/*

 * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.

 * Use is subject to license terms.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this library; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* *********************************************************************

 *

 * The Original Code is the elliptic curve math library.

 *

 * The Initial Developer of the Original Code is

 * Sun Microsystems, Inc.

 * Portions created by the Initial Developer are Copyright (C) 2003

 * the Initial Developer. All Rights Reserved.

 *

 * Contributor(s):

 *   Stephen Fung <fungstep@hotmail.com> and

 *   Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories

 *

 *********************************************************************** */

#ifndef _ECL_PRIV_H

#define _ECL_PRIV_H

#include "ecl.h"

#include "mpi.h"

#include "mplogic.h"

/* MAX_FIELD_SIZE_DIGITS is the maximum size of field element supported */

/* the following needs to go away... */

#if defined(MP_USE_LONG_LONG_DIGIT) || defined(MP_USE_LONG_DIGIT)

#define ECL_SIXTY_FOUR_BIT

#else

#define ECL_THIRTY_TWO_BIT

#endif

#define ECL_CURVE_DIGITS(curve_size_in_bits) \

        (((curve_size_in_bits)+(sizeof(mp_digit)*8-1))/(sizeof(mp_digit)*8))

#define ECL_BITS (sizeof(mp_digit)*8)

#define ECL_MAX_FIELD_SIZE_DIGITS (80/sizeof(mp_digit))

/* Gets the i'th bit in the binary representation of a. If i >= length(a),

 * then return 0. (The above behaviour differs from mpl_get_bit, which

 * causes an error if i >= length(a).) */

#define MP_GET_BIT(a, i) \

        ((i) >= mpl_significant_bits((a))) ? 0 : mpl_get_bit((a), (i))

#if !defined(MP_NO_MP_WORD) && !defined(MP_NO_ADD_WORD)

#define MP_ADD_CARRY(a1, a2, s, cin, cout)   \

    { mp_word w; \

    w = ((mp_word)(cin)) + (a1) + (a2); \

    s = ACCUM(w); \

    cout = CARRYOUT(w); }

/* Handle case when carry-in value is zero */

#define MP_ADD_CARRY_ZERO(a1, a2, s, cout)   \

    MP_ADD_CARRY(a1, a2, s, 0, cout);

#define MP_SUB_BORROW(a1, a2, s, bin, bout)   \

    { mp_word w; \

    w = ((mp_word)(a1)) - (a2) - (bin); \

    s = ACCUM(w); \

    bout = (w >> MP_DIGIT_BIT) & 1; }

#else

/* NOTE,

 * cin and cout could be the same variable.

 * bin and bout could be the same variable.

 * a1 or a2 and s could be the same variable.

 * don't trash those outputs until their respective inputs have

 * been read. */

#define MP_ADD_CARRY(a1, a2, s, cin, cout)   \

    { mp_digit tmp,sum; \

    tmp = (a1); \

    sum = tmp + (a2); \

    tmp = (sum < tmp);                     /* detect overflow */ \

    s = sum += (cin); \

    cout = tmp + (sum < (cin)); }

/* Handle case when carry-in value is zero */

#define MP_ADD_CARRY_ZERO(a1, a2, s, cout)   \

    { mp_digit tmp,sum; \

    tmp = (a1); \

    sum = tmp + (a2); \

    tmp = (sum < tmp);                     /* detect overflow */ \

    s = sum; \

    cout = tmp; }

#define MP_SUB_BORROW(a1, a2, s, bin, bout)   \

    { mp_digit tmp; \

    tmp = (a1); \

    s = tmp - (a2); \

    tmp = (s > tmp);                    /* detect borrow */ \

    if ((bin) && !s--) tmp++;   \

    bout = tmp; }

#endif

struct GFMethodStr;

typedef struct GFMethodStr GFMethod;

struct GFMethodStr {

        /* Indicates whether the structure was constructed from dynamic memory

         * or statically created. */

        int constructed;

        /* Irreducible that defines the field. For prime fields, this is the

         * prime p. For binary polynomial fields, this is the bitstring

         * representation of the irreducible polynomial. */

        mp_int irr;

        /* For prime fields, the value irr_arr[0] is the number of bits in the

         * field. For binary polynomial fields, the irreducible polynomial

         * f(t) is represented as an array of unsigned int[], where f(t) is

         * of the form: f(t) = t^p[0] + t^p[1] + ... + t^p[4] where m = p[0]

         * > p[1] > ... > p[4] = 0. */

        unsigned int irr_arr[5];

        /* Field arithmetic methods. All methods (except field_enc and

         * field_dec) are assumed to take field-encoded parameters and return

         * field-encoded values. All methods (except field_enc and field_dec)

         * are required to be implemented. */

        mp_err (*field_add) (const mp_int *a, const mp_int *b, mp_int *r,

                                                 const GFMethod *meth);

        mp_err (*field_neg) (const mp_int *a, mp_int *r, const GFMethod *meth);

        mp_err (*field_sub) (const mp_int *a, const mp_int *b, mp_int *r,

                                                 const GFMethod *meth);

        mp_err (*field_mod) (const mp_int *a, mp_int *r, const GFMethod *meth);

        mp_err (*field_mul) (const mp_int *a, const mp_int *b, mp_int *r,

                                                 const GFMethod *meth);

        mp_err (*field_sqr) (const mp_int *a, mp_int *r, const GFMethod *meth);

        mp_err (*field_div) (const mp_int *a, const mp_int *b, mp_int *r,

                                                 const GFMethod *meth);

        mp_err (*field_enc) (const mp_int *a, mp_int *r, const GFMethod *meth);

        mp_err (*field_dec) (const mp_int *a, mp_int *r, const GFMethod *meth);

        /* Extra storage for implementation-specific data.  Any memory

         * allocated to these extra fields will be cleared by extra_free. */

        void *extra1;

        void *extra2;

        void (*extra_free) (GFMethod *meth);

};

/* Construct generic GFMethods. */

GFMethod *GFMethod_consGFp(const mp_int *irr);

GFMethod *GFMethod_consGFp_mont(const mp_int *irr);

GFMethod *GFMethod_consGF2m(const mp_int *irr,

                                                        const unsigned int irr_arr[5]);

/* Free the memory allocated (if any) to a GFMethod object. */

void GFMethod_free(GFMethod *meth);

struct ECGroupStr {

        /* Indicates whether the structure was constructed from dynamic memory

         * or statically created. */

        int constructed;

        /* Field definition and arithmetic. */

        GFMethod *meth;

        /* Textual representation of curve name, if any. */

        char *text;

#ifdef _KERNEL

        int text_len;

#endif

        /* Curve parameters, field-encoded. */

        mp_int curvea, curveb;

        /* x and y coordinates of the base point, field-encoded. */

        mp_int genx, geny;

        /* Order and cofactor of the base point. */

        mp_int order;

        int cofactor;

        /* Point arithmetic methods. All methods are assumed to take

         * field-encoded parameters and return field-encoded values. All

         * methods (except base_point_mul and points_mul) are required to be

         * implemented. */

        mp_err (*point_add) (const mp_int *px, const mp_int *py,

                                                 const mp_int *qx, const mp_int *qy, mp_int *rx,

                                                 mp_int *ry, const ECGroup *group);

        mp_err (*point_sub) (const mp_int *px, const mp_int *py,

                                                 const mp_int *qx, const mp_int *qy, mp_int *rx,

                                                 mp_int *ry, const ECGroup *group);

        mp_err (*point_dbl) (const mp_int *px, const mp_int *py, mp_int *rx,

                                                 mp_int *ry, const ECGroup *group);

        mp_err (*point_mul) (const mp_int *n, const mp_int *px,

                                                 const mp_int *py, mp_int *rx, mp_int *ry,

                                                 const ECGroup *group);

        mp_err (*base_point_mul) (const mp_int *n, mp_int *rx, mp_int *ry,

                                                          const ECGroup *group);

        mp_err (*points_mul) (const mp_int *k1, const mp_int *k2,

                                                  const mp_int *px, const mp_int *py, mp_int *rx,

                                                  mp_int *ry, const ECGroup *group);

        mp_err (*validate_point) (const mp_int *px, const mp_int *py, const ECGroup *group);

        /* Extra storage for implementation-specific data.  Any memory

         * allocated to these extra fields will be cleared by extra_free. */

        void *extra1;

        void *extra2;

        void (*extra_free) (ECGroup *group);

};

/* Wrapper functions for generic prime field arithmetic. */

mp_err ec_GFp_add(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_neg(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GFp_sub(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

/* fixed length in-line adds. Count is in words */

mp_err ec_GFp_add_3(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_add_4(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_add_5(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_add_6(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_sub_3(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_sub_4(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_sub_5(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_sub_6(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_mod(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GFp_mul(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

mp_err ec_GFp_sqr(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GFp_div(const mp_int *a, const mp_int *b, mp_int *r,

                                  const GFMethod *meth);

/* Wrapper functions for generic binary polynomial field arithmetic. */

mp_err ec_GF2m_add(const mp_int *a, const mp_int *b, mp_int *r,

                                   const GFMethod *meth);

mp_err ec_GF2m_neg(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GF2m_mod(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GF2m_mul(const mp_int *a, const mp_int *b, mp_int *r,

                                   const GFMethod *meth);

mp_err ec_GF2m_sqr(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GF2m_div(const mp_int *a, const mp_int *b, mp_int *r,

                                   const GFMethod *meth);

/* Montgomery prime field arithmetic. */

mp_err ec_GFp_mul_mont(const mp_int *a, const mp_int *b, mp_int *r,

                                           const GFMethod *meth);

mp_err ec_GFp_sqr_mont(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GFp_div_mont(const mp_int *a, const mp_int *b, mp_int *r,

                                           const GFMethod *meth);

mp_err ec_GFp_enc_mont(const mp_int *a, mp_int *r, const GFMethod *meth);

mp_err ec_GFp_dec_mont(const mp_int *a, mp_int *r, const GFMethod *meth);

void ec_GFp_extra_free_mont(GFMethod *meth);

/* point multiplication */

mp_err ec_pts_mul_basic(const mp_int *k1, const mp_int *k2,

                                                const mp_int *px, const mp_int *py, mp_int *rx,

                                                mp_int *ry, const ECGroup *group);

mp_err ec_pts_mul_simul_w2(const mp_int *k1, const mp_int *k2,

                                                   const mp_int *px, const mp_int *py, mp_int *rx,

                                                   mp_int *ry, const ECGroup *group);

/* Computes the windowed non-adjacent-form (NAF) of a scalar. Out should

 * be an array of signed char's to output to, bitsize should be the number

 * of bits of out, in is the original scalar, and w is the window size.

 * NAF is discussed in the paper: D. Hankerson, J. Hernandez and A.

 * Menezes, "Software implementation of elliptic curve cryptography over

 * binary fields", Proc. CHES 2000. */

mp_err ec_compute_wNAF(signed char *out, int bitsize, const mp_int *in,

                                           int w);

/* Optimized field arithmetic */

mp_err ec_group_set_gfp192(ECGroup *group, ECCurveName);

mp_err ec_group_set_gfp224(ECGroup *group, ECCurveName);

mp_err ec_group_set_gfp256(ECGroup *group, ECCurveName);

mp_err ec_group_set_gfp384(ECGroup *group, ECCurveName);

mp_err ec_group_set_gfp521(ECGroup *group, ECCurveName);

mp_err ec_group_set_gf2m163(ECGroup *group, ECCurveName name);

mp_err ec_group_set_gf2m193(ECGroup *group, ECCurveName name);

mp_err ec_group_set_gf2m233(ECGroup *group, ECCurveName name);

/* Optimized floating-point arithmetic */

#ifdef ECL_USE_FP

mp_err ec_group_set_secp160r1_fp(ECGroup *group);

mp_err ec_group_set_nistp192_fp(ECGroup *group);

mp_err ec_group_set_nistp224_fp(ECGroup *group);

#endif

#endif /* _ECL_PRIV_H */