xref: /openssl/include/crypto/bn.h (revision 544fd23f)
1 /*
2  * Copyright 2014-2024 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 int ossl_bn_mask_bits_fixed_top(BIGNUM *a, int n);
91 int ossl_bn_is_word_fixed_top(const BIGNUM *a, const BN_ULONG w);
92 int ossl_bn_priv_rand_range_fixed_top(BIGNUM *r, const BIGNUM *range,
93                                       unsigned int strength, BN_CTX *ctx);
94 int ossl_bn_gen_dsa_nonce_fixed_top(BIGNUM *out, const BIGNUM *range,
95                                     const BIGNUM *priv,
96                                     const unsigned char *message,
97                                     size_t message_len, BN_CTX *ctx);
98 
99 #define BN_PRIMETEST_COMPOSITE                    0
100 #define BN_PRIMETEST_COMPOSITE_WITH_FACTOR        1
101 #define BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME 2
102 #define BN_PRIMETEST_PROBABLY_PRIME               3
103 
104 int ossl_bn_miller_rabin_is_prime(const BIGNUM *w, int iterations, BN_CTX *ctx,
105                                   BN_GENCB *cb, int enhanced, int *status);
106 int ossl_bn_check_generated_prime(const BIGNUM *w, int checks, BN_CTX *ctx,
107                                   BN_GENCB *cb);
108 
109 const BIGNUM *ossl_bn_get0_small_factors(void);
110 
111 int ossl_bn_rsa_fips186_4_gen_prob_primes(BIGNUM *p, BIGNUM *Xpout,
112                                           BIGNUM *p1, BIGNUM *p2,
113                                           const BIGNUM *Xp, const BIGNUM *Xp1,
114                                           const BIGNUM *Xp2, int nlen,
115                                           const BIGNUM *e, BN_CTX *ctx,
116                                           BN_GENCB *cb);
117 
118 int ossl_bn_rsa_fips186_4_derive_prime(BIGNUM *Y, BIGNUM *X, const BIGNUM *Xin,
119                                        const BIGNUM *r1, const BIGNUM *r2,
120                                        int nlen, const BIGNUM *e, BN_CTX *ctx,
121                                        BN_GENCB *cb);
122 
123 OSSL_LIB_CTX *ossl_bn_get_libctx(BN_CTX *ctx);
124 
125 extern const BIGNUM ossl_bn_inv_sqrt_2;
126 
127 #if defined(OPENSSL_SYS_LINUX) && !defined(FIPS_MODULE) && defined (__s390x__) \
128     && !defined (OPENSSL_NO_ASM)
129 # define S390X_MOD_EXP
130 #endif
131 
132 int s390x_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
133                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
134 int s390x_crt(BIGNUM *r, const BIGNUM *i, const BIGNUM *p, const BIGNUM *q,
135             const BIGNUM *dmp, const BIGNUM *dmq, const BIGNUM *iqmp);
136 
137 #endif
138 
139 int ossl_bn_mont_ctx_set(BN_MONT_CTX *ctx, const BIGNUM *modulus, int ri,
140                          const unsigned char *rr, size_t rrlen,
141                          uint32_t nlo, uint32_t nhi);
142 
143 int ossl_bn_mont_ctx_eq(const BN_MONT_CTX *m1, const BN_MONT_CTX *m2);
144