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_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)
129OPENSSL_MSVC_PRAGMA(warning(push, 3))
130#include <intrin.h>
131OPENSSL_MSVC_PRAGMA(warning(pop))
132#pragma intrinsic(__umulh, _umul128)
133#endif
134
135#include "../../internal.h"
136
137#if defined(__cplusplus)
138extern "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|.
202int 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.
206void 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.
211int 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.
215int 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.
223int 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.
227int 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.
231int 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.
235int 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.
241BN_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.
247BN_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|.
254void 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.
260BN_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.
267BN_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|.
271void 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|.
274void 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.
277void bn_sqr_comba8(BN_ULONG r[16], const BN_ULONG a[4]);
278
279// bn_sqr_comba4 sets |r| to |a|^2.
280void 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|.
284int 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|.
290int 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.
294int 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.
301int 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.)
311int 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
315int 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
318uint64_t bn_mont_n0(const BIGNUM *n);
319int 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.
332int 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.
338int 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.
343int 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.
347int 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.
352int 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.
356int 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.
378int 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.
384int 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.
393int 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.
401int 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.
408int 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.
421int 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.
436int 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.
444int 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