
196 ret=1;
197 err:
198 if (b->counter == 0)
199 b->counter = BN_BLINDING_COUNTER;
200 return(ret);
201 }
202
BN_BLINDING_convert(BIGNUM * n,BN_BLINDING * b,BN_CTX * ctx)203 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
204 {
205 return BN_BLINDING_convert_ex(n, NULL, b, ctx);
206 }
207
BN_BLINDING_convert_ex(BIGNUM * n,BIGNUM * r,BN_BLINDING * b,BN_CTX * ctx)208 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
209 {
210 int ret = 1;
211
212 bn_check_top(n);
213
214 if ((b->A == NULL) || (b->Ai == NULL))
215 {
216 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED);
217 return(0);
218 }
219
220 if (r != NULL)
221 {
222 if (!BN_copy(r, b->Ai)) ret=0;
223 }
224
225 if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;
226
227 return ret;
228 }
229
BN_BLINDING_invert(BIGNUM * n,BN_BLINDING * b,BN_CTX * ctx)230 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
231 {
232 return BN_BLINDING_invert_ex(n, NULL, b, ctx);
233 }
234
BN_BLINDING_invert_ex(BIGNUM * n,const BIGNUM * r,BN_BLINDING * b,BN_CTX * ctx)235 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
236 {
237 int ret;
238
239 bn_check_top(n);
240 if ((b->A == NULL) || (b->Ai == NULL))
241 {
242 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
243 return(0);
244 }
245
246 if (r != NULL)
247 ret = BN_mod_mul(n, n, r, b->mod, ctx);
248 else
249 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
250
251 if (ret >= 0)
252 {
253 if (!BN_BLINDING_update(b,ctx))
254 return(0);
255 }
256 bn_check_top(n);
257 return(ret);
258 }
259
BN_BLINDING_get_thread_id(const BN_BLINDING * b)260 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b)
261 {
262 return b->thread_id;
263 }
264
BN_BLINDING_set_thread_id(BN_BLINDING * b,unsigned long n)265 void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
266 {
267 b->thread_id = n;
268 }
269
BN_BLINDING_get_flags(const BN_BLINDING * b)270 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b)
271 {
272 return b->flags;
273 }
274
BN_BLINDING_set_flags(BN_BLINDING * b,unsigned long flags)275 void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
276 {
277 b->flags = flags;
278 }
279
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)280 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
281 const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
282 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
283 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
284 BN_MONT_CTX *m_ctx)
285 {
286 int retry_counter = 32;
287 BN_BLINDING *ret = NULL;
288
289 if (b == NULL)
290 ret = BN_BLINDING_new(NULL, NULL, m);
291 else
292 ret = b;
293
294 if (ret == NULL)
295 goto err;
296
297 if (ret->A == NULL && (ret->A = BN_new()) == NULL)
298 goto err;
299 if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
300 goto err;
301
302 if (e != NULL)
303 {
304 if (ret->e != NULL)
305 BN_free(ret->e);
306 ret->e = BN_dup(e);
307 }
308 if (ret->e == NULL)
309 goto err;
310
311 if (bn_mod_exp != NULL)
312 ret->bn_mod_exp = bn_mod_exp;
313 if (m_ctx != NULL)
314 ret->m_ctx = m_ctx;
315
316 do {
317 if (!BN_rand_range(ret->A, ret->mod)) goto err;
318 if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL)
319 {
320 /* this should almost never happen for good RSA keys */
321 unsigned long error = ERR_peek_last_error();
322 if (ERR_GET_REASON(error) == BN_R_NO_INVERSE)
323 {
324 if (retry_counter-- == 0)
325 {
326 BNerr(BN_F_BN_BLINDING_CREATE_PARAM,
327 BN_R_TOO_MANY_ITERATIONS);
328 goto err;
329 }
330 ERR_clear_error();
331 }
332 else
333 goto err;
334 }
335 else
336 break;
337 } while (1);
338
339 if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL)
340 {
341 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))
342 goto err;
343 }
344 else
345 {
346 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))
347 goto err;
348 }
349
350 return ret;
351 err:
352 if (b == NULL && ret != NULL)
353 {
354 BN_BLINDING_free(ret);
355 ret = NULL;
356 }
357
358 return ret;
359 }
360