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d02b48c6 | 1 | /* crypto/bn/bn_lib.c */ |
58964a49 | 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
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. | |
0f113f3e | 8 | * |
d02b48c6 RE |
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). | |
0f113f3e | 15 | * |
d02b48c6 RE |
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. | |
0f113f3e | 22 | * |
d02b48c6 RE |
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 :-). | |
0f113f3e | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 40 | * |
d02b48c6 RE |
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. | |
0f113f3e | 52 | * |
d02b48c6 RE |
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 | ||
bbb8de09 | 59 | #ifndef BN_DEBUG |
0f113f3e | 60 | # undef NDEBUG /* avoid conflicting definitions */ |
bbb8de09 BM |
61 | # define NDEBUG |
62 | #endif | |
63 | ||
64 | #include <assert.h> | |
addb309a | 65 | #include <limits.h> |
b39fc560 | 66 | #include "internal/cryptlib.h" |
d02b48c6 RE |
67 | #include "bn_lcl.h" |
68 | ||
df11e1e9 GT |
69 | /* This stuff appears to be completely unused, so is deprecated */ |
70 | #ifndef OPENSSL_NO_DEPRECATED | |
1d97c843 TH |
71 | /*- |
72 | * For a 32 bit machine | |
dfeab068 RE |
73 | * 2 - 4 == 128 |
74 | * 3 - 8 == 256 | |
75 | * 4 - 16 == 512 | |
76 | * 5 - 32 == 1024 | |
77 | * 6 - 64 == 2048 | |
78 | * 7 - 128 == 4096 | |
79 | * 8 - 256 == 8192 | |
80 | */ | |
0f113f3e MC |
81 | static int bn_limit_bits = 0; |
82 | static int bn_limit_num = 8; /* (1<<bn_limit_bits) */ | |
83 | static int bn_limit_bits_low = 0; | |
84 | static int bn_limit_num_low = 8; /* (1<<bn_limit_bits_low) */ | |
85 | static int bn_limit_bits_high = 0; | |
86 | static int bn_limit_num_high = 8; /* (1<<bn_limit_bits_high) */ | |
87 | static int bn_limit_bits_mont = 0; | |
88 | static int bn_limit_num_mont = 8; /* (1<<bn_limit_bits_mont) */ | |
dfeab068 | 89 | |
6b691a5c | 90 | void BN_set_params(int mult, int high, int low, int mont) |
0f113f3e MC |
91 | { |
92 | if (mult >= 0) { | |
93 | if (mult > (int)(sizeof(int) * 8) - 1) | |
94 | mult = sizeof(int) * 8 - 1; | |
95 | bn_limit_bits = mult; | |
96 | bn_limit_num = 1 << mult; | |
97 | } | |
98 | if (high >= 0) { | |
99 | if (high > (int)(sizeof(int) * 8) - 1) | |
100 | high = sizeof(int) * 8 - 1; | |
101 | bn_limit_bits_high = high; | |
102 | bn_limit_num_high = 1 << high; | |
103 | } | |
104 | if (low >= 0) { | |
105 | if (low > (int)(sizeof(int) * 8) - 1) | |
106 | low = sizeof(int) * 8 - 1; | |
107 | bn_limit_bits_low = low; | |
108 | bn_limit_num_low = 1 << low; | |
109 | } | |
110 | if (mont >= 0) { | |
111 | if (mont > (int)(sizeof(int) * 8) - 1) | |
112 | mont = sizeof(int) * 8 - 1; | |
113 | bn_limit_bits_mont = mont; | |
114 | bn_limit_num_mont = 1 << mont; | |
115 | } | |
116 | } | |
dfeab068 | 117 | |
6b691a5c | 118 | int BN_get_params(int which) |
0f113f3e MC |
119 | { |
120 | if (which == 0) | |
121 | return (bn_limit_bits); | |
122 | else if (which == 1) | |
123 | return (bn_limit_bits_high); | |
124 | else if (which == 2) | |
125 | return (bn_limit_bits_low); | |
126 | else if (which == 3) | |
127 | return (bn_limit_bits_mont); | |
128 | else | |
129 | return (0); | |
130 | } | |
df11e1e9 | 131 | #endif |
d02b48c6 | 132 | |
98499135 | 133 | const BIGNUM *BN_value_one(void) |
0f113f3e MC |
134 | { |
135 | static const BN_ULONG data_one = 1L; | |
136 | static const BIGNUM const_one = | |
137 | { (BN_ULONG *)&data_one, 1, 1, 0, BN_FLG_STATIC_DATA }; | |
d02b48c6 | 138 | |
0f113f3e MC |
139 | return (&const_one); |
140 | } | |
d02b48c6 | 141 | |
6b691a5c | 142 | int BN_num_bits_word(BN_ULONG l) |
0f113f3e MC |
143 | { |
144 | static const unsigned char bits[256] = { | |
145 | 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, | |
146 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
147 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
148 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
149 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
150 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
151 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
152 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
153 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
154 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
155 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
156 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
157 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
158 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
159 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
160 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
161 | }; | |
d02b48c6 | 162 | |
dfeab068 | 163 | #if defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
164 | if (l & 0xffffffff00000000L) { |
165 | if (l & 0xffff000000000000L) { | |
166 | if (l & 0xff00000000000000L) { | |
167 | return (bits[(int)(l >> 56)] + 56); | |
168 | } else | |
169 | return (bits[(int)(l >> 48)] + 48); | |
170 | } else { | |
171 | if (l & 0x0000ff0000000000L) { | |
172 | return (bits[(int)(l >> 40)] + 40); | |
173 | } else | |
174 | return (bits[(int)(l >> 32)] + 32); | |
175 | } | |
176 | } else | |
d02b48c6 | 177 | #else |
0f113f3e MC |
178 | # ifdef SIXTY_FOUR_BIT |
179 | if (l & 0xffffffff00000000LL) { | |
180 | if (l & 0xffff000000000000LL) { | |
181 | if (l & 0xff00000000000000LL) { | |
182 | return (bits[(int)(l >> 56)] + 56); | |
183 | } else | |
184 | return (bits[(int)(l >> 48)] + 48); | |
185 | } else { | |
186 | if (l & 0x0000ff0000000000LL) { | |
187 | return (bits[(int)(l >> 40)] + 40); | |
188 | } else | |
189 | return (bits[(int)(l >> 32)] + 32); | |
190 | } | |
191 | } else | |
192 | # endif | |
d02b48c6 | 193 | #endif |
0f113f3e | 194 | { |
d02b48c6 | 195 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
196 | if (l & 0xffff0000L) { |
197 | if (l & 0xff000000L) | |
198 | return (bits[(int)(l >> 24L)] + 24); | |
199 | else | |
200 | return (bits[(int)(l >> 16L)] + 16); | |
201 | } else | |
d02b48c6 | 202 | #endif |
0f113f3e | 203 | { |
4a47f556 | 204 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
205 | if (l & 0xff00L) |
206 | return (bits[(int)(l >> 8)] + 8); | |
207 | else | |
d02b48c6 | 208 | #endif |
0f113f3e MC |
209 | return (bits[(int)(l)]); |
210 | } | |
211 | } | |
212 | } | |
d02b48c6 | 213 | |
84c15db5 | 214 | int BN_num_bits(const BIGNUM *a) |
0f113f3e MC |
215 | { |
216 | int i = a->top - 1; | |
217 | bn_check_top(a); | |
dfeab068 | 218 | |
0f113f3e MC |
219 | if (BN_is_zero(a)) |
220 | return 0; | |
221 | return ((i * BN_BITS2) + BN_num_bits_word(a->d[i])); | |
222 | } | |
d02b48c6 | 223 | |
9f040d6d RS |
224 | static void bn_free_d(BIGNUM *a) |
225 | { | |
226 | if (BN_get_flags(a,BN_FLG_SECURE)) | |
227 | OPENSSL_secure_free(a->d); | |
228 | else | |
229 | OPENSSL_free(a->d); | |
230 | } | |
231 | ||
232 | ||
6b691a5c | 233 | void BN_clear_free(BIGNUM *a) |
0f113f3e MC |
234 | { |
235 | int i; | |
236 | ||
237 | if (a == NULL) | |
238 | return; | |
239 | bn_check_top(a); | |
240 | if (a->d != NULL) { | |
241 | OPENSSL_cleanse(a->d, a->dmax * sizeof(a->d[0])); | |
9f040d6d RS |
242 | if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) |
243 | bn_free_d(a); | |
0f113f3e MC |
244 | } |
245 | i = BN_get_flags(a, BN_FLG_MALLOCED); | |
9f040d6d | 246 | OPENSSL_cleanse(a, sizeof(*a)); |
0f113f3e MC |
247 | if (i) |
248 | OPENSSL_free(a); | |
249 | } | |
d02b48c6 | 250 | |
6b691a5c | 251 | void BN_free(BIGNUM *a) |
0f113f3e MC |
252 | { |
253 | if (a == NULL) | |
254 | return; | |
255 | bn_check_top(a); | |
b548a1f1 | 256 | if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) |
9f040d6d | 257 | bn_free_d(a); |
0f113f3e MC |
258 | if (a->flags & BN_FLG_MALLOCED) |
259 | OPENSSL_free(a); | |
260 | else { | |
21933811 | 261 | #ifndef OPENSSL_NO_DEPRECATED |
0f113f3e | 262 | a->flags |= BN_FLG_FREE; |
2ae1ea37 | 263 | #endif |
0f113f3e MC |
264 | a->d = NULL; |
265 | } | |
266 | } | |
dfeab068 | 267 | |
6b691a5c | 268 | void BN_init(BIGNUM *a) |
0f113f3e | 269 | { |
16f8d4eb | 270 | memset(a, 0, sizeof(*a)); |
0f113f3e MC |
271 | bn_check_top(a); |
272 | } | |
d02b48c6 | 273 | |
6b691a5c | 274 | BIGNUM *BN_new(void) |
0f113f3e MC |
275 | { |
276 | BIGNUM *ret; | |
277 | ||
64b25758 | 278 | if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) { |
0f113f3e MC |
279 | BNerr(BN_F_BN_NEW, ERR_R_MALLOC_FAILURE); |
280 | return (NULL); | |
281 | } | |
282 | ret->flags = BN_FLG_MALLOCED; | |
0f113f3e MC |
283 | bn_check_top(ret); |
284 | return (ret); | |
285 | } | |
d02b48c6 | 286 | |
74924dcb RS |
287 | BIGNUM *BN_secure_new(void) |
288 | { | |
289 | BIGNUM *ret = BN_new(); | |
90945fa3 | 290 | if (ret != NULL) |
74924dcb RS |
291 | ret->flags |= BN_FLG_SECURE; |
292 | return (ret); | |
293 | } | |
294 | ||
020fc820 RL |
295 | /* This is used both by bn_expand2() and bn_dup_expand() */ |
296 | /* The caller MUST check that words > b->dmax before calling this */ | |
6343829a | 297 | static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) |
0f113f3e MC |
298 | { |
299 | BN_ULONG *A, *a = NULL; | |
300 | const BN_ULONG *B; | |
301 | int i; | |
302 | ||
303 | bn_check_top(b); | |
304 | ||
305 | if (words > (INT_MAX / (4 * BN_BITS2))) { | |
306 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG); | |
307 | return NULL; | |
308 | } | |
309 | if (BN_get_flags(b, BN_FLG_STATIC_DATA)) { | |
310 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); | |
311 | return (NULL); | |
312 | } | |
74924dcb RS |
313 | if (BN_get_flags(b,BN_FLG_SECURE)) |
314 | a = A = OPENSSL_secure_malloc(words * sizeof(*a)); | |
315 | else | |
316 | a = A = OPENSSL_malloc(words * sizeof(*a)); | |
0f113f3e MC |
317 | if (A == NULL) { |
318 | BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE); | |
319 | return (NULL); | |
320 | } | |
f8571ce8 | 321 | #ifdef PURIFY |
0f113f3e MC |
322 | /* |
323 | * Valgrind complains in BN_consttime_swap because we process the whole | |
324 | * array even if it's not initialised yet. This doesn't matter in that | |
325 | * function - what's important is constant time operation (we're not | |
326 | * actually going to use the data) | |
327 | */ | |
16f8d4eb | 328 | memset(a, 0, sizeof(*a) * words); |
f8571ce8 MC |
329 | #endif |
330 | ||
dfeab068 | 331 | #if 1 |
0f113f3e MC |
332 | B = b->d; |
333 | /* Check if the previous number needs to be copied */ | |
334 | if (B != NULL) { | |
335 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
336 | /* | |
337 | * The fact that the loop is unrolled | |
338 | * 4-wise is a tribute to Intel. It's | |
339 | * the one that doesn't have enough | |
340 | * registers to accomodate more data. | |
341 | * I'd unroll it 8-wise otherwise:-) | |
342 | * | |
343 | * <appro@fy.chalmers.se> | |
344 | */ | |
345 | BN_ULONG a0, a1, a2, a3; | |
346 | a0 = B[0]; | |
347 | a1 = B[1]; | |
348 | a2 = B[2]; | |
349 | a3 = B[3]; | |
350 | A[0] = a0; | |
351 | A[1] = a1; | |
352 | A[2] = a2; | |
353 | A[3] = a3; | |
354 | } | |
355 | /* | |
356 | * workaround for ultrix cc: without 'case 0', the optimizer does | |
357 | * the switch table by doing a=top&3; a--; goto jump_table[a]; | |
358 | * which fails for top== 0 | |
359 | */ | |
360 | switch (b->top & 3) { | |
361 | case 3: | |
362 | A[2] = B[2]; | |
363 | case 2: | |
364 | A[1] = B[1]; | |
365 | case 1: | |
366 | A[0] = B[0]; | |
367 | case 0: | |
368 | ; | |
369 | } | |
370 | } | |
dfeab068 | 371 | #else |
16f8d4eb | 372 | memset(A, 0, sizeof(*A) * words); |
0f113f3e | 373 | memcpy(A, b->d, sizeof(b->d[0]) * b->top); |
dfeab068 | 374 | #endif |
dfeab068 | 375 | |
0f113f3e MC |
376 | return (a); |
377 | } | |
378 | ||
379 | /* | |
380 | * This is an internal function that should not be used in applications. It | |
381 | * ensures that 'b' has enough room for a 'words' word number and initialises | |
382 | * any unused part of b->d with leading zeros. It is mostly used by the | |
383 | * various BIGNUM routines. If there is an error, NULL is returned. If not, | |
384 | * 'b' is returned. | |
385 | */ | |
020fc820 | 386 | |
6343829a | 387 | BIGNUM *bn_expand2(BIGNUM *b, int words) |
0f113f3e MC |
388 | { |
389 | bn_check_top(b); | |
390 | ||
391 | if (words > b->dmax) { | |
392 | BN_ULONG *a = bn_expand_internal(b, words); | |
393 | if (!a) | |
394 | return NULL; | |
74924dcb | 395 | if (b->d) { |
9f040d6d RS |
396 | OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0])); |
397 | bn_free_d(b); | |
74924dcb | 398 | } |
0f113f3e MC |
399 | b->d = a; |
400 | b->dmax = words; | |
401 | } | |
2bfd2c74 | 402 | |
0f113f3e MC |
403 | bn_check_top(b); |
404 | return b; | |
405 | } | |
d02b48c6 | 406 | |
84c15db5 | 407 | BIGNUM *BN_dup(const BIGNUM *a) |
0f113f3e MC |
408 | { |
409 | BIGNUM *t; | |
410 | ||
411 | if (a == NULL) | |
412 | return NULL; | |
413 | bn_check_top(a); | |
414 | ||
74924dcb | 415 | t = BN_get_flags(a, BN_FLG_SECURE) ? BN_secure_new() : BN_new(); |
0f113f3e MC |
416 | if (t == NULL) |
417 | return NULL; | |
418 | if (!BN_copy(t, a)) { | |
419 | BN_free(t); | |
420 | return NULL; | |
421 | } | |
422 | bn_check_top(t); | |
423 | return t; | |
424 | } | |
d02b48c6 | 425 | |
84c15db5 | 426 | BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
427 | { |
428 | int i; | |
429 | BN_ULONG *A; | |
430 | const BN_ULONG *B; | |
58964a49 | 431 | |
0f113f3e | 432 | bn_check_top(b); |
dfeab068 | 433 | |
0f113f3e MC |
434 | if (a == b) |
435 | return (a); | |
436 | if (bn_wexpand(a, b->top) == NULL) | |
437 | return (NULL); | |
58964a49 RE |
438 | |
439 | #if 1 | |
0f113f3e MC |
440 | A = a->d; |
441 | B = b->d; | |
442 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
443 | BN_ULONG a0, a1, a2, a3; | |
444 | a0 = B[0]; | |
445 | a1 = B[1]; | |
446 | a2 = B[2]; | |
447 | a3 = B[3]; | |
448 | A[0] = a0; | |
449 | A[1] = a1; | |
450 | A[2] = a2; | |
451 | A[3] = a3; | |
452 | } | |
453 | /* ultrix cc workaround, see comments in bn_expand_internal */ | |
454 | switch (b->top & 3) { | |
455 | case 3: | |
456 | A[2] = B[2]; | |
457 | case 2: | |
458 | A[1] = B[1]; | |
459 | case 1: | |
460 | A[0] = B[0]; | |
461 | case 0:; | |
462 | } | |
58964a49 | 463 | #else |
0f113f3e | 464 | memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); |
58964a49 RE |
465 | #endif |
466 | ||
0f113f3e MC |
467 | a->top = b->top; |
468 | a->neg = b->neg; | |
469 | bn_check_top(a); | |
470 | return (a); | |
471 | } | |
d02b48c6 | 472 | |
78a0c1f1 | 473 | void BN_swap(BIGNUM *a, BIGNUM *b) |
0f113f3e MC |
474 | { |
475 | int flags_old_a, flags_old_b; | |
476 | BN_ULONG *tmp_d; | |
477 | int tmp_top, tmp_dmax, tmp_neg; | |
478 | ||
479 | bn_check_top(a); | |
480 | bn_check_top(b); | |
481 | ||
482 | flags_old_a = a->flags; | |
483 | flags_old_b = b->flags; | |
484 | ||
485 | tmp_d = a->d; | |
486 | tmp_top = a->top; | |
487 | tmp_dmax = a->dmax; | |
488 | tmp_neg = a->neg; | |
489 | ||
490 | a->d = b->d; | |
491 | a->top = b->top; | |
492 | a->dmax = b->dmax; | |
493 | a->neg = b->neg; | |
494 | ||
495 | b->d = tmp_d; | |
496 | b->top = tmp_top; | |
497 | b->dmax = tmp_dmax; | |
498 | b->neg = tmp_neg; | |
499 | ||
500 | a->flags = | |
501 | (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); | |
502 | b->flags = | |
503 | (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); | |
504 | bn_check_top(a); | |
505 | bn_check_top(b); | |
506 | } | |
78a0c1f1 | 507 | |
6b691a5c | 508 | void BN_clear(BIGNUM *a) |
0f113f3e MC |
509 | { |
510 | bn_check_top(a); | |
511 | if (a->d != NULL) | |
16f8d4eb | 512 | memset(a->d, 0, sizeof(*a->d) * a->dmax); |
0f113f3e MC |
513 | a->top = 0; |
514 | a->neg = 0; | |
515 | } | |
d02b48c6 | 516 | |
020fc820 | 517 | BN_ULONG BN_get_word(const BIGNUM *a) |
0f113f3e MC |
518 | { |
519 | if (a->top > 1) | |
520 | return BN_MASK2; | |
521 | else if (a->top == 1) | |
522 | return a->d[0]; | |
523 | /* a->top == 0 */ | |
524 | return 0; | |
525 | } | |
d02b48c6 | 526 | |
e042540f | 527 | int BN_set_word(BIGNUM *a, BN_ULONG w) |
0f113f3e MC |
528 | { |
529 | bn_check_top(a); | |
530 | if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL) | |
531 | return (0); | |
532 | a->neg = 0; | |
533 | a->d[0] = w; | |
534 | a->top = (w ? 1 : 0); | |
535 | bn_check_top(a); | |
536 | return (1); | |
537 | } | |
d02b48c6 | 538 | |
6343829a | 539 | BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) |
0f113f3e MC |
540 | { |
541 | unsigned int i, m; | |
542 | unsigned int n; | |
543 | BN_ULONG l; | |
544 | BIGNUM *bn = NULL; | |
545 | ||
546 | if (ret == NULL) | |
547 | ret = bn = BN_new(); | |
548 | if (ret == NULL) | |
549 | return (NULL); | |
550 | bn_check_top(ret); | |
22dc08d0 | 551 | /* Skip leading zero's. */ |
3c65047d | 552 | for ( ; len > 0 && *s == 0; s++, len--) |
22dc08d0 | 553 | continue; |
0f113f3e MC |
554 | n = len; |
555 | if (n == 0) { | |
556 | ret->top = 0; | |
557 | return (ret); | |
558 | } | |
559 | i = ((n - 1) / BN_BYTES) + 1; | |
560 | m = ((n - 1) % (BN_BYTES)); | |
561 | if (bn_wexpand(ret, (int)i) == NULL) { | |
23a1d5e9 | 562 | BN_free(bn); |
0f113f3e MC |
563 | return NULL; |
564 | } | |
565 | ret->top = i; | |
566 | ret->neg = 0; | |
22dc08d0 | 567 | l = 0; |
0f113f3e MC |
568 | while (n--) { |
569 | l = (l << 8L) | *(s++); | |
570 | if (m-- == 0) { | |
571 | ret->d[--i] = l; | |
572 | l = 0; | |
573 | m = BN_BYTES - 1; | |
574 | } | |
575 | } | |
576 | /* | |
577 | * need to call this due to clear byte at top if avoiding having the top | |
578 | * bit set (-ve number) | |
579 | */ | |
580 | bn_correct_top(ret); | |
581 | return (ret); | |
582 | } | |
d02b48c6 RE |
583 | |
584 | /* ignore negative */ | |
8623f693 | 585 | int BN_bn2bin(const BIGNUM *a, unsigned char *to) |
0f113f3e MC |
586 | { |
587 | int n, i; | |
588 | BN_ULONG l; | |
589 | ||
590 | bn_check_top(a); | |
591 | n = i = BN_num_bytes(a); | |
592 | while (i--) { | |
593 | l = a->d[i / BN_BYTES]; | |
594 | *(to++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; | |
595 | } | |
596 | return (n); | |
597 | } | |
d02b48c6 | 598 | |
84c15db5 | 599 | int BN_ucmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
600 | { |
601 | int i; | |
602 | BN_ULONG t1, t2, *ap, *bp; | |
603 | ||
604 | bn_check_top(a); | |
605 | bn_check_top(b); | |
606 | ||
607 | i = a->top - b->top; | |
608 | if (i != 0) | |
609 | return (i); | |
610 | ap = a->d; | |
611 | bp = b->d; | |
612 | for (i = a->top - 1; i >= 0; i--) { | |
613 | t1 = ap[i]; | |
614 | t2 = bp[i]; | |
615 | if (t1 != t2) | |
616 | return ((t1 > t2) ? 1 : -1); | |
617 | } | |
618 | return (0); | |
619 | } | |
d02b48c6 | 620 | |
84c15db5 | 621 | int BN_cmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
622 | { |
623 | int i; | |
624 | int gt, lt; | |
625 | BN_ULONG t1, t2; | |
626 | ||
627 | if ((a == NULL) || (b == NULL)) { | |
628 | if (a != NULL) | |
629 | return (-1); | |
630 | else if (b != NULL) | |
631 | return (1); | |
632 | else | |
633 | return (0); | |
634 | } | |
635 | ||
636 | bn_check_top(a); | |
637 | bn_check_top(b); | |
638 | ||
639 | if (a->neg != b->neg) { | |
640 | if (a->neg) | |
641 | return (-1); | |
642 | else | |
643 | return (1); | |
644 | } | |
645 | if (a->neg == 0) { | |
646 | gt = 1; | |
647 | lt = -1; | |
648 | } else { | |
649 | gt = -1; | |
650 | lt = 1; | |
651 | } | |
652 | ||
653 | if (a->top > b->top) | |
654 | return (gt); | |
655 | if (a->top < b->top) | |
656 | return (lt); | |
657 | for (i = a->top - 1; i >= 0; i--) { | |
658 | t1 = a->d[i]; | |
659 | t2 = b->d[i]; | |
660 | if (t1 > t2) | |
661 | return (gt); | |
662 | if (t1 < t2) | |
663 | return (lt); | |
664 | } | |
665 | return (0); | |
666 | } | |
d02b48c6 | 667 | |
6b691a5c | 668 | int BN_set_bit(BIGNUM *a, int n) |
0f113f3e MC |
669 | { |
670 | int i, j, k; | |
671 | ||
672 | if (n < 0) | |
673 | return 0; | |
674 | ||
675 | i = n / BN_BITS2; | |
676 | j = n % BN_BITS2; | |
677 | if (a->top <= i) { | |
678 | if (bn_wexpand(a, i + 1) == NULL) | |
679 | return (0); | |
680 | for (k = a->top; k < i + 1; k++) | |
681 | a->d[k] = 0; | |
682 | a->top = i + 1; | |
683 | } | |
684 | ||
685 | a->d[i] |= (((BN_ULONG)1) << j); | |
686 | bn_check_top(a); | |
687 | return (1); | |
688 | } | |
d02b48c6 | 689 | |
6b691a5c | 690 | int BN_clear_bit(BIGNUM *a, int n) |
0f113f3e MC |
691 | { |
692 | int i, j; | |
d02b48c6 | 693 | |
0f113f3e MC |
694 | bn_check_top(a); |
695 | if (n < 0) | |
696 | return 0; | |
1a017330 | 697 | |
0f113f3e MC |
698 | i = n / BN_BITS2; |
699 | j = n % BN_BITS2; | |
700 | if (a->top <= i) | |
701 | return (0); | |
d02b48c6 | 702 | |
0f113f3e MC |
703 | a->d[i] &= (~(((BN_ULONG)1) << j)); |
704 | bn_correct_top(a); | |
705 | return (1); | |
706 | } | |
d02b48c6 | 707 | |
84c15db5 | 708 | int BN_is_bit_set(const BIGNUM *a, int n) |
0f113f3e MC |
709 | { |
710 | int i, j; | |
711 | ||
712 | bn_check_top(a); | |
713 | if (n < 0) | |
714 | return 0; | |
715 | i = n / BN_BITS2; | |
716 | j = n % BN_BITS2; | |
717 | if (a->top <= i) | |
718 | return 0; | |
719 | return (int)(((a->d[i]) >> j) & ((BN_ULONG)1)); | |
720 | } | |
d02b48c6 | 721 | |
6b691a5c | 722 | int BN_mask_bits(BIGNUM *a, int n) |
0f113f3e MC |
723 | { |
724 | int b, w; | |
725 | ||
726 | bn_check_top(a); | |
727 | if (n < 0) | |
728 | return 0; | |
729 | ||
730 | w = n / BN_BITS2; | |
731 | b = n % BN_BITS2; | |
732 | if (w >= a->top) | |
733 | return 0; | |
734 | if (b == 0) | |
735 | a->top = w; | |
736 | else { | |
737 | a->top = w + 1; | |
738 | a->d[w] &= ~(BN_MASK2 << b); | |
739 | } | |
740 | bn_correct_top(a); | |
741 | return (1); | |
742 | } | |
dfeab068 | 743 | |
ff22e913 | 744 | void BN_set_negative(BIGNUM *a, int b) |
0f113f3e MC |
745 | { |
746 | if (b && !BN_is_zero(a)) | |
747 | a->neg = 1; | |
748 | else | |
749 | a->neg = 0; | |
750 | } | |
ff22e913 | 751 | |
cbd48ba6 | 752 | int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) |
0f113f3e MC |
753 | { |
754 | int i; | |
755 | BN_ULONG aa, bb; | |
756 | ||
757 | aa = a[n - 1]; | |
758 | bb = b[n - 1]; | |
759 | if (aa != bb) | |
760 | return ((aa > bb) ? 1 : -1); | |
761 | for (i = n - 2; i >= 0; i--) { | |
762 | aa = a[i]; | |
763 | bb = b[i]; | |
764 | if (aa != bb) | |
765 | return ((aa > bb) ? 1 : -1); | |
766 | } | |
767 | return (0); | |
768 | } | |
769 | ||
770 | /* | |
771 | * Here follows a specialised variants of bn_cmp_words(). It has the | |
772 | * property of performing the operation on arrays of different sizes. The | |
773 | * sizes of those arrays is expressed through cl, which is the common length | |
774 | * ( basicall, min(len(a),len(b)) ), and dl, which is the delta between the | |
775 | * two lengths, calculated as len(a)-len(b). All lengths are the number of | |
776 | * BN_ULONGs... | |
777 | */ | |
778 | ||
779 | int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl) | |
780 | { | |
781 | int n, i; | |
782 | n = cl - 1; | |
783 | ||
784 | if (dl < 0) { | |
785 | for (i = dl; i < 0; i++) { | |
786 | if (b[n - i] != 0) | |
787 | return -1; /* a < b */ | |
788 | } | |
789 | } | |
790 | if (dl > 0) { | |
791 | for (i = dl; i > 0; i--) { | |
792 | if (a[n + i] != 0) | |
793 | return 1; /* a > b */ | |
794 | } | |
795 | } | |
796 | return bn_cmp_words(a, b, cl); | |
797 | } | |
798 | ||
799 | /* | |
800 | * Constant-time conditional swap of a and b. | |
f9b6c0ba DSH |
801 | * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. |
802 | * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, | |
803 | * and that no more than nwords are used by either a or b. | |
804 | * a and b cannot be the same number | |
805 | */ | |
806 | void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) | |
0f113f3e MC |
807 | { |
808 | BN_ULONG t; | |
809 | int i; | |
f9b6c0ba | 810 | |
0f113f3e MC |
811 | bn_wcheck_size(a, nwords); |
812 | bn_wcheck_size(b, nwords); | |
f9b6c0ba | 813 | |
0f113f3e MC |
814 | assert(a != b); |
815 | assert((condition & (condition - 1)) == 0); | |
816 | assert(sizeof(BN_ULONG) >= sizeof(int)); | |
f9b6c0ba | 817 | |
0f113f3e | 818 | condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; |
f9b6c0ba | 819 | |
0f113f3e MC |
820 | t = (a->top ^ b->top) & condition; |
821 | a->top ^= t; | |
822 | b->top ^= t; | |
f9b6c0ba DSH |
823 | |
824 | #define BN_CONSTTIME_SWAP(ind) \ | |
0f113f3e MC |
825 | do { \ |
826 | t = (a->d[ind] ^ b->d[ind]) & condition; \ | |
827 | a->d[ind] ^= t; \ | |
828 | b->d[ind] ^= t; \ | |
829 | } while (0) | |
830 | ||
831 | switch (nwords) { | |
832 | default: | |
833 | for (i = 10; i < nwords; i++) | |
834 | BN_CONSTTIME_SWAP(i); | |
835 | /* Fallthrough */ | |
836 | case 10: | |
837 | BN_CONSTTIME_SWAP(9); /* Fallthrough */ | |
838 | case 9: | |
839 | BN_CONSTTIME_SWAP(8); /* Fallthrough */ | |
840 | case 8: | |
841 | BN_CONSTTIME_SWAP(7); /* Fallthrough */ | |
842 | case 7: | |
843 | BN_CONSTTIME_SWAP(6); /* Fallthrough */ | |
844 | case 6: | |
845 | BN_CONSTTIME_SWAP(5); /* Fallthrough */ | |
846 | case 5: | |
847 | BN_CONSTTIME_SWAP(4); /* Fallthrough */ | |
848 | case 4: | |
849 | BN_CONSTTIME_SWAP(3); /* Fallthrough */ | |
850 | case 3: | |
851 | BN_CONSTTIME_SWAP(2); /* Fallthrough */ | |
852 | case 2: | |
853 | BN_CONSTTIME_SWAP(1); /* Fallthrough */ | |
854 | case 1: | |
855 | BN_CONSTTIME_SWAP(0); | |
856 | } | |
f9b6c0ba DSH |
857 | #undef BN_CONSTTIME_SWAP |
858 | } | |
2514fa79 DSH |
859 | |
860 | /* Bits of security, see SP800-57 */ | |
861 | ||
862 | int BN_security_bits(int L, int N) | |
0f113f3e MC |
863 | { |
864 | int secbits, bits; | |
865 | if (L >= 15360) | |
866 | secbits = 256; | |
867 | else if (L >= 7690) | |
868 | secbits = 192; | |
869 | else if (L >= 3072) | |
870 | secbits = 128; | |
871 | else if (L >= 2048) | |
872 | secbits = 112; | |
873 | else if (L >= 1024) | |
874 | secbits = 80; | |
875 | else | |
876 | return 0; | |
877 | if (N == -1) | |
878 | return secbits; | |
879 | bits = N / 2; | |
880 | if (bits < 80) | |
881 | return 0; | |
882 | return bits >= secbits ? secbits : bits; | |
883 | } | |
85bcf27c MC |
884 | |
885 | void BN_zero_ex(BIGNUM *a) | |
0f113f3e MC |
886 | { |
887 | a->top = 0; | |
888 | a->neg = 0; | |
889 | } | |
85bcf27c MC |
890 | |
891 | int BN_abs_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
892 | { |
893 | return ((a->top == 1) && (a->d[0] == w)) || ((w == 0) && (a->top == 0)); | |
894 | } | |
85bcf27c MC |
895 | |
896 | int BN_is_zero(const BIGNUM *a) | |
0f113f3e MC |
897 | { |
898 | return a->top == 0; | |
899 | } | |
85bcf27c MC |
900 | |
901 | int BN_is_one(const BIGNUM *a) | |
0f113f3e MC |
902 | { |
903 | return BN_abs_is_word(a, 1) && !a->neg; | |
904 | } | |
85bcf27c MC |
905 | |
906 | int BN_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
907 | { |
908 | return BN_abs_is_word(a, w) && (!w || !a->neg); | |
909 | } | |
85bcf27c MC |
910 | |
911 | int BN_is_odd(const BIGNUM *a) | |
0f113f3e MC |
912 | { |
913 | return (a->top > 0) && (a->d[0] & 1); | |
914 | } | |
85bcf27c MC |
915 | |
916 | int BN_is_negative(const BIGNUM *a) | |
0f113f3e MC |
917 | { |
918 | return (a->neg != 0); | |
919 | } | |
85bcf27c | 920 | |
0f113f3e MC |
921 | int BN_to_montgomery(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont, |
922 | BN_CTX *ctx) | |
923 | { | |
924 | return BN_mod_mul_montgomery(r, a, &(mont->RR), mont, ctx); | |
925 | } | |
85bcf27c MC |
926 | |
927 | void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int n) | |
0f113f3e MC |
928 | { |
929 | dest->d = b->d; | |
930 | dest->top = b->top; | |
931 | dest->dmax = b->dmax; | |
932 | dest->neg = b->neg; | |
933 | dest->flags = ((dest->flags & BN_FLG_MALLOCED) | |
934 | | (b->flags & ~BN_FLG_MALLOCED) | |
935 | | BN_FLG_STATIC_DATA | n); | |
936 | } | |
85bcf27c MC |
937 | |
938 | BN_GENCB *BN_GENCB_new(void) | |
0f113f3e MC |
939 | { |
940 | BN_GENCB *ret; | |
85bcf27c | 941 | |
b4faea50 | 942 | if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) { |
0f113f3e MC |
943 | BNerr(BN_F_BN_GENCB_NEW, ERR_R_MALLOC_FAILURE); |
944 | return (NULL); | |
945 | } | |
85bcf27c | 946 | |
0f113f3e MC |
947 | return ret; |
948 | } | |
85bcf27c MC |
949 | |
950 | void BN_GENCB_free(BN_GENCB *cb) | |
0f113f3e MC |
951 | { |
952 | if (cb == NULL) | |
953 | return; | |
954 | OPENSSL_free(cb); | |
955 | } | |
85bcf27c MC |
956 | |
957 | void BN_set_flags(BIGNUM *b, int n) | |
0f113f3e MC |
958 | { |
959 | b->flags |= n; | |
960 | } | |
85bcf27c MC |
961 | |
962 | int BN_get_flags(const BIGNUM *b, int n) | |
0f113f3e MC |
963 | { |
964 | return b->flags & n; | |
965 | } | |
85bcf27c MC |
966 | |
967 | /* Populate a BN_GENCB structure with an "old"-style callback */ | |
0f113f3e MC |
968 | void BN_GENCB_set_old(BN_GENCB *gencb, void (*callback) (int, int, void *), |
969 | void *cb_arg) | |
970 | { | |
971 | BN_GENCB *tmp_gencb = gencb; | |
972 | tmp_gencb->ver = 1; | |
973 | tmp_gencb->arg = cb_arg; | |
974 | tmp_gencb->cb.cb_1 = callback; | |
975 | } | |
85bcf27c MC |
976 | |
977 | /* Populate a BN_GENCB structure with a "new"-style callback */ | |
0f113f3e MC |
978 | void BN_GENCB_set(BN_GENCB *gencb, int (*callback) (int, int, BN_GENCB *), |
979 | void *cb_arg) | |
980 | { | |
981 | BN_GENCB *tmp_gencb = gencb; | |
982 | tmp_gencb->ver = 2; | |
983 | tmp_gencb->arg = cb_arg; | |
984 | tmp_gencb->cb.cb_2 = callback; | |
985 | } | |
85bcf27c MC |
986 | |
987 | void *BN_GENCB_get_arg(BN_GENCB *cb) | |
0f113f3e MC |
988 | { |
989 | return cb->arg; | |
990 | } | |
85bcf27c MC |
991 | |
992 | BIGNUM *bn_wexpand(BIGNUM *a, int words) | |
0f113f3e MC |
993 | { |
994 | return (words <= a->dmax) ? a : bn_expand2(a, words); | |
995 | } | |
85bcf27c MC |
996 | |
997 | void bn_correct_top(BIGNUM *a) | |
0f113f3e MC |
998 | { |
999 | BN_ULONG *ftl; | |
1000 | int tmp_top = a->top; | |
1001 | ||
1002 | if (tmp_top > 0) { | |
1003 | for (ftl = &(a->d[tmp_top - 1]); tmp_top > 0; tmp_top--) | |
1004 | if (*(ftl--)) | |
1005 | break; | |
1006 | a->top = tmp_top; | |
1007 | } | |
1008 | bn_pollute(a); | |
1009 | } |