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58964a49 | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
2 | * All rights reserved. |
3 | * | |
4 | * This package is an SSL implementation written | |
5 | * by Eric Young (eay@cryptsoft.com). | |
6 | * The implementation was written so as to conform with Netscapes SSL. | |
0f113f3e | 7 | * |
d02b48c6 RE |
8 | * This library is free for commercial and non-commercial use as long as |
9 | * the following conditions are aheared to. The following conditions | |
10 | * apply to all code found in this distribution, be it the RC4, RSA, | |
11 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
12 | * included with this distribution is covered by the same copyright terms | |
13 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
0f113f3e | 14 | * |
d02b48c6 RE |
15 | * Copyright remains Eric Young's, and as such any Copyright notices in |
16 | * the code are not to be removed. | |
17 | * If this package is used in a product, Eric Young should be given attribution | |
18 | * as the author of the parts of the library used. | |
19 | * This can be in the form of a textual message at program startup or | |
20 | * in documentation (online or textual) provided with the package. | |
0f113f3e | 21 | * |
d02b48c6 RE |
22 | * Redistribution and use in source and binary forms, with or without |
23 | * modification, are permitted provided that the following conditions | |
24 | * are met: | |
25 | * 1. Redistributions of source code must retain the copyright | |
26 | * notice, this list of conditions and the following disclaimer. | |
27 | * 2. Redistributions in binary form must reproduce the above copyright | |
28 | * notice, this list of conditions and the following disclaimer in the | |
29 | * documentation and/or other materials provided with the distribution. | |
30 | * 3. All advertising materials mentioning features or use of this software | |
31 | * must display the following acknowledgement: | |
32 | * "This product includes cryptographic software written by | |
33 | * Eric Young (eay@cryptsoft.com)" | |
34 | * The word 'cryptographic' can be left out if the rouines from the library | |
35 | * being used are not cryptographic related :-). | |
0f113f3e | 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
37 | * the apps directory (application code) you must include an acknowledgement: |
38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 39 | * |
d02b48c6 RE |
40 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
50 | * SUCH DAMAGE. | |
0f113f3e | 51 | * |
d02b48c6 RE |
52 | * The licence and distribution terms for any publically available version or |
53 | * derivative of this code cannot be changed. i.e. this code cannot simply be | |
54 | * copied and put under another distribution licence | |
55 | * [including the GNU Public Licence.] | |
56 | */ | |
57 | ||
bbb8de09 | 58 | #ifndef BN_DEBUG |
0f113f3e | 59 | # undef NDEBUG /* avoid conflicting definitions */ |
bbb8de09 BM |
60 | # define NDEBUG |
61 | #endif | |
62 | ||
63 | #include <assert.h> | |
addb309a | 64 | #include <limits.h> |
b39fc560 | 65 | #include "internal/cryptlib.h" |
d02b48c6 | 66 | #include "bn_lcl.h" |
98186eb4 | 67 | #include <openssl/opensslconf.h> |
d02b48c6 | 68 | |
df11e1e9 | 69 | /* This stuff appears to be completely unused, so is deprecated */ |
98186eb4 | 70 | #if OPENSSL_API_COMPAT < 0x00908000L |
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 { | |
98186eb4 | 261 | #if OPENSSL_API_COMPAT < 0x00908000L |
0f113f3e | 262 | a->flags |= BN_FLG_FREE; |
2ae1ea37 | 263 | #endif |
0f113f3e MC |
264 | a->d = NULL; |
265 | } | |
266 | } | |
dfeab068 | 267 | |
d59c7c81 | 268 | void bn_init(BIGNUM *a) |
0f113f3e | 269 | { |
d59c7c81 RS |
270 | static BIGNUM nilbn; |
271 | ||
272 | *a = nilbn; | |
0f113f3e MC |
273 | bn_check_top(a); |
274 | } | |
d02b48c6 | 275 | |
6b691a5c | 276 | BIGNUM *BN_new(void) |
0f113f3e MC |
277 | { |
278 | BIGNUM *ret; | |
279 | ||
64b25758 | 280 | if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) { |
0f113f3e MC |
281 | BNerr(BN_F_BN_NEW, ERR_R_MALLOC_FAILURE); |
282 | return (NULL); | |
283 | } | |
284 | ret->flags = BN_FLG_MALLOCED; | |
0f113f3e MC |
285 | bn_check_top(ret); |
286 | return (ret); | |
287 | } | |
d02b48c6 | 288 | |
74924dcb RS |
289 | BIGNUM *BN_secure_new(void) |
290 | { | |
291 | BIGNUM *ret = BN_new(); | |
90945fa3 | 292 | if (ret != NULL) |
74924dcb RS |
293 | ret->flags |= BN_FLG_SECURE; |
294 | return (ret); | |
295 | } | |
296 | ||
8707e3be | 297 | /* This is used by bn_expand2() */ |
020fc820 | 298 | /* The caller MUST check that words > b->dmax before calling this */ |
6343829a | 299 | static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) |
0f113f3e MC |
300 | { |
301 | BN_ULONG *A, *a = NULL; | |
302 | const BN_ULONG *B; | |
303 | int i; | |
304 | ||
305 | bn_check_top(b); | |
306 | ||
307 | if (words > (INT_MAX / (4 * BN_BITS2))) { | |
308 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG); | |
309 | return NULL; | |
310 | } | |
311 | if (BN_get_flags(b, BN_FLG_STATIC_DATA)) { | |
312 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); | |
313 | return (NULL); | |
314 | } | |
74924dcb | 315 | if (BN_get_flags(b,BN_FLG_SECURE)) |
d8ca44ba | 316 | a = A = OPENSSL_secure_zalloc(words * sizeof(*a)); |
74924dcb | 317 | else |
d8ca44ba | 318 | a = A = OPENSSL_zalloc(words * sizeof(*a)); |
0f113f3e MC |
319 | if (A == NULL) { |
320 | BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE); | |
321 | return (NULL); | |
322 | } | |
f8571ce8 | 323 | |
dfeab068 | 324 | #if 1 |
0f113f3e MC |
325 | B = b->d; |
326 | /* Check if the previous number needs to be copied */ | |
327 | if (B != NULL) { | |
328 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
329 | /* | |
330 | * The fact that the loop is unrolled | |
331 | * 4-wise is a tribute to Intel. It's | |
332 | * the one that doesn't have enough | |
0d4fb843 | 333 | * registers to accommodate more data. |
0f113f3e MC |
334 | * I'd unroll it 8-wise otherwise:-) |
335 | * | |
336 | * <appro@fy.chalmers.se> | |
337 | */ | |
338 | BN_ULONG a0, a1, a2, a3; | |
339 | a0 = B[0]; | |
340 | a1 = B[1]; | |
341 | a2 = B[2]; | |
342 | a3 = B[3]; | |
343 | A[0] = a0; | |
344 | A[1] = a1; | |
345 | A[2] = a2; | |
346 | A[3] = a3; | |
347 | } | |
348 | /* | |
349 | * workaround for ultrix cc: without 'case 0', the optimizer does | |
350 | * the switch table by doing a=top&3; a--; goto jump_table[a]; | |
351 | * which fails for top== 0 | |
352 | */ | |
353 | switch (b->top & 3) { | |
354 | case 3: | |
355 | A[2] = B[2]; | |
356 | case 2: | |
357 | A[1] = B[1]; | |
358 | case 1: | |
359 | A[0] = B[0]; | |
360 | case 0: | |
361 | ; | |
362 | } | |
363 | } | |
dfeab068 | 364 | #else |
16f8d4eb | 365 | memset(A, 0, sizeof(*A) * words); |
0f113f3e | 366 | memcpy(A, b->d, sizeof(b->d[0]) * b->top); |
dfeab068 | 367 | #endif |
dfeab068 | 368 | |
0f113f3e MC |
369 | return (a); |
370 | } | |
371 | ||
372 | /* | |
373 | * This is an internal function that should not be used in applications. It | |
374 | * ensures that 'b' has enough room for a 'words' word number and initialises | |
375 | * any unused part of b->d with leading zeros. It is mostly used by the | |
376 | * various BIGNUM routines. If there is an error, NULL is returned. If not, | |
377 | * 'b' is returned. | |
378 | */ | |
020fc820 | 379 | |
6343829a | 380 | BIGNUM *bn_expand2(BIGNUM *b, int words) |
0f113f3e MC |
381 | { |
382 | bn_check_top(b); | |
383 | ||
384 | if (words > b->dmax) { | |
385 | BN_ULONG *a = bn_expand_internal(b, words); | |
386 | if (!a) | |
387 | return NULL; | |
74924dcb | 388 | if (b->d) { |
9f040d6d RS |
389 | OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0])); |
390 | bn_free_d(b); | |
74924dcb | 391 | } |
0f113f3e MC |
392 | b->d = a; |
393 | b->dmax = words; | |
394 | } | |
2bfd2c74 | 395 | |
0f113f3e MC |
396 | bn_check_top(b); |
397 | return b; | |
398 | } | |
d02b48c6 | 399 | |
84c15db5 | 400 | BIGNUM *BN_dup(const BIGNUM *a) |
0f113f3e MC |
401 | { |
402 | BIGNUM *t; | |
403 | ||
404 | if (a == NULL) | |
405 | return NULL; | |
406 | bn_check_top(a); | |
407 | ||
74924dcb | 408 | t = BN_get_flags(a, BN_FLG_SECURE) ? BN_secure_new() : BN_new(); |
0f113f3e MC |
409 | if (t == NULL) |
410 | return NULL; | |
411 | if (!BN_copy(t, a)) { | |
412 | BN_free(t); | |
413 | return NULL; | |
414 | } | |
415 | bn_check_top(t); | |
416 | return t; | |
417 | } | |
d02b48c6 | 418 | |
84c15db5 | 419 | BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
420 | { |
421 | int i; | |
422 | BN_ULONG *A; | |
423 | const BN_ULONG *B; | |
58964a49 | 424 | |
0f113f3e | 425 | bn_check_top(b); |
dfeab068 | 426 | |
0f113f3e MC |
427 | if (a == b) |
428 | return (a); | |
429 | if (bn_wexpand(a, b->top) == NULL) | |
430 | return (NULL); | |
58964a49 RE |
431 | |
432 | #if 1 | |
0f113f3e MC |
433 | A = a->d; |
434 | B = b->d; | |
435 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
436 | BN_ULONG a0, a1, a2, a3; | |
437 | a0 = B[0]; | |
438 | a1 = B[1]; | |
439 | a2 = B[2]; | |
440 | a3 = B[3]; | |
441 | A[0] = a0; | |
442 | A[1] = a1; | |
443 | A[2] = a2; | |
444 | A[3] = a3; | |
445 | } | |
446 | /* ultrix cc workaround, see comments in bn_expand_internal */ | |
447 | switch (b->top & 3) { | |
448 | case 3: | |
449 | A[2] = B[2]; | |
450 | case 2: | |
451 | A[1] = B[1]; | |
452 | case 1: | |
453 | A[0] = B[0]; | |
454 | case 0:; | |
455 | } | |
58964a49 | 456 | #else |
0f113f3e | 457 | memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); |
58964a49 RE |
458 | #endif |
459 | ||
0f113f3e MC |
460 | a->top = b->top; |
461 | a->neg = b->neg; | |
462 | bn_check_top(a); | |
463 | return (a); | |
464 | } | |
d02b48c6 | 465 | |
78a0c1f1 | 466 | void BN_swap(BIGNUM *a, BIGNUM *b) |
0f113f3e MC |
467 | { |
468 | int flags_old_a, flags_old_b; | |
469 | BN_ULONG *tmp_d; | |
470 | int tmp_top, tmp_dmax, tmp_neg; | |
471 | ||
472 | bn_check_top(a); | |
473 | bn_check_top(b); | |
474 | ||
475 | flags_old_a = a->flags; | |
476 | flags_old_b = b->flags; | |
477 | ||
478 | tmp_d = a->d; | |
479 | tmp_top = a->top; | |
480 | tmp_dmax = a->dmax; | |
481 | tmp_neg = a->neg; | |
482 | ||
483 | a->d = b->d; | |
484 | a->top = b->top; | |
485 | a->dmax = b->dmax; | |
486 | a->neg = b->neg; | |
487 | ||
488 | b->d = tmp_d; | |
489 | b->top = tmp_top; | |
490 | b->dmax = tmp_dmax; | |
491 | b->neg = tmp_neg; | |
492 | ||
493 | a->flags = | |
494 | (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); | |
495 | b->flags = | |
496 | (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); | |
497 | bn_check_top(a); | |
498 | bn_check_top(b); | |
499 | } | |
78a0c1f1 | 500 | |
6b691a5c | 501 | void BN_clear(BIGNUM *a) |
0f113f3e MC |
502 | { |
503 | bn_check_top(a); | |
504 | if (a->d != NULL) | |
16f8d4eb | 505 | memset(a->d, 0, sizeof(*a->d) * a->dmax); |
0f113f3e MC |
506 | a->top = 0; |
507 | a->neg = 0; | |
508 | } | |
d02b48c6 | 509 | |
020fc820 | 510 | BN_ULONG BN_get_word(const BIGNUM *a) |
0f113f3e MC |
511 | { |
512 | if (a->top > 1) | |
513 | return BN_MASK2; | |
514 | else if (a->top == 1) | |
515 | return a->d[0]; | |
516 | /* a->top == 0 */ | |
517 | return 0; | |
518 | } | |
d02b48c6 | 519 | |
e042540f | 520 | int BN_set_word(BIGNUM *a, BN_ULONG w) |
0f113f3e MC |
521 | { |
522 | bn_check_top(a); | |
523 | if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL) | |
524 | return (0); | |
525 | a->neg = 0; | |
526 | a->d[0] = w; | |
527 | a->top = (w ? 1 : 0); | |
528 | bn_check_top(a); | |
529 | return (1); | |
530 | } | |
d02b48c6 | 531 | |
6343829a | 532 | BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) |
0f113f3e MC |
533 | { |
534 | unsigned int i, m; | |
535 | unsigned int n; | |
536 | BN_ULONG l; | |
537 | BIGNUM *bn = NULL; | |
538 | ||
539 | if (ret == NULL) | |
540 | ret = bn = BN_new(); | |
541 | if (ret == NULL) | |
542 | return (NULL); | |
543 | bn_check_top(ret); | |
22dc08d0 | 544 | /* Skip leading zero's. */ |
3c65047d | 545 | for ( ; len > 0 && *s == 0; s++, len--) |
22dc08d0 | 546 | continue; |
0f113f3e MC |
547 | n = len; |
548 | if (n == 0) { | |
549 | ret->top = 0; | |
550 | return (ret); | |
551 | } | |
552 | i = ((n - 1) / BN_BYTES) + 1; | |
553 | m = ((n - 1) % (BN_BYTES)); | |
554 | if (bn_wexpand(ret, (int)i) == NULL) { | |
23a1d5e9 | 555 | BN_free(bn); |
0f113f3e MC |
556 | return NULL; |
557 | } | |
558 | ret->top = i; | |
559 | ret->neg = 0; | |
22dc08d0 | 560 | l = 0; |
0f113f3e MC |
561 | while (n--) { |
562 | l = (l << 8L) | *(s++); | |
563 | if (m-- == 0) { | |
564 | ret->d[--i] = l; | |
565 | l = 0; | |
566 | m = BN_BYTES - 1; | |
567 | } | |
568 | } | |
569 | /* | |
570 | * need to call this due to clear byte at top if avoiding having the top | |
571 | * bit set (-ve number) | |
572 | */ | |
573 | bn_correct_top(ret); | |
574 | return (ret); | |
575 | } | |
d02b48c6 RE |
576 | |
577 | /* ignore negative */ | |
85a4807f | 578 | static int bn2binpad(const BIGNUM *a, unsigned char *to, int tolen) |
0f113f3e | 579 | { |
85a4807f | 580 | int i; |
0f113f3e MC |
581 | BN_ULONG l; |
582 | ||
583 | bn_check_top(a); | |
85a4807f DSH |
584 | i = BN_num_bytes(a); |
585 | if (tolen == -1) | |
586 | tolen = i; | |
587 | else if (tolen < i) | |
588 | return -1; | |
589 | /* Add leading zeroes if necessary */ | |
590 | if (tolen > i) { | |
591 | memset(to, 0, tolen - i); | |
592 | to += tolen - i; | |
593 | } | |
0f113f3e MC |
594 | while (i--) { |
595 | l = a->d[i / BN_BYTES]; | |
596 | *(to++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; | |
597 | } | |
85a4807f DSH |
598 | return tolen; |
599 | } | |
600 | ||
601 | int BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen) | |
602 | { | |
603 | if (tolen < 0) | |
604 | return -1; | |
605 | return bn2binpad(a, to, tolen); | |
606 | } | |
607 | ||
608 | int BN_bn2bin(const BIGNUM *a, unsigned char *to) | |
609 | { | |
610 | return bn2binpad(a, to, -1); | |
611 | } | |
612 | ||
613 | BIGNUM *BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret) | |
614 | { | |
615 | unsigned int i, m; | |
616 | unsigned int n; | |
617 | BN_ULONG l; | |
618 | BIGNUM *bn = NULL; | |
619 | ||
620 | if (ret == NULL) | |
621 | ret = bn = BN_new(); | |
622 | if (ret == NULL) | |
623 | return (NULL); | |
624 | bn_check_top(ret); | |
625 | s += len - 1; | |
626 | /* Skip trailing zeroes. */ | |
627 | for ( ; len > 0 && *s == 0; s--, len--) | |
628 | continue; | |
629 | n = len; | |
630 | if (n == 0) { | |
631 | ret->top = 0; | |
632 | return ret; | |
633 | } | |
634 | i = ((n - 1) / BN_BYTES) + 1; | |
635 | m = ((n - 1) % (BN_BYTES)); | |
636 | if (bn_wexpand(ret, (int)i) == NULL) { | |
637 | BN_free(bn); | |
638 | return NULL; | |
639 | } | |
640 | ret->top = i; | |
641 | ret->neg = 0; | |
642 | l = 0; | |
643 | while (n--) { | |
644 | l = (l << 8L) | *(s--); | |
645 | if (m-- == 0) { | |
646 | ret->d[--i] = l; | |
647 | l = 0; | |
648 | m = BN_BYTES - 1; | |
649 | } | |
650 | } | |
651 | /* | |
652 | * need to call this due to clear byte at top if avoiding having the top | |
653 | * bit set (-ve number) | |
654 | */ | |
655 | bn_correct_top(ret); | |
656 | return ret; | |
657 | } | |
658 | ||
659 | int BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen) | |
660 | { | |
661 | int i; | |
662 | BN_ULONG l; | |
663 | bn_check_top(a); | |
664 | i = BN_num_bytes(a); | |
665 | if (tolen < i) | |
666 | return -1; | |
667 | /* Add trailing zeroes if necessary */ | |
668 | if (tolen > i) | |
669 | memset(to + i, 0, tolen - i); | |
670 | to += i - 1; | |
671 | while (i--) { | |
672 | l = a->d[i / BN_BYTES]; | |
673 | *(to--) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; | |
674 | } | |
675 | return tolen; | |
0f113f3e | 676 | } |
d02b48c6 | 677 | |
84c15db5 | 678 | int BN_ucmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
679 | { |
680 | int i; | |
681 | BN_ULONG t1, t2, *ap, *bp; | |
682 | ||
683 | bn_check_top(a); | |
684 | bn_check_top(b); | |
685 | ||
686 | i = a->top - b->top; | |
687 | if (i != 0) | |
688 | return (i); | |
689 | ap = a->d; | |
690 | bp = b->d; | |
691 | for (i = a->top - 1; i >= 0; i--) { | |
692 | t1 = ap[i]; | |
693 | t2 = bp[i]; | |
694 | if (t1 != t2) | |
695 | return ((t1 > t2) ? 1 : -1); | |
696 | } | |
697 | return (0); | |
698 | } | |
d02b48c6 | 699 | |
84c15db5 | 700 | int BN_cmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
701 | { |
702 | int i; | |
703 | int gt, lt; | |
704 | BN_ULONG t1, t2; | |
705 | ||
706 | if ((a == NULL) || (b == NULL)) { | |
707 | if (a != NULL) | |
708 | return (-1); | |
709 | else if (b != NULL) | |
710 | return (1); | |
711 | else | |
712 | return (0); | |
713 | } | |
714 | ||
715 | bn_check_top(a); | |
716 | bn_check_top(b); | |
717 | ||
718 | if (a->neg != b->neg) { | |
719 | if (a->neg) | |
720 | return (-1); | |
721 | else | |
722 | return (1); | |
723 | } | |
724 | if (a->neg == 0) { | |
725 | gt = 1; | |
726 | lt = -1; | |
727 | } else { | |
728 | gt = -1; | |
729 | lt = 1; | |
730 | } | |
731 | ||
732 | if (a->top > b->top) | |
733 | return (gt); | |
734 | if (a->top < b->top) | |
735 | return (lt); | |
736 | for (i = a->top - 1; i >= 0; i--) { | |
737 | t1 = a->d[i]; | |
738 | t2 = b->d[i]; | |
739 | if (t1 > t2) | |
740 | return (gt); | |
741 | if (t1 < t2) | |
742 | return (lt); | |
743 | } | |
744 | return (0); | |
745 | } | |
d02b48c6 | 746 | |
6b691a5c | 747 | int BN_set_bit(BIGNUM *a, int n) |
0f113f3e MC |
748 | { |
749 | int i, j, k; | |
750 | ||
751 | if (n < 0) | |
752 | return 0; | |
753 | ||
754 | i = n / BN_BITS2; | |
755 | j = n % BN_BITS2; | |
756 | if (a->top <= i) { | |
757 | if (bn_wexpand(a, i + 1) == NULL) | |
758 | return (0); | |
759 | for (k = a->top; k < i + 1; k++) | |
760 | a->d[k] = 0; | |
761 | a->top = i + 1; | |
762 | } | |
763 | ||
764 | a->d[i] |= (((BN_ULONG)1) << j); | |
765 | bn_check_top(a); | |
766 | return (1); | |
767 | } | |
d02b48c6 | 768 | |
6b691a5c | 769 | int BN_clear_bit(BIGNUM *a, int n) |
0f113f3e MC |
770 | { |
771 | int i, j; | |
d02b48c6 | 772 | |
0f113f3e MC |
773 | bn_check_top(a); |
774 | if (n < 0) | |
775 | return 0; | |
1a017330 | 776 | |
0f113f3e MC |
777 | i = n / BN_BITS2; |
778 | j = n % BN_BITS2; | |
779 | if (a->top <= i) | |
780 | return (0); | |
d02b48c6 | 781 | |
0f113f3e MC |
782 | a->d[i] &= (~(((BN_ULONG)1) << j)); |
783 | bn_correct_top(a); | |
784 | return (1); | |
785 | } | |
d02b48c6 | 786 | |
84c15db5 | 787 | int BN_is_bit_set(const BIGNUM *a, int n) |
0f113f3e MC |
788 | { |
789 | int i, j; | |
790 | ||
791 | bn_check_top(a); | |
792 | if (n < 0) | |
793 | return 0; | |
794 | i = n / BN_BITS2; | |
795 | j = n % BN_BITS2; | |
796 | if (a->top <= i) | |
797 | return 0; | |
798 | return (int)(((a->d[i]) >> j) & ((BN_ULONG)1)); | |
799 | } | |
d02b48c6 | 800 | |
6b691a5c | 801 | int BN_mask_bits(BIGNUM *a, int n) |
0f113f3e MC |
802 | { |
803 | int b, w; | |
804 | ||
805 | bn_check_top(a); | |
806 | if (n < 0) | |
807 | return 0; | |
808 | ||
809 | w = n / BN_BITS2; | |
810 | b = n % BN_BITS2; | |
811 | if (w >= a->top) | |
812 | return 0; | |
813 | if (b == 0) | |
814 | a->top = w; | |
815 | else { | |
816 | a->top = w + 1; | |
817 | a->d[w] &= ~(BN_MASK2 << b); | |
818 | } | |
819 | bn_correct_top(a); | |
820 | return (1); | |
821 | } | |
dfeab068 | 822 | |
ff22e913 | 823 | void BN_set_negative(BIGNUM *a, int b) |
0f113f3e MC |
824 | { |
825 | if (b && !BN_is_zero(a)) | |
826 | a->neg = 1; | |
827 | else | |
828 | a->neg = 0; | |
829 | } | |
ff22e913 | 830 | |
cbd48ba6 | 831 | int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) |
0f113f3e MC |
832 | { |
833 | int i; | |
834 | BN_ULONG aa, bb; | |
835 | ||
836 | aa = a[n - 1]; | |
837 | bb = b[n - 1]; | |
838 | if (aa != bb) | |
839 | return ((aa > bb) ? 1 : -1); | |
840 | for (i = n - 2; i >= 0; i--) { | |
841 | aa = a[i]; | |
842 | bb = b[i]; | |
843 | if (aa != bb) | |
844 | return ((aa > bb) ? 1 : -1); | |
845 | } | |
846 | return (0); | |
847 | } | |
848 | ||
849 | /* | |
850 | * Here follows a specialised variants of bn_cmp_words(). It has the | |
851 | * property of performing the operation on arrays of different sizes. The | |
852 | * sizes of those arrays is expressed through cl, which is the common length | |
853 | * ( basicall, min(len(a),len(b)) ), and dl, which is the delta between the | |
854 | * two lengths, calculated as len(a)-len(b). All lengths are the number of | |
855 | * BN_ULONGs... | |
856 | */ | |
857 | ||
858 | int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl) | |
859 | { | |
860 | int n, i; | |
861 | n = cl - 1; | |
862 | ||
863 | if (dl < 0) { | |
864 | for (i = dl; i < 0; i++) { | |
865 | if (b[n - i] != 0) | |
866 | return -1; /* a < b */ | |
867 | } | |
868 | } | |
869 | if (dl > 0) { | |
870 | for (i = dl; i > 0; i--) { | |
871 | if (a[n + i] != 0) | |
872 | return 1; /* a > b */ | |
873 | } | |
874 | } | |
875 | return bn_cmp_words(a, b, cl); | |
876 | } | |
877 | ||
878 | /* | |
879 | * Constant-time conditional swap of a and b. | |
f9b6c0ba DSH |
880 | * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. |
881 | * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, | |
882 | * and that no more than nwords are used by either a or b. | |
883 | * a and b cannot be the same number | |
884 | */ | |
885 | void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) | |
0f113f3e MC |
886 | { |
887 | BN_ULONG t; | |
888 | int i; | |
f9b6c0ba | 889 | |
0f113f3e MC |
890 | bn_wcheck_size(a, nwords); |
891 | bn_wcheck_size(b, nwords); | |
f9b6c0ba | 892 | |
0f113f3e MC |
893 | assert(a != b); |
894 | assert((condition & (condition - 1)) == 0); | |
895 | assert(sizeof(BN_ULONG) >= sizeof(int)); | |
f9b6c0ba | 896 | |
0f113f3e | 897 | condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; |
f9b6c0ba | 898 | |
0f113f3e MC |
899 | t = (a->top ^ b->top) & condition; |
900 | a->top ^= t; | |
901 | b->top ^= t; | |
f9b6c0ba DSH |
902 | |
903 | #define BN_CONSTTIME_SWAP(ind) \ | |
0f113f3e MC |
904 | do { \ |
905 | t = (a->d[ind] ^ b->d[ind]) & condition; \ | |
906 | a->d[ind] ^= t; \ | |
907 | b->d[ind] ^= t; \ | |
908 | } while (0) | |
909 | ||
910 | switch (nwords) { | |
911 | default: | |
912 | for (i = 10; i < nwords; i++) | |
913 | BN_CONSTTIME_SWAP(i); | |
914 | /* Fallthrough */ | |
915 | case 10: | |
916 | BN_CONSTTIME_SWAP(9); /* Fallthrough */ | |
917 | case 9: | |
918 | BN_CONSTTIME_SWAP(8); /* Fallthrough */ | |
919 | case 8: | |
920 | BN_CONSTTIME_SWAP(7); /* Fallthrough */ | |
921 | case 7: | |
922 | BN_CONSTTIME_SWAP(6); /* Fallthrough */ | |
923 | case 6: | |
924 | BN_CONSTTIME_SWAP(5); /* Fallthrough */ | |
925 | case 5: | |
926 | BN_CONSTTIME_SWAP(4); /* Fallthrough */ | |
927 | case 4: | |
928 | BN_CONSTTIME_SWAP(3); /* Fallthrough */ | |
929 | case 3: | |
930 | BN_CONSTTIME_SWAP(2); /* Fallthrough */ | |
931 | case 2: | |
932 | BN_CONSTTIME_SWAP(1); /* Fallthrough */ | |
933 | case 1: | |
934 | BN_CONSTTIME_SWAP(0); | |
935 | } | |
f9b6c0ba DSH |
936 | #undef BN_CONSTTIME_SWAP |
937 | } | |
2514fa79 DSH |
938 | |
939 | /* Bits of security, see SP800-57 */ | |
940 | ||
941 | int BN_security_bits(int L, int N) | |
0f113f3e MC |
942 | { |
943 | int secbits, bits; | |
944 | if (L >= 15360) | |
945 | secbits = 256; | |
946 | else if (L >= 7690) | |
947 | secbits = 192; | |
948 | else if (L >= 3072) | |
949 | secbits = 128; | |
950 | else if (L >= 2048) | |
951 | secbits = 112; | |
952 | else if (L >= 1024) | |
953 | secbits = 80; | |
954 | else | |
955 | return 0; | |
956 | if (N == -1) | |
957 | return secbits; | |
958 | bits = N / 2; | |
959 | if (bits < 80) | |
960 | return 0; | |
961 | return bits >= secbits ? secbits : bits; | |
962 | } | |
85bcf27c MC |
963 | |
964 | void BN_zero_ex(BIGNUM *a) | |
0f113f3e MC |
965 | { |
966 | a->top = 0; | |
967 | a->neg = 0; | |
968 | } | |
85bcf27c MC |
969 | |
970 | int BN_abs_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
971 | { |
972 | return ((a->top == 1) && (a->d[0] == w)) || ((w == 0) && (a->top == 0)); | |
973 | } | |
85bcf27c MC |
974 | |
975 | int BN_is_zero(const BIGNUM *a) | |
0f113f3e MC |
976 | { |
977 | return a->top == 0; | |
978 | } | |
85bcf27c MC |
979 | |
980 | int BN_is_one(const BIGNUM *a) | |
0f113f3e MC |
981 | { |
982 | return BN_abs_is_word(a, 1) && !a->neg; | |
983 | } | |
85bcf27c MC |
984 | |
985 | int BN_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
986 | { |
987 | return BN_abs_is_word(a, w) && (!w || !a->neg); | |
988 | } | |
85bcf27c MC |
989 | |
990 | int BN_is_odd(const BIGNUM *a) | |
0f113f3e MC |
991 | { |
992 | return (a->top > 0) && (a->d[0] & 1); | |
993 | } | |
85bcf27c MC |
994 | |
995 | int BN_is_negative(const BIGNUM *a) | |
0f113f3e MC |
996 | { |
997 | return (a->neg != 0); | |
998 | } | |
85bcf27c | 999 | |
0f113f3e MC |
1000 | int BN_to_montgomery(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont, |
1001 | BN_CTX *ctx) | |
1002 | { | |
1003 | return BN_mod_mul_montgomery(r, a, &(mont->RR), mont, ctx); | |
1004 | } | |
85bcf27c | 1005 | |
fd7d2520 | 1006 | void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags) |
0f113f3e MC |
1007 | { |
1008 | dest->d = b->d; | |
1009 | dest->top = b->top; | |
1010 | dest->dmax = b->dmax; | |
1011 | dest->neg = b->neg; | |
1012 | dest->flags = ((dest->flags & BN_FLG_MALLOCED) | |
1013 | | (b->flags & ~BN_FLG_MALLOCED) | |
fd7d2520 | 1014 | | BN_FLG_STATIC_DATA | flags); |
0f113f3e | 1015 | } |
85bcf27c MC |
1016 | |
1017 | BN_GENCB *BN_GENCB_new(void) | |
0f113f3e MC |
1018 | { |
1019 | BN_GENCB *ret; | |
85bcf27c | 1020 | |
b4faea50 | 1021 | if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) { |
0f113f3e MC |
1022 | BNerr(BN_F_BN_GENCB_NEW, ERR_R_MALLOC_FAILURE); |
1023 | return (NULL); | |
1024 | } | |
85bcf27c | 1025 | |
0f113f3e MC |
1026 | return ret; |
1027 | } | |
85bcf27c MC |
1028 | |
1029 | void BN_GENCB_free(BN_GENCB *cb) | |
0f113f3e MC |
1030 | { |
1031 | if (cb == NULL) | |
1032 | return; | |
1033 | OPENSSL_free(cb); | |
1034 | } | |
85bcf27c MC |
1035 | |
1036 | void BN_set_flags(BIGNUM *b, int n) | |
0f113f3e MC |
1037 | { |
1038 | b->flags |= n; | |
1039 | } | |
85bcf27c MC |
1040 | |
1041 | int BN_get_flags(const BIGNUM *b, int n) | |
0f113f3e MC |
1042 | { |
1043 | return b->flags & n; | |
1044 | } | |
85bcf27c MC |
1045 | |
1046 | /* Populate a BN_GENCB structure with an "old"-style callback */ | |
0f113f3e MC |
1047 | void BN_GENCB_set_old(BN_GENCB *gencb, void (*callback) (int, int, void *), |
1048 | void *cb_arg) | |
1049 | { | |
1050 | BN_GENCB *tmp_gencb = gencb; | |
1051 | tmp_gencb->ver = 1; | |
1052 | tmp_gencb->arg = cb_arg; | |
1053 | tmp_gencb->cb.cb_1 = callback; | |
1054 | } | |
85bcf27c MC |
1055 | |
1056 | /* Populate a BN_GENCB structure with a "new"-style callback */ | |
0f113f3e MC |
1057 | void BN_GENCB_set(BN_GENCB *gencb, int (*callback) (int, int, BN_GENCB *), |
1058 | void *cb_arg) | |
1059 | { | |
1060 | BN_GENCB *tmp_gencb = gencb; | |
1061 | tmp_gencb->ver = 2; | |
1062 | tmp_gencb->arg = cb_arg; | |
1063 | tmp_gencb->cb.cb_2 = callback; | |
1064 | } | |
85bcf27c MC |
1065 | |
1066 | void *BN_GENCB_get_arg(BN_GENCB *cb) | |
0f113f3e MC |
1067 | { |
1068 | return cb->arg; | |
1069 | } | |
85bcf27c MC |
1070 | |
1071 | BIGNUM *bn_wexpand(BIGNUM *a, int words) | |
0f113f3e MC |
1072 | { |
1073 | return (words <= a->dmax) ? a : bn_expand2(a, words); | |
1074 | } | |
85bcf27c MC |
1075 | |
1076 | void bn_correct_top(BIGNUM *a) | |
0f113f3e MC |
1077 | { |
1078 | BN_ULONG *ftl; | |
1079 | int tmp_top = a->top; | |
1080 | ||
1081 | if (tmp_top > 0) { | |
1082 | for (ftl = &(a->d[tmp_top - 1]); tmp_top > 0; tmp_top--) | |
1083 | if (*(ftl--)) | |
1084 | break; | |
1085 | a->top = tmp_top; | |
1086 | } | |
1087 | bn_pollute(a); | |
1088 | } |