/*
 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#ifndef OPENSSL_BN_H
#define OPENSSL_BN_H
#pragma once

#include <openssl/macros.h>
#ifndef OPENSSL_NO_DEPRECATED_3_0
#define HEADER_BN_H
#endif

#include <openssl/e_os2.h>
#ifndef OPENSSL_NO_STDIO
#include <stdio.h>
#endif
#include <openssl/opensslconf.h>
#include <openssl/types.h>
#include <openssl/crypto.h>
#include <openssl/bnerr.h>

#ifdef __cplusplus
extern "C"
{
#endif

/*
 * 64-bit processor with LP64 ABI
 */
#ifdef SIXTY_FOUR_BIT_LONG
#define BN_ULONG unsigned long
#define BN_BYTES 8
#endif

/*
 * 64-bit processor other than LP64 ABI
 */
#ifdef SIXTY_FOUR_BIT
#define BN_ULONG unsigned long long
#define BN_BYTES 8
#endif

#ifdef THIRTY_TWO_BIT
#define BN_ULONG unsigned int
#define BN_BYTES 4
#endif

#define BN_BITS2 (BN_BYTES * 8)
#define BN_BITS (BN_BITS2 * 2)
#define BN_TBIT ((BN_ULONG)1 << (BN_BITS2 - 1))

#define BN_FLG_MALLOCED 0x01
#define BN_FLG_STATIC_DATA 0x02

/*
 * avoid leaking exponent information through timing,
 * BN_mod_exp_mont() will call BN_mod_exp_mont_consttime,
 * BN_div() will call BN_div_no_branch,
 * BN_mod_inverse() will call bn_mod_inverse_no_branch.
 */
#define BN_FLG_CONSTTIME 0x04
#define BN_FLG_SECURE 0x08

#ifndef OPENSSL_NO_DEPRECATED_0_9_8
/* deprecated name for the flag */
#define BN_FLG_EXP_CONSTTIME BN_FLG_CONSTTIME
#define BN_FLG_FREE 0x8000 /* used for debugging */
#endif

    void BN_set_flags(BIGNUM* b, int n);
    int BN_get_flags(const BIGNUM* b, int n);

/* Values for |top| in BN_rand() */
#define BN_RAND_TOP_ANY -1
#define BN_RAND_TOP_ONE 0
#define BN_RAND_TOP_TWO 1

/* Values for |bottom| in BN_rand() */
#define BN_RAND_BOTTOM_ANY 0
#define BN_RAND_BOTTOM_ODD 1

    /*
     * get a clone of a BIGNUM with changed flags, for *temporary* use only (the
     * two BIGNUMs cannot be used in parallel!). Also only for *read only* use. The
     * value |dest| should be a newly allocated BIGNUM obtained via BN_new() that
     * has not been otherwise initialised or used.
     */
    void BN_with_flags(BIGNUM* dest, const BIGNUM* b, int flags);

    /* Wrapper function to make using BN_GENCB easier */
    int BN_GENCB_call(BN_GENCB* cb, int a, int b);

    BN_GENCB* BN_GENCB_new(void);
    void BN_GENCB_free(BN_GENCB* cb);

    /* Populate a BN_GENCB structure with an "old"-style callback */
    void BN_GENCB_set_old(BN_GENCB* gencb, void (*callback)(int, int, void*), void* cb_arg);

    /* Populate a BN_GENCB structure with a "new"-style callback */
    void BN_GENCB_set(BN_GENCB* gencb, int (*callback)(int, int, BN_GENCB*), void* cb_arg);

    void* BN_GENCB_get_arg(BN_GENCB* cb);

#ifndef OPENSSL_NO_DEPRECATED_3_0
#define BN_prime_checks 0 /* default: select number of iterations based \
                           * on the size of the number */

    /*
     * BN_prime_checks_for_size() returns the number of Miller-Rabin iterations
     * that will be done for checking that a random number is probably prime. The
     * error rate for accepting a composite number as prime depends on the size of
     * the prime |b|. The error rates used are for calculating an RSA key with 2 primes,
     * and so the level is what you would expect for a key of double the size of the
     * prime.
     *
     * This table is generated using the algorithm of FIPS PUB 186-4
     * Digital Signature Standard (DSS), section F.1, page 117.
     * (https://dx.doi.org/10.6028/NIST.FIPS.186-4)
     *
     * The following magma script was used to generate the output:
     * securitybits:=125;
     * k:=1024;
     * for t:=1 to 65 do
     *   for M:=3 to Floor(2*Sqrt(k-1)-1) do
     *     S:=0;
     *     // Sum over m
     *     for m:=3 to M do
     *       s:=0;
     *       // Sum over j
     *       for j:=2 to m do
     *         s+:=(RealField(32)!2)^-(j+(k-1)/j);
     *       end for;
     *       S+:=2^(m-(m-1)*t)*s;
     *     end for;
     *     A:=2^(k-2-M*t);
     *     B:=8*(Pi(RealField(32))^2-6)/3*2^(k-2)*S;
     *     pkt:=2.00743*Log(2)*k*2^-k*(A+B);
     *     seclevel:=Floor(-Log(2,pkt));
     *     if seclevel ge securitybits then
     *       printf "k: %5o, security: %o bits  (t: %o, M: %o)\n",k,seclevel,t,M;
     *       break;
     *     end if;
     *   end for;
     *   if seclevel ge securitybits then break; end if;
     * end for;
     *
     * It can be run online at:
     * http://magma.maths.usyd.edu.au/calc
     *
     * And will output:
     * k:  1024, security: 129 bits  (t: 6, M: 23)
     *
     * k is the number of bits of the prime, securitybits is the level we want to
     * reach.
     *
     * prime length | RSA key size | # MR tests | security level
     * -------------+--------------|------------+---------------
     *  (b) >= 6394 |     >= 12788 |          3 |        256 bit
     *  (b) >= 3747 |     >=  7494 |          3 |        192 bit
     *  (b) >= 1345 |     >=  2690 |          4 |        128 bit
     *  (b) >= 1080 |     >=  2160 |          5 |        128 bit
     *  (b) >=  852 |     >=  1704 |          5 |        112 bit
     *  (b) >=  476 |     >=   952 |          5 |         80 bit
     *  (b) >=  400 |     >=   800 |          6 |         80 bit
     *  (b) >=  347 |     >=   694 |          7 |         80 bit
     *  (b) >=  308 |     >=   616 |          8 |         80 bit
     *  (b) >=   55 |     >=   110 |         27 |         64 bit
     *  (b) >=    6 |     >=    12 |         34 |         64 bit
     */

#define BN_prime_checks_for_size(b) ((b) >= 3747 ? 3 : (b) >= 1345 ? 4 :  \
                                                   (b) >= 476      ? 5 :  \
                                                   (b) >= 400      ? 6 :  \
                                                   (b) >= 347      ? 7 :  \
                                                   (b) >= 308      ? 8 :  \
                                                   (b) >= 55       ? 27 : \
                                                                     /* b >= 6 */ 34)
#endif

#define BN_num_bytes(a) ((BN_num_bits(a) + 7) / 8)

    int BN_abs_is_word(const BIGNUM* a, const BN_ULONG w);
    int BN_is_zero(const BIGNUM* a);
    int BN_is_one(const BIGNUM* a);
    int BN_is_word(const BIGNUM* a, const BN_ULONG w);
    int BN_is_odd(const BIGNUM* a);

#define BN_one(a) (BN_set_word((a), 1))

    void BN_zero_ex(BIGNUM* a);

#if OPENSSL_API_LEVEL > 908
#define BN_zero(a) BN_zero_ex(a)
#else
#define BN_zero(a) (BN_set_word((a), 0))
#endif

    const BIGNUM* BN_value_one(void);
    char* BN_options(void);
    BN_CTX* BN_CTX_new_ex(OSSL_LIB_CTX* ctx);
    BN_CTX* BN_CTX_new(void);
    BN_CTX* BN_CTX_secure_new_ex(OSSL_LIB_CTX* ctx);
    BN_CTX* BN_CTX_secure_new(void);
    void BN_CTX_free(BN_CTX* c);
    void BN_CTX_start(BN_CTX* ctx);
    BIGNUM* BN_CTX_get(BN_CTX* ctx);
    void BN_CTX_end(BN_CTX* ctx);
    int BN_rand_ex(BIGNUM* rnd, int bits, int top, int bottom, unsigned int strength, BN_CTX* ctx);
    int BN_rand(BIGNUM* rnd, int bits, int top, int bottom);
    int BN_priv_rand_ex(BIGNUM* rnd, int bits, int top, int bottom, unsigned int strength, BN_CTX* ctx);
    int BN_priv_rand(BIGNUM* rnd, int bits, int top, int bottom);
    int BN_rand_range_ex(BIGNUM* r, const BIGNUM* range, unsigned int strength, BN_CTX* ctx);
    int BN_rand_range(BIGNUM* rnd, const BIGNUM* range);
    int BN_priv_rand_range_ex(BIGNUM* r, const BIGNUM* range, unsigned int strength, BN_CTX* ctx);
    int BN_priv_rand_range(BIGNUM* rnd, const BIGNUM* range);
#ifndef OPENSSL_NO_DEPRECATED_3_0
    OSSL_DEPRECATEDIN_3_0
    int BN_pseudo_rand(BIGNUM* rnd, int bits, int top, int bottom);
    OSSL_DEPRECATEDIN_3_0
    int BN_pseudo_rand_range(BIGNUM* rnd, const BIGNUM* range);
#endif
    int BN_num_bits(const BIGNUM* a);
    int BN_num_bits_word(BN_ULONG l);
    int BN_security_bits(int L, int N);
    BIGNUM* BN_new(void);
    BIGNUM* BN_secure_new(void);
    void BN_clear_free(BIGNUM* a);
    BIGNUM* BN_copy(BIGNUM* a, const BIGNUM* b);
    void BN_swap(BIGNUM* a, BIGNUM* b);
    BIGNUM* BN_bin2bn(const unsigned char* s, int len, BIGNUM* ret);
    int BN_bn2bin(const BIGNUM* a, unsigned char* to);
    int BN_bn2binpad(const BIGNUM* a, unsigned char* to, int tolen);
    BIGNUM* BN_lebin2bn(const unsigned char* s, int len, BIGNUM* ret);
    int BN_bn2lebinpad(const BIGNUM* a, unsigned char* to, int tolen);
    BIGNUM* BN_native2bn(const unsigned char* s, int len, BIGNUM* ret);
    int BN_bn2nativepad(const BIGNUM* a, unsigned char* to, int tolen);
    BIGNUM* BN_mpi2bn(const unsigned char* s, int len, BIGNUM* ret);
    int BN_bn2mpi(const BIGNUM* a, unsigned char* to);
    int BN_sub(BIGNUM* r, const BIGNUM* a, const BIGNUM* b);
    int BN_usub(BIGNUM* r, const BIGNUM* a, const BIGNUM* b);
    int BN_uadd(BIGNUM* r, const BIGNUM* a, const BIGNUM* b);
    int BN_add(BIGNUM* r, const BIGNUM* a, const BIGNUM* b);
    int BN_mul(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, BN_CTX* ctx);
    int BN_sqr(BIGNUM* r, const BIGNUM* a, BN_CTX* ctx);
    /** BN_set_negative sets sign of a BIGNUM
     * \param  b  pointer to the BIGNUM object
     * \param  n  0 if the BIGNUM b should be positive and a value != 0 otherwise
     */
    void BN_set_negative(BIGNUM* b, int n);
    /** BN_is_negative returns 1 if the BIGNUM is negative
     * \param  b  pointer to the BIGNUM object
     * \return 1 if a < 0 and 0 otherwise
     */
    int BN_is_negative(const BIGNUM* b);

    int BN_div(BIGNUM* dv, BIGNUM* rem, const BIGNUM* m, const BIGNUM* d, BN_CTX* ctx);
#define BN_mod(rem, m, d, ctx) BN_div(NULL, (rem), (m), (d), (ctx))
    int BN_nnmod(BIGNUM* r, const BIGNUM* m, const BIGNUM* d, BN_CTX* ctx);
    int BN_mod_add(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_add_quick(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* m);
    int BN_mod_sub(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_sub_quick(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* m);
    int BN_mod_mul(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_sqr(BIGNUM* r, const BIGNUM* a, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_lshift1(BIGNUM* r, const BIGNUM* a, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_lshift1_quick(BIGNUM* r, const BIGNUM* a, const BIGNUM* m);
    int BN_mod_lshift(BIGNUM* r, const BIGNUM* a, int n, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_lshift_quick(BIGNUM* r, const BIGNUM* a, int n, const BIGNUM* m);

    BN_ULONG BN_mod_word(const BIGNUM* a, BN_ULONG w);
    BN_ULONG BN_div_word(BIGNUM* a, BN_ULONG w);
    int BN_mul_word(BIGNUM* a, BN_ULONG w);
    int BN_add_word(BIGNUM* a, BN_ULONG w);
    int BN_sub_word(BIGNUM* a, BN_ULONG w);
    int BN_set_word(BIGNUM* a, BN_ULONG w);
    BN_ULONG BN_get_word(const BIGNUM* a);

    int BN_cmp(const BIGNUM* a, const BIGNUM* b);
    void BN_free(BIGNUM* a);
    int BN_is_bit_set(const BIGNUM* a, int n);
    int BN_lshift(BIGNUM* r, const BIGNUM* a, int n);
    int BN_lshift1(BIGNUM* r, const BIGNUM* a);
    int BN_exp(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);

    int BN_mod_exp(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_exp_mont(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx, BN_MONT_CTX* m_ctx);
    int BN_mod_exp_mont_consttime(BIGNUM* rr, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx, BN_MONT_CTX* in_mont);
    int BN_mod_exp_mont_word(BIGNUM* r, BN_ULONG a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx, BN_MONT_CTX* m_ctx);
    int BN_mod_exp2_mont(BIGNUM* r, const BIGNUM* a1, const BIGNUM* p1, const BIGNUM* a2, const BIGNUM* p2, const BIGNUM* m, BN_CTX* ctx, BN_MONT_CTX* m_ctx);
    int BN_mod_exp_simple(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx);
    int BN_mod_exp_mont_consttime_x2(BIGNUM* rr1, const BIGNUM* a1, const BIGNUM* p1, const BIGNUM* m1, BN_MONT_CTX* in_mont1, BIGNUM* rr2, const BIGNUM* a2, const BIGNUM* p2, const BIGNUM* m2, BN_MONT_CTX* in_mont2, BN_CTX* ctx);

    int BN_mask_bits(BIGNUM* a, int n);
#ifndef OPENSSL_NO_STDIO
    int BN_print_fp(FILE* fp, const BIGNUM* a);
#endif
    int BN_print(BIO* bio, const BIGNUM* a);
    int BN_reciprocal(BIGNUM* r, const BIGNUM* m, int len, BN_CTX* ctx);
    int BN_rshift(BIGNUM* r, const BIGNUM* a, int n);
    int BN_rshift1(BIGNUM* r, const BIGNUM* a);
    void BN_clear(BIGNUM* a);
    BIGNUM* BN_dup(const BIGNUM* a);
    int BN_ucmp(const BIGNUM* a, const BIGNUM* b);
    int BN_set_bit(BIGNUM* a, int n);
    int BN_clear_bit(BIGNUM* a, int n);
    char* BN_bn2hex(const BIGNUM* a);
    char* BN_bn2dec(const BIGNUM* a);
    int BN_hex2bn(BIGNUM** a, const char* str);
    int BN_dec2bn(BIGNUM** a, const char* str);
    int BN_asc2bn(BIGNUM** a, const char* str);
    int BN_gcd(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, BN_CTX* ctx);
    int BN_kronecker(const BIGNUM* a, const BIGNUM* b, BN_CTX* ctx); /* returns
                                                                      * -2 for
                                                                      * error */
    BIGNUM* BN_mod_inverse(BIGNUM* ret, const BIGNUM* a, const BIGNUM* n, BN_CTX* ctx);
    BIGNUM* BN_mod_sqrt(BIGNUM* ret, const BIGNUM* a, const BIGNUM* n, BN_CTX* ctx);

    void BN_consttime_swap(BN_ULONG swap, BIGNUM* a, BIGNUM* b, int nwords);

/* Deprecated versions */
#ifndef OPENSSL_NO_DEPRECATED_0_9_8
    OSSL_DEPRECATEDIN_0_9_8
    BIGNUM* BN_generate_prime(BIGNUM* ret, int bits, int safe, const BIGNUM* add, const BIGNUM* rem, void (*callback)(int, int, void*), void* cb_arg);
    OSSL_DEPRECATEDIN_0_9_8
    int BN_is_prime(const BIGNUM* p, int nchecks, void (*callback)(int, int, void*), BN_CTX* ctx, void* cb_arg);
    OSSL_DEPRECATEDIN_0_9_8
    int BN_is_prime_fasttest(const BIGNUM* p, int nchecks, void (*callback)(int, int, void*), BN_CTX* ctx, void* cb_arg, int do_trial_division);
#endif
#ifndef OPENSSL_NO_DEPRECATED_3_0
    OSSL_DEPRECATEDIN_3_0
    int BN_is_prime_ex(const BIGNUM* p, int nchecks, BN_CTX* ctx, BN_GENCB* cb);
    OSSL_DEPRECATEDIN_3_0
    int BN_is_prime_fasttest_ex(const BIGNUM* p, int nchecks, BN_CTX* ctx, int do_trial_division, BN_GENCB* cb);
#endif
    /* Newer versions */
    int BN_generate_prime_ex2(BIGNUM* ret, int bits, int safe, const BIGNUM* add, const BIGNUM* rem, BN_GENCB* cb, BN_CTX* ctx);
    int BN_generate_prime_ex(BIGNUM* ret, int bits, int safe, const BIGNUM* add, const BIGNUM* rem, BN_GENCB* cb);
    int BN_check_prime(const BIGNUM* p, BN_CTX* ctx, BN_GENCB* cb);

#ifndef OPENSSL_NO_DEPRECATED_3_0
    OSSL_DEPRECATEDIN_3_0
    int BN_X931_generate_Xpq(BIGNUM* Xp, BIGNUM* Xq, int nbits, BN_CTX* ctx);

    OSSL_DEPRECATEDIN_3_0
    int BN_X931_derive_prime_ex(BIGNUM* p, BIGNUM* p1, BIGNUM* p2, const BIGNUM* Xp, const BIGNUM* Xp1, const BIGNUM* Xp2, const BIGNUM* e, BN_CTX* ctx, BN_GENCB* cb);
    OSSL_DEPRECATEDIN_3_0
    int BN_X931_generate_prime_ex(BIGNUM* p, BIGNUM* p1, BIGNUM* p2, BIGNUM* Xp1, BIGNUM* Xp2, const BIGNUM* Xp, const BIGNUM* e, BN_CTX* ctx, BN_GENCB* cb);
#endif

    BN_MONT_CTX* BN_MONT_CTX_new(void);
    int BN_mod_mul_montgomery(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, BN_MONT_CTX* mont, BN_CTX* ctx);
    int BN_to_montgomery(BIGNUM* r, const BIGNUM* a, BN_MONT_CTX* mont, BN_CTX* ctx);
    int BN_from_montgomery(BIGNUM* r, const BIGNUM* a, BN_MONT_CTX* mont, BN_CTX* ctx);
    void BN_MONT_CTX_free(BN_MONT_CTX* mont);
    int BN_MONT_CTX_set(BN_MONT_CTX* mont, const BIGNUM* mod, BN_CTX* ctx);
    BN_MONT_CTX* BN_MONT_CTX_copy(BN_MONT_CTX* to, BN_MONT_CTX* from);
    BN_MONT_CTX* BN_MONT_CTX_set_locked(BN_MONT_CTX** pmont, CRYPTO_RWLOCK* lock, const BIGNUM* mod, BN_CTX* ctx);

/* BN_BLINDING flags */
#define BN_BLINDING_NO_UPDATE 0x00000001
#define BN_BLINDING_NO_RECREATE 0x00000002

    BN_BLINDING* BN_BLINDING_new(const BIGNUM* A, const BIGNUM* Ai, BIGNUM* mod);
    void BN_BLINDING_free(BN_BLINDING* b);
    int BN_BLINDING_update(BN_BLINDING* b, BN_CTX* ctx);
    int BN_BLINDING_convert(BIGNUM* n, BN_BLINDING* b, BN_CTX* ctx);
    int BN_BLINDING_invert(BIGNUM* n, BN_BLINDING* b, BN_CTX* ctx);
    int BN_BLINDING_convert_ex(BIGNUM* n, BIGNUM* r, BN_BLINDING* b, BN_CTX*);
    int BN_BLINDING_invert_ex(BIGNUM* n, const BIGNUM* r, BN_BLINDING* b, BN_CTX*);

    int BN_BLINDING_is_current_thread(BN_BLINDING* b);
    void BN_BLINDING_set_current_thread(BN_BLINDING* b);
    int BN_BLINDING_lock(BN_BLINDING* b);
    int BN_BLINDING_unlock(BN_BLINDING* b);

    unsigned long BN_BLINDING_get_flags(const BN_BLINDING*);
    void BN_BLINDING_set_flags(BN_BLINDING*, unsigned long);
    BN_BLINDING* BN_BLINDING_create_param(BN_BLINDING* b, const BIGNUM* e, BIGNUM* m, BN_CTX* ctx, int (*bn_mod_exp)(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx, BN_MONT_CTX* m_ctx), BN_MONT_CTX* m_ctx);
#ifndef OPENSSL_NO_DEPRECATED_0_9_8
    OSSL_DEPRECATEDIN_0_9_8
    void BN_set_params(int mul, int high, int low, int mont);
    OSSL_DEPRECATEDIN_0_9_8
    int BN_get_params(int which); /* 0, mul, 1 high, 2 low, 3 mont */
#endif

    BN_RECP_CTX* BN_RECP_CTX_new(void);
    void BN_RECP_CTX_free(BN_RECP_CTX* recp);
    int BN_RECP_CTX_set(BN_RECP_CTX* recp, const BIGNUM* rdiv, BN_CTX* ctx);
    int BN_mod_mul_reciprocal(BIGNUM* r, const BIGNUM* x, const BIGNUM* y, BN_RECP_CTX* recp, BN_CTX* ctx);
    int BN_mod_exp_recp(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, const BIGNUM* m, BN_CTX* ctx);
    int BN_div_recp(BIGNUM* dv, BIGNUM* rem, const BIGNUM* m, BN_RECP_CTX* recp, BN_CTX* ctx);

#ifndef OPENSSL_NO_EC2M

    /*
     * Functions for arithmetic over binary polynomials represented by BIGNUMs.
     * The BIGNUM::neg property of BIGNUMs representing binary polynomials is
     * ignored. Note that input arguments are not const so that their bit arrays
     * can be expanded to the appropriate size if needed.
     */

    /*
     * r = a + b
     */
    int BN_GF2m_add(BIGNUM* r, const BIGNUM* a, const BIGNUM* b);
#define BN_GF2m_sub(r, a, b) BN_GF2m_add(r, a, b)
    /*
     * r=a mod p
     */
    int BN_GF2m_mod(BIGNUM* r, const BIGNUM* a, const BIGNUM* p);
    /* r = (a * b) mod p */
    int BN_GF2m_mod_mul(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* p, BN_CTX* ctx);
    /* r = (a * a) mod p */
    int BN_GF2m_mod_sqr(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    /* r = (1 / b) mod p */
    int BN_GF2m_mod_inv(BIGNUM* r, const BIGNUM* b, const BIGNUM* p, BN_CTX* ctx);
    /* r = (a / b) mod p */
    int BN_GF2m_mod_div(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* p, BN_CTX* ctx);
    /* r = (a ^ b) mod p */
    int BN_GF2m_mod_exp(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const BIGNUM* p, BN_CTX* ctx);
    /* r = sqrt(a) mod p */
    int BN_GF2m_mod_sqrt(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    /* r^2 + r = a mod p */
    int BN_GF2m_mod_solve_quad(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
#define BN_GF2m_cmp(a, b) BN_ucmp((a), (b))
    /*-
     * Some functions allow for representation of the irreducible polynomials
     * as an unsigned int[], say p.  The irreducible f(t) is then of the form:
     *     t^p[0] + t^p[1] + ... + t^p[k]
     * where m = p[0] > p[1] > ... > p[k] = 0.
     */
    /* r = a mod p */
    int BN_GF2m_mod_arr(BIGNUM* r, const BIGNUM* a, const int p[]);
    /* r = (a * b) mod p */
    int BN_GF2m_mod_mul_arr(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const int p[], BN_CTX* ctx);
    /* r = (a * a) mod p */
    int BN_GF2m_mod_sqr_arr(BIGNUM* r, const BIGNUM* a, const int p[], BN_CTX* ctx);
    /* r = (1 / b) mod p */
    int BN_GF2m_mod_inv_arr(BIGNUM* r, const BIGNUM* b, const int p[], BN_CTX* ctx);
    /* r = (a / b) mod p */
    int BN_GF2m_mod_div_arr(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const int p[], BN_CTX* ctx);
    /* r = (a ^ b) mod p */
    int BN_GF2m_mod_exp_arr(BIGNUM* r, const BIGNUM* a, const BIGNUM* b, const int p[], BN_CTX* ctx);
    /* r = sqrt(a) mod p */
    int BN_GF2m_mod_sqrt_arr(BIGNUM* r, const BIGNUM* a, const int p[], BN_CTX* ctx);
    /* r^2 + r = a mod p */
    int BN_GF2m_mod_solve_quad_arr(BIGNUM* r, const BIGNUM* a, const int p[], BN_CTX* ctx);
    int BN_GF2m_poly2arr(const BIGNUM* a, int p[], int max);
    int BN_GF2m_arr2poly(const int p[], BIGNUM* a);

#endif

    /*
     * faster mod functions for the 'NIST primes' 0 <= a < p^2
     */
    int BN_nist_mod_192(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    int BN_nist_mod_224(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    int BN_nist_mod_256(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    int BN_nist_mod_384(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);
    int BN_nist_mod_521(BIGNUM* r, const BIGNUM* a, const BIGNUM* p, BN_CTX* ctx);

    const BIGNUM* BN_get0_nist_prime_192(void);
    const BIGNUM* BN_get0_nist_prime_224(void);
    const BIGNUM* BN_get0_nist_prime_256(void);
    const BIGNUM* BN_get0_nist_prime_384(void);
    const BIGNUM* BN_get0_nist_prime_521(void);

    int (*BN_nist_mod_func(const BIGNUM* p))(BIGNUM* r, const BIGNUM* a, const BIGNUM* field, BN_CTX* ctx);

    int BN_generate_dsa_nonce(BIGNUM* out, const BIGNUM* range, const BIGNUM* priv, const unsigned char* message, size_t message_len, BN_CTX* ctx);

    /* Primes from RFC 2409 */
    BIGNUM* BN_get_rfc2409_prime_768(BIGNUM* bn);
    BIGNUM* BN_get_rfc2409_prime_1024(BIGNUM* bn);

    /* Primes from RFC 3526 */
    BIGNUM* BN_get_rfc3526_prime_1536(BIGNUM* bn);
    BIGNUM* BN_get_rfc3526_prime_2048(BIGNUM* bn);
    BIGNUM* BN_get_rfc3526_prime_3072(BIGNUM* bn);
    BIGNUM* BN_get_rfc3526_prime_4096(BIGNUM* bn);
    BIGNUM* BN_get_rfc3526_prime_6144(BIGNUM* bn);
    BIGNUM* BN_get_rfc3526_prime_8192(BIGNUM* bn);

#ifndef OPENSSL_NO_DEPRECATED_1_1_0
#define get_rfc2409_prime_768 BN_get_rfc2409_prime_768
#define get_rfc2409_prime_1024 BN_get_rfc2409_prime_1024
#define get_rfc3526_prime_1536 BN_get_rfc3526_prime_1536
#define get_rfc3526_prime_2048 BN_get_rfc3526_prime_2048
#define get_rfc3526_prime_3072 BN_get_rfc3526_prime_3072
#define get_rfc3526_prime_4096 BN_get_rfc3526_prime_4096
#define get_rfc3526_prime_6144 BN_get_rfc3526_prime_6144
#define get_rfc3526_prime_8192 BN_get_rfc3526_prime_8192
#endif

    int BN_bntest_rand(BIGNUM* rnd, int bits, int top, int bottom);

#ifdef __cplusplus
}
#endif
#endif