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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. | |
8 | * | |
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). | |
15 | * | |
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. | |
22 | * | |
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 :-). | |
37 | * 4. If you include any Windows specific code (or a derivative thereof) from | |
38 | * the apps directory (application code) you must include an acknowledgement: | |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
40 | * | |
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. | |
52 | * | |
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 BM |
59 | #ifndef BN_DEBUG |
60 | # undef NDEBUG /* avoid conflicting definitions */ | |
61 | # define NDEBUG | |
62 | #endif | |
63 | ||
73e45b2d | 64 | |
7edfe674 | 65 | |
bbb8de09 | 66 | #include <assert.h> |
addb309a | 67 | #include <limits.h> |
d02b48c6 RE |
68 | #include "cryptlib.h" |
69 | #include "bn_lcl.h" | |
70 | ||
560b79cb | 71 | const char BN_version[]="Big Number" OPENSSL_VERSION_PTEXT; |
dfeab068 | 72 | |
df11e1e9 GT |
73 | /* This stuff appears to be completely unused, so is deprecated */ |
74 | #ifndef OPENSSL_NO_DEPRECATED | |
dfeab068 RE |
75 | /* For a 32 bit machine |
76 | * 2 - 4 == 128 | |
77 | * 3 - 8 == 256 | |
78 | * 4 - 16 == 512 | |
79 | * 5 - 32 == 1024 | |
80 | * 6 - 64 == 2048 | |
81 | * 7 - 128 == 4096 | |
82 | * 8 - 256 == 8192 | |
83 | */ | |
775c63fc UM |
84 | static int bn_limit_bits=0; |
85 | static int bn_limit_num=8; /* (1<<bn_limit_bits) */ | |
86 | static int bn_limit_bits_low=0; | |
87 | static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */ | |
88 | static int bn_limit_bits_high=0; | |
89 | static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */ | |
90 | static int bn_limit_bits_mont=0; | |
91 | static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */ | |
dfeab068 | 92 | |
6b691a5c | 93 | void BN_set_params(int mult, int high, int low, int mont) |
dfeab068 RE |
94 | { |
95 | if (mult >= 0) | |
96 | { | |
27545970 | 97 | if (mult > (int)(sizeof(int)*8)-1) |
dfeab068 RE |
98 | mult=sizeof(int)*8-1; |
99 | bn_limit_bits=mult; | |
100 | bn_limit_num=1<<mult; | |
101 | } | |
102 | if (high >= 0) | |
103 | { | |
27545970 | 104 | if (high > (int)(sizeof(int)*8)-1) |
dfeab068 RE |
105 | high=sizeof(int)*8-1; |
106 | bn_limit_bits_high=high; | |
107 | bn_limit_num_high=1<<high; | |
108 | } | |
109 | if (low >= 0) | |
110 | { | |
27545970 | 111 | if (low > (int)(sizeof(int)*8)-1) |
dfeab068 RE |
112 | low=sizeof(int)*8-1; |
113 | bn_limit_bits_low=low; | |
114 | bn_limit_num_low=1<<low; | |
115 | } | |
116 | if (mont >= 0) | |
117 | { | |
27545970 | 118 | if (mont > (int)(sizeof(int)*8)-1) |
dfeab068 RE |
119 | mont=sizeof(int)*8-1; |
120 | bn_limit_bits_mont=mont; | |
121 | bn_limit_num_mont=1<<mont; | |
122 | } | |
123 | } | |
124 | ||
6b691a5c | 125 | int BN_get_params(int which) |
dfeab068 RE |
126 | { |
127 | if (which == 0) return(bn_limit_bits); | |
128 | else if (which == 1) return(bn_limit_bits_high); | |
129 | else if (which == 2) return(bn_limit_bits_low); | |
130 | else if (which == 3) return(bn_limit_bits_mont); | |
131 | else return(0); | |
132 | } | |
df11e1e9 | 133 | #endif |
d02b48c6 | 134 | |
98499135 | 135 | const BIGNUM *BN_value_one(void) |
d02b48c6 | 136 | { |
f1455b30 AP |
137 | static const BN_ULONG data_one=1L; |
138 | static const BIGNUM const_one={(BN_ULONG *)&data_one,1,1,0,BN_FLG_STATIC_DATA}; | |
d02b48c6 RE |
139 | |
140 | return(&const_one); | |
141 | } | |
142 | ||
6b691a5c | 143 | int BN_num_bits_word(BN_ULONG l) |
d02b48c6 | 144 | { |
f1455b30 | 145 | static const unsigned char bits[256]={ |
d02b48c6 RE |
146 | 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4, |
147 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, | |
148 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, | |
149 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, | |
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 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, | |
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 | 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, | |
162 | }; | |
163 | ||
dfeab068 | 164 | #if defined(SIXTY_FOUR_BIT_LONG) |
d02b48c6 RE |
165 | if (l & 0xffffffff00000000L) |
166 | { | |
167 | if (l & 0xffff000000000000L) | |
168 | { | |
169 | if (l & 0xff00000000000000L) | |
170 | { | |
dfeab068 | 171 | return(bits[(int)(l>>56)]+56); |
d02b48c6 | 172 | } |
dfeab068 | 173 | else return(bits[(int)(l>>48)]+48); |
d02b48c6 RE |
174 | } |
175 | else | |
176 | { | |
177 | if (l & 0x0000ff0000000000L) | |
178 | { | |
dfeab068 | 179 | return(bits[(int)(l>>40)]+40); |
d02b48c6 | 180 | } |
dfeab068 | 181 | else return(bits[(int)(l>>32)]+32); |
d02b48c6 RE |
182 | } |
183 | } | |
184 | else | |
185 | #else | |
186 | #ifdef SIXTY_FOUR_BIT | |
187 | if (l & 0xffffffff00000000LL) | |
188 | { | |
189 | if (l & 0xffff000000000000LL) | |
190 | { | |
191 | if (l & 0xff00000000000000LL) | |
192 | { | |
dfeab068 | 193 | return(bits[(int)(l>>56)]+56); |
d02b48c6 | 194 | } |
dfeab068 | 195 | else return(bits[(int)(l>>48)]+48); |
d02b48c6 RE |
196 | } |
197 | else | |
198 | { | |
199 | if (l & 0x0000ff0000000000LL) | |
200 | { | |
dfeab068 | 201 | return(bits[(int)(l>>40)]+40); |
d02b48c6 | 202 | } |
dfeab068 | 203 | else return(bits[(int)(l>>32)]+32); |
d02b48c6 RE |
204 | } |
205 | } | |
206 | else | |
207 | #endif | |
208 | #endif | |
209 | { | |
210 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) | |
211 | if (l & 0xffff0000L) | |
212 | { | |
213 | if (l & 0xff000000L) | |
dfeab068 RE |
214 | return(bits[(int)(l>>24L)]+24); |
215 | else return(bits[(int)(l>>16L)]+16); | |
d02b48c6 RE |
216 | } |
217 | else | |
218 | #endif | |
219 | { | |
4a47f556 | 220 | #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
d02b48c6 | 221 | if (l & 0xff00L) |
dfeab068 | 222 | return(bits[(int)(l>>8)]+8); |
d02b48c6 RE |
223 | else |
224 | #endif | |
dfeab068 | 225 | return(bits[(int)(l )] ); |
d02b48c6 RE |
226 | } |
227 | } | |
228 | } | |
229 | ||
84c15db5 | 230 | int BN_num_bits(const BIGNUM *a) |
d02b48c6 | 231 | { |
2bfd2c74 | 232 | int i = a->top - 1; |
dfeab068 RE |
233 | bn_check_top(a); |
234 | ||
2bfd2c74 GT |
235 | if (BN_is_zero(a)) return 0; |
236 | return ((i*BN_BITS2) + BN_num_bits_word(a->d[i])); | |
d02b48c6 RE |
237 | } |
238 | ||
6b691a5c | 239 | void BN_clear_free(BIGNUM *a) |
d02b48c6 | 240 | { |
dfeab068 RE |
241 | int i; |
242 | ||
d02b48c6 | 243 | if (a == NULL) return; |
2bfd2c74 | 244 | bn_check_top(a); |
d02b48c6 RE |
245 | if (a->d != NULL) |
246 | { | |
43d60164 | 247 | OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0])); |
dfeab068 | 248 | if (!(BN_get_flags(a,BN_FLG_STATIC_DATA))) |
26a3a48d | 249 | OPENSSL_free(a->d); |
d02b48c6 | 250 | } |
dfeab068 | 251 | i=BN_get_flags(a,BN_FLG_MALLOCED); |
43d60164 | 252 | OPENSSL_cleanse(a,sizeof(BIGNUM)); |
dfeab068 | 253 | if (i) |
26a3a48d | 254 | OPENSSL_free(a); |
d02b48c6 RE |
255 | } |
256 | ||
6b691a5c | 257 | void BN_free(BIGNUM *a) |
d02b48c6 RE |
258 | { |
259 | if (a == NULL) return; | |
2bfd2c74 | 260 | bn_check_top(a); |
dfeab068 | 261 | if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA))) |
26a3a48d | 262 | OPENSSL_free(a->d); |
dfeab068 | 263 | if (a->flags & BN_FLG_MALLOCED) |
26a3a48d | 264 | OPENSSL_free(a); |
2ae1ea37 GT |
265 | else |
266 | { | |
267 | #ifndef OPENSSL_NO_DEPRECATED | |
268 | a->flags|=BN_FLG_FREE; | |
269 | #endif | |
270 | a->d = NULL; | |
271 | } | |
dfeab068 RE |
272 | } |
273 | ||
6b691a5c | 274 | void BN_init(BIGNUM *a) |
dfeab068 RE |
275 | { |
276 | memset(a,0,sizeof(BIGNUM)); | |
d870740c | 277 | bn_check_top(a); |
d02b48c6 RE |
278 | } |
279 | ||
6b691a5c | 280 | BIGNUM *BN_new(void) |
d02b48c6 RE |
281 | { |
282 | BIGNUM *ret; | |
d02b48c6 | 283 | |
26a3a48d | 284 | if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL) |
dfeab068 RE |
285 | { |
286 | BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE); | |
287 | return(NULL); | |
288 | } | |
289 | ret->flags=BN_FLG_MALLOCED; | |
d02b48c6 RE |
290 | ret->top=0; |
291 | ret->neg=0; | |
2d978cbd | 292 | ret->dmax=0; |
dfeab068 | 293 | ret->d=NULL; |
d870740c | 294 | bn_check_top(ret); |
d02b48c6 | 295 | return(ret); |
d02b48c6 RE |
296 | } |
297 | ||
020fc820 RL |
298 | /* This is used both by bn_expand2() and bn_dup_expand() */ |
299 | /* The caller MUST check that words > b->dmax before calling this */ | |
6343829a | 300 | static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) |
d02b48c6 | 301 | { |
020fc820 | 302 | BN_ULONG *A,*a = NULL; |
e14d4443 UM |
303 | const BN_ULONG *B; |
304 | int i; | |
dfeab068 | 305 | |
2bfd2c74 GT |
306 | bn_check_top(b); |
307 | ||
152a689c BM |
308 | if (words > (INT_MAX/(4*BN_BITS2))) |
309 | { | |
e5164b70 | 310 | BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG); |
152a689c BM |
311 | return NULL; |
312 | } | |
020fc820 | 313 | if (BN_get_flags(b,BN_FLG_STATIC_DATA)) |
d02b48c6 | 314 | { |
a08bcccc | 315 | BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); |
020fc820 RL |
316 | return(NULL); |
317 | } | |
e042540f | 318 | a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*words); |
020fc820 RL |
319 | if (A == NULL) |
320 | { | |
a08bcccc | 321 | BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE); |
020fc820 RL |
322 | return(NULL); |
323 | } | |
f8571ce8 MC |
324 | #ifdef PURIFY |
325 | /* Valgrind complains in BN_consttime_swap because we process the whole | |
326 | * array even if it's not initialised yet. This doesn't matter in that | |
327 | * function - what's important is constant time operation (we're not | |
328 | * actually going to use the data) | |
329 | */ | |
330 | memset(a, 0, sizeof(BN_ULONG)*words); | |
331 | #endif | |
332 | ||
dfeab068 | 333 | #if 1 |
020fc820 RL |
334 | B=b->d; |
335 | /* Check if the previous number needs to be copied */ | |
336 | if (B != NULL) | |
337 | { | |
020fc820 RL |
338 | for (i=b->top>>2; i>0; i--,A+=4,B+=4) |
339 | { | |
340 | /* | |
341 | * The fact that the loop is unrolled | |
342 | * 4-wise is a tribute to Intel. It's | |
343 | * the one that doesn't have enough | |
344 | * registers to accomodate more data. | |
345 | * I'd unroll it 8-wise otherwise:-) | |
346 | * | |
347 | * <appro@fy.chalmers.se> | |
348 | */ | |
349 | BN_ULONG a0,a1,a2,a3; | |
350 | a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; | |
351 | A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; | |
953937bd | 352 | } |
020fc820 | 353 | switch (b->top&3) |
953937bd | 354 | { |
020fc820 RL |
355 | case 3: A[2]=B[2]; |
356 | case 2: A[1]=B[1]; | |
357 | case 1: A[0]=B[0]; | |
a08bcccc BM |
358 | case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does |
359 | * the switch table by doing a=top&3; a--; goto jump_table[a]; | |
360 | * which fails for top== 0 */ | |
361 | ; | |
953937bd | 362 | } |
020fc820 RL |
363 | } |
364 | ||
dfeab068 | 365 | #else |
e042540f | 366 | memset(A,0,sizeof(BN_ULONG)*words); |
020fc820 | 367 | memcpy(A,b->d,sizeof(b->d[0])*b->top); |
dfeab068 RE |
368 | #endif |
369 | ||
020fc820 RL |
370 | return(a); |
371 | } | |
dfeab068 | 372 | |
020fc820 RL |
373 | /* This is an internal function that can be used instead of bn_expand2() |
374 | * when there is a need to copy BIGNUMs instead of only expanding the | |
375 | * data part, while still expanding them. | |
376 | * Especially useful when needing to expand BIGNUMs that are declared | |
377 | * 'const' and should therefore not be changed. | |
378 | * The reason to use this instead of a BN_dup() followed by a bn_expand2() | |
379 | * is memory allocation overhead. A BN_dup() followed by a bn_expand2() | |
380 | * will allocate new memory for the BIGNUM data twice, and free it once, | |
381 | * while bn_dup_expand() makes sure allocation is made only once. | |
382 | */ | |
383 | ||
e042540f | 384 | #ifndef OPENSSL_NO_DEPRECATED |
6343829a | 385 | BIGNUM *bn_dup_expand(const BIGNUM *b, int words) |
020fc820 RL |
386 | { |
387 | BIGNUM *r = NULL; | |
388 | ||
2bfd2c74 GT |
389 | bn_check_top(b); |
390 | ||
12593e6f BM |
391 | /* This function does not work if |
392 | * words <= b->dmax && top < words | |
393 | * because BN_dup() does not preserve 'dmax'! | |
394 | * (But bn_dup_expand() is not used anywhere yet.) | |
395 | */ | |
2bfd2c74 | 396 | |
020fc820 RL |
397 | if (words > b->dmax) |
398 | { | |
a08bcccc | 399 | BN_ULONG *a = bn_expand_internal(b, words); |
020fc820 RL |
400 | |
401 | if (a) | |
402 | { | |
403 | r = BN_new(); | |
58f0f52e BM |
404 | if (r) |
405 | { | |
406 | r->top = b->top; | |
407 | r->dmax = words; | |
408 | r->neg = b->neg; | |
409 | r->d = a; | |
410 | } | |
411 | else | |
412 | { | |
413 | /* r == NULL, BN_new failure */ | |
414 | OPENSSL_free(a); | |
415 | } | |
020fc820 | 416 | } |
58f0f52e | 417 | /* If a == NULL, there was an error in allocation in |
a08bcccc | 418 | bn_expand_internal(), and NULL should be returned */ |
020fc820 RL |
419 | } |
420 | else | |
421 | { | |
422 | r = BN_dup(b); | |
423 | } | |
424 | ||
d870740c | 425 | bn_check_top(r); |
020fc820 RL |
426 | return r; |
427 | } | |
e042540f | 428 | #endif |
020fc820 RL |
429 | |
430 | /* This is an internal function that should not be used in applications. | |
12593e6f | 431 | * It ensures that 'b' has enough room for a 'words' word number |
33d4e690 | 432 | * and initialises any unused part of b->d with leading zeros. |
020fc820 RL |
433 | * It is mostly used by the various BIGNUM routines. If there is an error, |
434 | * NULL is returned. If not, 'b' is returned. */ | |
435 | ||
6343829a | 436 | BIGNUM *bn_expand2(BIGNUM *b, int words) |
020fc820 | 437 | { |
2bfd2c74 GT |
438 | bn_check_top(b); |
439 | ||
020fc820 RL |
440 | if (words > b->dmax) |
441 | { | |
a08bcccc | 442 | BN_ULONG *a = bn_expand_internal(b, words); |
2bfd2c74 GT |
443 | if(!a) return NULL; |
444 | if(b->d) OPENSSL_free(b->d); | |
445 | b->d=a; | |
446 | b->dmax=words; | |
d02b48c6 | 447 | } |
2bfd2c74 | 448 | |
e042540f GT |
449 | /* None of this should be necessary because of what b->top means! */ |
450 | #if 0 | |
12593e6f | 451 | /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */ |
2bfd2c74 | 452 | if (b->top < b->dmax) |
12593e6f | 453 | { |
e042540f GT |
454 | int i; |
455 | BN_ULONG *A = &(b->d[b->top]); | |
18384774 | 456 | for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8) |
33d4e690 BM |
457 | { |
458 | A[0]=0; A[1]=0; A[2]=0; A[3]=0; | |
459 | A[4]=0; A[5]=0; A[6]=0; A[7]=0; | |
460 | } | |
18384774 | 461 | for (i=(b->dmax - b->top)&7; i>0; i--,A++) |
33d4e690 | 462 | A[0]=0; |
18384774 | 463 | assert(A == &(b->d[b->dmax])); |
12593e6f | 464 | } |
e042540f | 465 | #endif |
2bfd2c74 | 466 | bn_check_top(b); |
020fc820 | 467 | return b; |
d02b48c6 RE |
468 | } |
469 | ||
84c15db5 | 470 | BIGNUM *BN_dup(const BIGNUM *a) |
d02b48c6 | 471 | { |
2bfd2c74 | 472 | BIGNUM *t; |
d02b48c6 | 473 | |
8d85b33e | 474 | if (a == NULL) return NULL; |
dfeab068 RE |
475 | bn_check_top(a); |
476 | ||
e0bf5c11 | 477 | t = BN_new(); |
2bfd2c74 GT |
478 | if (t == NULL) return NULL; |
479 | if(!BN_copy(t, a)) | |
480 | { | |
e0bf5c11 | 481 | BN_free(t); |
2bfd2c74 GT |
482 | return NULL; |
483 | } | |
484 | bn_check_top(t); | |
485 | return t; | |
d02b48c6 RE |
486 | } |
487 | ||
84c15db5 | 488 | BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) |
d02b48c6 | 489 | { |
58964a49 | 490 | int i; |
e14d4443 UM |
491 | BN_ULONG *A; |
492 | const BN_ULONG *B; | |
58964a49 | 493 | |
dfeab068 RE |
494 | bn_check_top(b); |
495 | ||
58964a49 RE |
496 | if (a == b) return(a); |
497 | if (bn_wexpand(a,b->top) == NULL) return(NULL); | |
498 | ||
499 | #if 1 | |
500 | A=a->d; | |
501 | B=b->d; | |
e14d4443 | 502 | for (i=b->top>>2; i>0; i--,A+=4,B+=4) |
58964a49 | 503 | { |
e14d4443 UM |
504 | BN_ULONG a0,a1,a2,a3; |
505 | a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; | |
506 | A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; | |
58964a49 | 507 | } |
e14d4443 | 508 | switch (b->top&3) |
58964a49 | 509 | { |
e14d4443 UM |
510 | case 3: A[2]=B[2]; |
511 | case 2: A[1]=B[1]; | |
512 | case 1: A[0]=B[0]; | |
a08bcccc | 513 | case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */ |
58964a49 RE |
514 | } |
515 | #else | |
d02b48c6 | 516 | memcpy(a->d,b->d,sizeof(b->d[0])*b->top); |
58964a49 RE |
517 | #endif |
518 | ||
d02b48c6 RE |
519 | a->top=b->top; |
520 | a->neg=b->neg; | |
d870740c | 521 | bn_check_top(a); |
d02b48c6 RE |
522 | return(a); |
523 | } | |
524 | ||
78a0c1f1 BM |
525 | void BN_swap(BIGNUM *a, BIGNUM *b) |
526 | { | |
527 | int flags_old_a, flags_old_b; | |
528 | BN_ULONG *tmp_d; | |
529 | int tmp_top, tmp_dmax, tmp_neg; | |
530 | ||
657a9195 GT |
531 | bn_check_top(a); |
532 | bn_check_top(b); | |
533 | ||
78a0c1f1 BM |
534 | flags_old_a = a->flags; |
535 | flags_old_b = b->flags; | |
536 | ||
537 | tmp_d = a->d; | |
538 | tmp_top = a->top; | |
539 | tmp_dmax = a->dmax; | |
540 | tmp_neg = a->neg; | |
541 | ||
542 | a->d = b->d; | |
543 | a->top = b->top; | |
544 | a->dmax = b->dmax; | |
545 | a->neg = b->neg; | |
546 | ||
547 | b->d = tmp_d; | |
548 | b->top = tmp_top; | |
549 | b->dmax = tmp_dmax; | |
550 | b->neg = tmp_neg; | |
551 | ||
552 | a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); | |
553 | b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); | |
d870740c GT |
554 | bn_check_top(a); |
555 | bn_check_top(b); | |
78a0c1f1 BM |
556 | } |
557 | ||
6b691a5c | 558 | void BN_clear(BIGNUM *a) |
d02b48c6 | 559 | { |
657a9195 | 560 | bn_check_top(a); |
dfeab068 | 561 | if (a->d != NULL) |
2d978cbd | 562 | memset(a->d,0,a->dmax*sizeof(a->d[0])); |
d02b48c6 RE |
563 | a->top=0; |
564 | a->neg=0; | |
565 | } | |
566 | ||
020fc820 | 567 | BN_ULONG BN_get_word(const BIGNUM *a) |
d02b48c6 | 568 | { |
9088d5f2 GT |
569 | if (a->top > 1) |
570 | return BN_MASK2; | |
afbe74d3 | 571 | else if (a->top == 1) |
9088d5f2 | 572 | return a->d[0]; |
afbe74d3 GT |
573 | /* a->top == 0 */ |
574 | return 0; | |
d02b48c6 RE |
575 | } |
576 | ||
e042540f GT |
577 | int BN_set_word(BIGNUM *a, BN_ULONG w) |
578 | { | |
579 | bn_check_top(a); | |
580 | if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0); | |
581 | a->neg = 0; | |
582 | a->d[0] = w; | |
583 | a->top = (w ? 1 : 0); | |
584 | bn_check_top(a); | |
585 | return(1); | |
586 | } | |
d02b48c6 | 587 | |
6343829a | 588 | BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) |
d02b48c6 RE |
589 | { |
590 | unsigned int i,m; | |
591 | unsigned int n; | |
592 | BN_ULONG l; | |
d459e390 | 593 | BIGNUM *bn = NULL; |
d02b48c6 | 594 | |
d459e390 GT |
595 | if (ret == NULL) |
596 | ret = bn = BN_new(); | |
d02b48c6 | 597 | if (ret == NULL) return(NULL); |
657a9195 | 598 | bn_check_top(ret); |
d02b48c6 RE |
599 | l=0; |
600 | n=len; | |
601 | if (n == 0) | |
602 | { | |
603 | ret->top=0; | |
604 | return(ret); | |
605 | } | |
d02b48c6 RE |
606 | i=((n-1)/BN_BYTES)+1; |
607 | m=((n-1)%(BN_BYTES)); | |
6343829a | 608 | if (bn_wexpand(ret, (int)i) == NULL) |
d459e390 GT |
609 | { |
610 | if (bn) BN_free(bn); | |
611 | return NULL; | |
612 | } | |
91616729 BM |
613 | ret->top=i; |
614 | ret->neg=0; | |
d459e390 | 615 | while (n--) |
d02b48c6 RE |
616 | { |
617 | l=(l<<8L)| *(s++); | |
618 | if (m-- == 0) | |
619 | { | |
620 | ret->d[--i]=l; | |
621 | l=0; | |
622 | m=BN_BYTES-1; | |
623 | } | |
624 | } | |
625 | /* need to call this due to clear byte at top if avoiding | |
626 | * having the top bit set (-ve number) */ | |
d870740c | 627 | bn_correct_top(ret); |
d02b48c6 RE |
628 | return(ret); |
629 | } | |
630 | ||
631 | /* ignore negative */ | |
8623f693 | 632 | int BN_bn2bin(const BIGNUM *a, unsigned char *to) |
d02b48c6 RE |
633 | { |
634 | int n,i; | |
635 | BN_ULONG l; | |
636 | ||
657a9195 | 637 | bn_check_top(a); |
d02b48c6 | 638 | n=i=BN_num_bytes(a); |
d459e390 | 639 | while (i--) |
d02b48c6 RE |
640 | { |
641 | l=a->d[i/BN_BYTES]; | |
642 | *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff; | |
643 | } | |
644 | return(n); | |
645 | } | |
646 | ||
84c15db5 | 647 | int BN_ucmp(const BIGNUM *a, const BIGNUM *b) |
d02b48c6 RE |
648 | { |
649 | int i; | |
650 | BN_ULONG t1,t2,*ap,*bp; | |
651 | ||
dfeab068 RE |
652 | bn_check_top(a); |
653 | bn_check_top(b); | |
654 | ||
d02b48c6 RE |
655 | i=a->top-b->top; |
656 | if (i != 0) return(i); | |
657 | ap=a->d; | |
658 | bp=b->d; | |
659 | for (i=a->top-1; i>=0; i--) | |
660 | { | |
661 | t1= ap[i]; | |
662 | t2= bp[i]; | |
663 | if (t1 != t2) | |
2bfd2c74 | 664 | return((t1 > t2) ? 1 : -1); |
d02b48c6 RE |
665 | } |
666 | return(0); | |
667 | } | |
668 | ||
84c15db5 | 669 | int BN_cmp(const BIGNUM *a, const BIGNUM *b) |
d02b48c6 RE |
670 | { |
671 | int i; | |
672 | int gt,lt; | |
673 | BN_ULONG t1,t2; | |
674 | ||
675 | if ((a == NULL) || (b == NULL)) | |
676 | { | |
677 | if (a != NULL) | |
678 | return(-1); | |
679 | else if (b != NULL) | |
680 | return(1); | |
681 | else | |
682 | return(0); | |
683 | } | |
dfeab068 RE |
684 | |
685 | bn_check_top(a); | |
686 | bn_check_top(b); | |
687 | ||
d02b48c6 RE |
688 | if (a->neg != b->neg) |
689 | { | |
690 | if (a->neg) | |
691 | return(-1); | |
692 | else return(1); | |
693 | } | |
694 | if (a->neg == 0) | |
695 | { gt=1; lt= -1; } | |
696 | else { gt= -1; lt=1; } | |
697 | ||
698 | if (a->top > b->top) return(gt); | |
699 | if (a->top < b->top) return(lt); | |
700 | for (i=a->top-1; i>=0; i--) | |
701 | { | |
702 | t1=a->d[i]; | |
703 | t2=b->d[i]; | |
704 | if (t1 > t2) return(gt); | |
705 | if (t1 < t2) return(lt); | |
706 | } | |
707 | return(0); | |
708 | } | |
709 | ||
6b691a5c | 710 | int BN_set_bit(BIGNUM *a, int n) |
d02b48c6 | 711 | { |
6343829a | 712 | int i,j,k; |
d02b48c6 | 713 | |
1a017330 UM |
714 | if (n < 0) |
715 | return 0; | |
716 | ||
d02b48c6 RE |
717 | i=n/BN_BITS2; |
718 | j=n%BN_BITS2; | |
58964a49 RE |
719 | if (a->top <= i) |
720 | { | |
dfeab068 RE |
721 | if (bn_wexpand(a,i+1) == NULL) return(0); |
722 | for(k=a->top; k<i+1; k++) | |
723 | a->d[k]=0; | |
58964a49 RE |
724 | a->top=i+1; |
725 | } | |
d02b48c6 | 726 | |
e14d4443 | 727 | a->d[i]|=(((BN_ULONG)1)<<j); |
d870740c | 728 | bn_check_top(a); |
d02b48c6 RE |
729 | return(1); |
730 | } | |
731 | ||
6b691a5c | 732 | int BN_clear_bit(BIGNUM *a, int n) |
d02b48c6 RE |
733 | { |
734 | int i,j; | |
735 | ||
2bfd2c74 GT |
736 | bn_check_top(a); |
737 | if (n < 0) return 0; | |
1a017330 | 738 | |
d02b48c6 RE |
739 | i=n/BN_BITS2; |
740 | j=n%BN_BITS2; | |
741 | if (a->top <= i) return(0); | |
742 | ||
e14d4443 | 743 | a->d[i]&=(~(((BN_ULONG)1)<<j)); |
d870740c | 744 | bn_correct_top(a); |
d02b48c6 RE |
745 | return(1); |
746 | } | |
747 | ||
84c15db5 | 748 | int BN_is_bit_set(const BIGNUM *a, int n) |
d02b48c6 RE |
749 | { |
750 | int i,j; | |
751 | ||
2bfd2c74 GT |
752 | bn_check_top(a); |
753 | if (n < 0) return 0; | |
d02b48c6 RE |
754 | i=n/BN_BITS2; |
755 | j=n%BN_BITS2; | |
2bfd2c74 | 756 | if (a->top <= i) return 0; |
a68c7b91 | 757 | return (int)(((a->d[i])>>j)&((BN_ULONG)1)); |
d02b48c6 RE |
758 | } |
759 | ||
6b691a5c | 760 | int BN_mask_bits(BIGNUM *a, int n) |
d02b48c6 RE |
761 | { |
762 | int b,w; | |
763 | ||
2bfd2c74 GT |
764 | bn_check_top(a); |
765 | if (n < 0) return 0; | |
1a017330 | 766 | |
d02b48c6 RE |
767 | w=n/BN_BITS2; |
768 | b=n%BN_BITS2; | |
2bfd2c74 | 769 | if (w >= a->top) return 0; |
d02b48c6 RE |
770 | if (b == 0) |
771 | a->top=w; | |
772 | else | |
773 | { | |
774 | a->top=w+1; | |
775 | a->d[w]&= ~(BN_MASK2<<b); | |
d02b48c6 | 776 | } |
d870740c | 777 | bn_correct_top(a); |
d02b48c6 RE |
778 | return(1); |
779 | } | |
dfeab068 | 780 | |
ff22e913 NL |
781 | void BN_set_negative(BIGNUM *a, int b) |
782 | { | |
783 | if (b && !BN_is_zero(a)) | |
784 | a->neg = 1; | |
785 | else | |
786 | a->neg = 0; | |
787 | } | |
788 | ||
cbd48ba6 | 789 | int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) |
dfeab068 RE |
790 | { |
791 | int i; | |
792 | BN_ULONG aa,bb; | |
793 | ||
794 | aa=a[n-1]; | |
795 | bb=b[n-1]; | |
796 | if (aa != bb) return((aa > bb)?1:-1); | |
797 | for (i=n-2; i>=0; i--) | |
798 | { | |
799 | aa=a[i]; | |
800 | bb=b[i]; | |
801 | if (aa != bb) return((aa > bb)?1:-1); | |
802 | } | |
803 | return(0); | |
804 | } | |
52a1bab2 | 805 | |
c21c35e6 RL |
806 | /* Here follows a specialised variants of bn_cmp_words(). It has the |
807 | property of performing the operation on arrays of different sizes. | |
808 | The sizes of those arrays is expressed through cl, which is the | |
809 | common length ( basicall, min(len(a),len(b)) ), and dl, which is the | |
810 | delta between the two lengths, calculated as len(a)-len(b). | |
811 | All lengths are the number of BN_ULONGs... */ | |
812 | ||
52a1bab2 UM |
813 | int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, |
814 | int cl, int dl) | |
815 | { | |
816 | int n,i; | |
817 | n = cl-1; | |
818 | ||
819 | if (dl < 0) | |
820 | { | |
b26f84cb | 821 | for (i=dl; i<0; i++) |
52a1bab2 | 822 | { |
b26f84cb | 823 | if (b[n-i] != 0) |
52a1bab2 UM |
824 | return -1; /* a < b */ |
825 | } | |
826 | } | |
827 | if (dl > 0) | |
828 | { | |
829 | for (i=dl; i>0; i--) | |
830 | { | |
831 | if (a[n+i] != 0) | |
832 | return 1; /* a > b */ | |
833 | } | |
834 | } | |
835 | return bn_cmp_words(a,b,cl); | |
836 | } | |
f9b6c0ba DSH |
837 | |
838 | /* | |
839 | * Constant-time conditional swap of a and b. | |
840 | * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. | |
841 | * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, | |
842 | * and that no more than nwords are used by either a or b. | |
843 | * a and b cannot be the same number | |
844 | */ | |
845 | void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) | |
846 | { | |
847 | BN_ULONG t; | |
848 | int i; | |
849 | ||
850 | bn_wcheck_size(a, nwords); | |
851 | bn_wcheck_size(b, nwords); | |
852 | ||
853 | assert(a != b); | |
854 | assert((condition & (condition - 1)) == 0); | |
855 | assert(sizeof(BN_ULONG) >= sizeof(int)); | |
856 | ||
857 | condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; | |
858 | ||
859 | t = (a->top^b->top) & condition; | |
860 | a->top ^= t; | |
861 | b->top ^= t; | |
862 | ||
863 | #define BN_CONSTTIME_SWAP(ind) \ | |
864 | do { \ | |
865 | t = (a->d[ind] ^ b->d[ind]) & condition; \ | |
866 | a->d[ind] ^= t; \ | |
867 | b->d[ind] ^= t; \ | |
868 | } while (0) | |
869 | ||
870 | ||
871 | switch (nwords) { | |
872 | default: | |
873 | for (i = 10; i < nwords; i++) | |
874 | BN_CONSTTIME_SWAP(i); | |
875 | /* Fallthrough */ | |
876 | case 10: BN_CONSTTIME_SWAP(9); /* Fallthrough */ | |
877 | case 9: BN_CONSTTIME_SWAP(8); /* Fallthrough */ | |
878 | case 8: BN_CONSTTIME_SWAP(7); /* Fallthrough */ | |
879 | case 7: BN_CONSTTIME_SWAP(6); /* Fallthrough */ | |
880 | case 6: BN_CONSTTIME_SWAP(5); /* Fallthrough */ | |
881 | case 5: BN_CONSTTIME_SWAP(4); /* Fallthrough */ | |
882 | case 4: BN_CONSTTIME_SWAP(3); /* Fallthrough */ | |
883 | case 3: BN_CONSTTIME_SWAP(2); /* Fallthrough */ | |
884 | case 2: BN_CONSTTIME_SWAP(1); /* Fallthrough */ | |
885 | case 1: BN_CONSTTIME_SWAP(0); | |
886 | } | |
887 | #undef BN_CONSTTIME_SWAP | |
888 | } | |
2514fa79 DSH |
889 | |
890 | /* Bits of security, see SP800-57 */ | |
891 | ||
892 | int BN_security_bits(int L, int N) | |
893 | { | |
894 | int secbits, bits; | |
895 | if (L >= 15360) | |
896 | secbits = 256; | |
897 | else if (L >= 7690) | |
898 | secbits = 192; | |
899 | else if (L >= 3072) | |
900 | secbits = 128; | |
901 | else if (L >= 2048) | |
902 | secbits = 112; | |
903 | else if (L >= 1024) | |
904 | secbits = 80; | |
905 | else | |
906 | return 0; | |
907 | if (N == -1) | |
908 | return secbits; | |
909 | bits = N / 2; | |
910 | if (bits < 80) | |
911 | return 0; | |
912 | return bits >= secbits ? secbits : bits; | |
913 | } |