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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #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); }

 #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)); }

 #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;

 	/* 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 point multiplication */

 mp_err ec_group_set_gfp256_32(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_ */