2 * Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
10 #ifndef HEADER_BN_INT_H
11 # define HEADER_BN_INT_H
13 # include <openssl/bn.h>
16 BIGNUM *bn_wexpand(BIGNUM *a, int words);
17 BIGNUM *bn_expand2(BIGNUM *a, int words);
19 void bn_correct_top(BIGNUM *a);
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
29 signed char *bn_compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len);
31 int bn_get_top(const BIGNUM *a);
33 int bn_get_dmax(const BIGNUM *a);
35 /* Set all words to zero */
36 void bn_set_all_zero(BIGNUM *a);
39 * Copy the internal BIGNUM words into out which holds size elements (and size
40 * must be bigger than top)
42 int bn_copy_words(BN_ULONG *out, const BIGNUM *in, int size);
44 BN_ULONG *bn_get_words(const BIGNUM *a);
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
50 void bn_set_static_words(BIGNUM *a, const BN_ULONG *words, int size);
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.
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.
61 int bn_set_words(BIGNUM *a, const BN_ULONG *words, int num_words);
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.
70 int bn_mul_mont_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
71 BN_MONT_CTX *mont, BN_CTX *ctx);
72 int bn_to_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
74 int bn_from_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
76 int bn_mod_add_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
78 int bn_mod_sub_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
80 int bn_mul_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
81 int bn_sqr_fixed_top(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx);