/* crypto/ec/ec.h */
/*
 * Originally written by Bodo Moeller for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 1998-2003 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 OpenSSL open source
 * license provided above.
 *
 * The elliptic curve binary polynomial software is originally written by 
 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
 *
 */

#ifndef HEADER_EC_H
#define HEADER_EC_H

#include <openssl/opensslconf.h>

#ifdef OPENSSL_NO_EC
#error EC is disabled.
#endif

#include <openssl/asn1.h>
#include <openssl/symhacks.h>
#ifndef OPENSSL_NO_DEPRECATED
#include <openssl/bn.h>
#endif

#ifdef  __cplusplus
extern "C" {
#elif defined(__SUNPRO_C)
# if __SUNPRO_C >= 0x520
# pragma error_messages (off,E_ARRAY_OF_INCOMPLETE_NONAME,E_ARRAY_OF_INCOMPLETE)
# endif
#endif


#ifndef OPENSSL_ECC_MAX_FIELD_BITS
# define OPENSSL_ECC_MAX_FIELD_BITS 661
#endif

typedef enum {
	/* values as defined in X9.62 (ECDSA) and elsewhere */
	POINT_CONVERSION_COMPRESSED = 2,
	POINT_CONVERSION_UNCOMPRESSED = 4,
	POINT_CONVERSION_HYBRID = 6
} point_conversion_form_t;


typedef struct ec_method_st EC_METHOD;

typedef struct ec_group_st
	/*
	 EC_METHOD *meth;
	 -- field definition
	 -- curve coefficients
	 -- optional generator with associated information (order, cofactor)
	 -- optional extra data (precomputed table for fast computation of multiples of generator)
	 -- ASN1 stuff
	*/
	EC_GROUP;

typedef struct ec_point_st EC_POINT;


/* EC_METHODs for curves over GF(p).
 * EC_GFp_simple_method provides the basis for the optimized methods.
 */
const EC_METHOD *EC_GFp_simple_method(void);
const EC_METHOD *EC_GFp_mont_method(void);
const EC_METHOD *EC_GFp_nist_method(void);

/* EC_METHOD for curves over GF(2^m).
 */
const EC_METHOD *EC_GF2m_simple_method(void);


EC_GROUP *EC_GROUP_new(const EC_METHOD *);
void EC_GROUP_free(EC_GROUP *);
void EC_GROUP_clear_free(EC_GROUP *);
int EC_GROUP_copy(EC_GROUP *, const EC_GROUP *);
EC_GROUP *EC_GROUP_dup(const EC_GROUP *);

const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *);
int EC_METHOD_get_field_type(const EC_METHOD *);

int EC_GROUP_set_generator(EC_GROUP *, const EC_POINT *generator, const BIGNUM *order, const BIGNUM *cofactor);
const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *);
int EC_GROUP_get_order(const EC_GROUP *, BIGNUM *order, BN_CTX *);
int EC_GROUP_get_cofactor(const EC_GROUP *, BIGNUM *cofactor, BN_CTX *);

void EC_GROUP_set_curve_name(EC_GROUP *, int nid);
int EC_GROUP_get_curve_name(const EC_GROUP *);

void EC_GROUP_set_asn1_flag(EC_GROUP *, int flag);
int EC_GROUP_get_asn1_flag(const EC_GROUP *);

void EC_GROUP_set_point_conversion_form(EC_GROUP *, point_conversion_form_t);
point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP *);

unsigned char *EC_GROUP_get0_seed(const EC_GROUP *);
size_t EC_GROUP_get_seed_len(const EC_GROUP *);
size_t EC_GROUP_set_seed(EC_GROUP *, const unsigned char *, size_t len);

int EC_GROUP_set_curve_GFp(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
int EC_GROUP_get_curve_GFp(const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *);
int EC_GROUP_set_curve_GF2m(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
int EC_GROUP_get_curve_GF2m(const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *);

/* returns the number of bits needed to represent a field element */
int EC_GROUP_get_degree(const EC_GROUP *);

/* EC_GROUP_check() returns 1 if 'group' defines a valid group, 0 otherwise */
int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx);
/* EC_GROUP_check_discriminant() returns 1 if the discriminant of the
 * elliptic curve is not zero, 0 otherwise */
int EC_GROUP_check_discriminant(const EC_GROUP *, BN_CTX *);

/* EC_GROUP_cmp() returns 0 if both groups are equal and 1 otherwise */
int EC_GROUP_cmp(const EC_GROUP *, const EC_GROUP *, BN_CTX *);

/* EC_GROUP_new_GF*() calls EC_GROUP_new() and EC_GROUP_set_GF*()
 * after choosing an appropriate EC_METHOD */
EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *);

/* EC_GROUP_new_by_curve_name() creates a EC_GROUP structure
 * specified by a curve name (in form of a NID) */
EC_GROUP *EC_GROUP_new_by_curve_name(int nid);
/* handling of internal curves */
typedef struct { 
	int nid;
	const char *comment;
	} EC_builtin_curve;
/* EC_builtin_curves(EC_builtin_curve *r, size_t size) returns number 
 * of all available curves or zero if a error occurred. 
 * In case r ist not zero nitems EC_builtin_curve structures 
 * are filled with the data of the first nitems internal groups */
size_t EC_get_builtin_curves(EC_builtin_curve *r, size_t nitems);


/* EC_POINT functions */

EC_POINT *EC_POINT_new(const EC_GROUP *);
void EC_POINT_free(EC_POINT *);
void EC_POINT_clear_free(EC_POINT *);
int EC_POINT_copy(EC_POINT *, const EC_POINT *);
EC_POINT *EC_POINT_dup(const EC_POINT *, const EC_GROUP *);
 
const EC_METHOD *EC_POINT_method_of(const EC_POINT *);

int EC_POINT_set_to_infinity(const EC_GROUP *, EC_POINT *);
int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *, EC_POINT *,
	const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *);
int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *, const EC_POINT *,
	BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *);
int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *, EC_POINT *,
	const BIGNUM *x, const BIGNUM *y, BN_CTX *);
int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *, const EC_POINT *,
	BIGNUM *x, BIGNUM *y, BN_CTX *);
int EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *, EC_POINT *,
	const BIGNUM *x, int y_bit, BN_CTX *);

int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *, EC_POINT *,
	const BIGNUM *x, const BIGNUM *y, BN_CTX *);
int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *, const EC_POINT *,
	BIGNUM *x, BIGNUM *y, BN_CTX *);
int EC_POINT_set_compressed_coordinates_GF2m(const EC_GROUP *, EC_POINT *,
	const BIGNUM *x, int y_bit, BN_CTX *);

size_t EC_POINT_point2oct(const EC_GROUP *, const EC_POINT *, point_conversion_form_t form,
        unsigned char *buf, size_t len, BN_CTX *);
int EC_POINT_oct2point(const EC_GROUP *, EC_POINT *,
        const unsigned char *buf, size_t len, BN_CTX *);

/* other interfaces to point2oct/oct2point: */
BIGNUM *EC_POINT_point2bn(const EC_GROUP *, const EC_POINT *,
	point_conversion_form_t form, BIGNUM *, BN_CTX *);
EC_POINT *EC_POINT_bn2point(const EC_GROUP *, const BIGNUM *,
	EC_POINT *, BN_CTX *);
char *EC_POINT_point2hex(const EC_GROUP *, const EC_POINT *,
	point_conversion_form_t form, BN_CTX *);
EC_POINT *EC_POINT_hex2point(const EC_GROUP *, const char *,
	EC_POINT *, BN_CTX *);

int EC_POINT_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *);
int EC_POINT_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
int EC_POINT_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);

int EC_POINT_is_at_infinity(const EC_GROUP *, const EC_POINT *);
int EC_POINT_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
int EC_POINT_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b, BN_CTX *);

int EC_POINT_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
int EC_POINTs_make_affine(const EC_GROUP *, size_t num, EC_POINT *[], BN_CTX *);


int EC_POINTs_mul(const EC_GROUP *, EC_POINT *r, const BIGNUM *, size_t num, const EC_POINT *[], const BIGNUM *[], BN_CTX *);
int EC_POINT_mul(const EC_GROUP *, EC_POINT *r, const BIGNUM *, const EC_POINT *, const BIGNUM *, BN_CTX *);

/* EC_GROUP_precompute_mult() stores multiples of generator for faster point multiplication */
int EC_GROUP_precompute_mult(EC_GROUP *, BN_CTX *);
/* EC_GROUP_have_precompute_mult() reports whether such precomputation has been done */
int EC_GROUP_have_precompute_mult(const EC_GROUP *);