1 /* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
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@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@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@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@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@cryptsoft.com). This product includes software written by Tim
107 * Hudson (tjh@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. As this is a public header, bn.h
146 * does not define |__STDC_FORMAT_MACROS| itself. C++ source files which use the
147 * FMT macros must define it externally. */
148 #if defined(OPENSSL_64_BIT)
149 #define BN_ULONG uint64_t
150 #define BN_BITS2 64
151 #define BN_DEC_FMT1 "%" PRIu64
152 #define BN_DEC_FMT2 "%019" PRIu64
153 #define BN_HEX_FMT1 "%" PRIx64
154 #define BN_HEX_FMT2 "%016" PRIx64
155 #elif defined(OPENSSL_32_BIT)
156 #define BN_ULONG uint32_t
157 #define BN_BITS2 32
158 #define BN_DEC_FMT1 "%" PRIu32
159 #define BN_DEC_FMT2 "%09" PRIu32
160 #define BN_HEX_FMT1 "%" PRIx32
161 #define BN_HEX_FMT2 "%08" PRIx64
162 #else
163 #error "Must define either OPENSSL_32_BIT or OPENSSL_64_BIT"
164 #endif
165
166
167 /* Allocation and freeing. */
168
169 /* BN_new creates a new, allocated BIGNUM and initialises it. */
170 OPENSSL_EXPORT BIGNUM *BN_new(void);
171
172 /* BN_init initialises a stack allocated |BIGNUM|. */
173 OPENSSL_EXPORT void BN_init(BIGNUM *bn);
174
175 /* BN_free frees the data referenced by |bn| and, if |bn| was originally
176 * allocated on the heap, frees |bn| also. */
177 OPENSSL_EXPORT void BN_free(BIGNUM *bn);
178
179 /* BN_clear_free erases and frees the data referenced by |bn| and, if |bn| was
180 * originally allocated on the heap, frees |bn| also. */
181 OPENSSL_EXPORT void BN_clear_free(BIGNUM *bn);
182
183 /* BN_dup allocates a new BIGNUM and sets it equal to |src|. It returns the
184 * allocated BIGNUM on success or NULL otherwise. */
185 OPENSSL_EXPORT BIGNUM *BN_dup(const BIGNUM *src);
186
187 /* BN_copy sets |dest| equal to |src| and returns |dest| or NULL on allocation
188 * failure. */
189 OPENSSL_EXPORT BIGNUM *BN_copy(BIGNUM *dest, const BIGNUM *src);
190
191 /* BN_clear sets |bn| to zero and erases the old data. */
192 OPENSSL_EXPORT void BN_clear(BIGNUM *bn);
193
194 /* BN_value_one returns a static BIGNUM with value 1. */
195 OPENSSL_EXPORT const BIGNUM *BN_value_one(void);
196
197
198 /* Basic functions. */
199
200 /* BN_num_bits returns the minimum number of bits needed to represent the
201 * absolute value of |bn|. */
202 OPENSSL_EXPORT unsigned BN_num_bits(const BIGNUM *bn);
203
204 /* BN_num_bytes returns the minimum number of bytes needed to represent the
205 * absolute value of |bn|. */
206 OPENSSL_EXPORT unsigned BN_num_bytes(const BIGNUM *bn);
207
208 /* BN_zero sets |bn| to zero. */
209 OPENSSL_EXPORT void BN_zero(BIGNUM *bn);
210
211 /* BN_one sets |bn| to one. It returns one on success or zero on allocation
212 * failure. */
213 OPENSSL_EXPORT int BN_one(BIGNUM *bn);
214
215 /* BN_set_word sets |bn| to |value|. It returns one on success or zero on
216 * allocation failure. */
217 OPENSSL_EXPORT int BN_set_word(BIGNUM *bn, BN_ULONG value);
218
219 /* BN_set_u64 sets |bn| to |value|. It returns one on success or zero on
220 * allocation failure. */
221 OPENSSL_EXPORT int BN_set_u64(BIGNUM *bn, uint64_t value);
222
223 /* BN_set_negative sets the sign of |bn|. */
224 OPENSSL_EXPORT void BN_set_negative(BIGNUM *bn, int sign);
225
226 /* BN_is_negative returns one if |bn| is negative and zero otherwise. */
227 OPENSSL_EXPORT int BN_is_negative(const BIGNUM *bn);
228
229
230 /* Conversion functions. */
231
232 /* BN_bin2bn sets |*ret| to the value of |len| bytes from |in|, interpreted as
233 * a big-endian number, and returns |ret|. If |ret| is NULL then a fresh
234 * |BIGNUM| is allocated and returned. It returns NULL on allocation
235 * failure. */
236 OPENSSL_EXPORT BIGNUM *BN_bin2bn(const uint8_t *in, size_t len, BIGNUM *ret);
237
238 /* BN_bn2bin serialises the absolute value of |in| to |out| as a big-endian
239 * integer, which must have |BN_num_bytes| of space available. It returns the
240 * number of bytes written. */
241 OPENSSL_EXPORT size_t BN_bn2bin(const BIGNUM *in, uint8_t *out);
242
243 /* BN_le2bn sets |*ret| to the value of |len| bytes from |in|, interpreted as
244 * a little-endian number, and returns |ret|. If |ret| is NULL then a fresh
245 * |BIGNUM| is allocated and returned. It returns NULL on allocation
246 * failure. */
247 OPENSSL_EXPORT BIGNUM *BN_le2bn(const uint8_t *in, size_t len, BIGNUM *ret);
248
249 /* BN_bn2le_padded serialises the absolute value of |in| to |out| as a
250 * little-endian integer, which must have |len| of space available, padding
251 * out the remainder of out with zeros. If |len| is smaller than |BN_num_bytes|,
252 * the function fails and returns 0. Otherwise, it returns 1. */
253 OPENSSL_EXPORT int BN_bn2le_padded(uint8_t *out, size_t len, const BIGNUM *in);
254
255 /* BN_bn2bin_padded serialises the absolute value of |in| to |out| as a
256 * big-endian integer. The integer is padded with leading zeros up to size
257 * |len|. If |len| is smaller than |BN_num_bytes|, the function fails and
258 * returns 0. Otherwise, it returns 1. */
259 OPENSSL_EXPORT int BN_bn2bin_padded(uint8_t *out, size_t len, const BIGNUM *in);
260
261 /* BN_bn2cbb_padded behaves like |BN_bn2bin_padded| but writes to a |CBB|. */
262 OPENSSL_EXPORT int BN_bn2cbb_padded(CBB *out, size_t len, const BIGNUM *in);
263
264 /* BN_bn2hex returns an allocated string that contains a NUL-terminated, hex
265 * representation of |bn|. If |bn| is negative, the first char in the resulting
266 * string will be '-'. Returns NULL on allocation failure. */
267 OPENSSL_EXPORT char *BN_bn2hex(const BIGNUM *bn);
268
269 /* BN_hex2bn parses the leading hex number from |in|, which may be proceeded by
270 * a '-' to indicate a negative number and may contain trailing, non-hex data.
271 * If |outp| is not NULL, it constructs a BIGNUM equal to the hex number and
272 * stores it in |*outp|. If |*outp| is NULL then it allocates a new BIGNUM and
273 * updates |*outp|. It returns the number of bytes of |in| processed or zero on
274 * error. */
275 OPENSSL_EXPORT int BN_hex2bn(BIGNUM **outp, const char *in);
276
277 /* BN_bn2dec returns an allocated string that contains a NUL-terminated,
278 * decimal representation of |bn|. If |bn| is negative, the first char in the
279 * resulting string will be '-'. Returns NULL on allocation failure. */
280 OPENSSL_EXPORT char *BN_bn2dec(const BIGNUM *a);
281
282 /* BN_dec2bn parses the leading decimal number from |in|, which may be
283 * proceeded by a '-' to indicate a negative number and may contain trailing,
284 * non-decimal data. If |outp| is not NULL, it constructs a BIGNUM equal to the
285 * decimal number and stores it in |*outp|. If |*outp| is NULL then it
286 * allocates a new BIGNUM and updates |*outp|. It returns the number of bytes
287 * of |in| processed or zero on error. */
288 OPENSSL_EXPORT int BN_dec2bn(BIGNUM **outp, const char *in);
289
290 /* BN_asc2bn acts like |BN_dec2bn| or |BN_hex2bn| depending on whether |in|
291 * begins with "0X" or "0x" (indicating hex) or not (indicating decimal). A
292 * leading '-' is still permitted and comes before the optional 0X/0x. It
293 * returns one on success or zero on error. */
294 OPENSSL_EXPORT int BN_asc2bn(BIGNUM **outp, const char *in);
295
296 /* BN_print writes a hex encoding of |a| to |bio|. It returns one on success
297 * and zero on error. */
298 OPENSSL_EXPORT int BN_print(BIO *bio, const BIGNUM *a);
299
300 /* BN_print_fp acts like |BIO_print|, but wraps |fp| in a |BIO| first. */
301 OPENSSL_EXPORT int BN_print_fp(FILE *fp, const BIGNUM *a);
302
303 /* BN_get_word returns the absolute value of |bn| as a single word. If |bn| is
304 * too large to be represented as a single word, the maximum possible value
305 * will be returned. */
306 OPENSSL_EXPORT BN_ULONG BN_get_word(const BIGNUM *bn);
307
308 /* BN_get_u64 sets |*out| to the absolute value of |bn| as a |uint64_t| and
309 * returns one. If |bn| is too large to be represented as a |uint64_t|, it
310 * returns zero. */
311 OPENSSL_EXPORT int BN_get_u64(const BIGNUM *bn, uint64_t *out);
312
313
314 /* ASN.1 functions. */
315
316 /* BN_parse_asn1_unsigned parses a non-negative DER INTEGER from |cbs| writes
317 * the result to |ret|. It returns one on success and zero on failure. */
318 OPENSSL_EXPORT int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret);
319
320 /* BN_parse_asn1_unsigned_buggy acts like |BN_parse_asn1_unsigned| but tolerates
321 * some invalid encodings. Do not use this function. */
322 OPENSSL_EXPORT int BN_parse_asn1_unsigned_buggy(CBS *cbs, BIGNUM *ret);
323
324 /* BN_marshal_asn1 marshals |bn| as a non-negative DER INTEGER and appends the
325 * result to |cbb|. It returns one on success and zero on failure. */
326 OPENSSL_EXPORT int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn);
327
328
329 /* BIGNUM pools.
330 *
331 * Certain BIGNUM operations need to use many temporary variables and
332 * allocating and freeing them can be quite slow. Thus such operations typically
333 * take a |BN_CTX| parameter, which contains a pool of |BIGNUMs|. The |ctx|
334 * argument to a public function may be NULL, in which case a local |BN_CTX|
335 * will be created just for the lifetime of that call.
336 *
337 * A function must call |BN_CTX_start| first. Then, |BN_CTX_get| may be called
338 * repeatedly to obtain temporary |BIGNUM|s. All |BN_CTX_get| calls must be made
339 * before calling any other functions that use the |ctx| as an argument.
340 *
341 * Finally, |BN_CTX_end| must be called before returning from the function.
342 * When |BN_CTX_end| is called, the |BIGNUM| pointers obtained from
343 * |BN_CTX_get| become invalid. */
344
345 /* BN_CTX_new returns a new, empty BN_CTX or NULL on allocation failure. */
346 OPENSSL_EXPORT BN_CTX *BN_CTX_new(void);
347
348 /* BN_CTX_free frees all BIGNUMs contained in |ctx| and then frees |ctx|
349 * itself. */
350 OPENSSL_EXPORT void BN_CTX_free(BN_CTX *ctx);
351
352 /* BN_CTX_start "pushes" a new entry onto the |ctx| stack and allows future
353 * calls to |BN_CTX_get|. */
354 OPENSSL_EXPORT void BN_CTX_start(BN_CTX *ctx);
355
356 /* BN_CTX_get returns a new |BIGNUM|, or NULL on allocation failure. Once
357 * |BN_CTX_get| has returned NULL, all future calls will also return NULL until
358 * |BN_CTX_end| is called. */
359 OPENSSL_EXPORT BIGNUM *BN_CTX_get(BN_CTX *ctx);
360
361 /* BN_CTX_end invalidates all |BIGNUM|s returned from |BN_CTX_get| since the
362 * matching |BN_CTX_start| call. */
363 OPENSSL_EXPORT void BN_CTX_end(BN_CTX *ctx);
364
365
366 /* Simple arithmetic */
367
368 /* BN_add sets |r| = |a| + |b|, where |r| may be the same pointer as either |a|
369 * or |b|. It returns one on success and zero on allocation failure. */
370 OPENSSL_EXPORT int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);
371
372 /* BN_uadd sets |r| = |a| + |b|, where |a| and |b| are non-negative and |r| may
373 * be the same pointer as either |a| or |b|. It returns one on success and zero
374 * on allocation failure. */
375 OPENSSL_EXPORT int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);
376
377 /* BN_add_word adds |w| to |a|. It returns one on success and zero otherwise. */
378 OPENSSL_EXPORT int BN_add_word(BIGNUM *a, BN_ULONG w);
379
380 /* BN_sub sets |r| = |a| - |b|, where |r| may be the same pointer as either |a|
381 * or |b|. It returns one on success and zero on allocation failure. */
382 OPENSSL_EXPORT int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);
383
384 /* BN_usub sets |r| = |a| - |b|, where |a| and |b| are non-negative integers,
385 * |b| < |a| and |r| may be the same pointer as either |a| or |b|. It returns
386 * one on success and zero on allocation failure. */
387 OPENSSL_EXPORT int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);
388
389 /* BN_sub_word subtracts |w| from |a|. It returns one on success and zero on
390 * allocation failure. */
391 OPENSSL_EXPORT int BN_sub_word(BIGNUM *a, BN_ULONG w);
392
393 /* BN_mul sets |r| = |a| * |b|, where |r| may be the same pointer as |a| or
394 * |b|. Returns one on success and zero otherwise. */
395 OPENSSL_EXPORT int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
396 BN_CTX *ctx);
397
398 /* BN_mul_word sets |bn| = |bn| * |w|. It returns one on success or zero on
399 * allocation failure. */
400 OPENSSL_EXPORT int BN_mul_word(BIGNUM *bn, BN_ULONG w);
401
402 /* BN_sqr sets |r| = |a|^2 (i.e. squares), where |r| may be the same pointer as
403 * |a|. Returns one on success and zero otherwise. This is more efficient than
404 * BN_mul(r, a, a, ctx). */
405 OPENSSL_EXPORT int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx);
406
407 /* BN_div divides |numerator| by |divisor| and places the result in |quotient|
408 * and the remainder in |rem|. Either of |quotient| or |rem| may be NULL, in
409 * which case the respective value is not returned. The result is rounded
410 * towards zero; thus if |numerator| is negative, the remainder will be zero or
411 * negative. It returns one on success or zero on error. */
412 OPENSSL_EXPORT int BN_div(BIGNUM *quotient, BIGNUM *rem,
413 const BIGNUM *numerator, const BIGNUM *divisor,
414 BN_CTX *ctx);
415
416 /* BN_div_word sets |numerator| = |numerator|/|divisor| and returns the
417 * remainder or (BN_ULONG)-1 on error. */
418 OPENSSL_EXPORT BN_ULONG BN_div_word(BIGNUM *numerator, BN_ULONG divisor);
419
420 /* BN_sqrt sets |*out_sqrt| (which may be the same |BIGNUM| as |in|) to the
421 * square root of |in|, using |ctx|. It returns one on success or zero on
422 * error. Negative numbers and non-square numbers will result in an error with
423 * appropriate errors on the error queue. */
424 OPENSSL_EXPORT int BN_sqrt(BIGNUM *out_sqrt, const BIGNUM *in, BN_CTX *ctx);
425
426
427 /* Comparison functions */
428
429 /* BN_cmp returns a value less than, equal to or greater than zero if |a| is
430 * less than, equal to or greater than |b|, respectively. */
431 OPENSSL_EXPORT int BN_cmp(const BIGNUM *a, const BIGNUM *b);
432
433 /* BN_cmp_word is like |BN_cmp| except it takes its second argument as a
434 * |BN_ULONG| instead of a |BIGNUM|. */
435 OPENSSL_EXPORT int BN_cmp_word(const BIGNUM *a, BN_ULONG b);
436
437 /* BN_ucmp returns a value less than, equal to or greater than zero if the
438 * absolute value of |a| is less than, equal to or greater than the absolute
439 * value of |b|, respectively. */
440 OPENSSL_EXPORT int BN_ucmp(const BIGNUM *a, const BIGNUM *b);
441
442 /* BN_equal_consttime returns one if |a| is equal to |b|, and zero otherwise.
443 * It takes an amount of time dependent on the sizes of |a| and |b|, but
444 * independent of the contents (including the signs) of |a| and |b|. */
445 OPENSSL_EXPORT int BN_equal_consttime(const BIGNUM *a, const BIGNUM *b);
446
447 /* BN_abs_is_word returns one if the absolute value of |bn| equals |w| and zero
448 * otherwise. */
449 OPENSSL_EXPORT int BN_abs_is_word(const BIGNUM *bn, BN_ULONG w);
450
451 /* BN_is_zero returns one if |bn| is zero and zero otherwise. */
452 OPENSSL_EXPORT int BN_is_zero(const BIGNUM *bn);
453
454 /* BN_is_one returns one if |bn| equals one and zero otherwise. */
455 OPENSSL_EXPORT int BN_is_one(const BIGNUM *bn);
456
457 /* BN_is_word returns one if |bn| is exactly |w| and zero otherwise. */
458 OPENSSL_EXPORT int BN_is_word(const BIGNUM *bn, BN_ULONG w);
459
460 /* BN_is_odd returns one if |bn| is odd and zero otherwise. */
461 OPENSSL_EXPORT int BN_is_odd(const BIGNUM *bn);
462
463 /* BN_is_pow2 returns 1 if |a| is a power of two, and 0 otherwise. */
464 OPENSSL_EXPORT int BN_is_pow2(const BIGNUM *a);
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 the value of the |n|th, least-significant bit in |a|,
495 * or zero if the bit doesn't exist. */
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 greater than the length of |a| already. */
500 OPENSSL_EXPORT int BN_mask_bits(BIGNUM *a, int n);
501
502
503 /* Modulo arithmetic. */
504
505 /* BN_mod_word returns |a| mod |w| or (BN_ULONG)-1 on error. */
506 OPENSSL_EXPORT BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w);
507
508 /* BN_mod_pow2 sets |r| = |a| mod 2^|e|. It returns 1 on success and
509 * 0 on error. */
510 OPENSSL_EXPORT int BN_mod_pow2(BIGNUM *r, const BIGNUM *a, size_t e);
511
512 /* BN_nnmod_pow2 sets |r| = |a| mod 2^|e| where |r| is always positive.
513 * It returns 1 on success and 0 on error. */
514 OPENSSL_EXPORT int BN_nnmod_pow2(BIGNUM *r, const BIGNUM *a, size_t e);
515
516 /* BN_mod is a helper macro that calls |BN_div| and discards the quotient. */
517 #define BN_mod(rem, numerator, divisor, ctx) \
518 BN_div(NULL, (rem), (numerator), (divisor), (ctx))
519
520 /* BN_nnmod is a non-negative modulo function. It acts like |BN_mod|, but 0 <=
521 * |rem| < |divisor| is always true. It returns one on success and zero on
522 * error. */
523 OPENSSL_EXPORT int BN_nnmod(BIGNUM *rem, const BIGNUM *numerator,
524 const BIGNUM *divisor, BN_CTX *ctx);
525
526 /* BN_mod_add sets |r| = |a| + |b| mod |m|. It returns one on success and zero
527 * on error. */
528 OPENSSL_EXPORT int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
529 const BIGNUM *m, BN_CTX *ctx);
530
531 /* BN_mod_add_quick acts like |BN_mod_add| but requires that |a| and |b| be
532 * non-negative and less than |m|. */
533 OPENSSL_EXPORT int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
534 const BIGNUM *m);
535
536 /* BN_mod_sub sets |r| = |a| - |b| mod |m|. It returns one on success and zero
537 * on error. */
538 OPENSSL_EXPORT int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
539 const BIGNUM *m, BN_CTX *ctx);
540
541 /* BN_mod_sub_quick acts like |BN_mod_sub| but requires that |a| and |b| be
542 * non-negative and less than |m|. */
543 OPENSSL_EXPORT int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
544 const BIGNUM *m);
545
546 /* BN_mod_mul sets |r| = |a|*|b| mod |m|. It returns one on success and zero
547 * on error. */
548 OPENSSL_EXPORT int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
549 const BIGNUM *m, BN_CTX *ctx);
550
551 /* BN_mod_sqr sets |r| = |a|^2 mod |m|. It returns one on success and zero
552 * on error. */
553 OPENSSL_EXPORT int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m,
554 BN_CTX *ctx);
555
556 /* BN_mod_lshift sets |r| = (|a| << n) mod |m|, where |r| and |a| may be the
557 * same pointer. It returns one on success and zero on error. */
558 OPENSSL_EXPORT int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n,
559 const BIGNUM *m, BN_CTX *ctx);
560
561 /* BN_mod_lshift_quick acts like |BN_mod_lshift| but requires that |a| be
562 * non-negative and less than |m|. */
563 OPENSSL_EXPORT int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n,
564 const BIGNUM *m);
565
566 /* BN_mod_lshift1 sets |r| = (|a| << 1) 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_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m,
569 BN_CTX *ctx);
570
571 /* BN_mod_lshift1_quick acts like |BN_mod_lshift1| but requires that |a| be
572 * non-negative and less than |m|. */
573 OPENSSL_EXPORT int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a,
574 const BIGNUM *m);
575
576 /* BN_mod_sqrt returns a newly-allocated |BIGNUM|, r, such that
577 * r^2 == a (mod p). |p| must be a prime. It returns NULL on error or if |a| is
578 * not a square mod |p|. In the latter case, it will add |BN_R_NOT_A_SQUARE| to
579 * the error queue. */
580 OPENSSL_EXPORT BIGNUM *BN_mod_sqrt(BIGNUM *in, const BIGNUM *a, const BIGNUM *p,
581 BN_CTX *ctx);
582
583
584 /* Random and prime number generation. */
585
586 /* The following are values for the |top| parameter of |BN_rand|. */
587 #define BN_RAND_TOP_ANY (-1)
588 #define BN_RAND_TOP_ONE 0
589 #define BN_RAND_TOP_TWO 1
590
591 /* The following are values for the |bottom| parameter of |BN_rand|. */
592 #define BN_RAND_BOTTOM_ANY 0
593 #define BN_RAND_BOTTOM_ODD 1
594
595 /* BN_rand sets |rnd| to a random number of length |bits|. It returns one on
596 * success and zero otherwise.
597 *
598 * |top| must be one of the |BN_RAND_TOP_*| values. If |BN_RAND_TOP_ONE|, the
599 * most-significant bit, if any, will be set. If |BN_RAND_TOP_TWO|, the two
600 * most significant bits, if any, will be set. If |BN_RAND_TOP_ANY|, no extra
601 * action will be taken and |BN_num_bits(rnd)| may not equal |bits| if the most
602 * significant bits randomly ended up as zeros.
603 *
604 * |bottom| must be one of the |BN_RAND_BOTTOM_*| values. If
605 * |BN_RAND_BOTTOM_ODD|, the least-significant bit, if any, will be set. If
606 * |BN_RAND_BOTTOM_ANY|, no extra action will be taken. */
607 OPENSSL_EXPORT int BN_rand(BIGNUM *rnd, int bits, int top, int bottom);
608
609 /* BN_pseudo_rand is an alias for |BN_rand|. */
610 OPENSSL_EXPORT int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom);
611
612 /* BN_rand_range is equivalent to |BN_rand_range_ex| with |min_inclusive| set
613 * to zero and |max_exclusive| set to |range|. */
614 OPENSSL_EXPORT int BN_rand_range(BIGNUM *rnd, const BIGNUM *range);
615
616 /* BN_rand_range_ex sets |rnd| to a random value in
617 * [min_inclusive..max_exclusive). It returns one on success and zero
618 * otherwise. */
619 OPENSSL_EXPORT int BN_rand_range_ex(BIGNUM *r, BN_ULONG min_inclusive,
620 const BIGNUM *max_exclusive);
621
622 /* BN_pseudo_rand_range is an alias for BN_rand_range. */
623 OPENSSL_EXPORT int BN_pseudo_rand_range(BIGNUM *rnd, const BIGNUM *range);
624
625 /* BN_generate_dsa_nonce generates a random number 0 <= out < range. Unlike
626 * BN_rand_range, it also includes the contents of |priv| and |message| in the
627 * generation so that an RNG failure isn't fatal as long as |priv| remains
628 * secret. This is intended for use in DSA and ECDSA where an RNG weakness
629 * leads directly to private key exposure unless this function is used.
630 * It returns one on success and zero on error. */
631 OPENSSL_EXPORT int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range,
632 const BIGNUM *priv,
633 const uint8_t *message,
634 size_t message_len, BN_CTX *ctx);
635
636 /* BN_GENCB holds a callback function that is used by generation functions that
637 * can take a very long time to complete. Use |BN_GENCB_set| to initialise a
638 * |BN_GENCB| structure.
639 *
640 * The callback receives the address of that |BN_GENCB| structure as its last
641 * argument and the user is free to put an arbitrary pointer in |arg|. The other
642 * arguments are set as follows:
643 * event=BN_GENCB_GENERATED, n=i: after generating the i'th possible prime
644 * number.
645 * event=BN_GENCB_PRIME_TEST, n=-1: when finished trial division primality
646 * checks.
647 * event=BN_GENCB_PRIME_TEST, n=i: when the i'th primality test has finished.
648 *
649 * The callback can return zero to abort the generation progress or one to
650 * allow it to continue.
651 *
652 * When other code needs to call a BN generation function it will often take a
653 * BN_GENCB argument and may call the function with other argument values. */
654 #define BN_GENCB_GENERATED 0
655 #define BN_GENCB_PRIME_TEST 1
656
657 struct bn_gencb_st {
658 void *arg; /* callback-specific data */
659 int (*callback)(int event, int n, struct bn_gencb_st *);
660 };
661
662 /* BN_GENCB_set configures |callback| to call |f| and sets |callout->arg| to
663 * |arg|. */
664 OPENSSL_EXPORT void BN_GENCB_set(BN_GENCB *callback,
665 int (*f)(int event, int n,
666 struct bn_gencb_st *),
667 void *arg);
668
669 /* BN_GENCB_call calls |callback|, if not NULL, and returns the return value of
670 * the callback, or 1 if |callback| is NULL. */
671 OPENSSL_EXPORT int BN_GENCB_call(BN_GENCB *callback, int event, int n);
672
673 /* BN_generate_prime_ex sets |ret| to a prime number of |bits| length. If safe
674 * is non-zero then the prime will be such that (ret-1)/2 is also a prime.
675 * (This is needed for Diffie-Hellman groups to ensure that the only subgroups
676 * are of size 2 and (p-1)/2.).
677 *
678 * If |add| is not NULL, the prime will fulfill the condition |ret| % |add| ==
679 * |rem| in order to suit a given generator. (If |rem| is NULL then |ret| %
680 * |add| == 1.)
681 *
682 * If |cb| is not NULL, it will be called during processing to give an
683 * indication of progress. See the comments for |BN_GENCB|. It returns one on
684 * success and zero otherwise. */
685 OPENSSL_EXPORT int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe,
686 const BIGNUM *add, const BIGNUM *rem,
687 BN_GENCB *cb);
688
689 /* BN_prime_checks is magic value that can be used as the |checks| argument to
690 * the primality testing functions in order to automatically select a number of
691 * Miller-Rabin checks that gives a false positive rate of ~2^{-80}. */
692 #define BN_prime_checks 0
693
694 /* bn_primality_result_t enumerates the outcomes of primality-testing. */
695 enum bn_primality_result_t {
696 bn_probably_prime,
697 bn_composite,
698 bn_non_prime_power_composite,
699 };
700
701 /* BN_enhanced_miller_rabin_primality_test tests whether |w| is probably a prime
702 * number using the Enhanced Miller-Rabin Test (FIPS 186-4 C.3.2) with
703 * |iterations| iterations and returns the result in |out_result|. Enhanced
704 * Miller-Rabin tests primality for odd integers greater than 3, returning
705 * |bn_probably_prime| if the number is probably prime,
706 * |bn_non_prime_power_composite| if the number is a composite that is not the
707 * power of a single prime, and |bn_composite| otherwise. If |iterations| is
708 * |BN_prime_checks|, then a value that results in a false positive rate lower
709 * than the number-field sieve security level of |w| is used. It returns one on
710 * success and zero on failure. If |cb| is not NULL, then it is called during
711 * each iteration of the primality test. */
712 int BN_enhanced_miller_rabin_primality_test(
713 enum bn_primality_result_t *out_result, const BIGNUM *w, int iterations,
714 BN_CTX *ctx, BN_GENCB *cb);
715
716 /* BN_primality_test sets |*is_probably_prime| to one if |candidate| is
717 * probably a prime number by the Miller-Rabin test or zero if it's certainly
718 * not.
719 *
720 * If |do_trial_division| is non-zero then |candidate| will be tested against a
721 * list of small primes before Miller-Rabin tests. The probability of this
722 * function returning a false positive is 2^{2*checks}. If |checks| is
723 * |BN_prime_checks| then a value that results in a false positive rate lower
724 * than the number-field sieve security level of |candidate| is used. If |cb| is
725 * not NULL then it is called during the checking process. See the comment above
726 * |BN_GENCB|.
727 *
728 * The function returns one on success and zero on error.
729 *
730 * (If you are unsure whether you want |do_trial_division|, don't set it.) */
731 OPENSSL_EXPORT int BN_primality_test(int *is_probably_prime,
732 const BIGNUM *candidate, int checks,
733 BN_CTX *ctx, int do_trial_division,
734 BN_GENCB *cb);
735
736 /* BN_is_prime_fasttest_ex returns one if |candidate| is probably a prime
737 * number by the Miller-Rabin test, zero if it's certainly not and -1 on error.
738 *
739 * If |do_trial_division| is non-zero then |candidate| will be tested against a
740 * list of small primes before Miller-Rabin tests. The probability of this
741 * function returning one when |candidate| is composite is 2^{2*checks}. If
742 * |checks| is |BN_prime_checks| then a value that results in a false positive
743 * rate lower than the number-field sieve security level of |candidate| is used.
744 * If |cb| is not NULL then it is called during the checking process. See the
745 * comment above |BN_GENCB|.
746 *
747 * WARNING: deprecated. Use |BN_primality_test|. */
748 OPENSSL_EXPORT int BN_is_prime_fasttest_ex(const BIGNUM *candidate, int checks,
749 BN_CTX *ctx, int do_trial_division,
750 BN_GENCB *cb);
751
752 /* BN_is_prime_ex acts the same as |BN_is_prime_fasttest_ex| with
753 * |do_trial_division| set to zero.
754 *
755 * WARNING: deprecated: Use |BN_primality_test|. */
756 OPENSSL_EXPORT int BN_is_prime_ex(const BIGNUM *candidate, int checks,
757 BN_CTX *ctx, BN_GENCB *cb);
758
759
760 /* Number theory functions */
761
762 /* BN_gcd sets |r| = gcd(|a|, |b|). It returns one on success and zero
763 * otherwise. */
764 OPENSSL_EXPORT int BN_gcd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
765 BN_CTX *ctx);
766
767 /* BN_mod_inverse sets |out| equal to |a|^-1, mod |n|. If |out| is NULL, a
768 * fresh BIGNUM is allocated. It returns the result or NULL on error.
769 *
770 * If |n| is even then the operation is performed using an algorithm that avoids
771 * some branches but which isn't constant-time. This function shouldn't be used
772 * for secret values; use |BN_mod_inverse_blinded| instead. Or, if |n| is
773 * guaranteed to be prime, use
774 * |BN_mod_exp_mont_consttime(out, a, m_minus_2, m, ctx, m_mont)|, taking
775 * advantage of Fermat's Little Theorem. */
776 OPENSSL_EXPORT BIGNUM *BN_mod_inverse(BIGNUM *out, const BIGNUM *a,
777 const BIGNUM *n, BN_CTX *ctx);
778
779 /* BN_mod_inverse_blinded sets |out| equal to |a|^-1, mod |n|, where |n| is the
780 * Montgomery modulus for |mont|. |a| must be non-negative and must be less
781 * than |n|. |n| must be greater than 1. |a| is blinded (masked by a random
782 * value) to protect it against side-channel attacks. On failure, if the failure
783 * was caused by |a| having no inverse mod |n| then |*out_no_inverse| will be
784 * set to one; otherwise it will be set to zero. */
785 int BN_mod_inverse_blinded(BIGNUM *out, int *out_no_inverse, const BIGNUM *a,
786 const BN_MONT_CTX *mont, BN_CTX *ctx);
787
788 /* BN_mod_inverse_odd sets |out| equal to |a|^-1, mod |n|. |a| must be
789 * non-negative and must be less than |n|. |n| must be odd. This function
790 * shouldn't be used for secret values; use |BN_mod_inverse_blinded| instead.
791 * Or, if |n| is guaranteed to be prime, use
792 * |BN_mod_exp_mont_consttime(out, a, m_minus_2, m, ctx, m_mont)|, taking
793 * advantage of Fermat's Little Theorem. It returns one on success or zero on
794 * failure. On failure, if the failure was caused by |a| having no inverse mod
795 * |n| then |*out_no_inverse| will be set to one; otherwise it will be set to
796 * zero. */
797 int BN_mod_inverse_odd(BIGNUM *out, int *out_no_inverse, const BIGNUM *a,
798 const BIGNUM *n, BN_CTX *ctx);
799
800
801 /* Montgomery arithmetic. */
802
803 /* BN_MONT_CTX contains the precomputed values needed to work in a specific
804 * Montgomery domain. */
805
806 /* BN_MONT_CTX_new returns a fresh BN_MONT_CTX or NULL on allocation failure. */
807 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_new(void);
808
809 /* BN_MONT_CTX_free frees memory associated with |mont|. */
810 OPENSSL_EXPORT void BN_MONT_CTX_free(BN_MONT_CTX *mont);
811
812 /* BN_MONT_CTX_copy sets |to| equal to |from|. It returns |to| on success or
813 * NULL on error. */
814 OPENSSL_EXPORT BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to,
815 const BN_MONT_CTX *from);
816
817 /* BN_MONT_CTX_set sets up a Montgomery context given the modulus, |mod|. It
818 * returns one on success and zero on error. */
819 OPENSSL_EXPORT int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod,
820 BN_CTX *ctx);
821
822 /* BN_MONT_CTX_set_locked takes |lock| and checks whether |*pmont| is NULL. If
823 * so, it creates a new |BN_MONT_CTX| and sets the modulus for it to |mod|. It
824 * then stores it as |*pmont|. It returns one on success and zero on error.
825 *
826 * If |*pmont| is already non-NULL then it does nothing and returns one. */
827 int BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
828 const BIGNUM *mod, BN_CTX *bn_ctx);
829
830 /* BN_to_montgomery sets |ret| equal to |a| in the Montgomery domain. |a| is
831 * assumed to be in the range [0, n), where |n| is the Montgomery modulus. It
832 * returns one on success or zero on error. */
833 OPENSSL_EXPORT int BN_to_montgomery(BIGNUM *ret, const BIGNUM *a,
834 const BN_MONT_CTX *mont, BN_CTX *ctx);
835
836 /* BN_from_montgomery sets |ret| equal to |a| * R^-1, i.e. translates values out
837 * of the Montgomery domain. |a| is assumed to be in the range [0, n), where |n|
838 * is the Montgomery modulus. It returns one on success or zero on error. */
839 OPENSSL_EXPORT int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a,
840 const BN_MONT_CTX *mont, BN_CTX *ctx);
841
842 /* BN_mod_mul_montgomery set |r| equal to |a| * |b|, in the Montgomery domain.
843 * Both |a| and |b| must already be in the Montgomery domain (by
844 * |BN_to_montgomery|). In particular, |a| and |b| are assumed to be in the
845 * range [0, n), where |n| is the Montgomery modulus. It returns one on success
846 * or zero on error. */
847 OPENSSL_EXPORT int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a,
848 const BIGNUM *b,
849 const BN_MONT_CTX *mont, BN_CTX *ctx);
850
851
852 /* Exponentiation. */
853
854 /* BN_exp sets |r| equal to |a|^{|p|}. It does so with a square-and-multiply
855 * algorithm that leaks side-channel information. It returns one on success or
856 * zero otherwise. */
857 OPENSSL_EXPORT int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
858 BN_CTX *ctx);
859
860 /* BN_mod_exp sets |r| equal to |a|^{|p|} mod |m|. It does so with the best
861 * algorithm for the values provided. It returns one on success or zero
862 * otherwise. The |BN_mod_exp_mont_consttime| variant must be used if the
863 * exponent is secret. */
864 OPENSSL_EXPORT int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
865 const BIGNUM *m, BN_CTX *ctx);
866
867 OPENSSL_EXPORT int BN_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
868 const BIGNUM *m, BN_CTX *ctx,
869 const BN_MONT_CTX *mont);
870
871 OPENSSL_EXPORT int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a,
872 const BIGNUM *p, const BIGNUM *m,
873 BN_CTX *ctx,
874 const BN_MONT_CTX *mont);
875
876
877 /* Deprecated functions */
878
879 /* BN_bn2mpi serialises the value of |in| to |out|, using a format that consists
880 * of the number's length in bytes represented as a 4-byte big-endian number,
881 * and the number itself in big-endian format, where the most significant bit
882 * signals a negative number. (The representation of numbers with the MSB set is
883 * prefixed with null byte). |out| must have sufficient space available; to
884 * find the needed amount of space, call the function with |out| set to NULL. */
885 OPENSSL_EXPORT size_t BN_bn2mpi(const BIGNUM *in, uint8_t *out);
886
887 /* BN_mpi2bn parses |len| bytes from |in| and returns the resulting value. The
888 * bytes at |in| are expected to be in the format emitted by |BN_bn2mpi|.
889 *
890 * If |out| is NULL then a fresh |BIGNUM| is allocated and returned, otherwise
891 * |out| is reused and returned. On error, NULL is returned and the error queue
892 * is updated. */
893 OPENSSL_EXPORT BIGNUM *BN_mpi2bn(const uint8_t *in, size_t len, BIGNUM *out);
894
895 /* BN_mod_exp_mont_word is like |BN_mod_exp_mont| except that the base |a| is
896 * given as a |BN_ULONG| instead of a |BIGNUM *|. It returns one on success
897 * or zero otherwise. */
898 OPENSSL_EXPORT int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p,
899 const BIGNUM *m, BN_CTX *ctx,
900 const BN_MONT_CTX *mont);
901
902 /* BN_mod_exp2_mont calculates (a1^p1) * (a2^p2) mod m. It returns 1 on success
903 * or zero otherwise. */
904 OPENSSL_EXPORT int BN_mod_exp2_mont(BIGNUM *r, const BIGNUM *a1,
905 const BIGNUM *p1, const BIGNUM *a2,
906 const BIGNUM *p2, const BIGNUM *m,
907 BN_CTX *ctx, const BN_MONT_CTX *mont);
908
909
910 /* Private functions */
911
912 struct bignum_st {
913 BN_ULONG *d; /* Pointer to an array of 'BN_BITS2' bit chunks in little-endian
914 order. */
915 int top; /* Index of last used element in |d|, plus one. */
916 int dmax; /* Size of |d|, in words. */
917 int neg; /* one if the number is negative */
918 int flags; /* bitmask of BN_FLG_* values */
919 };
920
921 struct bn_mont_ctx_st {
922 BIGNUM RR; /* used to convert to montgomery form */
923 BIGNUM N; /* The modulus */
924 BN_ULONG n0[2]; /* least significant words of (R*Ri-1)/N */
925 };
926
927 OPENSSL_EXPORT unsigned BN_num_bits_word(BN_ULONG l);
928
929 #define BN_FLG_MALLOCED 0x01
930 #define BN_FLG_STATIC_DATA 0x02
931 /* |BN_FLG_CONSTTIME| has been removed and intentionally omitted so code relying
932 * on it will not compile. Consumers outside BoringSSL should use the
933 * higher-level cryptographic algorithms exposed by other modules. Consumers
934 * within the library should call the appropriate timing-sensitive algorithm
935 * directly. */
936
937
938 #if defined(__cplusplus)
939 } /* extern C */
940
941 #if (__cplusplus >= 201103L || (__cplusplus < 200000 && __cplusplus > 199711L)) && !defined(OPENSSL_NO_CXX)
942
943 extern "C++" {
944
945 namespace bssl {
946
BORINGSSL_MAKE_DELETER(BIGNUM,BN_free)947 BORINGSSL_MAKE_DELETER(BIGNUM, BN_free)
948 BORINGSSL_MAKE_DELETER(BN_CTX, BN_CTX_free)
949 BORINGSSL_MAKE_DELETER(BN_MONT_CTX, BN_MONT_CTX_free)
950
951 class BN_CTXScope {
952 public:
953 BN_CTXScope(BN_CTX *ctx) : ctx_(ctx) { BN_CTX_start(ctx_); }
954 ~BN_CTXScope() { BN_CTX_end(ctx_); }
955
956 private:
957 BN_CTX *ctx_;
958
959 BN_CTXScope(BN_CTXScope &) = delete;
960 BN_CTXScope &operator=(BN_CTXScope &) = delete;
961 };
962
963 } // namespace bssl
964
965 } /* extern C++ */
966 #endif
967
968 #endif
969
970 #define BN_R_ARG2_LT_ARG3 100
971 #define BN_R_BAD_RECIPROCAL 101
972 #define BN_R_BIGNUM_TOO_LONG 102
973 #define BN_R_BITS_TOO_SMALL 103
974 #define BN_R_CALLED_WITH_EVEN_MODULUS 104
975 #define BN_R_DIV_BY_ZERO 105
976 #define BN_R_EXPAND_ON_STATIC_BIGNUM_DATA 106
977 #define BN_R_INPUT_NOT_REDUCED 107
978 #define BN_R_INVALID_RANGE 108
979 #define BN_R_NEGATIVE_NUMBER 109
980 #define BN_R_NOT_A_SQUARE 110
981 #define BN_R_NOT_INITIALIZED 111
982 #define BN_R_NO_INVERSE 112
983 #define BN_R_PRIVATE_KEY_TOO_LARGE 113
984 #define BN_R_P_IS_NOT_PRIME 114
985 #define BN_R_TOO_MANY_ITERATIONS 115
986 #define BN_R_TOO_MANY_TEMPORARY_VARIABLES 116
987 #define BN_R_BAD_ENCODING 117
988 #define BN_R_ENCODE_ERROR 118
989 #define BN_R_INVALID_INPUT 119
990
991 #endif /* OPENSSL_HEADER_BN_H */
992