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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 | ||
0f113f3e | 69 | const char BN_version[] = "Big Number" OPENSSL_VERSION_PTEXT; |
dfeab068 | 70 | |
df11e1e9 GT |
71 | /* This stuff appears to be completely unused, so is deprecated */ |
72 | #ifndef OPENSSL_NO_DEPRECATED | |
1d97c843 TH |
73 | /*- |
74 | * For a 32 bit machine | |
dfeab068 RE |
75 | * 2 - 4 == 128 |
76 | * 3 - 8 == 256 | |
77 | * 4 - 16 == 512 | |
78 | * 5 - 32 == 1024 | |
79 | * 6 - 64 == 2048 | |
80 | * 7 - 128 == 4096 | |
81 | * 8 - 256 == 8192 | |
82 | */ | |
0f113f3e MC |
83 | static int bn_limit_bits = 0; |
84 | static int bn_limit_num = 8; /* (1<<bn_limit_bits) */ | |
85 | static int bn_limit_bits_low = 0; | |
86 | static int bn_limit_num_low = 8; /* (1<<bn_limit_bits_low) */ | |
87 | static int bn_limit_bits_high = 0; | |
88 | static int bn_limit_num_high = 8; /* (1<<bn_limit_bits_high) */ | |
89 | static int bn_limit_bits_mont = 0; | |
90 | static int bn_limit_num_mont = 8; /* (1<<bn_limit_bits_mont) */ | |
dfeab068 | 91 | |
6b691a5c | 92 | void BN_set_params(int mult, int high, int low, int mont) |
0f113f3e MC |
93 | { |
94 | if (mult >= 0) { | |
95 | if (mult > (int)(sizeof(int) * 8) - 1) | |
96 | mult = sizeof(int) * 8 - 1; | |
97 | bn_limit_bits = mult; | |
98 | bn_limit_num = 1 << mult; | |
99 | } | |
100 | if (high >= 0) { | |
101 | if (high > (int)(sizeof(int) * 8) - 1) | |
102 | high = sizeof(int) * 8 - 1; | |
103 | bn_limit_bits_high = high; | |
104 | bn_limit_num_high = 1 << high; | |
105 | } | |
106 | if (low >= 0) { | |
107 | if (low > (int)(sizeof(int) * 8) - 1) | |
108 | low = sizeof(int) * 8 - 1; | |
109 | bn_limit_bits_low = low; | |
110 | bn_limit_num_low = 1 << low; | |
111 | } | |
112 | if (mont >= 0) { | |
113 | if (mont > (int)(sizeof(int) * 8) - 1) | |
114 | mont = sizeof(int) * 8 - 1; | |
115 | bn_limit_bits_mont = mont; | |
116 | bn_limit_num_mont = 1 << mont; | |
117 | } | |
118 | } | |
dfeab068 | 119 | |
6b691a5c | 120 | int BN_get_params(int which) |
0f113f3e MC |
121 | { |
122 | if (which == 0) | |
123 | return (bn_limit_bits); | |
124 | else if (which == 1) | |
125 | return (bn_limit_bits_high); | |
126 | else if (which == 2) | |
127 | return (bn_limit_bits_low); | |
128 | else if (which == 3) | |
129 | return (bn_limit_bits_mont); | |
130 | else | |
131 | return (0); | |
132 | } | |
df11e1e9 | 133 | #endif |
d02b48c6 | 134 | |
98499135 | 135 | const BIGNUM *BN_value_one(void) |
0f113f3e MC |
136 | { |
137 | static const BN_ULONG data_one = 1L; | |
138 | static const BIGNUM const_one = | |
139 | { (BN_ULONG *)&data_one, 1, 1, 0, BN_FLG_STATIC_DATA }; | |
d02b48c6 | 140 | |
0f113f3e MC |
141 | return (&const_one); |
142 | } | |
d02b48c6 | 143 | |
6b691a5c | 144 | int BN_num_bits_word(BN_ULONG l) |
0f113f3e MC |
145 | { |
146 | static const unsigned char bits[256] = { | |
147 | 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, | |
148 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
149 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
150 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
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 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
154 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
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 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
162 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, | |
163 | }; | |
d02b48c6 | 164 | |
dfeab068 | 165 | #if defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
166 | if (l & 0xffffffff00000000L) { |
167 | if (l & 0xffff000000000000L) { | |
168 | if (l & 0xff00000000000000L) { | |
169 | return (bits[(int)(l >> 56)] + 56); | |
170 | } else | |
171 | return (bits[(int)(l >> 48)] + 48); | |
172 | } else { | |
173 | if (l & 0x0000ff0000000000L) { | |
174 | return (bits[(int)(l >> 40)] + 40); | |
175 | } else | |
176 | return (bits[(int)(l >> 32)] + 32); | |
177 | } | |
178 | } else | |
d02b48c6 | 179 | #else |
0f113f3e MC |
180 | # ifdef SIXTY_FOUR_BIT |
181 | if (l & 0xffffffff00000000LL) { | |
182 | if (l & 0xffff000000000000LL) { | |
183 | if (l & 0xff00000000000000LL) { | |
184 | return (bits[(int)(l >> 56)] + 56); | |
185 | } else | |
186 | return (bits[(int)(l >> 48)] + 48); | |
187 | } else { | |
188 | if (l & 0x0000ff0000000000LL) { | |
189 | return (bits[(int)(l >> 40)] + 40); | |
190 | } else | |
191 | return (bits[(int)(l >> 32)] + 32); | |
192 | } | |
193 | } else | |
194 | # endif | |
d02b48c6 | 195 | #endif |
0f113f3e | 196 | { |
d02b48c6 | 197 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
198 | if (l & 0xffff0000L) { |
199 | if (l & 0xff000000L) | |
200 | return (bits[(int)(l >> 24L)] + 24); | |
201 | else | |
202 | return (bits[(int)(l >> 16L)] + 16); | |
203 | } else | |
d02b48c6 | 204 | #endif |
0f113f3e | 205 | { |
4a47f556 | 206 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
0f113f3e MC |
207 | if (l & 0xff00L) |
208 | return (bits[(int)(l >> 8)] + 8); | |
209 | else | |
d02b48c6 | 210 | #endif |
0f113f3e MC |
211 | return (bits[(int)(l)]); |
212 | } | |
213 | } | |
214 | } | |
d02b48c6 | 215 | |
84c15db5 | 216 | int BN_num_bits(const BIGNUM *a) |
0f113f3e MC |
217 | { |
218 | int i = a->top - 1; | |
219 | bn_check_top(a); | |
dfeab068 | 220 | |
0f113f3e MC |
221 | if (BN_is_zero(a)) |
222 | return 0; | |
223 | return ((i * BN_BITS2) + BN_num_bits_word(a->d[i])); | |
224 | } | |
d02b48c6 | 225 | |
6b691a5c | 226 | void BN_clear_free(BIGNUM *a) |
0f113f3e MC |
227 | { |
228 | int i; | |
229 | ||
230 | if (a == NULL) | |
231 | return; | |
232 | bn_check_top(a); | |
233 | if (a->d != NULL) { | |
234 | OPENSSL_cleanse(a->d, a->dmax * sizeof(a->d[0])); | |
74924dcb RS |
235 | if (!(BN_get_flags(a, BN_FLG_STATIC_DATA))) { |
236 | if (BN_get_flags(a,BN_FLG_SECURE)) | |
237 | OPENSSL_secure_free(a->d); | |
238 | else | |
239 | OPENSSL_free(a->d); | |
240 | } | |
0f113f3e MC |
241 | } |
242 | i = BN_get_flags(a, BN_FLG_MALLOCED); | |
243 | OPENSSL_cleanse(a, sizeof(BIGNUM)); | |
244 | if (i) | |
245 | OPENSSL_free(a); | |
246 | } | |
d02b48c6 | 247 | |
6b691a5c | 248 | void BN_free(BIGNUM *a) |
0f113f3e MC |
249 | { |
250 | if (a == NULL) | |
251 | return; | |
252 | bn_check_top(a); | |
b548a1f1 | 253 | if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) |
74924dcb RS |
254 | if ((a->d != NULL) && !(BN_get_flags(a, BN_FLG_STATIC_DATA))) { |
255 | if (BN_get_flags(a, BN_FLG_SECURE)) | |
256 | OPENSSL_secure_free(a->d); | |
257 | else | |
258 | OPENSSL_free(a->d); | |
259 | } | |
0f113f3e MC |
260 | if (a->flags & BN_FLG_MALLOCED) |
261 | OPENSSL_free(a); | |
262 | else { | |
21933811 | 263 | #ifndef OPENSSL_NO_DEPRECATED |
0f113f3e | 264 | a->flags |= BN_FLG_FREE; |
2ae1ea37 | 265 | #endif |
0f113f3e MC |
266 | a->d = NULL; |
267 | } | |
268 | } | |
dfeab068 | 269 | |
6b691a5c | 270 | void BN_init(BIGNUM *a) |
0f113f3e | 271 | { |
16f8d4eb | 272 | memset(a, 0, sizeof(*a)); |
0f113f3e MC |
273 | bn_check_top(a); |
274 | } | |
d02b48c6 | 275 | |
6b691a5c | 276 | BIGNUM *BN_new(void) |
0f113f3e MC |
277 | { |
278 | BIGNUM *ret; | |
279 | ||
b4faea50 | 280 | if ((ret = OPENSSL_malloc(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; | |
285 | ret->top = 0; | |
286 | ret->neg = 0; | |
287 | ret->dmax = 0; | |
288 | ret->d = NULL; | |
289 | bn_check_top(ret); | |
290 | return (ret); | |
291 | } | |
d02b48c6 | 292 | |
74924dcb RS |
293 | BIGNUM *BN_secure_new(void) |
294 | { | |
295 | BIGNUM *ret = BN_new(); | |
296 | if (ret) | |
297 | ret->flags |= BN_FLG_SECURE; | |
298 | return (ret); | |
299 | } | |
300 | ||
020fc820 RL |
301 | /* This is used both by bn_expand2() and bn_dup_expand() */ |
302 | /* The caller MUST check that words > b->dmax before calling this */ | |
6343829a | 303 | static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) |
0f113f3e MC |
304 | { |
305 | BN_ULONG *A, *a = NULL; | |
306 | const BN_ULONG *B; | |
307 | int i; | |
308 | ||
309 | bn_check_top(b); | |
310 | ||
311 | if (words > (INT_MAX / (4 * BN_BITS2))) { | |
312 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG); | |
313 | return NULL; | |
314 | } | |
315 | if (BN_get_flags(b, BN_FLG_STATIC_DATA)) { | |
316 | BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); | |
317 | return (NULL); | |
318 | } | |
74924dcb RS |
319 | if (BN_get_flags(b,BN_FLG_SECURE)) |
320 | a = A = OPENSSL_secure_malloc(words * sizeof(*a)); | |
321 | else | |
322 | a = A = OPENSSL_malloc(words * sizeof(*a)); | |
0f113f3e MC |
323 | if (A == NULL) { |
324 | BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE); | |
325 | return (NULL); | |
326 | } | |
f8571ce8 | 327 | #ifdef PURIFY |
0f113f3e MC |
328 | /* |
329 | * Valgrind complains in BN_consttime_swap because we process the whole | |
330 | * array even if it's not initialised yet. This doesn't matter in that | |
331 | * function - what's important is constant time operation (we're not | |
332 | * actually going to use the data) | |
333 | */ | |
16f8d4eb | 334 | memset(a, 0, sizeof(*a) * words); |
f8571ce8 MC |
335 | #endif |
336 | ||
dfeab068 | 337 | #if 1 |
0f113f3e MC |
338 | B = b->d; |
339 | /* Check if the previous number needs to be copied */ | |
340 | if (B != NULL) { | |
341 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
342 | /* | |
343 | * The fact that the loop is unrolled | |
344 | * 4-wise is a tribute to Intel. It's | |
345 | * the one that doesn't have enough | |
346 | * registers to accomodate more data. | |
347 | * I'd unroll it 8-wise otherwise:-) | |
348 | * | |
349 | * <appro@fy.chalmers.se> | |
350 | */ | |
351 | BN_ULONG a0, a1, a2, a3; | |
352 | a0 = B[0]; | |
353 | a1 = B[1]; | |
354 | a2 = B[2]; | |
355 | a3 = B[3]; | |
356 | A[0] = a0; | |
357 | A[1] = a1; | |
358 | A[2] = a2; | |
359 | A[3] = a3; | |
360 | } | |
361 | /* | |
362 | * workaround for ultrix cc: without 'case 0', the optimizer does | |
363 | * the switch table by doing a=top&3; a--; goto jump_table[a]; | |
364 | * which fails for top== 0 | |
365 | */ | |
366 | switch (b->top & 3) { | |
367 | case 3: | |
368 | A[2] = B[2]; | |
369 | case 2: | |
370 | A[1] = B[1]; | |
371 | case 1: | |
372 | A[0] = B[0]; | |
373 | case 0: | |
374 | ; | |
375 | } | |
376 | } | |
dfeab068 | 377 | #else |
16f8d4eb | 378 | memset(A, 0, sizeof(*A) * words); |
0f113f3e | 379 | memcpy(A, b->d, sizeof(b->d[0]) * b->top); |
dfeab068 | 380 | #endif |
dfeab068 | 381 | |
0f113f3e MC |
382 | return (a); |
383 | } | |
384 | ||
385 | /* | |
386 | * This is an internal function that should not be used in applications. It | |
387 | * ensures that 'b' has enough room for a 'words' word number and initialises | |
388 | * any unused part of b->d with leading zeros. It is mostly used by the | |
389 | * various BIGNUM routines. If there is an error, NULL is returned. If not, | |
390 | * 'b' is returned. | |
391 | */ | |
020fc820 | 392 | |
6343829a | 393 | BIGNUM *bn_expand2(BIGNUM *b, int words) |
0f113f3e MC |
394 | { |
395 | bn_check_top(b); | |
396 | ||
397 | if (words > b->dmax) { | |
398 | BN_ULONG *a = bn_expand_internal(b, words); | |
399 | if (!a) | |
400 | return NULL; | |
74924dcb RS |
401 | if (b->d) { |
402 | if (BN_get_flags(b,BN_FLG_SECURE)) | |
403 | OPENSSL_secure_free(b->d); | |
404 | else | |
405 | OPENSSL_free(b->d); | |
406 | } | |
0f113f3e MC |
407 | b->d = a; |
408 | b->dmax = words; | |
409 | } | |
2bfd2c74 | 410 | |
0f113f3e MC |
411 | bn_check_top(b); |
412 | return b; | |
413 | } | |
d02b48c6 | 414 | |
84c15db5 | 415 | BIGNUM *BN_dup(const BIGNUM *a) |
0f113f3e MC |
416 | { |
417 | BIGNUM *t; | |
418 | ||
419 | if (a == NULL) | |
420 | return NULL; | |
421 | bn_check_top(a); | |
422 | ||
74924dcb | 423 | t = BN_get_flags(a, BN_FLG_SECURE) ? BN_secure_new() : BN_new(); |
0f113f3e MC |
424 | if (t == NULL) |
425 | return NULL; | |
426 | if (!BN_copy(t, a)) { | |
427 | BN_free(t); | |
428 | return NULL; | |
429 | } | |
430 | bn_check_top(t); | |
431 | return t; | |
432 | } | |
d02b48c6 | 433 | |
84c15db5 | 434 | BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
435 | { |
436 | int i; | |
437 | BN_ULONG *A; | |
438 | const BN_ULONG *B; | |
58964a49 | 439 | |
0f113f3e | 440 | bn_check_top(b); |
dfeab068 | 441 | |
0f113f3e MC |
442 | if (a == b) |
443 | return (a); | |
444 | if (bn_wexpand(a, b->top) == NULL) | |
445 | return (NULL); | |
58964a49 RE |
446 | |
447 | #if 1 | |
0f113f3e MC |
448 | A = a->d; |
449 | B = b->d; | |
450 | for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) { | |
451 | BN_ULONG a0, a1, a2, a3; | |
452 | a0 = B[0]; | |
453 | a1 = B[1]; | |
454 | a2 = B[2]; | |
455 | a3 = B[3]; | |
456 | A[0] = a0; | |
457 | A[1] = a1; | |
458 | A[2] = a2; | |
459 | A[3] = a3; | |
460 | } | |
461 | /* ultrix cc workaround, see comments in bn_expand_internal */ | |
462 | switch (b->top & 3) { | |
463 | case 3: | |
464 | A[2] = B[2]; | |
465 | case 2: | |
466 | A[1] = B[1]; | |
467 | case 1: | |
468 | A[0] = B[0]; | |
469 | case 0:; | |
470 | } | |
58964a49 | 471 | #else |
0f113f3e | 472 | memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); |
58964a49 RE |
473 | #endif |
474 | ||
0f113f3e MC |
475 | a->top = b->top; |
476 | a->neg = b->neg; | |
477 | bn_check_top(a); | |
478 | return (a); | |
479 | } | |
d02b48c6 | 480 | |
78a0c1f1 | 481 | void BN_swap(BIGNUM *a, BIGNUM *b) |
0f113f3e MC |
482 | { |
483 | int flags_old_a, flags_old_b; | |
484 | BN_ULONG *tmp_d; | |
485 | int tmp_top, tmp_dmax, tmp_neg; | |
486 | ||
487 | bn_check_top(a); | |
488 | bn_check_top(b); | |
489 | ||
490 | flags_old_a = a->flags; | |
491 | flags_old_b = b->flags; | |
492 | ||
493 | tmp_d = a->d; | |
494 | tmp_top = a->top; | |
495 | tmp_dmax = a->dmax; | |
496 | tmp_neg = a->neg; | |
497 | ||
498 | a->d = b->d; | |
499 | a->top = b->top; | |
500 | a->dmax = b->dmax; | |
501 | a->neg = b->neg; | |
502 | ||
503 | b->d = tmp_d; | |
504 | b->top = tmp_top; | |
505 | b->dmax = tmp_dmax; | |
506 | b->neg = tmp_neg; | |
507 | ||
508 | a->flags = | |
509 | (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); | |
510 | b->flags = | |
511 | (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); | |
512 | bn_check_top(a); | |
513 | bn_check_top(b); | |
514 | } | |
78a0c1f1 | 515 | |
6b691a5c | 516 | void BN_clear(BIGNUM *a) |
0f113f3e MC |
517 | { |
518 | bn_check_top(a); | |
519 | if (a->d != NULL) | |
16f8d4eb | 520 | memset(a->d, 0, sizeof(*a->d) * a->dmax); |
0f113f3e MC |
521 | a->top = 0; |
522 | a->neg = 0; | |
523 | } | |
d02b48c6 | 524 | |
020fc820 | 525 | BN_ULONG BN_get_word(const BIGNUM *a) |
0f113f3e MC |
526 | { |
527 | if (a->top > 1) | |
528 | return BN_MASK2; | |
529 | else if (a->top == 1) | |
530 | return a->d[0]; | |
531 | /* a->top == 0 */ | |
532 | return 0; | |
533 | } | |
d02b48c6 | 534 | |
e042540f | 535 | int BN_set_word(BIGNUM *a, BN_ULONG w) |
0f113f3e MC |
536 | { |
537 | bn_check_top(a); | |
538 | if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL) | |
539 | return (0); | |
540 | a->neg = 0; | |
541 | a->d[0] = w; | |
542 | a->top = (w ? 1 : 0); | |
543 | bn_check_top(a); | |
544 | return (1); | |
545 | } | |
d02b48c6 | 546 | |
6343829a | 547 | BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) |
0f113f3e MC |
548 | { |
549 | unsigned int i, m; | |
550 | unsigned int n; | |
551 | BN_ULONG l; | |
552 | BIGNUM *bn = NULL; | |
553 | ||
554 | if (ret == NULL) | |
555 | ret = bn = BN_new(); | |
556 | if (ret == NULL) | |
557 | return (NULL); | |
558 | bn_check_top(ret); | |
559 | l = 0; | |
560 | n = len; | |
561 | if (n == 0) { | |
562 | ret->top = 0; | |
563 | return (ret); | |
564 | } | |
565 | i = ((n - 1) / BN_BYTES) + 1; | |
566 | m = ((n - 1) % (BN_BYTES)); | |
567 | if (bn_wexpand(ret, (int)i) == NULL) { | |
23a1d5e9 | 568 | BN_free(bn); |
0f113f3e MC |
569 | return NULL; |
570 | } | |
571 | ret->top = i; | |
572 | ret->neg = 0; | |
573 | while (n--) { | |
574 | l = (l << 8L) | *(s++); | |
575 | if (m-- == 0) { | |
576 | ret->d[--i] = l; | |
577 | l = 0; | |
578 | m = BN_BYTES - 1; | |
579 | } | |
580 | } | |
581 | /* | |
582 | * need to call this due to clear byte at top if avoiding having the top | |
583 | * bit set (-ve number) | |
584 | */ | |
585 | bn_correct_top(ret); | |
586 | return (ret); | |
587 | } | |
d02b48c6 RE |
588 | |
589 | /* ignore negative */ | |
8623f693 | 590 | int BN_bn2bin(const BIGNUM *a, unsigned char *to) |
0f113f3e MC |
591 | { |
592 | int n, i; | |
593 | BN_ULONG l; | |
594 | ||
595 | bn_check_top(a); | |
596 | n = i = BN_num_bytes(a); | |
597 | while (i--) { | |
598 | l = a->d[i / BN_BYTES]; | |
599 | *(to++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; | |
600 | } | |
601 | return (n); | |
602 | } | |
d02b48c6 | 603 | |
84c15db5 | 604 | int BN_ucmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
605 | { |
606 | int i; | |
607 | BN_ULONG t1, t2, *ap, *bp; | |
608 | ||
609 | bn_check_top(a); | |
610 | bn_check_top(b); | |
611 | ||
612 | i = a->top - b->top; | |
613 | if (i != 0) | |
614 | return (i); | |
615 | ap = a->d; | |
616 | bp = b->d; | |
617 | for (i = a->top - 1; i >= 0; i--) { | |
618 | t1 = ap[i]; | |
619 | t2 = bp[i]; | |
620 | if (t1 != t2) | |
621 | return ((t1 > t2) ? 1 : -1); | |
622 | } | |
623 | return (0); | |
624 | } | |
d02b48c6 | 625 | |
84c15db5 | 626 | int BN_cmp(const BIGNUM *a, const BIGNUM *b) |
0f113f3e MC |
627 | { |
628 | int i; | |
629 | int gt, lt; | |
630 | BN_ULONG t1, t2; | |
631 | ||
632 | if ((a == NULL) || (b == NULL)) { | |
633 | if (a != NULL) | |
634 | return (-1); | |
635 | else if (b != NULL) | |
636 | return (1); | |
637 | else | |
638 | return (0); | |
639 | } | |
640 | ||
641 | bn_check_top(a); | |
642 | bn_check_top(b); | |
643 | ||
644 | if (a->neg != b->neg) { | |
645 | if (a->neg) | |
646 | return (-1); | |
647 | else | |
648 | return (1); | |
649 | } | |
650 | if (a->neg == 0) { | |
651 | gt = 1; | |
652 | lt = -1; | |
653 | } else { | |
654 | gt = -1; | |
655 | lt = 1; | |
656 | } | |
657 | ||
658 | if (a->top > b->top) | |
659 | return (gt); | |
660 | if (a->top < b->top) | |
661 | return (lt); | |
662 | for (i = a->top - 1; i >= 0; i--) { | |
663 | t1 = a->d[i]; | |
664 | t2 = b->d[i]; | |
665 | if (t1 > t2) | |
666 | return (gt); | |
667 | if (t1 < t2) | |
668 | return (lt); | |
669 | } | |
670 | return (0); | |
671 | } | |
d02b48c6 | 672 | |
6b691a5c | 673 | int BN_set_bit(BIGNUM *a, int n) |
0f113f3e MC |
674 | { |
675 | int i, j, k; | |
676 | ||
677 | if (n < 0) | |
678 | return 0; | |
679 | ||
680 | i = n / BN_BITS2; | |
681 | j = n % BN_BITS2; | |
682 | if (a->top <= i) { | |
683 | if (bn_wexpand(a, i + 1) == NULL) | |
684 | return (0); | |
685 | for (k = a->top; k < i + 1; k++) | |
686 | a->d[k] = 0; | |
687 | a->top = i + 1; | |
688 | } | |
689 | ||
690 | a->d[i] |= (((BN_ULONG)1) << j); | |
691 | bn_check_top(a); | |
692 | return (1); | |
693 | } | |
d02b48c6 | 694 | |
6b691a5c | 695 | int BN_clear_bit(BIGNUM *a, int n) |
0f113f3e MC |
696 | { |
697 | int i, j; | |
d02b48c6 | 698 | |
0f113f3e MC |
699 | bn_check_top(a); |
700 | if (n < 0) | |
701 | return 0; | |
1a017330 | 702 | |
0f113f3e MC |
703 | i = n / BN_BITS2; |
704 | j = n % BN_BITS2; | |
705 | if (a->top <= i) | |
706 | return (0); | |
d02b48c6 | 707 | |
0f113f3e MC |
708 | a->d[i] &= (~(((BN_ULONG)1) << j)); |
709 | bn_correct_top(a); | |
710 | return (1); | |
711 | } | |
d02b48c6 | 712 | |
84c15db5 | 713 | int BN_is_bit_set(const BIGNUM *a, int n) |
0f113f3e MC |
714 | { |
715 | int i, j; | |
716 | ||
717 | bn_check_top(a); | |
718 | if (n < 0) | |
719 | return 0; | |
720 | i = n / BN_BITS2; | |
721 | j = n % BN_BITS2; | |
722 | if (a->top <= i) | |
723 | return 0; | |
724 | return (int)(((a->d[i]) >> j) & ((BN_ULONG)1)); | |
725 | } | |
d02b48c6 | 726 | |
6b691a5c | 727 | int BN_mask_bits(BIGNUM *a, int n) |
0f113f3e MC |
728 | { |
729 | int b, w; | |
730 | ||
731 | bn_check_top(a); | |
732 | if (n < 0) | |
733 | return 0; | |
734 | ||
735 | w = n / BN_BITS2; | |
736 | b = n % BN_BITS2; | |
737 | if (w >= a->top) | |
738 | return 0; | |
739 | if (b == 0) | |
740 | a->top = w; | |
741 | else { | |
742 | a->top = w + 1; | |
743 | a->d[w] &= ~(BN_MASK2 << b); | |
744 | } | |
745 | bn_correct_top(a); | |
746 | return (1); | |
747 | } | |
dfeab068 | 748 | |
ff22e913 | 749 | void BN_set_negative(BIGNUM *a, int b) |
0f113f3e MC |
750 | { |
751 | if (b && !BN_is_zero(a)) | |
752 | a->neg = 1; | |
753 | else | |
754 | a->neg = 0; | |
755 | } | |
ff22e913 | 756 | |
cbd48ba6 | 757 | int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) |
0f113f3e MC |
758 | { |
759 | int i; | |
760 | BN_ULONG aa, bb; | |
761 | ||
762 | aa = a[n - 1]; | |
763 | bb = b[n - 1]; | |
764 | if (aa != bb) | |
765 | return ((aa > bb) ? 1 : -1); | |
766 | for (i = n - 2; i >= 0; i--) { | |
767 | aa = a[i]; | |
768 | bb = b[i]; | |
769 | if (aa != bb) | |
770 | return ((aa > bb) ? 1 : -1); | |
771 | } | |
772 | return (0); | |
773 | } | |
774 | ||
775 | /* | |
776 | * Here follows a specialised variants of bn_cmp_words(). It has the | |
777 | * property of performing the operation on arrays of different sizes. The | |
778 | * sizes of those arrays is expressed through cl, which is the common length | |
779 | * ( basicall, min(len(a),len(b)) ), and dl, which is the delta between the | |
780 | * two lengths, calculated as len(a)-len(b). All lengths are the number of | |
781 | * BN_ULONGs... | |
782 | */ | |
783 | ||
784 | int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl) | |
785 | { | |
786 | int n, i; | |
787 | n = cl - 1; | |
788 | ||
789 | if (dl < 0) { | |
790 | for (i = dl; i < 0; i++) { | |
791 | if (b[n - i] != 0) | |
792 | return -1; /* a < b */ | |
793 | } | |
794 | } | |
795 | if (dl > 0) { | |
796 | for (i = dl; i > 0; i--) { | |
797 | if (a[n + i] != 0) | |
798 | return 1; /* a > b */ | |
799 | } | |
800 | } | |
801 | return bn_cmp_words(a, b, cl); | |
802 | } | |
803 | ||
804 | /* | |
805 | * Constant-time conditional swap of a and b. | |
f9b6c0ba DSH |
806 | * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. |
807 | * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, | |
808 | * and that no more than nwords are used by either a or b. | |
809 | * a and b cannot be the same number | |
810 | */ | |
811 | void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) | |
0f113f3e MC |
812 | { |
813 | BN_ULONG t; | |
814 | int i; | |
f9b6c0ba | 815 | |
0f113f3e MC |
816 | bn_wcheck_size(a, nwords); |
817 | bn_wcheck_size(b, nwords); | |
f9b6c0ba | 818 | |
0f113f3e MC |
819 | assert(a != b); |
820 | assert((condition & (condition - 1)) == 0); | |
821 | assert(sizeof(BN_ULONG) >= sizeof(int)); | |
f9b6c0ba | 822 | |
0f113f3e | 823 | condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; |
f9b6c0ba | 824 | |
0f113f3e MC |
825 | t = (a->top ^ b->top) & condition; |
826 | a->top ^= t; | |
827 | b->top ^= t; | |
f9b6c0ba DSH |
828 | |
829 | #define BN_CONSTTIME_SWAP(ind) \ | |
0f113f3e MC |
830 | do { \ |
831 | t = (a->d[ind] ^ b->d[ind]) & condition; \ | |
832 | a->d[ind] ^= t; \ | |
833 | b->d[ind] ^= t; \ | |
834 | } while (0) | |
835 | ||
836 | switch (nwords) { | |
837 | default: | |
838 | for (i = 10; i < nwords; i++) | |
839 | BN_CONSTTIME_SWAP(i); | |
840 | /* Fallthrough */ | |
841 | case 10: | |
842 | BN_CONSTTIME_SWAP(9); /* Fallthrough */ | |
843 | case 9: | |
844 | BN_CONSTTIME_SWAP(8); /* Fallthrough */ | |
845 | case 8: | |
846 | BN_CONSTTIME_SWAP(7); /* Fallthrough */ | |
847 | case 7: | |
848 | BN_CONSTTIME_SWAP(6); /* Fallthrough */ | |
849 | case 6: | |
850 | BN_CONSTTIME_SWAP(5); /* Fallthrough */ | |
851 | case 5: | |
852 | BN_CONSTTIME_SWAP(4); /* Fallthrough */ | |
853 | case 4: | |
854 | BN_CONSTTIME_SWAP(3); /* Fallthrough */ | |
855 | case 3: | |
856 | BN_CONSTTIME_SWAP(2); /* Fallthrough */ | |
857 | case 2: | |
858 | BN_CONSTTIME_SWAP(1); /* Fallthrough */ | |
859 | case 1: | |
860 | BN_CONSTTIME_SWAP(0); | |
861 | } | |
f9b6c0ba DSH |
862 | #undef BN_CONSTTIME_SWAP |
863 | } | |
2514fa79 DSH |
864 | |
865 | /* Bits of security, see SP800-57 */ | |
866 | ||
867 | int BN_security_bits(int L, int N) | |
0f113f3e MC |
868 | { |
869 | int secbits, bits; | |
870 | if (L >= 15360) | |
871 | secbits = 256; | |
872 | else if (L >= 7690) | |
873 | secbits = 192; | |
874 | else if (L >= 3072) | |
875 | secbits = 128; | |
876 | else if (L >= 2048) | |
877 | secbits = 112; | |
878 | else if (L >= 1024) | |
879 | secbits = 80; | |
880 | else | |
881 | return 0; | |
882 | if (N == -1) | |
883 | return secbits; | |
884 | bits = N / 2; | |
885 | if (bits < 80) | |
886 | return 0; | |
887 | return bits >= secbits ? secbits : bits; | |
888 | } | |
85bcf27c MC |
889 | |
890 | void BN_zero_ex(BIGNUM *a) | |
0f113f3e MC |
891 | { |
892 | a->top = 0; | |
893 | a->neg = 0; | |
894 | } | |
85bcf27c MC |
895 | |
896 | int BN_abs_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
897 | { |
898 | return ((a->top == 1) && (a->d[0] == w)) || ((w == 0) && (a->top == 0)); | |
899 | } | |
85bcf27c MC |
900 | |
901 | int BN_is_zero(const BIGNUM *a) | |
0f113f3e MC |
902 | { |
903 | return a->top == 0; | |
904 | } | |
85bcf27c MC |
905 | |
906 | int BN_is_one(const BIGNUM *a) | |
0f113f3e MC |
907 | { |
908 | return BN_abs_is_word(a, 1) && !a->neg; | |
909 | } | |
85bcf27c MC |
910 | |
911 | int BN_is_word(const BIGNUM *a, const BN_ULONG w) | |
0f113f3e MC |
912 | { |
913 | return BN_abs_is_word(a, w) && (!w || !a->neg); | |
914 | } | |
85bcf27c MC |
915 | |
916 | int BN_is_odd(const BIGNUM *a) | |
0f113f3e MC |
917 | { |
918 | return (a->top > 0) && (a->d[0] & 1); | |
919 | } | |
85bcf27c MC |
920 | |
921 | int BN_is_negative(const BIGNUM *a) | |
0f113f3e MC |
922 | { |
923 | return (a->neg != 0); | |
924 | } | |
85bcf27c | 925 | |
0f113f3e MC |
926 | int BN_to_montgomery(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont, |
927 | BN_CTX *ctx) | |
928 | { | |
929 | return BN_mod_mul_montgomery(r, a, &(mont->RR), mont, ctx); | |
930 | } | |
85bcf27c MC |
931 | |
932 | void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int n) | |
0f113f3e MC |
933 | { |
934 | dest->d = b->d; | |
935 | dest->top = b->top; | |
936 | dest->dmax = b->dmax; | |
937 | dest->neg = b->neg; | |
938 | dest->flags = ((dest->flags & BN_FLG_MALLOCED) | |
939 | | (b->flags & ~BN_FLG_MALLOCED) | |
940 | | BN_FLG_STATIC_DATA | n); | |
941 | } | |
85bcf27c MC |
942 | |
943 | BN_GENCB *BN_GENCB_new(void) | |
0f113f3e MC |
944 | { |
945 | BN_GENCB *ret; | |
85bcf27c | 946 | |
b4faea50 | 947 | if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) { |
0f113f3e MC |
948 | BNerr(BN_F_BN_GENCB_NEW, ERR_R_MALLOC_FAILURE); |
949 | return (NULL); | |
950 | } | |
85bcf27c | 951 | |
0f113f3e MC |
952 | return ret; |
953 | } | |
85bcf27c MC |
954 | |
955 | void BN_GENCB_free(BN_GENCB *cb) | |
0f113f3e MC |
956 | { |
957 | if (cb == NULL) | |
958 | return; | |
959 | OPENSSL_free(cb); | |
960 | } | |
85bcf27c MC |
961 | |
962 | void BN_set_flags(BIGNUM *b, int n) | |
0f113f3e MC |
963 | { |
964 | b->flags |= n; | |
965 | } | |
85bcf27c MC |
966 | |
967 | int BN_get_flags(const BIGNUM *b, int n) | |
0f113f3e MC |
968 | { |
969 | return b->flags & n; | |
970 | } | |
85bcf27c MC |
971 | |
972 | /* Populate a BN_GENCB structure with an "old"-style callback */ | |
0f113f3e MC |
973 | void BN_GENCB_set_old(BN_GENCB *gencb, void (*callback) (int, int, void *), |
974 | void *cb_arg) | |
975 | { | |
976 | BN_GENCB *tmp_gencb = gencb; | |
977 | tmp_gencb->ver = 1; | |
978 | tmp_gencb->arg = cb_arg; | |
979 | tmp_gencb->cb.cb_1 = callback; | |
980 | } | |
85bcf27c MC |
981 | |
982 | /* Populate a BN_GENCB structure with a "new"-style callback */ | |
0f113f3e MC |
983 | void BN_GENCB_set(BN_GENCB *gencb, int (*callback) (int, int, BN_GENCB *), |
984 | void *cb_arg) | |
985 | { | |
986 | BN_GENCB *tmp_gencb = gencb; | |
987 | tmp_gencb->ver = 2; | |
988 | tmp_gencb->arg = cb_arg; | |
989 | tmp_gencb->cb.cb_2 = callback; | |
990 | } | |
85bcf27c MC |
991 | |
992 | void *BN_GENCB_get_arg(BN_GENCB *cb) | |
0f113f3e MC |
993 | { |
994 | return cb->arg; | |
995 | } | |
85bcf27c MC |
996 | |
997 | BIGNUM *bn_wexpand(BIGNUM *a, int words) | |
0f113f3e MC |
998 | { |
999 | return (words <= a->dmax) ? a : bn_expand2(a, words); | |
1000 | } | |
85bcf27c MC |
1001 | |
1002 | void bn_correct_top(BIGNUM *a) | |
0f113f3e MC |
1003 | { |
1004 | BN_ULONG *ftl; | |
1005 | int tmp_top = a->top; | |
1006 | ||
1007 | if (tmp_top > 0) { | |
1008 | for (ftl = &(a->d[tmp_top - 1]); tmp_top > 0; tmp_top--) | |
1009 | if (*(ftl--)) | |
1010 | break; | |
1011 | a->top = tmp_top; | |
1012 | } | |
1013 | bn_pollute(a); | |
1014 | } |