1 /* Copyright (C) 1995-1997 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 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 (at) cryptsoft.com). 14 * 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. 21 * 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 (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 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. 51 * 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 /* ==================================================================== 58 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. 59 * 60 * Redistribution and use in source and binary forms, with or without 61 * modification, are permitted provided that the following conditions 62 * are met: 63 * 64 * 1. Redistributions of source code must retain the above copyright 65 * notice, this list of conditions and the following disclaimer. 66 * 67 * 2. Redistributions in binary form must reproduce the above copyright 68 * notice, this list of conditions and the following disclaimer in 69 * the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3. All advertising materials mentioning features or use of this 73 * software must display the following acknowledgment: 74 * "This product includes software developed by the OpenSSL Project 75 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 76 * 77 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 78 * endorse or promote products derived from this software without 79 * prior written permission. For written permission, please contact 80 * openssl-core (at) openssl.org. 81 * 82 * 5. Products derived from this software may not be called "OpenSSL" 83 * nor may "OpenSSL" appear in their names without prior written 84 * permission of the OpenSSL Project. 85 * 86 * 6. Redistributions of any form whatsoever must retain the following 87 * acknowledgment: 88 * "This product includes software developed by the OpenSSL Project 89 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 90 * 91 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 92 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 93 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 95 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 96 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 97 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 98 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 99 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 100 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 101 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 102 * OF THE POSSIBILITY OF SUCH DAMAGE. 103 * ==================================================================== 104 * 105 * This product includes cryptographic software written by Eric Young 106 * (eay (at) cryptsoft.com). This product includes software written by Tim 107 * Hudson (tjh (at) cryptsoft.com). 108 * 109 */ 110 /* ==================================================================== 111 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. 112 * 113 * Portions of the attached software ("Contribution") are developed by 114 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. 115 * 116 * The Contribution is licensed pursuant to the Eric Young open source 117 * license provided above. 118 * 119 * The binary polynomial arithmetic software is originally written by 120 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems 121 * Laboratories. */ 122 123 #ifndef OPENSSL_HEADER_BN_H 124 #define OPENSSL_HEADER_BN_H 125 126 #include <openssl/base.h> 127 #include <openssl/thread.h> 128 129 #include <inttypes.h> // for PRIu64 and friends 130 #include <stdio.h> // for FILE* 131 132 #if defined(__cplusplus) 133 extern "C" { 134 #endif 135 136 137 // BN provides support for working with arbitrary sized integers. For example, 138 // although the largest integer supported by the compiler might be 64 bits, BN 139 // will allow you to work with numbers until you run out of memory. 140 141 142 // BN_ULONG is the native word size when working with big integers. 143 // 144 // Note: on some platforms, inttypes.h does not define print format macros in 145 // C++ unless |__STDC_FORMAT_MACROS| defined. This is due to text in C99 which 146 // was never adopted in any C++ standard and explicitly overruled in C++11. As 147 // this is a public header, bn.h does not define |__STDC_FORMAT_MACROS| itself. 148 // Projects which use |BN_*_FMT*| with outdated C headers may need to define it 149 // externally. 150 #if defined(OPENSSL_64_BIT) 151 #define BN_ULONG uint64_t 152 #define BN_BITS2 64 153 #define BN_DEC_FMT1 "%" PRIu64 154 #define BN_DEC_FMT2 "%019" PRIu64 155 #define BN_HEX_FMT1 "%" PRIx64 156 #define BN_HEX_FMT2 "%016" PRIx64 157 #elif defined(OPENSSL_32_BIT) 158 #define BN_ULONG uint32_t 159 #define BN_BITS2 32 160 #define BN_DEC_FMT1 "%" PRIu32 161 #define BN_DEC_FMT2 "%09" PRIu32 162 #define BN_HEX_FMT1 "%" PRIx32 163 #define BN_HEX_FMT2 "%08" PRIx32 164 #else 165 #error "Must define either OPENSSL_32_BIT or OPENSSL_64_BIT" 166 #endif 167 168 169 // Allocation and freeing. 170 171 // BN_new creates a new, allocated BIGNUM and initialises it. 172 OPENSSL_EXPORT BIGNUM *BN_new(void); 173 174 // BN_init initialises a stack allocated |BIGNUM|. 175 OPENSSL_EXPORT void BN_init(BIGNUM *bn); 176 177 // BN_free frees the data referenced by |bn| and, if |bn| was originally 178 // allocated on the heap, frees |bn| also. 179 OPENSSL_EXPORT void BN_free(BIGNUM *bn); 180 181 // BN_clear_free erases and frees the data referenced by |bn| and, if |bn| was 182 // originally allocated on the heap, frees |bn| also. 183 OPENSSL_EXPORT void BN_clear_free(BIGNUM *bn); 184 185 // BN_dup allocates a new BIGNUM and sets it equal to |src|. It returns the 186 // allocated BIGNUM on success or NULL otherwise. 187 OPENSSL_EXPORT BIGNUM *BN_dup(const BIGNUM *src); 188 189 // BN_copy sets |dest| equal to |src| and returns |dest| or NULL on allocation 190 // failure. 191 OPENSSL_EXPORT BIGNUM *BN_copy(BIGNUM *dest, const BIGNUM *src); 192 193 // BN_clear sets |bn| to zero and erases the old data. 194 OPENSSL_EXPORT void BN_clear(BIGNUM *bn); 195 196 // BN_value_one returns a static BIGNUM with value 1. 197 OPENSSL_EXPORT const BIGNUM *BN_value_one(void); 198 199 200 // Basic functions. 201 202 // BN_num_bits returns the minimum number of bits needed to represent the 203 // absolute value of |bn|. 204 OPENSSL_EXPORT unsigned BN_num_bits(const BIGNUM *bn); 205 206 // BN_num_bytes returns the minimum number of bytes needed to represent the 207 // absolute value of |bn|. 208 OPENSSL_EXPORT unsigned BN_num_bytes(const BIGNUM *bn); 209 210 // BN_zero sets |bn| to zero. 211 OPENSSL_EXPORT void BN_zero(BIGNUM *bn); 212 213 // BN_one sets |bn| to one. It returns one on success or zero on allocation 214 // failure. 215 OPENSSL_EXPORT int BN_one(BIGNUM *bn); 216 217 // BN_set_word sets |bn| to |value|. It returns one on success or zero on 218 // allocation failure. 219 OPENSSL_EXPORT int BN_set_word(BIGNUM *bn, BN_ULONG value); 220 221 // BN_set_u64 sets |bn| to |value|. It returns one on success or zero on 222 // allocation failure. 223 OPENSSL_EXPORT int BN_set_u64(BIGNUM *bn, uint64_t value); 224 225 // BN_set_negative sets the sign of |bn|. 226 OPENSSL_EXPORT void BN_set_negative(BIGNUM *bn, int sign); 227 228 // BN_is_negative returns one if |bn| is negative and zero otherwise. 229 OPENSSL_EXPORT int BN_is_negative(const BIGNUM *bn); 230 231 232 // Conversion functions. 233 234 // BN_bin2bn sets |*ret| to the value of |len| bytes from |in|, interpreted as 235 // a big-endian number, and returns |ret|. If |ret| is NULL then a fresh 236 // |BIGNUM| is allocated and returned. It returns NULL on allocation 237 // failure. 238 OPENSSL_EXPORT BIGNUM *BN_bin2bn(const uint8_t *in, size_t len, BIGNUM *ret); 239 240 // BN_bn2bin serialises the absolute value of |in| to |out| as a big-endian 241 // integer, which must have |BN_num_bytes| of space available. It returns the 242 // number of bytes written. Note this function leaks the magnitude of |in|. If 243 // |in| is secret, use |BN_bn2bin_padded| instead. 244 OPENSSL_EXPORT size_t BN_bn2bin(const BIGNUM *in, uint8_t *out); 245 246 // BN_le2bn sets |*ret| to the value of |len| bytes from |in|, interpreted as 247 // a little-endian number, and returns |ret|. If |ret| is NULL then a fresh 248 // |BIGNUM| is allocated and returned. It returns NULL on allocation 249 // failure. 250 OPENSSL_EXPORT BIGNUM *BN_le2bn(const uint8_t *in, size_t len, BIGNUM *ret); 251 252 // BN_bn2le_padded serialises the absolute value of |in| to |out| as a 253 // little-endian integer, which must have |len| of space available, padding 254 // out the remainder of out with zeros. If |len| is smaller than |BN_num_bytes|, 255 // the function fails and returns 0. Otherwise, it returns 1. 256 OPENSSL_EXPORT int BN_bn2le_padded(uint8_t *out, size_t len, const BIGNUM *in); 257 258 // BN_bn2bin_padded serialises the absolute value of |in| to |out| as a 259 // big-endian integer. The integer is padded with leading zeros up to size 260 // |len|. If |len| is smaller than |BN_num_bytes|, the function fails and 261 // returns 0. Otherwise, it returns 1. 262 OPENSSL_EXPORT int BN_bn2bin_padded(uint8_t *out, size_t len, const BIGNUM *in); 263 264 // BN_bn2cbb_padded behaves like |BN_bn2bin_padded| but writes to a |CBB|. 265 OPENSSL_EXPORT int BN_bn2cbb_padded(CBB *out, size_t len, const BIGNUM *in); 266 267 // BN_bn2hex returns an allocated string that contains a NUL-terminated, hex 268 // representation of |bn|. If |bn| is negative, the first char in the resulting 269 // string will be '-'. Returns NULL on allocation failure. 270 OPENSSL_EXPORT char *BN_bn2hex(const BIGNUM *bn); 271 272 // BN_hex2bn parses the leading hex number from |in|, which may be proceeded by 273 // a '-' to indicate a negative number and may contain trailing, non-hex data. 274 // If |outp| is not NULL, it constructs a BIGNUM equal to the hex number and 275 // stores it in |*outp|. If |*outp| is NULL then it allocates a new BIGNUM and 276 // updates |*outp|. It returns the number of bytes of |in| processed or zero on 277 // error. 278 OPENSSL_EXPORT int BN_hex2bn(BIGNUM **outp, const char *in); 279 280 // BN_bn2dec returns an allocated string that contains a NUL-terminated, 281 // decimal representation of |bn|. If |bn| is negative, the first char in the 282 // resulting string will be '-'. Returns NULL on allocation failure. 283 OPENSSL_EXPORT char *BN_bn2dec(const BIGNUM *a); 284 285 // BN_dec2bn parses the leading decimal number from |in|, which may be 286 // proceeded by a '-' to indicate a negative number and may contain trailing, 287 // non-decimal data. If |outp| is not NULL, it constructs a BIGNUM equal to the 288 // decimal number and stores it in |*outp|. If |*outp| is NULL then it 289 // allocates a new BIGNUM and updates |*outp|. It returns the number of bytes 290 // of |in| processed or zero on error. 291 OPENSSL_EXPORT int BN_dec2bn(BIGNUM **outp, const char *in); 292 293 // BN_asc2bn acts like |BN_dec2bn| or |BN_hex2bn| depending on whether |in| 294 // begins with "0X" or "0x" (indicating hex) or not (indicating decimal). A 295 // leading '-' is still permitted and comes before the optional 0X/0x. It 296 // returns one on success or zero on error. 297 OPENSSL_EXPORT int BN_asc2bn(BIGNUM **outp, const char *in); 298 299 // BN_print writes a hex encoding of |a| to |bio|. It returns one on success 300 // and zero on error. 301 OPENSSL_EXPORT int BN_print(BIO *bio, const BIGNUM *a); 302 303 // BN_print_fp acts like |BIO_print|, but wraps |fp| in a |BIO| first. 304 OPENSSL_EXPORT int BN_print_fp(FILE *fp, const BIGNUM *a); 305 306 // BN_get_word returns the absolute value of |bn| as a single word. If |bn| is 307 // too large to be represented as a single word, the maximum possible value 308 // will be returned. 309 OPENSSL_EXPORT BN_ULONG BN_get_word(const BIGNUM *bn); 310 311 // BN_get_u64 sets |*out| to the absolute value of |bn| as a |uint64_t| and 312 // returns one. If |bn| is too large to be represented as a |uint64_t|, it 313 // returns zero. 314 OPENSSL_EXPORT int BN_get_u64(const BIGNUM *bn, uint64_t *out); 315 316 317 // ASN.1 functions. 318 319 // BN_parse_asn1_unsigned parses a non-negative DER INTEGER from |cbs| writes 320 // the result to |ret|. It returns one on success and zero on failure. 321 OPENSSL_EXPORT int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret); 322 323 // BN_marshal_asn1 marshals |bn| as a non-negative DER INTEGER and appends the 324 // result to |cbb|. It returns one on success and zero on failure. 325 OPENSSL_EXPORT int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn); 326 327 328 // BIGNUM pools. 329 // 330 // Certain BIGNUM operations need to use many temporary variables and 331 // allocating and freeing them can be quite slow. Thus such operations typically 332 // take a |BN_CTX| parameter, which contains a pool of |BIGNUMs|. The |ctx| 333 // argument to a public function may be NULL, in which case a local |BN_CTX| 334 // will be created just for the lifetime of that call. 335 // 336 // A function must call |BN_CTX_start| first. Then, |BN_CTX_get| may be called 337 // repeatedly to obtain temporary |BIGNUM|s. All |BN_CTX_get| calls must be made 338 // before calling any other functions that use the |ctx| as an argument. 339 // 340 // Finally, |BN_CTX_end| must be called before returning from the function. 341 // When |BN_CTX_end| is called, the |BIGNUM| pointers obtained from 342 // |BN_CTX_get| become invalid. 343 344 // BN_CTX_new returns a new, empty BN_CTX or NULL on allocation failure. 345 OPENSSL_EXPORT BN_CTX *BN_CTX_new(void); 346 347 // BN_CTX_free frees all BIGNUMs contained in |ctx| and then frees |ctx| 348 // itself. 349 OPENSSL_EXPORT void BN_CTX_free(BN_CTX *ctx); 350 351 // BN_CTX_start "pushes" a new entry onto the |ctx| stack and allows future 352 // calls to |BN_CTX_get|. 353 OPENSSL_EXPORT void BN_CTX_start(BN_CTX *ctx); 354 355 // BN_CTX_get returns a new |BIGNUM|, or NULL on allocation failure. Once 356 // |BN_CTX_get| has returned NULL, all future calls will also return NULL until 357 // |BN_CTX_end| is called. 358 OPENSSL_EXPORT BIGNUM *BN_CTX_get(BN_CTX *ctx); 359 360 // BN_CTX_end invalidates all |BIGNUM|s returned from |BN_CTX_get| since the 361 // matching |BN_CTX_start| call. 362 OPENSSL_EXPORT void BN_CTX_end(BN_CTX *ctx); 363 364 365 // Simple arithmetic 366 367 // BN_add sets |r| = |a| + |b|, where |r| may be the same pointer as either |a| 368 // or |b|. It returns one on success and zero on allocation failure. 369 OPENSSL_EXPORT int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); 370 371 // BN_uadd sets |r| = |a| + |b|, where |a| and |b| are non-negative and |r| may 372 // be the same pointer as either |a| or |b|. It returns one on success and zero 373 // on allocation failure. 374 OPENSSL_EXPORT int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); 375 376 // BN_add_word adds |w| to |a|. It returns one on success and zero otherwise. 377 OPENSSL_EXPORT int BN_add_word(BIGNUM *a, BN_ULONG w); 378 379 // BN_sub sets |r| = |a| - |b|, where |r| may be the same pointer as either |a| 380 // or |b|. It returns one on success and zero on allocation failure. 381 OPENSSL_EXPORT int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); 382 383 // BN_usub sets |r| = |a| - |b|, where |a| and |b| are non-negative integers, 384 // |b| < |a| and |r| may be the same pointer as either |a| or |b|. It returns 385 // one on success and zero on allocation failure. 386 OPENSSL_EXPORT int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b); 387 388 // BN_sub_word subtracts |w| from |a|. It returns one on success and zero on 389 // allocation failure. 390 OPENSSL_EXPORT int BN_sub_word(BIGNUM *a, BN_ULONG w); 391 392 // BN_mul sets |r| = |a| * |b|, where |r| may be the same pointer as |a| or 393 // |b|. Returns one on success and zero otherwise. 394 OPENSSL_EXPORT int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 395 BN_CTX *ctx); 396 397 // BN_mul_word sets |bn| = |bn| * |w|. It returns one on success or zero on 398 // allocation failure. 399 OPENSSL_EXPORT int BN_mul_word(BIGNUM *bn, BN_ULONG w); 400 401 // BN_sqr sets |r| = |a|^2 (i.e. squares), where |r| may be the same pointer as 402 // |a|. Returns one on success and zero otherwise. This is more efficient than 403 // BN_mul(r, a, a, ctx). 404 OPENSSL_EXPORT int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx); 405 406 // BN_div divides |numerator| by |divisor| and places the result in |quotient| 407 // and the remainder in |rem|. Either of |quotient| or |rem| may be NULL, in 408 // which case the respective value is not returned. The result is rounded 409 // towards zero; thus if |numerator| is negative, the remainder will be zero or 410 // negative. It returns one on success or zero on error. 411 OPENSSL_EXPORT int BN_div(BIGNUM *quotient, BIGNUM *rem, 412 const BIGNUM *numerator, const BIGNUM *divisor, 413 BN_CTX *ctx); 414 415 // BN_div_word sets |numerator| = |numerator|/|divisor| and returns the 416 // remainder or (BN_ULONG)-1 on error. 417 OPENSSL_EXPORT BN_ULONG BN_div_word(BIGNUM *numerator, BN_ULONG divisor); 418 419 // BN_sqrt sets |*out_sqrt| (which may be the same |BIGNUM| as |in|) to the 420 // square root of |in|, using |ctx|. It returns one on success or zero on 421 // error. Negative numbers and non-square numbers will result in an error with 422 // appropriate errors on the error queue. 423 OPENSSL_EXPORT int BN_sqrt(BIGNUM *out_sqrt, const BIGNUM *in, BN_CTX *ctx); 424 425 426 // Comparison functions 427 428 // BN_cmp returns a value less than, equal to or greater than zero if |a| is 429 // less than, equal to or greater than |b|, respectively. 430 OPENSSL_EXPORT int BN_cmp(const BIGNUM *a, const BIGNUM *b); 431 432 // BN_cmp_word is like |BN_cmp| except it takes its second argument as a 433 // |BN_ULONG| instead of a |BIGNUM|. 434 OPENSSL_EXPORT int BN_cmp_word(const BIGNUM *a, BN_ULONG b); 435 436 // BN_ucmp returns a value less than, equal to or greater than zero if the 437 // absolute value of |a| is less than, equal to or greater than the absolute 438 // value of |b|, respectively. 439 OPENSSL_EXPORT int BN_ucmp(const BIGNUM *a, const BIGNUM *b); 440 441 // BN_equal_consttime returns one if |a| is equal to |b|, and zero otherwise. 442 // It takes an amount of time dependent on the sizes of |a| and |b|, but 443 // independent of the contents (including the signs) of |a| and |b|. 444 OPENSSL_EXPORT int BN_equal_consttime(const BIGNUM *a, const BIGNUM *b); 445 446 // BN_abs_is_word returns one if the absolute value of |bn| equals |w| and zero 447 // otherwise. 448 OPENSSL_EXPORT int BN_abs_is_word(const BIGNUM *bn, BN_ULONG w); 449 450 // BN_is_zero returns one if |bn| is zero and zero otherwise. 451 OPENSSL_EXPORT int BN_is_zero(const BIGNUM *bn); 452 453 // BN_is_one returns one if |bn| equals one and zero otherwise. 454 OPENSSL_EXPORT int BN_is_one(const BIGNUM *bn); 455 456 // BN_is_word returns one if |bn| is exactly |w| and zero otherwise. 457 OPENSSL_EXPORT int BN_is_word(const BIGNUM *bn, BN_ULONG w); 458 459 // BN_is_odd returns one if |bn| is odd and zero otherwise. 460 OPENSSL_EXPORT int BN_is_odd(const BIGNUM *bn); 461 462 // BN_is_pow2 returns 1 if |a| is a power of two, and 0 otherwise. 463 OPENSSL_EXPORT int BN_is_pow2(const BIGNUM *a); 464 465 466 // Bitwise operations. 467 468 // BN_lshift sets |r| equal to |a| << n. The |a| and |r| arguments may be the 469 // same |BIGNUM|. It returns one on success and zero on allocation failure. 470 OPENSSL_EXPORT int BN_lshift(BIGNUM *r, const BIGNUM *a, int n); 471 472 // BN_lshift1 sets |r| equal to |a| << 1, where |r| and |a| may be the same 473 // pointer. It returns one on success and zero on allocation failure. 474 OPENSSL_EXPORT int BN_lshift1(BIGNUM *r, const BIGNUM *a); 475 476 // BN_rshift sets |r| equal to |a| >> n, where |r| and |a| may be the same 477 // pointer. It returns one on success and zero on allocation failure. 478 OPENSSL_EXPORT int BN_rshift(BIGNUM *r, const BIGNUM *a, int n); 479 480 // BN_rshift1 sets |r| equal to |a| >> 1, where |r| and |a| may be the same 481 // pointer. It returns one on success and zero on allocation failure. 482 OPENSSL_EXPORT int BN_rshift1(BIGNUM *r, const BIGNUM *a); 483 484 // BN_set_bit sets the |n|th, least-significant bit in |a|. For example, if |a| 485 // is 2 then setting bit zero will make it 3. It returns one on success or zero 486 // on allocation failure. 487 OPENSSL_EXPORT int BN_set_bit(BIGNUM *a, int n); 488 489 // BN_clear_bit clears the |n|th, least-significant bit in |a|. For example, if 490 // |a| is 3, clearing bit zero will make it two. It returns one on success or 491 // zero on allocation failure. 492 OPENSSL_EXPORT int BN_clear_bit(BIGNUM *a, int n); 493 494 // BN_is_bit_set returns one if the |n|th least-significant bit in |a| exists 495 // and is set. Otherwise, it returns zero. 496 OPENSSL_EXPORT int BN_is_bit_set(const BIGNUM *a, int n); 497 498 // BN_mask_bits truncates |a| so that it is only |n| bits long. It returns one 499 // on success or zero if |n| is negative. 500 // 501 // This differs from OpenSSL which additionally returns zero if |a|'s word 502 // length is less than or equal to |n|, rounded down to a number of words. Note 503 // word size is platform-dependent, so this behavior is also difficult to rely 504 // on in OpenSSL and not very useful. 505 OPENSSL_EXPORT int BN_mask_bits(BIGNUM *a, int n); 506 507 // BN_count_low_zero_bits returns the number of low-order zero bits in |bn|, or 508 // the number of factors of two which divide it. It returns zero if |bn| is 509 // zero. 510 OPENSSL_EXPORT int BN_count_low_zero_bits(const BIGNUM *bn); 511 512 513 // Modulo arithmetic. 514 515 // BN_mod_word returns |a| mod |w| or (BN_ULONG)-1 on error. 516 OPENSSL_EXPORT BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w); 517 518 // BN_mod_pow2 sets |r| = |a| mod 2^|e|. It returns 1 on success and 519 // 0 on error. 520 OPENSSL_EXPORT int BN_mod_pow2(BIGNUM *r, const BIGNUM *a, size_t e); 521 522 // BN_nnmod_pow2 sets |r| = |a| mod 2^|e| where |r| is always positive. 523 // It returns 1 on success and 0 on error. 524 OPENSSL_EXPORT int BN_nnmod_pow2(BIGNUM *r, const BIGNUM *a, size_t e); 525 526 // BN_mod is a helper macro that calls |BN_div| and discards the quotient. 527 #define BN_mod(rem, numerator, divisor, ctx) \ 528 BN_div(NULL, (rem), (numerator), (divisor), (ctx)) 529 530 // BN_nnmod is a non-negative modulo function. It acts like |BN_mod|, but 0 <= 531 // |rem| < |divisor| is always true. It returns one on success and zero on 532 // error. 533 OPENSSL_EXPORT int BN_nnmod(BIGNUM *rem, const BIGNUM *numerator, 534 const BIGNUM *divisor, BN_CTX *ctx); 535 536 // BN_mod_add sets |r| = |a| + |b| mod |m|. It returns one on success and zero 537 // on error. 538 OPENSSL_EXPORT int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 539 const BIGNUM *m, BN_CTX *ctx); 540 541 // BN_mod_add_quick acts like |BN_mod_add| but requires that |a| and |b| be 542 // non-negative and less than |m|. 543 OPENSSL_EXPORT int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 544 const BIGNUM *m); 545 546 // BN_mod_sub sets |r| = |a| - |b| mod |m|. It returns one on success and zero 547 // on error. 548 OPENSSL_EXPORT int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 549 const BIGNUM *m, BN_CTX *ctx); 550 551 // BN_mod_sub_quick acts like |BN_mod_sub| but requires that |a| and |b| be 552 // non-negative and less than |m|. 553 OPENSSL_EXPORT int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 554 const BIGNUM *m); 555 556 // BN_mod_mul sets |r| = |a|*|b| mod |m|. It returns one on success and zero 557 // on error. 558 OPENSSL_EXPORT int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 559 const BIGNUM *m, BN_CTX *ctx); 560 561 // BN_mod_sqr sets |r| = |a|^2 mod |m|. It returns one on success and zero 562 // on error. 563 OPENSSL_EXPORT int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, 564 BN_CTX *ctx); 565 566 // BN_mod_lshift sets |r| = (|a| << n) mod |m|, where |r| and |a| may be the 567 // same pointer. It returns one on success and zero on error. 568 OPENSSL_EXPORT int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, 569 const BIGNUM *m, BN_CTX *ctx); 570 571 // BN_mod_lshift_quick acts like |BN_mod_lshift| but requires that |a| be 572 // non-negative and less than |m|. 573 OPENSSL_EXPORT int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, 574 const BIGNUM *m); 575 576 // BN_mod_lshift1 sets |r| = (|a| << 1) mod |m|, where |r| and |a| may be the 577 // same pointer. It returns one on success and zero on error. 578 OPENSSL_EXPORT int BN_mod_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, 579 BN_CTX *ctx); 580 581 // BN_mod_lshift1_quick acts like |BN_mod_lshift1| but requires that |a| be 582 // non-negative and less than |m|. 583 OPENSSL_EXPORT int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a, 584 const BIGNUM *m); 585 586 // BN_mod_sqrt returns a newly-allocated |BIGNUM|, r, such that 587 // r^2 == a (mod p). |p| must be a prime. It returns NULL on error or if |a| is 588 // not a square mod |p|. In the latter case, it will add |BN_R_NOT_A_SQUARE| to 589 // the error queue. 590 OPENSSL_EXPORT BIGNUM *BN_mod_sqrt(BIGNUM *in, const BIGNUM *a, const BIGNUM *p, 591 BN_CTX *ctx); 592 593 594 // Random and prime number generation. 595 596 // The following are values for the |top| parameter of |BN_rand|. 597 #define BN_RAND_TOP_ANY (-1) 598 #define BN_RAND_TOP_ONE 0 599 #define BN_RAND_TOP_TWO 1 600 601 // The following are values for the |bottom| parameter of |BN_rand|. 602 #define BN_RAND_BOTTOM_ANY 0 603 #define BN_RAND_BOTTOM_ODD 1 604 605 // BN_rand sets |rnd| to a random number of length |bits|. It returns one on 606 // success and zero otherwise. 607 // 608 // |top| must be one of the |BN_RAND_TOP_*| values. If |BN_RAND_TOP_ONE|, the 609 // most-significant bit, if any, will be set. If |BN_RAND_TOP_TWO|, the two 610 // most significant bits, if any, will be set. If |BN_RAND_TOP_ANY|, no extra 611 // action will be taken and |BN_num_bits(rnd)| may not equal |bits| if the most 612 // significant bits randomly ended up as zeros. 613 // 614 // |bottom| must be one of the |BN_RAND_BOTTOM_*| values. If 615 // |BN_RAND_BOTTOM_ODD|, the least-significant bit, if any, will be set. If 616 // |BN_RAND_BOTTOM_ANY|, no extra action will be taken. 617 OPENSSL_EXPORT int BN_rand(BIGNUM *rnd, int bits, int top, int bottom); 618 619 // BN_pseudo_rand is an alias for |BN_rand|. 620 OPENSSL_EXPORT int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom); 621 622 // BN_rand_range is equivalent to |BN_rand_range_ex| with |min_inclusive| set 623 // to zero and |max_exclusive| set to |range|. 624 OPENSSL_EXPORT int BN_rand_range(BIGNUM *rnd, const BIGNUM *range); 625 626 // BN_rand_range_ex sets |rnd| to a random value in 627 // [min_inclusive..max_exclusive). It returns one on success and zero 628 // otherwise. 629 OPENSSL_EXPORT int BN_rand_range_ex(BIGNUM *r, BN_ULONG min_inclusive, 630 const BIGNUM *max_exclusive); 631 632 // BN_pseudo_rand_range is an alias for BN_rand_range. 633 OPENSSL_EXPORT int BN_pseudo_rand_range(BIGNUM *rnd, const BIGNUM *range); 634 635 #define BN_GENCB_GENERATED 0 636 #define BN_GENCB_PRIME_TEST 1 637 638 // bn_gencb_st, or |BN_GENCB|, holds a callback function that is used by 639 // generation functions that can take a very long time to complete. Use 640 // |BN_GENCB_set| to initialise a |BN_GENCB| structure. 641 // 642 // The callback receives the address of that |BN_GENCB| structure as its last 643 // argument and the user is free to put an arbitrary pointer in |arg|. The other 644 // arguments are set as follows: 645 // event=BN_GENCB_GENERATED, n=i: after generating the i'th possible prime 646 // number. 647 // event=BN_GENCB_PRIME_TEST, n=-1: when finished trial division primality 648 // checks. 649 // event=BN_GENCB_PRIME_TEST, n=i: when the i'th primality test has finished. 650 // 651 // The callback can return zero to abort the generation progress or one to 652 // allow it to continue. 653 // 654 // When other code needs to call a BN generation function it will often take a 655 // BN_GENCB argument and may call the function with other argument values. 656 struct bn_gencb_st { 657 void *arg; // callback-specific data 658 int (*callback)(int event, int n, struct bn_gencb_st *); 659 }; 660 661 // BN_GENCB_set configures |callback| to call |f| and sets |callout->arg| to 662 // |arg|. 663 OPENSSL_EXPORT void BN_GENCB_set(BN_GENCB *callback, 664 int (*f)(int event, int n, BN_GENCB *), 665 void *arg); 666 667 // BN_GENCB_call calls |callback|, if not NULL, and returns the return value of 668 // the callback, or 1 if |callback| is NULL. 669 OPENSSL_EXPORT int BN_GENCB_call(BN_GENCB *callback, int event, int n); 670 671 // BN_generate_prime_ex sets |ret| to a prime number of |bits| length. If safe 672 // is non-zero then the prime will be such that (ret-1)/2 is also a prime. 673 // (This is needed for Diffie-Hellman groups to ensure that the only subgroups 674 // are of size 2 and (p-1)/2.). 675 // 676 // If |add| is not NULL, the prime will fulfill the condition |ret| % |add| == 677 // |rem| in order to suit a given generator. (If |rem| is NULL then |ret| % 678 // |add| == 1.) 679 // 680 // If |cb| is not NULL, it will be called during processing to give an 681 // indication of progress. See the comments for |BN_GENCB|. It returns one on 682 // success and zero otherwise. 683 OPENSSL_EXPORT int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, 684 const BIGNUM *add, const BIGNUM *rem, 685 BN_GENCB *cb); 686 687 // BN_prime_checks is magic value that can be used as the |checks| argument to 688 // the primality testing functions in order to automatically select a number of 689 // Miller-Rabin checks that gives a false positive rate of ~2^{-80}. 690 #define BN_prime_checks 0 691 692 // bn_primality_result_t enumerates the outcomes of primality-testing. 693 enum bn_primality_result_t { 694 bn_probably_prime, 695 bn_composite, 696 bn_non_prime_power_composite, 697 }; 698 699 // BN_enhanced_miller_rabin_primality_test tests whether |w| is probably a prime 700 // number using the Enhanced Miller-Rabin Test (FIPS 186-4 C.3.2) with 701 // |iterations| iterations and returns the result in |out_result|. Enhanced 702 // Miller-Rabin tests primality for odd integers greater than 3, returning 703 // |bn_probably_prime| if the number is probably prime, 704 // |bn_non_prime_power_composite| if the number is a composite that is not the 705 // power of a single prime, and |bn_composite| otherwise. It returns one on 706 // success and zero on failure. If |cb| is not NULL, then it is called during 707 // each iteration of the primality test. 708 // 709 // If |iterations| is |BN_prime_checks|, then a value that results in a false 710 // positive rate lower than the number-field sieve security level of |w| is 711 // used, provided |w| was generated randomly. |BN_prime_checks| is not suitable 712 // for inputs potentially crafted by an adversary. 713 OPENSSL_EXPORT int BN_enhanced_miller_rabin_primality_test( 714 enum bn_primality_result_t *out_result, const BIGNUM *w, int iterations, 715 BN_CTX *ctx, BN_GENCB *cb); 716 717 // BN_primality_test sets |*is_probably_prime| to one if |candidate| is 718 // probably a prime number by the Miller-Rabin test or zero if it's certainly 719 // not. 720 // 721 // If |do_trial_division| is non-zero then |candidate| will be tested against a 722 // list of small primes before Miller-Rabin tests. The probability of this 723 // function returning a false positive is 2^{2*checks}. If |checks| is 724 // |BN_prime_checks| then a value that results in a false positive rate lower 725 // than the number-field sieve security level of |candidate| is used, provided 726 // |candidate| was generated randomly. |BN_prime_checks| is not suitable for 727 // inputs potentially crafted by an adversary. 728 // 729 // If |cb| is not NULL then it is called during the checking process. See the 730 // comment above |BN_GENCB|. 731 // 732 // The function returns one on success and zero on error. 733 OPENSSL_EXPORT int BN_primality_test(int *is_probably_prime, 734 const BIGNUM *candidate, int checks, 735 BN_CTX *ctx, int do_trial_division, 736 BN_GENCB *cb); 737 738 // BN_is_prime_fasttest_ex returns one if |candidate| is probably a prime 739 // number by the Miller-Rabin test, zero if it's certainly not and -1 on error. 740 // 741 // If |do_trial_division| is non-zero then |candidate| will be tested against a 742 // list of small primes before Miller-Rabin tests. The probability of this 743 // function returning one when |candidate| is composite is 2^{2*checks}. If 744 // |checks| is |BN_prime_checks| then a value that results in a false positive 745 // rate lower than the number-field sieve security level of |candidate| is used, 746 // provided |candidate| was generated randomly. |BN_prime_checks| is not 747 // suitable for inputs potentially crafted by an adversary. 748 // 749 // If |cb| is not NULL then it is called during the checking process. See the 750 // comment above |BN_GENCB|. 751 // 752 // WARNING: deprecated. Use |BN_primality_test|. 753 OPENSSL_EXPORT int BN_is_prime_fasttest_ex(const BIGNUM *candidate, int checks, 754 BN_CTX *ctx, int do_trial_division, 755 BN_GENCB *cb); 756 757 // BN_is_prime_ex acts the same as |BN_is_prime_fasttest_ex| with 758 // |do_trial_division| set to zero. 759 // 760 // WARNING: deprecated: Use |BN_primality_test|. 761 OPENSSL_EXPORT int BN_is_prime_ex(const BIGNUM *candidate, int checks, 762 BN_CTX *ctx, BN_GENCB *cb); 763 764 765 // Number theory functions 766 767 // BN_gcd sets |r| = gcd(|a|, |b|). It returns one on success and zero 768 // otherwise. 769 OPENSSL_EXPORT int BN_gcd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, 770 BN_CTX *ctx); 771 772 // BN_mod_inverse sets |out| equal to |a|^-1, mod |n|. If |out| is NULL, a 773 // fresh BIGNUM is allocated. It returns the result or NULL on error. 774 // 775 // If |n| is even then the operation is performed using an algorithm that avoids 776 // some branches but which isn't constant-time. This function shouldn't be used 777 // for secret values; use |BN_mod_inverse_blinded| instead. Or, if |n| is 778 // guaranteed to be prime, use 779 // |BN_mod_exp_mont_consttime(out, a, m_minus_2, m, ctx, m_mont)|, taking 780 // advantage of Fermat's Little Theorem. 781 OPENSSL_EXPORT BIGNUM *BN_mod_inverse(BIGNUM *out, const BIGNUM *a, 782 const BIGNUM *n, BN_CTX *ctx); 783 784 // BN_mod_inverse_blinded sets |out| equal to |a|^-1, mod |n|, where |n| is the 785 // Montgomery modulus for |mont|. |a| must be non-negative and must be less 786 // than |n|. |n| must be greater than 1. |a| is blinded (masked by a random 787 // value) to protect it against side-channel attacks. On failure, if the failure 788 // was caused by |a| having no inverse mod |n| then |*out_no_inverse| will be 789 // set to one; otherwise it will be set to zero. 790 // 791 // Note this function may incorrectly report |a| has no inverse if the random 792 // blinding value has no inverse. It should only be used when |n| has few 793 // non-invertible elements, such as an RSA modulus. 794 int BN_mod_inverse_blinded(BIGNUM *out, int *out_no_inverse, const BIGNUM *a, 795 const BN_MONT_CTX *mont, BN_CTX *ctx); 796 797 // BN_mod_inverse_odd sets |out| equal to |a|^-1, mod |n|. |a| must be 798 // non-negative and must be less than |n|. |n| must be odd. This function 799 // shouldn't be used for secret values; use |BN_mod_inverse_blinded| instead. 800 // Or, if |n| is guaranteed to be prime, use 801 // |BN_mod_exp_mont_consttime(out, a, m_minus_2, m, ctx, m_mont)|, taking 802 // advantage of Fermat's Little Theorem. It returns one on success or zero on 803 // failure. On failure, if the failure was caused by |a| having no inverse mod 804 // |n| then |*out_no_inverse| will be set to one; otherwise it will be set to 805 // zero. 806 int BN_mod_inverse_odd(BIGNUM *out, int *out_no_inverse, const BIGNUM *a, 807 const BIGNUM *n, BN_CTX *ctx); 808 809 810 // Montgomery arithmetic. 811 812 // BN_MONT_CTX contains the precomputed values needed to work in a specific 813 // Montgomery domain. 814 815 // BN_MONT_CTX_new_for_modulus returns a fresh |BN_MONT_CTX| given the modulus, 816 // |mod| or NULL on error. Note this function assumes |mod| is public. 817 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_new_for_modulus(const BIGNUM *mod, 818 BN_CTX *ctx); 819 820 // BN_MONT_CTX_new_consttime behaves like |BN_MONT_CTX_new_for_modulus| but 821 // treats |mod| as secret. 822 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_new_consttime(const BIGNUM *mod, 823 BN_CTX *ctx); 824 825 // BN_MONT_CTX_free frees memory associated with |mont|. 826 OPENSSL_EXPORT void BN_MONT_CTX_free(BN_MONT_CTX *mont); 827 828 // BN_MONT_CTX_copy sets |to| equal to |from|. It returns |to| on success or 829 // NULL on error. 830 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, 831 const BN_MONT_CTX *from); 832 833 // BN_MONT_CTX_set_locked takes |lock| and checks whether |*pmont| is NULL. If 834 // so, it creates a new |BN_MONT_CTX| and sets the modulus for it to |mod|. It 835 // then stores it as |*pmont|. It returns one on success and zero on error. Note 836 // this function assumes |mod| is public. 837 // 838 // If |*pmont| is already non-NULL then it does nothing and returns one. 839 int BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock, 840 const BIGNUM *mod, BN_CTX *bn_ctx); 841 842 // BN_to_montgomery sets |ret| equal to |a| in the Montgomery domain. |a| is 843 // assumed to be in the range [0, n), where |n| is the Montgomery modulus. It 844 // returns one on success or zero on error. 845 OPENSSL_EXPORT int BN_to_montgomery(BIGNUM *ret, const BIGNUM *a, 846 const BN_MONT_CTX *mont, BN_CTX *ctx); 847 848 // BN_from_montgomery sets |ret| equal to |a| * R^-1, i.e. translates values out 849 // of the Montgomery domain. |a| is assumed to be in the range [0, n), where |n| 850 // is the Montgomery modulus. It returns one on success or zero on error. 851 OPENSSL_EXPORT int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, 852 const BN_MONT_CTX *mont, BN_CTX *ctx); 853 854 // BN_mod_mul_montgomery set |r| equal to |a| * |b|, in the Montgomery domain. 855 // Both |a| and |b| must already be in the Montgomery domain (by 856 // |BN_to_montgomery|). In particular, |a| and |b| are assumed to be in the 857 // range [0, n), where |n| is the Montgomery modulus. It returns one on success 858 // or zero on error. 859 OPENSSL_EXPORT int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, 860 const BIGNUM *b, 861 const BN_MONT_CTX *mont, BN_CTX *ctx); 862 863 864 // Exponentiation. 865 866 // BN_exp sets |r| equal to |a|^{|p|}. It does so with a square-and-multiply 867 // algorithm that leaks side-channel information. It returns one on success or 868 // zero otherwise. 869 OPENSSL_EXPORT int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 870 BN_CTX *ctx); 871 872 // BN_mod_exp sets |r| equal to |a|^{|p|} mod |m|. It does so with the best 873 // algorithm for the values provided. It returns one on success or zero 874 // otherwise. The |BN_mod_exp_mont_consttime| variant must be used if the 875 // exponent is secret. 876 OPENSSL_EXPORT int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 877 const BIGNUM *m, BN_CTX *ctx); 878 879 // BN_mod_exp_mont behaves like |BN_mod_exp| but treats |a| as secret and 880 // requires 0 <= |a| < |m|. 881 OPENSSL_EXPORT int BN_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 882 const BIGNUM *m, BN_CTX *ctx, 883 const BN_MONT_CTX *mont); 884 885 // BN_mod_exp_mont_consttime behaves like |BN_mod_exp| but treats |a|, |p|, and 886 // |m| as secret and requires 0 <= |a| < |m|. 887 OPENSSL_EXPORT int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, 888 const BIGNUM *p, const BIGNUM *m, 889 BN_CTX *ctx, 890 const BN_MONT_CTX *mont); 891 892 893 // Deprecated functions 894 895 // BN_bn2mpi serialises the value of |in| to |out|, using a format that consists 896 // of the number's length in bytes represented as a 4-byte big-endian number, 897 // and the number itself in big-endian format, where the most significant bit 898 // signals a negative number. (The representation of numbers with the MSB set is 899 // prefixed with null byte). |out| must have sufficient space available; to 900 // find the needed amount of space, call the function with |out| set to NULL. 901 OPENSSL_EXPORT size_t BN_bn2mpi(const BIGNUM *in, uint8_t *out); 902 903 // BN_mpi2bn parses |len| bytes from |in| and returns the resulting value. The 904 // bytes at |in| are expected to be in the format emitted by |BN_bn2mpi|. 905 // 906 // If |out| is NULL then a fresh |BIGNUM| is allocated and returned, otherwise 907 // |out| is reused and returned. On error, NULL is returned and the error queue 908 // is updated. 909 OPENSSL_EXPORT BIGNUM *BN_mpi2bn(const uint8_t *in, size_t len, BIGNUM *out); 910 911 // BN_mod_exp_mont_word is like |BN_mod_exp_mont| except that the base |a| is 912 // given as a |BN_ULONG| instead of a |BIGNUM *|. It returns one on success 913 // or zero otherwise. 914 OPENSSL_EXPORT int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p, 915 const BIGNUM *m, BN_CTX *ctx, 916 const BN_MONT_CTX *mont); 917 918 // BN_mod_exp2_mont calculates (a1^p1) * (a2^p2) mod m. It returns 1 on success 919 // or zero otherwise. 920 OPENSSL_EXPORT int BN_mod_exp2_mont(BIGNUM *r, const BIGNUM *a1, 921 const BIGNUM *p1, const BIGNUM *a2, 922 const BIGNUM *p2, const BIGNUM *m, 923 BN_CTX *ctx, const BN_MONT_CTX *mont); 924 925 // BN_MONT_CTX_new returns a fresh |BN_MONT_CTX| or NULL on allocation failure. 926 // Use |BN_MONT_CTX_new_for_modulus| instead. 927 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_new(void); 928 929 // BN_MONT_CTX_set sets up a Montgomery context given the modulus, |mod|. It 930 // returns one on success and zero on error. Use |BN_MONT_CTX_new_for_modulus| 931 // instead. 932 OPENSSL_EXPORT int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, 933 BN_CTX *ctx); 934 935 // BN_bn2binpad behaves like |BN_bn2bin_padded|, but it returns |len| on success 936 // and -1 on error. 937 // 938 // Use |BN_bn2bin_padded| instead. It is |size_t|-clean. 939 OPENSSL_EXPORT int BN_bn2binpad(const BIGNUM *in, uint8_t *out, int len); 940 941 942 // Private functions 943 944 struct bignum_st { 945 // d is a pointer to an array of |width| |BN_BITS2|-bit chunks in 946 // little-endian order. This stores the absolute value of the number. 947 BN_ULONG *d; 948 // width is the number of elements of |d| which are valid. This value is not 949 // necessarily minimal; the most-significant words of |d| may be zero. 950 // |width| determines a potentially loose upper-bound on the absolute value 951 // of the |BIGNUM|. 952 // 953 // Functions taking |BIGNUM| inputs must compute the same answer for all 954 // possible widths. |bn_minimal_width|, |bn_set_minimal_width|, and other 955 // helpers may be used to recover the minimal width, provided it is not 956 // secret. If it is secret, use a different algorithm. Functions may output 957 // minimal or non-minimal |BIGNUM|s depending on secrecy requirements, but 958 // those which cause widths to unboundedly grow beyond the minimal value 959 // should be documented such. 960 // 961 // Note this is different from historical |BIGNUM| semantics. 962 int width; 963 // dmax is number of elements of |d| which are allocated. 964 int dmax; 965 // neg is one if the number if negative and zero otherwise. 966 int neg; 967 // flags is a bitmask of |BN_FLG_*| values 968 int flags; 969 }; 970 971 struct bn_mont_ctx_st { 972 // RR is R^2, reduced modulo |N|. It is used to convert to Montgomery form. It 973 // is guaranteed to have the same width as |N|. 974 BIGNUM RR; 975 // N is the modulus. It is always stored in minimal form, so |N.width| 976 // determines R. 977 BIGNUM N; 978 BN_ULONG n0[2]; // least significant words of (R*Ri-1)/N 979 }; 980 981 OPENSSL_EXPORT unsigned BN_num_bits_word(BN_ULONG l); 982 983 #define BN_FLG_MALLOCED 0x01 984 #define BN_FLG_STATIC_DATA 0x02 985 // |BN_FLG_CONSTTIME| has been removed and intentionally omitted so code relying 986 // on it will not compile. Consumers outside BoringSSL should use the 987 // higher-level cryptographic algorithms exposed by other modules. Consumers 988 // within the library should call the appropriate timing-sensitive algorithm 989 // directly. 990 991 992 #if defined(__cplusplus) 993 } // extern C 994 995 #if !defined(BORINGSSL_NO_CXX) 996 extern "C++" { 997 998 BSSL_NAMESPACE_BEGIN 999 1000 BORINGSSL_MAKE_DELETER(BIGNUM, BN_free) 1001 BORINGSSL_MAKE_DELETER(BN_CTX, BN_CTX_free) 1002 BORINGSSL_MAKE_DELETER(BN_MONT_CTX, BN_MONT_CTX_free) 1003 1004 class BN_CTXScope { 1005 public: 1006 BN_CTXScope(BN_CTX *ctx) : ctx_(ctx) { BN_CTX_start(ctx_); } 1007 ~BN_CTXScope() { BN_CTX_end(ctx_); } 1008 1009 private: 1010 BN_CTX *ctx_; 1011 1012 BN_CTXScope(BN_CTXScope &) = delete; 1013 BN_CTXScope &operator=(BN_CTXScope &) = delete; 1014 }; 1015 1016 BSSL_NAMESPACE_END 1017 1018 } // extern C++ 1019 #endif 1020 1021 #endif 1022 1023 #define BN_R_ARG2_LT_ARG3 100 1024 #define BN_R_BAD_RECIPROCAL 101 1025 #define BN_R_BIGNUM_TOO_LONG 102 1026 #define BN_R_BITS_TOO_SMALL 103 1027 #define BN_R_CALLED_WITH_EVEN_MODULUS 104 1028 #define BN_R_DIV_BY_ZERO 105 1029 #define BN_R_EXPAND_ON_STATIC_BIGNUM_DATA 106 1030 #define BN_R_INPUT_NOT_REDUCED 107 1031 #define BN_R_INVALID_RANGE 108 1032 #define BN_R_NEGATIVE_NUMBER 109 1033 #define BN_R_NOT_A_SQUARE 110 1034 #define BN_R_NOT_INITIALIZED 111 1035 #define BN_R_NO_INVERSE 112 1036 #define BN_R_PRIVATE_KEY_TOO_LARGE 113 1037 #define BN_R_P_IS_NOT_PRIME 114 1038 #define BN_R_TOO_MANY_ITERATIONS 115 1039 #define BN_R_TOO_MANY_TEMPORARY_VARIABLES 116 1040 #define BN_R_BAD_ENCODING 117 1041 #define BN_R_ENCODE_ERROR 118 1042 #define BN_R_INVALID_INPUT 119 1043 1044 #endif // OPENSSL_HEADER_BN_H 1045