/* crypto/dh/dh.h */

/* Copyright (C) 1995-1998 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.]

 */

#ifndef HEADER_DH_H

#define HEADER_DH_H

#include <openssl/e_os2.h>

#ifdef OPENSSL_NO_DH

#error DH is disabled.

#endif

#ifndef OPENSSL_NO_BIO

#include <openssl/bio.h>

#endif

#include <openssl/ossl_typ.h>

#ifndef OPENSSL_NO_DEPRECATED

#include <openssl/bn.h>

#endif

#ifndef OPENSSL_DH_MAX_MODULUS_BITS

# define OPENSSL_DH_MAX_MODULUS_BITS	10000

#endif

#define DH_FLAG_CACHE_MONT_P     0x01

#define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH

                                       * implementation now uses constant time

                                       * modular exponentiation for secret exponents

                                       * by default. This flag causes the

                                       * faster variable sliding window method to

                                       * be used for all exponents.

                                       */

#ifdef  __cplusplus

extern "C" {

#endif

/* Already defined in ossl_typ.h */

/* typedef struct dh_st DH; */

/* typedef struct dh_method DH_METHOD; */

struct dh_method

	{

	const char *name;

	/* Methods here */

	int (*generate_key)(DH *dh);

	int (*compute_key)(unsigned char *key,const BIGNUM *pub_key,DH *dh);

	int (*bn_mod_exp)(const DH *dh, BIGNUM *r, const BIGNUM *a,

				const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,

				BN_MONT_CTX *m_ctx); /* Can be null */

	int (*init)(DH *dh);

	int (*finish)(DH *dh);

	int flags;

	char *app_data;

	/* If this is non-NULL, it will be used to generate parameters */

	int (*generate_params)(DH *dh, int prime_len, int generator, BN_GENCB *cb);

	};

struct dh_st

	{

	/* This first argument is used to pick up errors when

	 * a DH is passed instead of a EVP_PKEY */

	int pad;

	int version;

	BIGNUM *p;

	BIGNUM *g;

	long length; /* optional */

	BIGNUM *pub_key;	/* g^x */

	BIGNUM *priv_key;	/* x */

	int flags;

	BN_MONT_CTX *method_mont_p;

	/* Place holders if we want to do X9.42 DH */

	BIGNUM *q;

	BIGNUM *j;

	unsigned char *seed;

	int seedlen;

	BIGNUM *counter;

	int references;

	CRYPTO_EX_DATA ex_data;

	const DH_METHOD *meth;

	ENGINE *engine;

	};

#define DH_GENERATOR_2		2

/* #define DH_GENERATOR_3	3 */

#define DH_GENERATOR_5		5

/* DH_check error codes */

#define DH_CHECK_P_NOT_PRIME		0x01

#define DH_CHECK_P_NOT_SAFE_PRIME	0x02

#define DH_UNABLE_TO_CHECK_GENERATOR	0x04

#define DH_NOT_SUITABLE_GENERATOR	0x08

/* DH_check_pub_key error codes */

#define DH_CHECK_PUBKEY_TOO_SMALL	0x01

#define DH_CHECK_PUBKEY_TOO_LARGE	0x02

/* primes p where (p-1)/2 is prime too are called "safe"; we define

   this for backward compatibility: */

#define DH_CHECK_P_NOT_STRONG_PRIME	DH_CHECK_P_NOT_SAFE_PRIME

#define DHparams_dup(x) ASN1_dup_of_const(DH,i2d_DHparams,d2i_DHparams,x)

#define d2i_DHparams_fp(fp,x) (DH *)ASN1_d2i_fp((char *(*)())DH_new, \

		(char *(*)())d2i_DHparams,(fp),(unsigned char **)(x))

#define i2d_DHparams_fp(fp,x) ASN1_i2d_fp(i2d_DHparams,(fp), \

		(unsigned char *)(x))

#define d2i_DHparams_bio(bp,x) ASN1_d2i_bio_of(DH,DH_new,d2i_DHparams,bp,x)

#define i2d_DHparams_bio(bp,x) ASN1_i2d_bio_of_const(DH,i2d_DHparams,bp,x)

IMPORT_C const DH_METHOD *DH_OpenSSL(void);

IMPORT_C void DH_set_default_method(const DH_METHOD *meth);

IMPORT_C const DH_METHOD *DH_get_default_method(void);

IMPORT_C int DH_set_method(DH *dh, const DH_METHOD *meth);

IMPORT_C DH *DH_new_method(ENGINE *engine);

IMPORT_C DH *	DH_new(void);

IMPORT_C void	DH_free(DH *dh);

IMPORT_C int	DH_up_ref(DH *dh);

IMPORT_C int	DH_size(const DH *dh);

IMPORT_C int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,

	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func);

IMPORT_C int DH_set_ex_data(DH *d, int idx, void *arg);

IMPORT_C void *DH_get_ex_data(DH *d, int idx);

/* Deprecated version */

#ifndef OPENSSL_NO_DEPRECATED

IMPORT_C DH *	DH_generate_parameters(int prime_len,int generator,

		void (*callback)(int,int,void *),void *cb_arg);

#endif /* !defined(OPENSSL_NO_DEPRECATED) */

/* New version */

IMPORT_C int	DH_generate_parameters_ex(DH *dh, int prime_len,int generator, BN_GENCB *cb);

IMPORT_C int	DH_check(const DH *dh,int *codes);

IMPORT_C int	DH_check_pub_key(const DH *dh,const BIGNUM *pub_key, int *codes);

IMPORT_C int	DH_generate_key(DH *dh);

IMPORT_C int	DH_compute_key(unsigned char *key,const BIGNUM *pub_key,DH *dh);

IMPORT_C DH *	d2i_DHparams(DH **a,const unsigned char **pp, long length);

IMPORT_C int	i2d_DHparams(const DH *a,unsigned char **pp);

#ifndef OPENSSL_NO_FP_API

IMPORT_C int	DHparams_print_fp(FILE *fp, const DH *x);

#endif

#ifndef OPENSSL_NO_BIO

IMPORT_C int	DHparams_print(BIO *bp, const DH *x);

#else

IMPORT_C int	DHparams_print(char *bp, const DH *x);

#endif

/* 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.

 */

IMPORT_C void ERR_load_DH_strings(void);

/* Error codes for the DH functions. */

/* Function codes. */

#define DH_F_COMPUTE_KEY				 102

#define DH_F_DHPARAMS_PRINT				 100

#define DH_F_DHPARAMS_PRINT_FP				 101

#define DH_F_DH_BUILTIN_GENPARAMS			 106

#define DH_F_DH_NEW_METHOD				 105

#define DH_F_GENERATE_KEY				 103

#define DH_F_GENERATE_PARAMETERS			 104

/* Reason codes. */

#define DH_R_BAD_GENERATOR				 101

#define DH_R_NO_PRIVATE_VALUE				 100

#define DH_R_MODULUS_TOO_LARGE				 103

#define DH_R_INVALID_PUBKEY				 102

#ifdef  __cplusplus

}

#endif

#endif