include/crypto/bn.h

   1 /*
   2  * Copyright 2014-2021 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 # pragma once
  13
  14 # include <openssl/bn.h>
  15 # include <limits.h>
  16
  17 BIGNUM *bn_wexpand(BIGNUM *a, int words);
  18 BIGNUM *bn_expand2(BIGNUM *a, int words);
  19
  20 void bn_correct_top(BIGNUM *a);
  21
  22 /*
  23  * Determine the modified width-(w+1) Non-Adjacent Form (wNAF) of 'scalar'.
  24  * This is an array r[] of values that are either zero or odd with an
  25  * absolute value less than 2^w satisfying scalar = \sum_j r[j]*2^j where at
  26  * most one of any w+1 consecutive digits is non-zero with the exception that
  27  * the most significant digit may be only w-1 zeros away from that next
  28  * non-zero digit.
  29  */
  30 signed char *bn_compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len);
  31
  32 int bn_get_top(const BIGNUM *a);
  33
  34 int bn_get_dmax(const BIGNUM *a);
  35
  36 /* Set all words to zero */
  37 void bn_set_all_zero(BIGNUM *a);
  38
  39 /*
  40  * Copy the internal BIGNUM words into out which holds size elements (and size
  41  * must be bigger than top)
  42  */
  43 int bn_copy_words(BN_ULONG *out, const BIGNUM *in, int size);
  44
  45 BN_ULONG *bn_get_words(const BIGNUM *a);
  46
  47 /*
  48  * Set the internal data words in a to point to words which contains size
  49  * elements. The BN_FLG_STATIC_DATA flag is set
  50  */
  51 void bn_set_static_words(BIGNUM *a, const BN_ULONG *words, int size);
  52
  53 /*
  54  * Copy words into the BIGNUM |a|, reallocating space as necessary.
  55  * The negative flag of |a| is not modified.
  56  * Returns 1 on success and 0 on failure.
  57  */
  58 /*
  59  * |num_words| is int because bn_expand2 takes an int. This is an internal
  60  * function so we simply trust callers not to pass negative values.
  61  */
  62 int bn_set_words(BIGNUM *a, const BN_ULONG *words, int num_words);
  63
  64 /*
  65  * Some BIGNUM functions assume most significant limb to be non-zero, which
  66  * is customarily arranged by bn_correct_top. Output from below functions
  67  * is not processed with bn_correct_top, and for this reason it may not be
  68  * returned out of public API. It may only be passed internally into other
  69  * functions known to support non-minimal or zero-padded BIGNUMs. Even
  70  * though the goal is to facilitate constant-time-ness, not each subroutine
  71  * is constant-time by itself. They all have pre-conditions, consult source
  72  * code...
  73  */
  74 int bn_mul_mont_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
  75                           BN_MONT_CTX *mont, BN_CTX *ctx);
  76 int bn_to_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
  77                          BN_CTX *ctx);
  78 int bn_from_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
  79                            BN_CTX *ctx);
  80 int bn_mod_add_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
  81                          const BIGNUM *m);
  82 int bn_mod_sub_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
  83                          const BIGNUM *m);
  84 int bn_mul_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
  85 int bn_sqr_fixed_top(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx);
  86 int bn_lshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n);
  87 int bn_rshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n);
  88 int bn_div_fixed_top(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
  89                      const BIGNUM *d, BN_CTX *ctx);
  90
  91 #define BN_PRIMETEST_COMPOSITE                    0
  92 #define BN_PRIMETEST_COMPOSITE_WITH_FACTOR        1
  93 #define BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME 2
  94 #define BN_PRIMETEST_PROBABLY_PRIME               3
  95
  96 int bn_miller_rabin_is_prime(const BIGNUM *w, int iterations, BN_CTX *ctx,
  97                              BN_GENCB *cb, int enhanced, int *status);
  98
  99 const BIGNUM *bn_get0_small_factors(void);
 100
 101 int bn_rsa_fips186_4_prime_MR_min_checks(int nbits);
 102
 103 int bn_rsa_fips186_4_gen_prob_primes(BIGNUM *p, BIGNUM *Xpout,
 104                                      BIGNUM *p1, BIGNUM *p2,
 105                                      const BIGNUM *Xp, const BIGNUM *Xp1,
 106                                      const BIGNUM *Xp2, int nlen,
 107                                      const BIGNUM *e, BN_CTX *ctx,
 108                                      BN_GENCB *cb);
 109
 110 int bn_rsa_fips186_4_derive_prime(BIGNUM *Y, BIGNUM *X, const BIGNUM *Xin,
 111                                   const BIGNUM *r1, const BIGNUM *r2, int nlen,
 112                                   const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb);
 113
 114 OSSL_LIB_CTX *bn_get_libctx(BN_CTX *ctx);
 115
 116 extern const BIGNUM bn_inv_sqrt_2;
 117
 118 #endif