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_INTERNAL_H 124 #define OPENSSL_HEADER_BN_INTERNAL_H 125 126 #include <openssl/base.h> 127 128 #if defined(OPENSSL_X86_64) && defined(_MSC_VER) 129 OPENSSL_MSVC_PRAGMA(warning(push, 3)) 130 #include <intrin.h> 131 OPENSSL_MSVC_PRAGMA(warning(pop)) 132 #pragma intrinsic(__umulh, _umul128) 133 #endif 134 135 #include "../../internal.h" 136 137 #if defined(__cplusplus) 138 extern "C" { 139 #endif 140 141 #if defined(OPENSSL_64_BIT) 142 143 #if defined(BORINGSSL_HAS_UINT128) 144 // MSVC doesn't support two-word integers on 64-bit. 145 #define BN_ULLONG uint128_t 146 #if defined(BORINGSSL_CAN_DIVIDE_UINT128) 147 #define BN_CAN_DIVIDE_ULLONG 148 #endif 149 #endif 150 151 #define BN_BITS2 64 152 #define BN_BYTES 8 153 #define BN_BITS4 32 154 #define BN_MASK2 (0xffffffffffffffffUL) 155 #define BN_MASK2l (0xffffffffUL) 156 #define BN_MASK2h (0xffffffff00000000UL) 157 #define BN_MASK2h1 (0xffffffff80000000UL) 158 #define BN_MONT_CTX_N0_LIMBS 1 159 #define BN_DEC_CONV (10000000000000000000UL) 160 #define BN_DEC_NUM 19 161 #define TOBN(hi, lo) ((BN_ULONG)(hi) << 32 | (lo)) 162 163 #elif defined(OPENSSL_32_BIT) 164 165 #define BN_ULLONG uint64_t 166 #define BN_CAN_DIVIDE_ULLONG 167 #define BN_BITS2 32 168 #define BN_BYTES 4 169 #define BN_BITS4 16 170 #define BN_MASK2 (0xffffffffUL) 171 #define BN_MASK2l (0xffffUL) 172 #define BN_MASK2h1 (0xffff8000UL) 173 #define BN_MASK2h (0xffff0000UL) 174 // On some 32-bit platforms, Montgomery multiplication is done using 64-bit 175 // arithmetic with SIMD instructions. On such platforms, |BN_MONT_CTX::n0| 176 // needs to be two words long. Only certain 32-bit platforms actually make use 177 // of n0[1] and shorter R value would suffice for the others. However, 178 // currently only the assembly files know which is which. 179 #define BN_MONT_CTX_N0_LIMBS 2 180 #define BN_DEC_CONV (1000000000UL) 181 #define BN_DEC_NUM 9 182 #define TOBN(hi, lo) (lo), (hi) 183 184 #else 185 #error "Must define either OPENSSL_32_BIT or OPENSSL_64_BIT" 186 #endif 187 188 189 #define STATIC_BIGNUM(x) \ 190 { \ 191 (BN_ULONG *)(x), sizeof(x) / sizeof(BN_ULONG), \ 192 sizeof(x) / sizeof(BN_ULONG), 0, BN_FLG_STATIC_DATA \ 193 } 194 195 #if defined(BN_ULLONG) 196 #define Lw(t) ((BN_ULONG)(t)) 197 #define Hw(t) ((BN_ULONG)((t) >> BN_BITS2)) 198 #endif 199 200 // bn_minimal_width returns the minimal value of |bn->top| which fits the 201 // value of |bn|. 202 int bn_minimal_width(const BIGNUM *bn); 203 204 // bn_correct_top decrements |bn->top| to |bn_minimal_width|. If |bn| is zero, 205 // |bn->neg| is set to zero. 206 void bn_correct_top(BIGNUM *bn); 207 208 // bn_wexpand ensures that |bn| has at least |words| works of space without 209 // altering its value. It returns one on success or zero on allocation 210 // failure. 211 int bn_wexpand(BIGNUM *bn, size_t words); 212 213 // bn_expand acts the same as |bn_wexpand|, but takes a number of bits rather 214 // than a number of words. 215 int bn_expand(BIGNUM *bn, size_t bits); 216 217 // bn_resize_words adjusts |bn->top| to be |words|. It returns one on success 218 // and zero on allocation error or if |bn|'s value is too large. 219 // 220 // Do not call this function outside of unit tests. Most functions currently 221 // require |BIGNUM|s be minimal. This function breaks that invariant. It is 222 // introduced early so the invariant may be relaxed incrementally. 223 int bn_resize_words(BIGNUM *bn, size_t words); 224 225 // bn_set_words sets |bn| to the value encoded in the |num| words in |words|, 226 // least significant word first. 227 int bn_set_words(BIGNUM *bn, const BN_ULONG *words, size_t num); 228 229 // bn_fits_in_words returns one if |bn| may be represented in |num| words, plus 230 // a sign bit, and zero otherwise. 231 int bn_fits_in_words(const BIGNUM *bn, size_t num); 232 233 // bn_copy_words copies the value of |bn| to |out| and returns one if the value 234 // is representable in |num| words. Otherwise, it returns zero. 235 int bn_copy_words(BN_ULONG *out, size_t num, const BIGNUM *bn); 236 237 // bn_mul_add_words multiples |ap| by |w|, adds the result to |rp|, and places 238 // the result in |rp|. |ap| and |rp| must both be |num| words long. It returns 239 // the carry word of the operation. |ap| and |rp| may be equal but otherwise may 240 // not alias. 241 BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num, 242 BN_ULONG w); 243 244 // bn_mul_words multiples |ap| by |w| and places the result in |rp|. |ap| and 245 // |rp| must both be |num| words long. It returns the carry word of the 246 // operation. |ap| and |rp| may be equal but otherwise may not alias. 247 BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num, BN_ULONG w); 248 249 // bn_sqr_words sets |rp[2*i]| and |rp[2*i+1]| to |ap[i]|'s square, for all |i| 250 // up to |num|. |ap| is an array of |num| words and |rp| an array of |2*num| 251 // words. |ap| and |rp| may not alias. 252 // 253 // This gives the contribution of the |ap[i]*ap[i]| terms when squaring |ap|. 254 void bn_sqr_words(BN_ULONG *rp, const BN_ULONG *ap, size_t num); 255 256 // bn_add_words adds |ap| to |bp| and places the result in |rp|, each of which 257 // are |num| words long. It returns the carry bit, which is one if the operation 258 // overflowed and zero otherwise. Any pair of |ap|, |bp|, and |rp| may be equal 259 // to each other but otherwise may not alias. 260 BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, 261 size_t num); 262 263 // bn_sub_words subtracts |bp| from |ap| and places the result in |rp|. It 264 // returns the borrow bit, which is one if the computation underflowed and zero 265 // otherwise. Any pair of |ap|, |bp|, and |rp| may be equal to each other but 266 // otherwise may not alias. 267 BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, 268 size_t num); 269 270 // bn_mul_comba4 sets |r| to the product of |a| and |b|. 271 void bn_mul_comba4(BN_ULONG r[8], const BN_ULONG a[4], const BN_ULONG b[4]); 272 273 // bn_mul_comba8 sets |r| to the product of |a| and |b|. 274 void bn_mul_comba8(BN_ULONG r[16], const BN_ULONG a[8], const BN_ULONG b[8]); 275 276 // bn_sqr_comba8 sets |r| to |a|^2. 277 void bn_sqr_comba8(BN_ULONG r[16], const BN_ULONG a[4]); 278 279 // bn_sqr_comba4 sets |r| to |a|^2. 280 void bn_sqr_comba4(BN_ULONG r[8], const BN_ULONG a[4]); 281 282 // bn_cmp_words returns a value less than, equal to or greater than zero if 283 // the, length |n|, array |a| is less than, equal to or greater than |b|. 284 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n); 285 286 // bn_cmp_words returns a value less than, equal to or greater than zero if the 287 // array |a| is less than, equal to or greater than |b|. The arrays can be of 288 // different lengths: |cl| gives the minimum of the two lengths and |dl| gives 289 // the length of |a| minus the length of |b|. 290 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl); 291 292 // bn_less_than_words returns one if |a| < |b| and zero otherwise, where |a| 293 // and |b| both are |len| words long. It runs in constant time. 294 int bn_less_than_words(const BN_ULONG *a, const BN_ULONG *b, size_t len); 295 296 // bn_in_range_words returns one if |min_inclusive| <= |a| < |max_exclusive|, 297 // where |a| and |max_exclusive| both are |len| words long. This function leaks 298 // which of [0, min_inclusive), [min_inclusive, max_exclusive), and 299 // [max_exclusive, 2^(BN_BITS2*len)) contains |a|, but otherwise the value of 300 // |a| is secret. 301 int bn_in_range_words(const BN_ULONG *a, BN_ULONG min_inclusive, 302 const BN_ULONG *max_exclusive, size_t len); 303 304 // bn_rand_range_words sets |out| to a uniformly distributed random number from 305 // |min_inclusive| to |max_exclusive|. Both |out| and |max_exclusive| are |len| 306 // words long. 307 // 308 // This function runs in time independent of the result, but |min_inclusive| and 309 // |max_exclusive| are public data. (Information about the range is unavoidably 310 // leaked by how many iterations it took to select a number.) 311 int bn_rand_range_words(BN_ULONG *out, BN_ULONG min_inclusive, 312 const BN_ULONG *max_exclusive, size_t len, 313 const uint8_t additional_data[32]); 314 315 int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, 316 const BN_ULONG *np, const BN_ULONG *n0, int num); 317 318 uint64_t bn_mont_n0(const BIGNUM *n); 319 int bn_mod_exp_base_2_vartime(BIGNUM *r, unsigned p, const BIGNUM *n); 320 321 #if defined(OPENSSL_X86_64) && defined(_MSC_VER) 322 #define BN_UMULT_LOHI(low, high, a, b) ((low) = _umul128((a), (b), &(high))) 323 #endif 324 325 #if !defined(BN_ULLONG) && !defined(BN_UMULT_LOHI) 326 #error "Either BN_ULLONG or BN_UMULT_LOHI must be defined on every platform." 327 #endif 328 329 // bn_mod_inverse_prime sets |out| to the modular inverse of |a| modulo |p|, 330 // computed with Fermat's Little Theorem. It returns one on success and zero on 331 // error. If |mont_p| is NULL, one will be computed temporarily. 332 int bn_mod_inverse_prime(BIGNUM *out, const BIGNUM *a, const BIGNUM *p, 333 BN_CTX *ctx, const BN_MONT_CTX *mont_p); 334 335 // bn_mod_inverse_secret_prime behaves like |bn_mod_inverse_prime| but uses 336 // |BN_mod_exp_mont_consttime| instead of |BN_mod_exp_mont| in hopes of 337 // protecting the exponent. 338 int bn_mod_inverse_secret_prime(BIGNUM *out, const BIGNUM *a, const BIGNUM *p, 339 BN_CTX *ctx, const BN_MONT_CTX *mont_p); 340 341 // bn_jacobi returns the Jacobi symbol of |a| and |b| (which is -1, 0 or 1), or 342 // -2 on error. 343 int bn_jacobi(const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx); 344 345 // bn_is_bit_set_words returns one if bit |bit| is set in |a| and zero 346 // otherwise. 347 int bn_is_bit_set_words(const BN_ULONG *a, size_t num, unsigned bit); 348 349 // bn_one_to_montgomery sets |r| to one in Montgomery form. It returns one on 350 // success and zero on error. This function treats the bit width of the modulus 351 // as public. 352 int bn_one_to_montgomery(BIGNUM *r, const BN_MONT_CTX *mont, BN_CTX *ctx); 353 354 // bn_less_than_montgomery_R returns one if |bn| is less than the Montgomery R 355 // value for |mont| and zero otherwise. 356 int bn_less_than_montgomery_R(const BIGNUM *bn, const BN_MONT_CTX *mont); 357 358 359 // Low-level operations for small numbers. 360 // 361 // The following functions implement algorithms suitable for use with scalars 362 // and field elements in elliptic curves. They rely on the number being small 363 // both to stack-allocate various temporaries and because they do not implement 364 // optimizations useful for the larger values used in RSA. 365 366 // BN_SMALL_MAX_WORDS is the largest size input these functions handle. This 367 // limit allows temporaries to be more easily stack-allocated. This limit is set 368 // to accommodate P-521. 369 #if defined(OPENSSL_32_BIT) 370 #define BN_SMALL_MAX_WORDS 17 371 #else 372 #define BN_SMALL_MAX_WORDS 9 373 #endif 374 375 // bn_mul_small sets |r| to |a|*|b|. |num_r| must be |num_a| + |num_b|. |r| may 376 // not alias with |a| or |b|. This function returns one on success and zero if 377 // lengths are inconsistent. 378 int bn_mul_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, size_t num_a, 379 const BN_ULONG *b, size_t num_b); 380 381 // bn_sqr_small sets |r| to |a|^2. |num_a| must be at most |BN_SMALL_MAX_WORDS|. 382 // |num_r| must be |num_a|*2. |r| and |a| may not alias. This function returns 383 // one on success and zero on programmer error. 384 int bn_sqr_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, size_t num_a); 385 386 // In the following functions, the modulus must be at most |BN_SMALL_MAX_WORDS| 387 // words long. 388 389 // bn_to_montgomery_small sets |r| to |a| translated to the Montgomery domain. 390 // |num_a| and |num_r| must be the length of the modulus, which is 391 // |mont->N.top|. |a| must be fully reduced. This function returns one on 392 // success and zero if lengths are inconsistent. |r| and |a| may alias. 393 int bn_to_montgomery_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, 394 size_t num_a, const BN_MONT_CTX *mont); 395 396 // bn_from_montgomery_small sets |r| to |a| translated out of the Montgomery 397 // domain. |num_r| must be the length of the modulus, which is |mont->N.top|. 398 // |a| must be at most |mont->N.top| * R and |num_a| must be at most 2 * 399 // |mont->N.top|. This function returns one on success and zero if lengths are 400 // inconsistent. |r| and |a| may alias. 401 int bn_from_montgomery_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, 402 size_t num_a, const BN_MONT_CTX *mont); 403 404 // bn_one_to_montgomery_small sets |r| to one in Montgomery form. It returns one 405 // on success and zero on error. |num_r| must be the length of the modulus, 406 // which is |mont->N.top|. This function treats the bit width of the modulus as 407 // public. 408 int bn_one_to_montgomery_small(BN_ULONG *r, size_t num_r, 409 const BN_MONT_CTX *mont); 410 411 // bn_mod_mul_montgomery_small sets |r| to |a| * |b| mod |mont->N|. Both inputs 412 // and outputs are in the Montgomery domain. |num_r| must be the length of the 413 // modulus, which is |mont->N.top|. This function returns one on success and 414 // zero on internal error or inconsistent lengths. Any two of |r|, |a|, and |b| 415 // may alias. 416 // 417 // This function requires |a| * |b| < N * R, where N is the modulus and R is the 418 // Montgomery divisor, 2^(N.top * BN_BITS2). This should generally be satisfied 419 // by ensuring |a| and |b| are fully reduced, however ECDSA has one computation 420 // which requires the more general bound. 421 int bn_mod_mul_montgomery_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, 422 size_t num_a, const BN_ULONG *b, size_t num_b, 423 const BN_MONT_CTX *mont); 424 425 // bn_mod_exp_mont_small sets |r| to |a|^|p| mod |mont->N|. It returns one on 426 // success and zero on programmer or internal error. Both inputs and outputs are 427 // in the Montgomery domain. |num_r| and |num_a| must be |mont->N.top|, which 428 // must be at most |BN_SMALL_MAX_WORDS|. |a| must be fully-reduced. This 429 // function runs in time independent of |a|, but |p| and |mont->N| are public 430 // values. 431 // 432 // Note this function differs from |BN_mod_exp_mont| which uses Montgomery 433 // reduction but takes input and output outside the Montgomery domain. Combine 434 // this function with |bn_from_montgomery_small| and |bn_to_montgomery_small| 435 // if necessary. 436 int bn_mod_exp_mont_small(BN_ULONG *r, size_t num_r, const BN_ULONG *a, 437 size_t num_a, const BN_ULONG *p, size_t num_p, 438 const BN_MONT_CTX *mont); 439 440 // bn_mod_inverse_prime_mont_small sets |r| to |a|^-1 mod |mont->N|. |mont->N| 441 // must be a prime. |num_r| and |num_a| must be |mont->N.top|, which must be at 442 // most |BN_SMALL_MAX_WORDS|. |a| must be fully-reduced. This function runs in 443 // time independent of |a|, but |mont->N| is a public value. 444 int bn_mod_inverse_prime_mont_small(BN_ULONG *r, size_t num_r, 445 const BN_ULONG *a, size_t num_a, 446 const BN_MONT_CTX *mont); 447 448 449 #if defined(__cplusplus) 450 } // extern C 451 #endif 452 453 #endif // OPENSSL_HEADER_BN_INTERNAL_H 454