#ifndef KEYSTORENDK_BIGNUM_H
#define KEYSTORENDK_BIGNUM_H

/**
 * \file bignum.h
 *
 *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
 *
 *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * 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.
 *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "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 COPYRIGHT
 *  OWNER 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.
 */
#ifndef POLARSSL_BIGNUM_H
#define POLARSSL_BIGNUM_H

#include <stdio.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C"
{
#endif

#define BN_SUCCESS 0

#define POLARSSL_ERR_MPI_FILE_IO_ERROR                     -0x0002
#define POLARSSL_ERR_MPI_BAD_INPUT_DATA                    -0x0004
#define POLARSSL_ERR_MPI_INVALID_CHARACTER                 -0x0006
#define POLARSSL_ERR_MPI_BUFFER_TOO_SMALL                  -0x0008
#define POLARSSL_ERR_MPI_NEGATIVE_VALUE                    -0x000A
#define POLARSSL_ERR_MPI_DIVISION_BY_ZERO                  -0x000C
#define POLARSSL_ERR_MPI_NOT_ACCEPTABLE                    -0x000E

#define MPI_CHK(f) if( ( ret = f ) != 0 ) goto cleanup

/*
 * Define the base integer type, architecture-wise
 */
#if defined(POLARSSL_HAVE_INT8)
typedef unsigned char  t_int;
	typedef unsigned short t_dbl;
#else
#if defined(POLARSSL_HAVE_INT16)
typedef unsigned short t_int;
	typedef unsigned long  t_dbl;
#else
typedef unsigned long t_int;
#if defined(_MSC_VER) && defined(_M_IX86)
typedef unsigned __int64 t_dbl;
#else
#if defined(__amd64__) || defined(__x86_64__)    || \
        defined(__ppc64__) || defined(__powerpc64__) || \
        defined(__ia64__)  || defined(__alpha__)
typedef unsigned int t_dbl __attribute__((mode(TI)));
#else
typedef unsigned long long t_dbl;
#endif
#endif
#endif
#endif

/**
 * \brief          MPI structure
 */
typedef struct
{
    int s;              /*!<  integer sign      */
    int n;              /*!<  total # of limbs  */
    t_int *p;           /*!<  pointer to limbs  */
} mpi;


/**
 * \brief          Initialize one or more mpi
 */
void mpi_init(mpi *X, ...);

/**
 * \brief          Unallocate one or more mpi
 */
void mpi_free(mpi *X, ...);

/**
 * \brief          Enlarge to the specified number of limbs
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_grow(mpi *X, int nblimbs);

/**
 * \brief          Copy the contents of Y into X
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_copy(mpi *X, mpi *Y);

/**
 * \brief          Swap the contents of X and Y
 */
void mpi_swap(mpi *X, mpi *Y);

/**
 * \brief          Set value from integer
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_lset(mpi *X, int z);

/**
 * \brief          Return the number of least significant bits
 */
int mpi_lsb(mpi *X);

/**
 * \brief          Return the number of most significant bits
 */
int mpi_msb(mpi *X);

/**
 * \brief          Return the total size in bytes
 */
int mpi_size(mpi *X);

/**
 * \brief          Import from an ASCII string
 *
 * \param X        destination mpi
 * \param radix    input numeric base
 * \param s        null-terminated string buffer
 *
 * \return         0 if successful, or an POLARSSL_ERR_MPI_XXX error code
 */
int mpi_read_string(mpi *X, int radix, char *s);

/**
 * \brief          Export into an ASCII string
 *
 * \param X        source mpi
 * \param radix    output numeric base
 * \param s        string buffer
 * \param slen     string buffer size
 *
 * \return         0 if successful, or an POLARSSL_ERR_MPI_XXX error code
 *
 * \note           Call this function with *slen = 0 to obtain the
 *                 minimum required buffer size in *slen.
 */
int mpi_write_string(mpi *X, int radix, char *s, int *slen);

/**
 * \brief          Import X from unsigned binary data, big endian
 *
 * \param X        destination mpi
 * \param buf      input buffer
 * \param buflen   input buffer size
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_read_binary(mpi *X, unsigned char *buf, int buflen);

/**
 * \brief          Export X into unsigned binary data, big endian
 *
 * \param X        source mpi
 * \param buf      output buffer
 * \param buflen   output buffer size
 *
 * \return         0 if successful,
 *                 POLARSSL_ERR_MPI_BUFFER_TOO_SMALL if buf isn't large enough
 *
 * \note           Call this function with *buflen = 0 to obtain the
 *                 minimum required buffer size in *buflen.
 */
int mpi_write_binary(mpi *X, unsigned char *buf, int buflen);

/**
 * \brief          Left-shift: X <<= count
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_shift_l(mpi *X, int count);

/**
 * \brief          Right-shift: X >>= count
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_shift_r(mpi *X, int count);

/**
 * \brief          Compare unsigned values
 *
 * \return         1 if |X| is greater than |Y|,
 *                -1 if |X| is lesser  than |Y| or
 *                 0 if |X| is equal to |Y|
 */
int mpi_cmp_abs(mpi *X, mpi *Y);

/**
 * \brief          Compare signed values
 *
 * \return         1 if X is greater than Y,
 *                -1 if X is lesser  than Y or
 *                 0 if X is equal to Y
 */
int mpi_cmp_mpi(mpi *X, mpi *Y);

/**
 * \brief          Compare signed values
 *
 * \return         1 if X is greater than z,
 *                -1 if X is lesser  than z or
 *                 0 if X is equal to z
 */
int mpi_cmp_int(mpi *X, int z);

/**
 * \brief          Unsigned addition: X = |A| + |B|
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_add_abs(mpi *X, mpi *A, mpi *B);

/**
 * \brief          Unsigned substraction: X = |A| - |B|
 *
 * \return         0 if successful,
 *                 POLARSSL_ERR_MPI_NEGATIVE_VALUE if B is greater than A
 */
int mpi_sub_abs(mpi *X, mpi *A, mpi *B);

/**
 * \brief          Signed addition: X = A + B
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_add_mpi(mpi *X, mpi *A, mpi *B);

/**
 * \brief          Signed substraction: X = A - B
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_sub_mpi(mpi *X, mpi *A, mpi *B);

/**
 * \brief          Signed addition: X = A + b
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_add_int(mpi *X, mpi *A, int b);

/**
 * \brief          Signed substraction: X = A - b
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_sub_int(mpi *X, mpi *A, int b);

/**
 * \brief          Baseline multiplication: X = A * B
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_mul_mpi(mpi *X, mpi *A, mpi *B);

/**
 * \brief          Baseline multiplication: X = A * b
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_mul_int(mpi *X, mpi *A, t_int b);

/**
 * \brief          Division by mpi: A = Q * B + R
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_DIVISION_BY_ZERO if B == 0
 *
 * \note           Either Q or R can be NULL.
 */
int mpi_div_mpi(mpi *Q, mpi *R, mpi *A, mpi *B);

/**
 * \brief          Division by int: A = Q * b + R
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_DIVISION_BY_ZERO if b == 0
 *
 * \note           Either Q or R can be NULL.
 */
int mpi_div_int(mpi *Q, mpi *R, mpi *A, int b);

/**
 * \brief          Modulo: R = A mod B
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_DIVISION_BY_ZERO if B == 0
 */
int mpi_mod_mpi(mpi *R, mpi *A, mpi *B);

/**
 * \brief          Modulo: r = A mod b
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_DIVISION_BY_ZERO if b == 0
 */
int mpi_mod_int(t_int *r, mpi *A, int b);

/**
 * \brief          Sliding-window exponentiation: X = A^E mod N
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_BAD_INPUT_DATA if N is negative or even
 *
 * \note           _RR is used to avoid re-computing R*R mod N across
 *                 multiple calls, which speeds up things a bit. It can
 *                 be set to NULL if the extra performance is unneeded.
 */
int mpi_exp_mod(mpi *X, mpi *A, mpi *E, mpi *N, mpi *_RR);

/**
 * \brief          Greatest common divisor: G = gcd(A, B)
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed
 */
int mpi_gcd(mpi *G, mpi *A, mpi *B);

/**
 * \brief          Modular inverse: X = A^-1 mod N
 *
 * \return         0 if successful,
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_BAD_INPUT_DATA if N is negative or nil
 *                 POLARSSL_ERR_MPI_NOT_ACCEPTABLE if A has no inverse mod N
 */
int mpi_inv_mod(mpi *X, mpi *A, mpi *N);

/**
 * \brief          Miller-Rabin primality test
 *
 * \return         0 if successful (probably prime),
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_NOT_ACCEPTABLE if X is not prime
 */
int mpi_is_prime(mpi *X, int(*f_rng)(void *), void *p_rng);

/**
 * \brief          Prime number generation
 *
 * \param X        destination mpi
 * \param nbits    required size of X in bits
 * \param dh_flag  if 1, then (X-1)/2 will be prime too
 * \param f_rng    RNG function
 * \param p_rng    RNG parameter
 *
 * \return         0 if successful (probably prime),
 *                 1 if memory allocation failed,
 *                 POLARSSL_ERR_MPI_BAD_INPUT_DATA if nbits is < 3
 */
int mpi_gen_prime(mpi *X, int nbits, int dh_flag,
                  int(*f_rng)(void *), void *p_rng);

/**
 * \brief          Checkup routine
 *
 * \return         0 if successful, or 1 if the test failed
 */
int mpi_self_test(int verbose);

#ifdef __cplusplus
}
#endif

#endif /* POLARSSL_BIGNUM_H */

#endif //KEYSTORENDK_BIGNUM_H