1/*
2 * Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#ifndef OSSL_CRYPTO_BN_H
11# define OSSL_CRYPTO_BN_H
12
13# include <openssl/bn.h>
14# include <limits.h>
15
16BIGNUM *bn_wexpand(BIGNUM *a, int words);
17BIGNUM *bn_expand2(BIGNUM *a, int words);
18
19void bn_correct_top(BIGNUM *a);
20
21/*
22 * Determine the modified width-(w+1) Non-Adjacent Form (wNAF) of 'scalar'.
23 * This is an array r[] of values that are either zero or odd with an
24 * absolute value less than 2^w satisfying scalar = \sum_j r[j]*2^j where at
25 * most one of any w+1 consecutive digits is non-zero with the exception that
26 * the most significant digit may be only w-1 zeros away from that next
27 * non-zero digit.
28 */
29signed char *bn_compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len);
30
31int bn_get_top(const BIGNUM *a);
32
33int bn_get_dmax(const BIGNUM *a);
34
35/* Set all words to zero */
36void bn_set_all_zero(BIGNUM *a);
37
38/*
39 * Copy the internal BIGNUM words into out which holds size elements (and size
40 * must be bigger than top)
41 */
42int bn_copy_words(BN_ULONG *out, const BIGNUM *in, int size);
43
44BN_ULONG *bn_get_words(const BIGNUM *a);
45
46/*
47 * Set the internal data words in a to point to words which contains size
48 * elements. The BN_FLG_STATIC_DATA flag is set
49 */
50void bn_set_static_words(BIGNUM *a, const BN_ULONG *words, int size);
51
52/*
53 * Copy words into the BIGNUM |a|, reallocating space as necessary.
54 * The negative flag of |a| is not modified.
55 * Returns 1 on success and 0 on failure.
56 */
57/*
58 * |num_words| is int because bn_expand2 takes an int. This is an internal
59 * function so we simply trust callers not to pass negative values.
60 */
61int bn_set_words(BIGNUM *a, const BN_ULONG *words, int num_words);
62
63/*
64 * Some BIGNUM functions assume most significant limb to be non-zero, which
65 * is customarily arranged by bn_correct_top. Output from below functions
66 * is not processed with bn_correct_top, and for this reason it may not be
67 * returned out of public API. It may only be passed internally into other
68 * functions known to support non-minimal or zero-padded BIGNUMs. Even
69 * though the goal is to facilitate constant-time-ness, not each subroutine
70 * is constant-time by itself. They all have pre-conditions, consult source
71 * code...
72 */
73int bn_mul_mont_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
74 BN_MONT_CTX *mont, BN_CTX *ctx);
75int bn_to_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
76 BN_CTX *ctx);
77int bn_from_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
78 BN_CTX *ctx);
79int bn_mod_add_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
80 const BIGNUM *m);
81int bn_mod_sub_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
82 const BIGNUM *m);
83int bn_mul_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
84int bn_sqr_fixed_top(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx);
85int bn_lshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n);
86int bn_rshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n);
87int bn_div_fixed_top(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
88 const BIGNUM *d, BN_CTX *ctx);
89
90#define BN_PRIMETEST_COMPOSITE 0
91#define BN_PRIMETEST_COMPOSITE_WITH_FACTOR 1
92#define BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME 2
93#define BN_PRIMETEST_PROBABLY_PRIME 3
94
95int bn_miller_rabin_is_prime(const BIGNUM *w, int iterations, BN_CTX *ctx,
96 BN_GENCB *cb, int enhanced, int *status);
97
98const BIGNUM *bn_get0_small_factors(void);
99
100int bn_rsa_fips186_4_prime_MR_min_checks(int nbits);
101
102int bn_rsa_fips186_4_gen_prob_primes(BIGNUM *p, BIGNUM *Xpout,
103 BIGNUM *p1, BIGNUM *p2,
104 const BIGNUM *Xp, const BIGNUM *Xp1,
105 const BIGNUM *Xp2, int nlen,
106 const BIGNUM *e, BN_CTX *ctx,
107 BN_GENCB *cb);
108
109int bn_rsa_fips186_4_derive_prime(BIGNUM *Y, BIGNUM *X, const BIGNUM *Xin,
110 const BIGNUM *r1, const BIGNUM *r2, int nlen,
111 const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb);
112
113OPENSSL_CTX *bn_get_lib_ctx(BN_CTX *ctx);
114
115extern const BIGNUM bn_inv_sqrt_2;
116
117#endif
118