GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libcrypto/bn/bn_blind.c Lines: 65 102 63.7 %
Date: 2017-11-13 Branches: 52 99 52.5 %

Line Branch Exec Source
1
/* $OpenBSD: bn_blind.c,v 1.17 2017/01/29 17:49:22 beck Exp $ */
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
114
#include <openssl/opensslconf.h>
115
116
#include <openssl/err.h>
117
118
#include "bn_lcl.h"
119
120
#define BN_BLINDING_COUNTER	32
121
122
struct bn_blinding_st {
123
	BIGNUM *A;
124
	BIGNUM *Ai;
125
	BIGNUM *e;
126
	BIGNUM *mod; /* just a reference */
127
#ifndef OPENSSL_NO_DEPRECATED
128
	unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
129
				  * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
130
#endif
131
	CRYPTO_THREADID tid;
132
	int counter;
133
	unsigned long flags;
134
	BN_MONT_CTX *m_ctx;
135
	int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
136
	    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
137
};
138
139
BN_BLINDING *
140
BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
141
{
142
	BN_BLINDING *ret = NULL;
143
144
	bn_check_top(mod);
145
146
516
	if ((ret = calloc(1, sizeof(BN_BLINDING))) == NULL) {
147
		BNerror(ERR_R_MALLOC_FAILURE);
148
		return (NULL);
149
	}
150
258
	if (A != NULL) {
151
		if ((ret->A = BN_dup(A))  == NULL)
152
			goto err;
153
	}
154
258
	if (Ai != NULL) {
155
		if ((ret->Ai = BN_dup(Ai)) == NULL)
156
			goto err;
157
	}
158
159
	/* save a copy of mod in the BN_BLINDING structure */
160
258
	if ((ret->mod = BN_dup(mod)) == NULL)
161
		goto err;
162
258
	if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
163
258
		BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
164
165
	/* Set the counter to the special value -1
166
	 * to indicate that this is never-used fresh blinding
167
	 * that does not need updating before first use. */
168
258
	ret->counter = -1;
169
258
	CRYPTO_THREADID_current(&ret->tid);
170
258
	return (ret);
171
172
err:
173
	if (ret != NULL)
174
		BN_BLINDING_free(ret);
175
	return (NULL);
176
258
}
177
178
void
179
BN_BLINDING_free(BN_BLINDING *r)
180
{
181
9296
	if (r == NULL)
182
		return;
183
184
255
	BN_clear_free(r->A);
185
255
	BN_clear_free(r->Ai);
186
255
	BN_clear_free(r->e);
187
255
	BN_clear_free(r->mod);
188
255
	free(r);
189
4903
}
190
191
int
192
BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
193
{
194
	int ret = 0;
195
196

69144
	if ((b->A == NULL) || (b->Ai == NULL)) {
197
		BNerror(BN_R_NOT_INITIALIZED);
198
		goto err;
199
	}
200
201
23048
	if (b->counter == -1)
202
		b->counter = 0;
203
204

24480
	if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
205
716
	    !(b->flags & BN_BLINDING_NO_RECREATE)) {
206
		/* re-create blinding parameters */
207
716
		if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL))
208
			goto err;
209
22332
	} else if (!(b->flags & BN_BLINDING_NO_UPDATE)) {
210
22332
		if (!BN_mod_mul(b->A, b->A, b->A, b->mod, ctx))
211
			goto err;
212
22332
		if (!BN_mod_mul(b->Ai, b->Ai, b->Ai, b->mod, ctx))
213
			goto err;
214
	}
215
216
23048
	ret = 1;
217
218
err:
219
23048
	if (b->counter == BN_BLINDING_COUNTER)
220
716
		b->counter = 0;
221
23048
	return (ret);
222
}
223
224
int
225
BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
226
{
227
	return BN_BLINDING_convert_ex(n, NULL, b, ctx);
228
}
229
230
int
231
BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
232
{
233
	int ret = 1;
234
235
	bn_check_top(n);
236
237

69918
	if ((b->A == NULL) || (b->Ai == NULL)) {
238
		BNerror(BN_R_NOT_INITIALIZED);
239
		return (0);
240
	}
241
242
23306
	if (b->counter == -1)
243
		/* Fresh blinding, doesn't need updating. */
244
258
		b->counter = 0;
245
23048
	else if (!BN_BLINDING_update(b, ctx))
246
		return (0);
247
248
23306
	if (r != NULL) {
249
		if (!BN_copy(r, b->Ai))
250
			ret = 0;
251
	}
252
253
23306
	if (!BN_mod_mul(n, n,b->A, b->mod, ctx))
254
		ret = 0;
255
256
23306
	return ret;
257
23306
}
258
259
int
260
BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
261
{
262
	return BN_BLINDING_invert_ex(n, NULL, b, ctx);
263
}
264
265
int
266
BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
267
{
268
	int ret;
269
270
	bn_check_top(n);
271
272
46612
	if (r != NULL)
273
		ret = BN_mod_mul(n, n, r, b->mod, ctx);
274
	else {
275
23306
		if (b->Ai == NULL) {
276
			BNerror(BN_R_NOT_INITIALIZED);
277
			return (0);
278
		}
279
23306
		ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
280
	}
281
282
	bn_check_top(n);
283
23306
	return (ret);
284
23306
}
285
286
#ifndef OPENSSL_NO_DEPRECATED
287
unsigned long
288
BN_BLINDING_get_thread_id(const BN_BLINDING *b)
289
{
290
	return b->thread_id;
291
}
292
293
void
294
BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n)
295
{
296
	b->thread_id = n;
297
}
298
#endif
299
300
CRYPTO_THREADID *
301
BN_BLINDING_thread_id(BN_BLINDING *b)
302
{
303
47128
	return &b->tid;
304
}
305
306
unsigned long
307
BN_BLINDING_get_flags(const BN_BLINDING *b)
308
{
309
	return b->flags;
310
}
311
312
void
313
BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
314
{
315
	b->flags = flags;
316
}
317
318
BN_BLINDING *
319
BN_BLINDING_create_param(BN_BLINDING *b, const BIGNUM *e, BIGNUM *m,
320
    BN_CTX *ctx, int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
321
    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx), BN_MONT_CTX *m_ctx)
322
{
323
	int    retry_counter = 32;
324
	BN_BLINDING *ret = NULL;
325
326
1948
	if (b == NULL)
327
258
		ret = BN_BLINDING_new(NULL, NULL, m);
328
	else
329
		ret = b;
330
331
974
	if (ret == NULL)
332
		goto err;
333
334

1232
	if (ret->A  == NULL && (ret->A = BN_new()) == NULL)
335
		goto err;
336

1232
	if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)
337
		goto err;
338
339
974
	if (e != NULL) {
340
258
		BN_free(ret->e);
341
258
		ret->e = BN_dup(e);
342
258
	}
343
974
	if (ret->e == NULL)
344
		goto err;
345
346
974
	if (bn_mod_exp != NULL)
347
258
		ret->bn_mod_exp = bn_mod_exp;
348
974
	if (m_ctx != NULL)
349
18
		ret->m_ctx = m_ctx;
350
351
974
	do {
352
974
		if (!BN_rand_range(ret->A, ret->mod))
353
			goto err;
354
974
		if (BN_mod_inverse_ct(ret->Ai, ret->A, ret->mod, ctx) == NULL) {
355
			/* this should almost never happen for good RSA keys */
356
			unsigned long error = ERR_peek_last_error();
357
			if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) {
358
				if (retry_counter-- == 0) {
359
					BNerror(BN_R_TOO_MANY_ITERATIONS);
360
					goto err;
361
				}
362
				ERR_clear_error();
363
			} else
364
				goto err;
365
		} else
366
			break;
367
	} while (1);
368
369

1948
	if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) {
370
108
		if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod,
371
		    ctx, ret->m_ctx))
372
			goto err;
373
	} else {
374
866
		if (!BN_mod_exp_ct(ret->A, ret->A, ret->e, ret->mod, ctx))
375
			goto err;
376
	}
377
378
974
	return ret;
379
380
err:
381
	if (b == NULL && ret != NULL) {
382
		BN_BLINDING_free(ret);
383
		ret = NULL;
384
	}
385
386
	return ret;
387
974
}