/* crypto/bn/bn.h */
/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *   notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *   must display the following acknowledgement:
 *   "This product includes cryptographic software written by
 *    Eric Young (eay@cryptsoft.com)"
 *   The word 'cryptographic' can be left out if the rouines from the library
 *   being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *   the apps directory (application code) you must include an acknowledgement:
 *   "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *   software must display the following acknowledgment:
 *   "This product includes software developed by the OpenSSL Project
 *   for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *   endorse or promote products derived from this software without
 *   prior written permission. For written permission, please contact
 *   openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *   nor may "OpenSSL" appear in their names without prior written
 *   permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *   acknowledgment:
 *   "This product includes software developed by the OpenSSL Project
 *   for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 *
 * Portions of the attached software ("Contribution") are developed by
 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
 *
 * The Contribution is licensed pursuant to the Eric Young open source
 * license provided above.
 *
 * The binary polynomial arithmetic software is originally written by
 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
 *
 */

module deimos.openssl.bn;

import deimos.openssl._d_util;

public import deimos.openssl.e_os2;
version(OPENSSL_NO_FP_API) {} else {
import core.stdc.stdio; /* FILE */
}
public import deimos.openssl.ossl_typ;
public import deimos.openssl.crypto;

extern (C):
nothrow:

/+ Not ported, internal only.
/* These preprocessor symbols control various aspects of the bignum headers and
 * library code. They're not defined by any "normal" configuration, as they are
 * intended for development and testing purposes. NB: defining all three can be
 * useful for debugging application code as well as openssl itself.
 *
 * BN_DEBUG - turn on various debugging alterations to the bignum code
 * BN_DEBUG_RAND - uses random poisoning of unused words to trip up
 * mismanagement of bignum internals. You must also define BN_DEBUG.
 */
/* #define BN_DEBUG */
/* #define BN_DEBUG_RAND */

// #ifndef OPENSSL_SMALL_FOOTPRINT
// #define BN_MUL_COMBA
// #define BN_SQR_COMBA
// #define BN_RECURSION
// #endif

/* This next option uses the C libraries (2 word)/(1 word) function.
 * If it is not defined, I use my C version (which is slower).
 * The reason for this flag is that when the particular C compiler
 * library routine is used, and the library is linked with a different
 * compiler, the library is missing.  This mostly happens when the
 * library is built with gcc and then linked using normal cc.  This would
 * be a common occurrence because gcc normally produces code that is
 * 2 times faster than system compilers for the big number stuff.
 * For machines with only one compiler (or shared libraries), this should
 * be on.  Again this in only really a problem on machines
 * using "long long's", are 32bit, and are not using my assembler code. */
#if defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_WINDOWS) || \
    defined(OPENSSL_SYS_WIN32) || defined(linux)
# ifndef BN_DIV2W
#  define BN_DIV2W
# endif
#endif


/* assuming c_long is 64bit - this is the DEC Alpha
 * c_ulong c_long is only 64 bits :-(, don't define
 * BN_LLONG for the DEC Alpha */
#ifdef SIXTY_FOUR_BIT_LONG
alias c_ulong BN_ULLONG; c_long
alias c_ulong BN_ULONG;
alias c_long BN_LONG;
enum BN_BITS = 128;
enum BN_BYTES = 8;
enum BN_BITS2 = 64;
enum BN_BITS4 = 32;
#define BN_MASK		(0xffffffffffffffffffffffffffffffffLL)
#define BN_MASK2	(0xffffffffffffffffL)
#define BN_MASK2l	(0xffffffffL)
#define BN_MASK2h	(0xffffffff00000000L)
#define BN_MASK2h1	(0xffffffff80000000L)
#define BN_TBIT		(0x8000000000000000L)
enum BN_DEC_CONV = (10000000000000000000UL);
enum BN_DEC_FMT1 = "%lu";
enum BN_DEC_FMT2 = "%019lu";
enum BN_DEC_NUM = 19;
enum BN_HEX_FMT1 = "%lX";
enum BN_HEX_FMT2 = "%016lX";
#endif

/* This is where the c_long long data type is 64 bits, but c_long is 32.
 * For machines where there are 64bit registers, this is the mode to use.
 * IRIX, on R4000 and above should use this mode, along with the relevant
 * assembler code :-).  Do NOT define BN_LLONG.
 */
#ifdef SIXTY_FOUR_BIT
#undef BN_LLONG
#undef BN_ULLONG
alias c_ulong BN_ULONG; c_long
alias c_long BN_LONG; long
enum BN_BITS = 128;
enum BN_BYTES = 8;
enum BN_BITS2 = 64;
enum BN_BITS4 = 32;
#define BN_MASK2	(0xffffffffffffffffLL)
#define BN_MASK2l	(0xffffffffL)
#define BN_MASK2h	(0xffffffff00000000LL)
#define BN_MASK2h1	(0xffffffff80000000LL)
#define BN_TBIT		(0x8000000000000000LL)
enum BN_DEC_CONV = (10000000000000000000ULL);
enum BN_DEC_FMT1 = "%llu";
enum BN_DEC_FMT2 = "%019llu";
enum BN_DEC_NUM = 19;
enum BN_HEX_FMT1 = "%llX";
enum BN_HEX_FMT2 = "%016llX";
#endif

#ifdef THIRTY_TWO_BIT+/
// #ifdef BN_LLONG
// # if defined(_WIN32) && !defined(__GNUC__)
// #  define BN_ULLONG	unsigned __int64
// #  define BN_MASK	(0xffffffffffffffffI64)
// # else
// #  define BN_ULLONG	c_ulong c_long
// #  define BN_MASK	(0xffffffffffffffffLL)
// # endif
// #endif
// FIXME: Is this correct?
alias ulong BN_ULLONG;
alias uint BN_ULONG;
alias int BN_LONG;
enum BN_BITS = 64;
enum BN_BYTES = 4;
enum BN_BITS2 = 32;
enum BN_BITS4 = 16;
enum BN_MASK2 = 0xffffffff;
enum BN_MASK2l = 0xffff;
enum BN_MASK2h1 = 0xffff8000;
enum BN_MASK2h = 0xffff0000;
enum BN_TBIT = 0x80000000;
enum BN_DEC_CONV = 1000000000;
enum BN_DEC_FMT1 = "%u";
enum BN_DEC_FMT2 = "%09u";
enum BN_DEC_NUM = 9;
enum BN_HEX_FMT1 = "%X";
enum BN_HEX_FMT2 = "%08X";
/+#endif

/* 2011-02-22 SMS.
 * In various places, a size_t variable or a type cast to size_t was
 * used to perform integer-only operations on pointers.  This failed on
 * VMS with 64-bit pointers (CC /POINTER_SIZE = 64) because size_t is
 * still only 32 bits.  What's needed in these cases is an integer type
 * with the same size as a pointer, which size_t is not certain to be.
 * The only fix here is VMS-specific.
 */
#if defined(OPENSSL_SYS_VMS)
# if __INITIAL_POINTER_SIZE == 64
#  define PTR_SIZE_INT c_long long
# else /* __INITIAL_POINTER_SIZE == 64 */
#  define PTR_SIZE_INT int
# endif /* __INITIAL_POINTER_SIZE == 64 [else] */
#else /* defined(OPENSSL_SYS_VMS) */
# define PTR_SIZE_INT size_t
#endif /* defined(OPENSSL_SYS_VMS) [else] */
+/
enum BN_DEFAULT_BITS = 1280;

enum BN_FLG_MALLOCED = 0x01;
enum BN_FLG_STATIC_DATA = 0x02;
enum BN_FLG_CONSTTIME = 0x04; /* 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.
                                      */

version(OPENSSL_NO_DEPRECATED) {} else {
alias BN_FLG_CONSTTIME BN_FLG_EXP_CONSTTIME; /* deprecated name for the flag */
                                      /* avoid leaking exponent information through timings
                                      * (BN_mod_exp_mont() will call BN_mod_exp_mont_consttime) */
}

version(OPENSSL_NO_DEPRECATED) {} else {
enum BN_FLG_FREE = 0x8000;	/* used for debuging */
}
void BN_set_flags()(BIGNUM* b, int n) { b.flags |= n; }
int BN_get_flags()(BIGNUM* b, int n) { return b.flags & n; }

/* get a clone of a BIGNUM with changed flags, for* temporary* use only
 * (the two BIGNUMs cannot not be used in parallel!) */
void BN_with_flags()(BIGNUM* dest, BIGNUM* b, int n) {
	dest.d=b.d;
	dest.top=b.top;
	dest.dmax=b.dmax;
	dest.neg=b.neg;
	dest.flags=(dest.flags & BN_FLG_MALLOCED)
		| (b.flags & ~BN_FLG_MALLOCED)
		| BN_FLG_STATIC_DATA
		| n;
}

/* Already declared in ossl_typ.h */
version (none) {
alias bignum_st BIGNUM;
/* Used for temp variables (declaration hidden in bn_lcl.h) */
alias bignum_ctx BN_CTX;
alias bn_blinding_st BN_BLINDING;
alias bn_mont_ctx_st BN_MONT_CTX;
alias bn_recp_ctx_st BN_RECP_CTX;
alias bn_gencb_st BN_GENCB;
}

struct bignum_st
	{
	BN_ULONG* d;	/* Pointer to an array of 'BN_BITS2' bit chunks. */
	int top;	/* Index of last used d +1. */
	/* The next are internal book keeping for bn_expand. */
	int dmax;	/* Size of the d array. */
	int neg;	/* one if the number is negative */
	int flags;
	};

/* Used for montgomery multiplication */
struct bn_mont_ctx_st
	{
	int ri;        /* number of bits in R */
	BIGNUM RR;     /* used to convert to montgomery form */
	BIGNUM N;      /* The modulus */
	BIGNUM Ni;     /* R*(1/R mod N) - N*Ni = 1
	                * (Ni is only stored for bignum algorithm) */
	BN_ULONG n0[2];/* least significant word(s) of Ni;
	                  (type changed with 0.9.9, was "BN_ULONG n0;" before) */
	int flags;
	};

/* Used for reciprocal division/mod functions
 * It cannot be shared between threads
 */
struct bn_recp_ctx_st
	{
	BIGNUM N;	/* the divisor */
	BIGNUM Nr;	/* the reciprocal */
	int num_bits;
	int shift;
	int flags;
	};

/* Used for slow "generation" functions. */
struct bn_gencb_st
	{
	uint ver;	/* To handle binary (in)compatibility */
	void* arg;		/* callback-specific data */
	union cb_
		{
		/* if(ver==1) - handles old style callbacks */
		ExternC!(void function(int, int, void*)) cb_1;
		/* if(ver==2) - new callback style */
		ExternC!(int function(int, int, BN_GENCB*)) cb_2;
		}
	cb_ cb;
	};
/* Wrapper function to make using BN_GENCB easier,  */
int BN_GENCB_call(BN_GENCB* cb, int a, int b);
/* Macro to populate a BN_GENCB structure with an "old"-style callback */
void BN_GENCB_set_old()(gencb, callback, cb_arg) {
		BN_GENCB* tmp_gencb = (gencb);
		tmp_gencb.ver = 1;
		tmp_gencb.arg = (cb_arg);
		tmp_gencb.cb.cb_1 = (callback);
}
/* Macro to populate a BN_GENCB structure with a "new"-style callback */
void BN_GENCB_set()(gencb, callback, cb_arg) {
		BN_GENCB* tmp_gencb = (gencb);
		tmp_gencb.ver = 2;
		tmp_gencb.arg = (cb_arg);
		tmp_gencb.cb.cb_2 = (callback);
}

enum BN_prime_checks = 0; /* default: select number of iterations
			     based on the size of the number */

/* number of Miller-Rabin iterations for an error rate  of less than 2^-80
 * for random 'b'-bit input, b >= 100 (taken from table 4.4 in the Handbook
 * of Applied Cryptography [Menezes, van Oorschot, Vanstone; CRC Press 1996];
 * original paper: Damgaard, Landrock, Pomerance: Average case error estimates
 * for the strong probable prime test. -- Math. Comp. 61 (1993) 177-194) */
auto BN_prime_checks_for_size(T)(T b) {
	return ((b) >= 1300 ?  2 :
	(b) >=  850 ?  3 :
	(b) >=  650 ?  4 :
	(b) >=  550 ?  5 :
	(b) >=  450 ?  6 :
	(b) >=  400 ?  7 :
	(b) >=  350 ?  8 :
	(b) >=  300 ?  9 :
	(b) >=  250 ? 12 :
	(b) >=  200 ? 15 :
	(b) >=  150 ? 18 :
	/* b >= 100 */ 27);
}

auto BN_num_bytes()(BIGNUM* a) { return (BN_num_bits(a)+7)/8; }

/* Note that BN_abs_is_word didn't work reliably for w == 0 until 0.9.8 */
auto BN_abs_is_word()(BIGNUM* a, BN_ULONG w) { return (((a.top == 1) && (a.d[0] == (w))) ||
				(((w) == 0) && (a.top == 0))); }
auto BN_is_zero()(BIGNUM* a) { return (a.top == 0); }
auto BN_is_one()(BIGNUM* a) { return (BN_abs_is_word((a),1) && !a.neg); }
auto BN_is_word()(BIGNUM* a, BN_ULONG w) { return (BN_abs_is_word((a),(w)) && (!(w) || !a.neg)); }
auto BN_is_odd()(BIGNUM* a) { return ((a.top > 0) && (a.d[0] & 1)); }

auto BN_one()(BIGNUM* a) { return BN_set_word((a),1); }
auto BN_zero_ex()(BIGNUM* a) {
	a.top = 0;
	a.neg = 0;
}
version (OPENSSL_NO_DEPRECATED) {
alias BN_zero_ex BN_zero;
} else {
auto BN_zero()(BIGNUM* a) { return BN_set_word(a,0); }
}

const(BIGNUM)* BN_value_one();
char* 	BN_options();
BN_CTX* BN_CTX_new();
version(OPENSSL_NO_DEPRECATED) {} else {
void	BN_CTX_init(BN_CTX* c);
}
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(BIGNUM* rnd, int bits, int top,int bottom);
int     BN_pseudo_rand(BIGNUM* rnd, int bits, int top,int bottom);
int	BN_rand_range(BIGNUM* rnd, const(BIGNUM)* range);
int	BN_pseudo_rand_range(BIGNUM* rnd, const(BIGNUM)* range);
int	BN_num_bits(const(BIGNUM)* a);
int	BN_num_bits_word(BN_ULONG);
BIGNUM* BN_new();
void	BN_init(BIGNUM*);
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(ubyte)* s,int len,BIGNUM* ret);
int	BN_bn2bin(const(BIGNUM)* a, ubyte* to);
BIGNUM* BN_mpi2bn(const(ubyte)* s,int len,BIGNUM* ret);
int	BN_bn2mpi(const(BIGNUM)* a, ubyte* 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  a  pointer to the BIGNUM object
 * \return 1 if a < 0 and 0 otherwise
 */
auto BN_is_negative()(BIGNUM* a) { return a.neg != 0; }

int	BN_div(BIGNUM* dv, BIGNUM* rem, const(BIGNUM)* m, const(BIGNUM)* d,
	BN_CTX* ctx);
auto BN_mod()(BIGNUM* rem,BIGNUM* m,BIGNUM* d,BN_CTX* ctx) { return 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_mask_bits(BIGNUM* a,int n);
version(OPENSSL_NO_FP_API) {} else {
int	BN_print_fp(FILE* fp, const(BIGNUM)* a);
}
// #ifdef HEADER_BIO_H
import deimos.openssl.bio;
int	BN_print(BIO* fp, const(BIGNUM)* a);
// #else
// int	BN_print(void* fp, const(BIGNUM)* a);
// #endif
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);

/* Deprecated versions */
version(OPENSSL_NO_DEPRECATED) {} else {
BIGNUM* BN_generate_prime(BIGNUM* ret,int bits,int safe,
	const(BIGNUM)* add, const(BIGNUM)* rem,
	ExternC!(void function(int,int,void*)) callback,void* cb_arg);
int	BN_is_prime(const(BIGNUM)* p,int nchecks,
	ExternC!(void function(int,int,void*)) callback,
	BN_CTX* ctx,void* cb_arg);
int	BN_is_prime_fasttest(const(BIGNUM)* p,int nchecks,
	ExternC!(void function(int,int,void*)) callback,BN_CTX* ctx,void* cb_arg,
	int do_trial_division);
} /* !defined(OPENSSL_NO_DEPRECATED) */

/* Newer versions */
int	BN_generate_prime_ex(BIGNUM* ret,int bits,int safe, const(BIGNUM)* add,
		const(BIGNUM)* rem, BN_GENCB* cb);
int	BN_is_prime_ex(const(BIGNUM)* p,int nchecks, BN_CTX* ctx, BN_GENCB* cb);
int	BN_is_prime_fasttest_ex(const(BIGNUM)* p,int nchecks, BN_CTX* ctx,
		int do_trial_division, BN_GENCB* cb);

BN_MONT_CTX* BN_MONT_CTX_new();
void BN_MONT_CTX_init(BN_MONT_CTX* ctx);
int BN_mod_mul_montgomery(BIGNUM* r,const(BIGNUM)* a,const(BIGNUM)* b,
	BN_MONT_CTX* mont, BN_CTX* ctx);
auto BN_to_montgomery()(BIGNUM* r,const(BIGNUM)* a,BN_MONT_CTX* mont,BN_CTX* ctx) {
	BN_mod_mul_montgomery((r),(a),&(mont.RR),(mont),(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, int lock,
					const(BIGNUM)* mod, BN_CTX* ctx);

/* BN_BLINDING flags */
enum BN_BLINDING_NO_UPDATE = 0x00000001;
enum 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*);
version(OPENSSL_NO_DEPRECATED) {} else {
c_ulong BN_BLINDING_get_thread_id(const(BN_BLINDING)*);
void BN_BLINDING_set_thread_id(BN_BLINDING*, c_ulong);
}
CRYPTO_THREADID* BN_BLINDING_thread_id(BN_BLINDING*);
c_ulong BN_BLINDING_get_flags(const(BN_BLINDING)*);
void BN_BLINDING_set_flags(BN_BLINDING*, c_ulong);
BN_BLINDING* BN_BLINDING_create_param(BN_BLINDING* b,
	const(BIGNUM)* e, BIGNUM* m, BN_CTX* ctx,
	ExternC!(int function(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* p,
			  const(BIGNUM)* m, BN_CTX* ctx, BN_MONT_CTX* m_ctx)) bn_mod_exp,
	BN_MONT_CTX* m_ctx);

version(OPENSSL_NO_DEPRECATED) {} else {
void BN_set_params(int mul,int high,int low,int mont);
int BN_get_params(int which); /* 0, mul, 1 high, 2 low, 3 mont */
}

void	BN_RECP_CTX_init(BN_RECP_CTX* recp);
BN_RECP_CTX* BN_RECP_CTX_new();
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);

/* 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.
 */

int	BN_GF2m_add(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* b); /*r = a + b*/
alias BN_GF2m_add BN_GF2m_sub;
int	BN_GF2m_mod(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* p); /*r=a mod p*/
int	BN_GF2m_mod_mul(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* b,
	const(BIGNUM)* p, BN_CTX* ctx); /* r = (a* b) mod p */
int	BN_GF2m_mod_sqr(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* p,
	BN_CTX* ctx); /* r = (a* a) mod p */
int	BN_GF2m_mod_inv(BIGNUM* r, const(BIGNUM)* b, const(BIGNUM)* p,
	BN_CTX* ctx); /* r = (1 / 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 = (a ^ b) mod p */
int	BN_GF2m_mod_sqrt(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* p,
	BN_CTX* ctx); /* r = sqrt(a) mod p */
int	BN_GF2m_mod_solve_quad(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* p,
	BN_CTX* ctx); /* r^2 + r = a mod p */
alias BN_ucmp BN_GF2m_cmp;
/* Some functions allow for representation of the irreducible polynomials
 * as an uint[], 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.
 */
int	BN_GF2m_mod_arr(BIGNUM* r, const(BIGNUM)* a, const int p[]);
	/* r = a mod p */
int	BN_GF2m_mod_mul_arr(BIGNUM* r, const(BIGNUM)* a, const(BIGNUM)* b,
	const int p[], BN_CTX* ctx); /* r = (a* b) mod p */
int	BN_GF2m_mod_sqr_arr(BIGNUM* r, const(BIGNUM)* a, const int p[],
	BN_CTX* ctx); /* r = (a* a) mod p */
int	BN_GF2m_mod_inv_arr(BIGNUM* r, const(BIGNUM)* b, const int p[],
	BN_CTX* ctx); /* r = (1 / 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 = (a ^ b) mod p */
int	BN_GF2m_mod_sqrt_arr(BIGNUM* r, const(BIGNUM)* a,
	const int p[], BN_CTX* ctx); /* r = sqrt(a) mod p */
int	BN_GF2m_mod_solve_quad_arr(BIGNUM* r, const(BIGNUM)* a,
	const int p[], BN_CTX* ctx); /* r^2 + r = a mod p */
int	BN_GF2m_poly2arr(const(BIGNUM)* a, int p[], int max);
int	BN_GF2m_arr2poly(const int p[], BIGNUM* a);

/* 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();
const(BIGNUM)* BN_get0_nist_prime_224();
const(BIGNUM)* BN_get0_nist_prime_256();
const(BIGNUM)* BN_get0_nist_prime_384();
const(BIGNUM)* BN_get0_nist_prime_521();

/* library internal functions */

auto bn_expand()(BIGNUM* a, int bits) { return ((((((bits+BN_BITS2-1))/BN_BITS2)) <= a.dmax)?
	(a):bn_expand2((a),(bits+BN_BITS2-1)/BN_BITS2)); }
auto bn_wexpand()(BIGNUM* a, int words) { return (((words) <= a.dmax)?(a):bn_expand2((a),(words))); }
BIGNUM* bn_expand2(BIGNUM* a, int words);
version(OPENSSL_NO_DEPRECATED) {} else {
BIGNUM* bn_dup_expand(const(BIGNUM)* a, int words); /* unused */
}

/+ FIXME: Not yet ported.
/* Bignum consistency macros
 * There is one "API" macro, bn_fix_top(), for stripping leading zeroes from
 * bignum data after direct manipulations on the data. There is also an
 * "internal" macro, bn_check_top(), for verifying that there are no leading
 * zeroes. Unfortunately, some auditing is required due to the fact that
 * bn_fix_top() has become an overabused duct-tape because bignum data is
 * occasionally passed around in an inconsistent state. So the following
 * changes have been made to sort this out_;
 * - bn_fix_top()s implementation has been moved to bn_correct_top()
 * - if BN_DEBUG isn't defined, bn_fix_top() maps to bn_correct_top(), and
 *  bn_check_top() is as before.
 * - if BN_DEBUG* is* defined;
 *  - bn_check_top() tries to pollute unused words even if the bignum 'top' is
 *    consistent. (ed: only if BN_DEBUG_RAND is defined)
 *  - bn_fix_top() maps to bn_check_top() rather than "fixing" anything.
 * The idea is to have debug builds flag up inconsistent bignums when they
 * occur. If that occurs in a bn_fix_top(), we examine the code in question; if
 * the use of bn_fix_top() was appropriate (ie. it follows directly after code
 * that manipulates the bignum) it is converted to bn_correct_top(), and if it
 * was not appropriate, we convert it permanently to bn_check_top() and track
 * down the cause of the bug. Eventually, no internal code should be using the
 * bn_fix_top() macro. External applications and libraries should try this with
 * their own code too, both in terms of building against the openssl headers
 * with BN_DEBUG defined* and* linking with a version of OpenSSL built with it
 * defined. This not only improves external code, it provides more test
 * coverage for openssl's own code.
 */

#ifdef BN_DEBUG

/* We only need assert() when debugging */
#include <assert.h>

#ifdef BN_DEBUG_RAND
/* To avoid "make update" cvs wars due to BN_DEBUG, use some tricks */
#ifndef RAND_pseudo_bytes
int RAND_pseudo_bytes(ubyte* buf,int num);
#define BN_DEBUG_TRIX
#endif
#define bn_pollute(a) \
	do { \
		const(BIGNUM)* _bnum1 = (a); \
		if(_bnum1->top < _bnum1->dmax) { \
			ubyte _tmp_char; \
			/* We cast away const without the compiler knowing, any \
			 ** genuinely* constant variables that aren't mutable \
			 * wouldn't be constructed with top!=dmax. */ \
			BN_ULONG* _not_const; \
			memcpy(&_not_const, &_bnum1->d, sizeof(BN_ULONG*)); \
			RAND_pseudo_bytes(&_tmp_char, 1); \
			memset((ubyte*)(_not_const + _bnum1->top), _tmp_char, \
				(_bnum1->dmax - _bnum1->top) * sizeof(BN_ULONG)); \
		} \
	} while(0)
#ifdef BN_DEBUG_TRIX
#undef RAND_pseudo_bytes
#endif
#else
#define bn_pollute(a)
#endif
#define bn_check_top(a) \
	do { \
		const(BIGNUM)* _bnum2 = (a); \
		if (_bnum2 != NULL) { \
			assert((_bnum2->top == 0) || \
				(_bnum2->d[_bnum2->top - 1] != 0)); \
			bn_pollute(_bnum2); \
		} \
	} while(0)

#define bn_fix_top(a)		bn_check_top(a)

#else /* !BN_DEBUG */
+/
void bn_pollute()(BIGNUM* a) {}
void bn_check_top()(BIGNUM* a) {}
alias bn_correct_top bn_fix_top;

// #endif

auto bn_correct_top()(BIGNUM* a) {
        BN_ULONG* ftl;
	int tmp_top = a.top;
	if (tmp_top > 0)
		{
		for (ftl= &(a.d[tmp_top-1]); tmp_top > 0; tmp_top--)
			if (*(ftl--)) break;
		a.top = tmp_top;
		}
	bn_pollute(a);
}

BN_ULONG bn_mul_add_words(BN_ULONG* rp, const(BN_ULONG)* ap, int num, BN_ULONG w);
BN_ULONG bn_mul_words(BN_ULONG* rp, const(BN_ULONG)* ap, int num, BN_ULONG w);
void     bn_sqr_words(BN_ULONG* rp, const(BN_ULONG)* ap, int num);
BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d);
BN_ULONG bn_add_words(BN_ULONG* rp, const(BN_ULONG)* ap, const(BN_ULONG)* bp,int num);
BN_ULONG bn_sub_words(BN_ULONG* rp, const(BN_ULONG)* ap, const(BN_ULONG)* bp,int num);

/* Primes from RFC 2409 */
BIGNUM* get_rfc2409_prime_768(BIGNUM* bn);
BIGNUM* get_rfc2409_prime_1024(BIGNUM* bn);

/* Primes from RFC 3526 */
BIGNUM* get_rfc3526_prime_1536(BIGNUM* bn);
BIGNUM* get_rfc3526_prime_2048(BIGNUM* bn);
BIGNUM* get_rfc3526_prime_3072(BIGNUM* bn);
BIGNUM* get_rfc3526_prime_4096(BIGNUM* bn);
BIGNUM* get_rfc3526_prime_6144(BIGNUM* bn);
BIGNUM* get_rfc3526_prime_8192(BIGNUM* bn);

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

/* BEGIN ERROR CODES */
/* The following lines are auto generated by the script mkerr.pl. Any changes
 * made after this point may be overwritten when the script is next run.
 */
void ERR_load_BN_strings();

/* Error codes for the BN functions. */

/* Function codes. */
enum BN_F_BNRAND = 127;
enum BN_F_BN_BLINDING_CONVERT_EX = 100;
enum BN_F_BN_BLINDING_CREATE_PARAM = 128;
enum BN_F_BN_BLINDING_INVERT_EX = 101;
enum BN_F_BN_BLINDING_NEW = 102;
enum BN_F_BN_BLINDING_UPDATE = 103;
enum BN_F_BN_BN2DEC = 104;
enum BN_F_BN_BN2HEX = 105;
enum BN_F_BN_CTX_GET = 116;
enum BN_F_BN_CTX_NEW = 106;
enum BN_F_BN_CTX_START = 129;
enum BN_F_BN_DIV = 107;
enum BN_F_BN_DIV_NO_BRANCH = 138;
enum BN_F_BN_DIV_RECP = 130;
enum BN_F_BN_EXP = 123;
enum BN_F_BN_EXPAND2 = 108;
enum BN_F_BN_EXPAND_INTERNAL = 120;
enum BN_F_BN_GF2M_MOD = 131;
enum BN_F_BN_GF2M_MOD_EXP = 132;
enum BN_F_BN_GF2M_MOD_MUL = 133;
enum BN_F_BN_GF2M_MOD_SOLVE_QUAD = 134;
enum BN_F_BN_GF2M_MOD_SOLVE_QUAD_ARR = 135;
enum BN_F_BN_GF2M_MOD_SQR = 136;
enum BN_F_BN_GF2M_MOD_SQRT = 137;
enum BN_F_BN_MOD_EXP2_MONT = 118;
enum BN_F_BN_MOD_EXP_MONT = 109;
enum BN_F_BN_MOD_EXP_MONT_CONSTTIME = 124;
enum BN_F_BN_MOD_EXP_MONT_WORD = 117;
enum BN_F_BN_MOD_EXP_RECP = 125;
enum BN_F_BN_MOD_EXP_SIMPLE = 126;
enum BN_F_BN_MOD_INVERSE = 110;
enum BN_F_BN_MOD_INVERSE_NO_BRANCH = 139;
enum BN_F_BN_MOD_LSHIFT_QUICK = 119;
enum BN_F_BN_MOD_MUL_RECIPROCAL = 111;
enum BN_F_BN_MOD_SQRT = 121;
enum BN_F_BN_MPI2BN = 112;
enum BN_F_BN_NEW = 113;
enum BN_F_BN_RAND = 114;
enum BN_F_BN_RAND_RANGE = 122;
enum BN_F_BN_USUB = 115;

/* Reason codes. */
enum BN_R_ARG2_LT_ARG3 = 100;
enum BN_R_BAD_RECIPROCAL = 101;
enum BN_R_BIGNUM_TOO_LONG = 114;
enum BN_R_CALLED_WITH_EVEN_MODULUS = 102;
enum BN_R_DIV_BY_ZERO = 103;
enum BN_R_ENCODING_ERROR = 104;
enum BN_R_EXPAND_ON_STATIC_BIGNUM_DATA = 105;
enum BN_R_INPUT_NOT_REDUCED = 110;
enum BN_R_INVALID_LENGTH = 106;
enum BN_R_INVALID_RANGE = 115;
enum BN_R_NOT_A_SQUARE = 111;
enum BN_R_NOT_INITIALIZED = 107;
enum BN_R_NO_INVERSE = 108;
enum BN_R_NO_SOLUTION = 116;
enum BN_R_P_IS_NOT_PRIME = 112;
enum BN_R_TOO_MANY_ITERATIONS = 113;
enum BN_R_TOO_MANY_TEMPORARY_VARIABLES = 109;
