/*
 * Copyright (C) 2010 Martin Willi
 * Copyright (C) 2010 revosec AG
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program 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 General Public License
 * for more details.
 */

/**
 * @defgroup tls_crypto tls_crypto
 * @{ @ingroup libtls
 */

#ifndef TLS_CRYPTO_H_
#define TLS_CRYPTO_H_

typedef struct tls_crypto_t tls_crypto_t;
typedef enum tls_cipher_suite_t tls_cipher_suite_t;
typedef enum tls_hash_algorithm_t tls_hash_algorithm_t;
typedef enum tls_signature_algorithm_t tls_signature_algorithm_t;
typedef enum tls_client_certificate_type_t tls_client_certificate_type_t;
typedef enum tls_ecc_curve_type_t tls_ecc_curve_type_t;
typedef enum tls_named_curve_t tls_named_curve_t;
typedef enum tls_ansi_point_format_t tls_ansi_point_format_t;
typedef enum tls_ec_point_format_t tls_ec_point_format_t;

#include "tls.h"
#include "tls_prf.h"
#include "tls_protection.h"

#include <library.h>

#include <credentials/keys/private_key.h>

/**
 * TLS cipher suites
 */
enum tls_cipher_suite_t {
	TLS_NULL_WITH_NULL_NULL =					0x0000,
	TLS_RSA_WITH_NULL_MD5 =						0x0001,
	TLS_RSA_WITH_NULL_SHA =						0x0002,
	TLS_RSA_EXPORT_WITH_RC4_40_MD5 =			0x0003,
	TLS_RSA_WITH_RC4_128_MD5 =					0x0004,
	TLS_RSA_WITH_RC4_128_SHA =					0x0005,
	TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 =		0x0006,
	TLS_RSA_WITH_IDEA_CBC_SHA =					0x0007,
	TLS_RSA_EXPORT_WITH_DES40_CBC_SHA =			0x0008,
	TLS_RSA_WITH_DES_CBC_SHA =					0x0009,
	TLS_RSA_WITH_3DES_EDE_CBC_SHA =				0x000A,
	TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA =		0x000B,
	TLS_DH_DSS_WITH_DES_CBC_SHA =				0x000C,
	TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA =			0x000D,
	TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA =		0x000E,
	TLS_DH_RSA_WITH_DES_CBC_SHA =				0x000F,
	TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA =			0x0010,
	TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA =		0x0011,
	TLS_DHE_DSS_WITH_DES_CBC_SHA =				0x0012,
	TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA =			0x0013,
	TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA =		0x0014,
	TLS_DHE_RSA_WITH_DES_CBC_SHA =				0x0015,
	TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA =			0x0016,
	TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 =		0x0017,
	TLS_DH_anon_WITH_RC4_128_MD5 =				0x0018,
	TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA =		0x0019,
	TLS_DH_anon_WITH_DES_CBC_SHA =				0x001A,
	TLS_DH_anon_WITH_3DES_EDE_CBC_SHA =			0x001B,

	TLS_KRB5_WITH_DES_CBC_SHA =					0x001E,
	TLS_KRB5_WITH_3DES_EDE_CBC_SHA =			0x001F,
	TLS_KRB5_WITH_RC4_128_SHA =					0x0020,
	TLS_KRB5_WITH_IDEA_CBC_SHA =				0x0021,
	TLS_KRB5_WITH_DES_CBC_MD5 =					0x0022,
	TLS_KRB5_WITH_3DES_EDE_CBC_MD5 =			0x0023,
	TLS_KRB5_WITH_RC4_128_MD5 =					0x0024,
	TLS_KRB5_WITH_IDEA_CBC_MD5 =				0x0025,
	TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA =		0x0026,
	TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA =		0x0027,
	TLS_KRB5_EXPORT_WITH_RC4_40_SHA =			0x0028,
	TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5 =		0x0029,
	TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5 =		0x002A,
	TLS_KRB5_EXPORT_WITH_RC4_40_MD5 =			0x002B,
	TLS_PSK_WITH_NULL_SHA =						0x002C,
	TLS_DHE_PSK_WITH_NULL_SHA =					0x002D,
	TLS_RSA_PSK_WITH_NULL_SHA =					0x002E,
	TLS_RSA_WITH_AES_128_CBC_SHA =				0x002F,
	TLS_DH_DSS_WITH_AES_128_CBC_SHA =			0x0030,
	TLS_DH_RSA_WITH_AES_128_CBC_SHA =			0x0031,
	TLS_DHE_DSS_WITH_AES_128_CBC_SHA =			0x0032,
	TLS_DHE_RSA_WITH_AES_128_CBC_SHA =			0x0033,
	TLS_DH_anon_WITH_AES_128_CBC_SHA =			0x0034,
	TLS_RSA_WITH_AES_256_CBC_SHA =				0x0035,
	TLS_DH_DSS_WITH_AES_256_CBC_SHA =			0x0036,
	TLS_DH_RSA_WITH_AES_256_CBC_SHA =			0x0037,
	TLS_DHE_DSS_WITH_AES_256_CBC_SHA =			0x0038,
	TLS_DHE_RSA_WITH_AES_256_CBC_SHA =			0x0039,
	TLS_DH_anon_WITH_AES_256_CBC_SHA =			0x003A,
	TLS_RSA_WITH_NULL_SHA256 =					0x003B,
	TLS_RSA_WITH_AES_128_CBC_SHA256 =			0x003C,
	TLS_RSA_WITH_AES_256_CBC_SHA256 =			0x003D,
	TLS_DH_DSS_WITH_AES_128_CBC_SHA256 =		0x003E,
	TLS_DH_RSA_WITH_AES_128_CBC_SHA256 =		0x003F,
	TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 =		0x0040,
	TLS_RSA_WITH_CAMELLIA_128_CBC_SHA =			0x0041,
	TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA =		0x0042,
	TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA =		0x0043,
	TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA =		0x0044,
	TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA =		0x0045,
	TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA =		0x0046,

	TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 =		0x0067,
	TLS_DH_DSS_WITH_AES_256_CBC_SHA256 =		0x0068,
	TLS_DH_RSA_WITH_AES_256_CBC_SHA256 =		0x0069,
	TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 =		0x006A,
	TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 =		0x006B,
	TLS_DH_anon_WITH_AES_128_CBC_SHA256 =		0x006C,
	TLS_DH_anon_WITH_AES_256_CBC_SHA256 =		0x006D,

	TLS_RSA_WITH_CAMELLIA_256_CBC_SHA =			0x0084,
	TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA =		0x0085,
	TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA =		0x0086,
	TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA =		0x0087,
	TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA =		0x0088,
	TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA =		0x0089,
	TLS_PSK_WITH_RC4_128_SHA =					0x008A,
	TLS_PSK_WITH_3DES_EDE_CBC_SHA =				0x008B,
	TLS_PSK_WITH_AES_128_CBC_SHA =				0x008C,
	TLS_PSK_WITH_AES_256_CBC_SHA =				0x008D,
	TLS_DHE_PSK_WITH_RC4_128_SHA =				0x008E,
	TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA =			0x008F,
	TLS_DHE_PSK_WITH_AES_128_CBC_SHA =			0x0090,
	TLS_DHE_PSK_WITH_AES_256_CBC_SHA =			0x0091,
	TLS_RSA_PSK_WITH_RC4_128_SHA =				0x0092,
	TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA =			0x0093,
	TLS_RSA_PSK_WITH_AES_128_CBC_SHA =			0x0094,
	TLS_RSA_PSK_WITH_AES_256_CBC_SHA =			0x0095,
	TLS_RSA_WITH_SEED_CBC_SHA =					0x0096,
	TLS_DH_DSS_WITH_SEED_CBC_SHA =				0x0097,
	TLS_DH_RSA_WITH_SEED_CBC_SHA =				0x0098,
	TLS_DHE_DSS_WITH_SEED_CBC_SHA =				0x0099,
	TLS_DHE_RSA_WITH_SEED_CBC_SHA =				0x009A,
	TLS_DH_anon_WITH_SEED_CBC_SHA =				0x009B,
	TLS_RSA_WITH_AES_128_GCM_SHA256 =			0x009C,
	TLS_RSA_WITH_AES_256_GCM_SHA384 =			0x009D,
	TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 =		0x009E,
	TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 =		0x009F,
	TLS_DH_RSA_WITH_AES_128_GCM_SHA256 =		0x00A0,
	TLS_DH_RSA_WITH_AES_256_GCM_SHA384 =		0x00A1,
	TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 =		0x00A2,
	TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 =		0x00A3,
	TLS_DH_DSS_WITH_AES_128_GCM_SHA256 =		0x00A4,
	TLS_DH_DSS_WITH_AES_256_GCM_SHA384 =		0x00A5,
	TLS_DH_anon_WITH_AES_128_GCM_SHA256 =		0x00A6,
	TLS_DH_anon_WITH_AES_256_GCM_SHA384 =		0x00A7,
	TLS_PSK_WITH_AES_128_GCM_SHA256 =			0x00A8,
	TLS_PSK_WITH_AES_256_GCM_SHA384 =			0x00A9,
	TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 =		0x00AA,
	TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 =		0x00AB,
	TLS_RSA_PSK_WITH_AES_128_GCM_SHA256 =		0x00AC,
	TLS_RSA_PSK_WITH_AES_256_GCM_SHA384 =		0x00AD,
	TLS_PSK_WITH_AES_128_CBC_SHA256 =			0x00AE,
	TLS_PSK_WITH_AES_256_CBC_SHA384 =			0x00AF,
	TLS_PSK_WITH_NULL_SHA256 =					0x00B0,
	TLS_PSK_WITH_NULL_SHA384 =					0x00B1,
	TLS_DHE_PSK_WITH_AES_128_CBC_SHA256 =		0x00B2,
	TLS_DHE_PSK_WITH_AES_256_CBC_SHA384 =		0x00B3,
	TLS_DHE_PSK_WITH_NULL_SHA256 =				0x00B4,
	TLS_DHE_PSK_WITH_NULL_SHA384 =				0x00B5,
	TLS_RSA_PSK_WITH_AES_128_CBC_SHA256 =		0x00B6,
	TLS_RSA_PSK_WITH_AES_256_CBC_SHA384 =		0x00B7,
	TLS_RSA_PSK_WITH_NULL_SHA256 =				0x00B8,
	TLS_RSA_PSK_WITH_NULL_SHA384 =				0x00B9,
	TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256 =		0x00BA,
	TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256 =	0x00BB,
	TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256 =	0x00BC,
	TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256 =	0x00BD,
	TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 =	0x00BE,
	TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256 =	0x00BF,
	TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256 =		0x00C0,
	TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256 =	0x00C1,
	TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256 =	0x00C2,
	TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256 =	0x00C3,
	TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 =	0x00C4,
	TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256 =	0x00C5,

	TLS_EMPTY_RENEGOTIATION_INFO_SCSV =			0x00FF,

	TLS_ECDH_ECDSA_WITH_NULL_SHA =				0xC001,
	TLS_ECDH_ECDSA_WITH_RC4_128_SHA =			0xC002,
	TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA =		0xC003,
	TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA =		0xC004,
	TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA =		0xC005,
	TLS_ECDHE_ECDSA_WITH_NULL_SHA =				0xC006,
	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA =			0xC007,
	TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA =		0xC008,
	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA =		0xC009,
	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA =		0xC00A,
	TLS_ECDH_RSA_WITH_NULL_SHA =				0xC00B,
	TLS_ECDH_RSA_WITH_RC4_128_SHA =				0xC00C,
	TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA =		0xC00D,
	TLS_ECDH_RSA_WITH_AES_128_CBC_SHA =			0xC00E,
	TLS_ECDH_RSA_WITH_AES_256_CBC_SHA =			0xC00F,
	TLS_ECDHE_RSA_WITH_NULL_SHA =				0xC010,
	TLS_ECDHE_RSA_WITH_RC4_128_SHA =			0xC011,
	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA =		0xC012,
	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA =		0xC013,
	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA =		0xC014,
	TLS_ECDH_anon_WITH_NULL_SHA =				0xC015,
	TLS_ECDH_anon_WITH_RC4_128_SHA =			0xC016,
	TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA =		0xC017,
	TLS_ECDH_anon_WITH_AES_128_CBC_SHA =		0xC018,
	TLS_ECDH_anon_WITH_AES_256_CBC_SHA =		0xC019,
	TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA =			0xC01A,
	TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA =		0xC01B,
	TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA =		0xC01C,
	TLS_SRP_SHA_WITH_AES_128_CBC_SHA =			0xC01D,
	TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA =		0xC01E,
	TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA =		0xC01F,
	TLS_SRP_SHA_WITH_AES_256_CBC_SHA =			0xC020,
	TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA =		0xC021,
	TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA =		0xC022,
	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 =	0xC023,
	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 =	0xC024,
	TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 =	0xC025,
	TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 =	0xC026,
	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 =		0xC027,
	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 =		0xC028,
	TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 =		0xC029,
	TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 =		0xC02A,
	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 =	0xC02B,
	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 =	0xC02C,
	TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 =	0xC02D,
	TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 =	0xC02E,
	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 =		0xC02F,
	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 =		0xC030,
	TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 =		0xC031,
	TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 =		0xC032,
	TLS_ECDHE_PSK_WITH_RC4_128_SHA =			0xC033,
	TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA =		0xC034,
	TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA =		0xC035,
	TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA =		0xC036,
	TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 =		0xC037,
	TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 =		0xC038,
	TLS_ECDHE_PSK_WITH_NULL_SHA =				0xC039,
	TLS_ECDHE_PSK_WITH_NULL_SHA256 =			0xC03A,
	TLS_ECDHE_PSK_WITH_NULL_SHA384 =			0xC03B
};

/**
 * Enum names for tls_cipher_suite_t
 */
extern enum_name_t *tls_cipher_suite_names;

/**
 * TLS HashAlgorithm identifiers
 */
enum tls_hash_algorithm_t {
	TLS_HASH_NONE =		0,
	TLS_HASH_MD5 =		1,
	TLS_HASH_SHA1 =		2,
	TLS_HASH_SHA224 =	3,
	TLS_HASH_SHA256 =	4,
	TLS_HASH_SHA384 =	5,
	TLS_HASH_SHA512 =	6,
};

/**
 * Enum names for tls_hash_algorithm_t
 */
extern enum_name_t *tls_hash_algorithm_names;

/**
 * TLS SignatureAlgorithm identifiers
 */
enum tls_signature_algorithm_t {
	TLS_SIG_RSA =		1,
	TLS_SIG_DSA =		2,
	TLS_SIG_ECDSA =		3,
};

/**
 * Enum names for tls_signature_algorithm_t
 */
extern enum_name_t *tls_signature_algorithm_names;

/**
 * TLS ClientCertificateType
 */
enum tls_client_certificate_type_t {
	TLS_RSA_SIGN =			1,
	TLS_DSA_SIGN =			2,
	TLS_RSA_FIXED_DH =		3,
	TLS_DSS_FIXED_DH =		4,
	TLS_RSA_EPHEMERAL_DH =	5,
	TLS_DSS_EPHEMERAL_DH =	6,
	TLS_FORTEZZA_DMS =		20,
	TLS_ECDSA_SIGN =		64,
	TLS_RSA_FIXED_ECDH =	65,
	TLS_ECDSA_FIXED_ECDH =	66,
};

/**
 * Enum names for tls_client_certificate_type_t
 */
extern enum_name_t *tls_client_certificate_type_names;

/**
 * TLS EccCurveType
 */
enum tls_ecc_curve_type_t {
	TLS_ECC_EXPLICIT_PRIME =	1,
	TLS_ECC_EXPLICIT_CHAR2 =	2,
	TLS_ECC_NAMED_CURVE =		3,
};

/**
 * Enum names for tls_ecc_curve_type_t
 */
extern enum_name_t *tls_ecc_curve_type_names;

/**
 * TLS Named Curve identifiers
 */
enum tls_named_curve_t {
	TLS_SECT163K1 =		 1,
	TLS_SECT163R1 =		 2,
	TLS_SECT163R2 =		 3,
	TLS_SECT193R1 =		 4,
	TLS_SECT193R2 =		 5,
	TLS_SECT233K1 =		 6,
	TLS_SECT233R1 =		 7,
	TLS_SECT239K1 =		 8,
	TLS_SECT283K1 =		 9,
	TLS_SECT283R1 =		10,
	TLS_SECT409K1 =		11,
	TLS_SECT409R1 =		12,
	TLS_SECT571K1 =		13,
	TLS_SECT571R1 =		14,
	TLS_SECP160K1 =		15,
	TLS_SECP160R1 =		16,
	TLS_SECP160R2 =		17,
	TLS_SECP192K1 =		18,
	TLS_SECP192R1 =		19,
	TLS_SECP224K1 =		20,
	TLS_SECP224R1 =		21,
	TLS_SECP256K1 =		22,
	TLS_SECP256R1 =		23,
	TLS_SECP384R1 =		24,
	TLS_SECP521R1 =		25,
};

/**
 * Enum names for tls_named_curve_t
 */
extern enum_name_t *tls_named_curve_names;

/**
 * EC Point format, ANSI X9.62.
 */
enum tls_ansi_point_format_t {
	TLS_ANSI_COMPRESSED =	2,
	TLS_ANSI_COMPRESSED_Y =	3,
	TLS_ANSI_UNCOMPRESSED =	4,
	TLS_ANSI_HYBRID =		6,
	TLS_ANSI_HYBRID_Y =		7,
};

/**
 * Enum names for tls_ansi_point_format_t.
 */
extern enum_name_t *tls_ansi_point_format_names;

/**
 * EC Point format, TLS specific identifiers.
 */
enum tls_ec_point_format_t {
	TLS_EC_POINT_UNCOMPRESSED = 0,
	TLS_EC_POINT_ANSIX962_COMPRESSED_PRIME = 1,
	TLS_EC_POINT_ANSIX962_COMPRESSED_CHAR2 = 2,
};

/**
 * Enum names for tls_ec_point_format_t.
 */
extern enum_name_t *tls_ec_point_format_names;

/**
 * TLS crypto helper functions.
 */
struct tls_crypto_t {

	/**
	 * Get a list of supported TLS cipher suites.
	 *
	 * @param suites		list of suites, points to internal data
	 * @return				number of suites returned
	 */
	int (*get_cipher_suites)(tls_crypto_t *this, tls_cipher_suite_t **suites);

	/**
	 * Select and store a cipher suite from a given list of candidates.
	 *
	 * @param suites		list of candidates to select from
	 * @param count			number of suites
	 * @param key			key type used, or KEY_ANY
	 * @return				selected suite, 0 if none acceptable
	 */
	tls_cipher_suite_t (*select_cipher_suite)(tls_crypto_t *this,
										tls_cipher_suite_t *suites, int count,
										key_type_t key);

	/**
	 * Get the Diffie-Hellman group to use, if any.
	 *
	 * @return				Diffie Hellman group, ord MODP_NONE
	 */
	diffie_hellman_group_t (*get_dh_group)(tls_crypto_t *this);

	/**
	 * Write the list of supported hash/sig algorithms to writer.
	 *
	 * @param writer		writer to write supported hash/sig algorithms
	 */
	void (*get_signature_algorithms)(tls_crypto_t *this, bio_writer_t *writer);

	/**
	 * Create an enumerator over supported ECDH groups.
	 *
	 * Enumerates over (diffie_hellman_group_t, tls_named_curve_t)
	 *
	 * @return				enumerator
	 */
	enumerator_t* (*create_ec_enumerator)(tls_crypto_t *this);

	/**
	 * Set the protection layer of the TLS stack to control it.
	 *
	 * @param protection		protection layer to work on
	 */
	void (*set_protection)(tls_crypto_t *this, tls_protection_t *protection);

	/**
	 * Store exchanged handshake data, used for cryptographic operations.
	 *
	 * @param type			handshake sub type
	 * @param data			data to append to handshake buffer
	 */
	void (*append_handshake)(tls_crypto_t *this,
							 tls_handshake_type_t type, chunk_t data);

	/**
	 * Sign a blob of data, append signature to writer.
	 *
	 * @param key			private key to use for signature
	 * @param writer		TLS writer to write signature to
	 * @param data			data to sign
	 * @param hashsig		list of TLS1.2 hash/sig algorithms to select from
	 * @return				TRUE if signature create successfully
	 */
	bool (*sign)(tls_crypto_t *this, private_key_t *key,
				 bio_writer_t *writer, chunk_t data, chunk_t hashsig);

	/**
	 * Verify a blob of data, read signature from a reader.
	 *
	 * @param key			public key to verify signature with
	 * @param reader		TLS reader to read signature from
	 * @param data			data to verify signature
	 * @return				TRUE if signature valid
	 */
	bool (*verify)(tls_crypto_t *this, public_key_t *key,
				   bio_reader_t *reader, chunk_t data);

	/**
	 * Create a signature of the handshake data using a given private key.
	 *
	 * @param key			private key to use for signature
	 * @param writer		TLS writer to write signature to
	 * @param hashsig		list of TLS1.2 hash/sig algorithms to select from
	 * @return				TRUE if signature create successfully
	 */
	bool (*sign_handshake)(tls_crypto_t *this, private_key_t *key,
						   bio_writer_t *writer, chunk_t hashsig);

	/**
	 * Verify the signature over handshake data using a given public key.
	 *
	 * @param key			public key to verify signature with
	 * @param reader		TLS reader to read signature from
	 * @return				TRUE if signature valid
	 */
	bool (*verify_handshake)(tls_crypto_t *this, public_key_t *key,
							 bio_reader_t *reader);

	/**
	 * Calculate the data of a TLS finished message.
	 *
	 * @param label			ASCII label to use for calculation
	 * @param out			buffer to write finished data to
	 * @return				TRUE if calculation successful
	 */
	bool (*calculate_finished)(tls_crypto_t *this, char *label, char out[12]);

	/**
	 * Derive the master secret, MAC and encryption keys.
	 *
	 * @param premaster		premaster secret
	 * @param session		session identifier to cache master secret
	 * @param id			identity the session is bound to
	 * @param client_random	random data from client hello
	 * @param server_random	random data from server hello
	 * @return				TRUE if secrets derived successfully
	 */
	bool (*derive_secrets)(tls_crypto_t *this, chunk_t premaster,
						   chunk_t session, identification_t *id,
						   chunk_t client_random, chunk_t server_random);

	/**
	 * Try to resume a TLS session, derive key material.
	 *
	 * @param session		session identifier
	 * @param id			identity the session is bound to
	 * @param client_random	random data from client hello
	 * @param server_random	random data from server hello
	 * @return				selected suite
	 */
	tls_cipher_suite_t (*resume_session)(tls_crypto_t *this, chunk_t session,
										 identification_t *id,
										 chunk_t client_random,
										 chunk_t server_random);

	/**
	 * Check if we have a session to resume as a client.
	 *
	 * @param id			server identity to get a session for
	 * @return				allocated session identifier, or chunk_empty
	 */
	chunk_t (*get_session)(tls_crypto_t *this, identification_t *id);

	/**
	 * Change the cipher used at protection layer.
	 *
	 * @param inbound		TRUE to change inbound cipher, FALSE for outbound
	 */
	void (*change_cipher)(tls_crypto_t *this, bool inbound);

	/**
	 * Get the MSK to use in EAP-TLS.
	 *
	 * @return				MSK, points to internal data
	 */
	chunk_t (*get_eap_msk)(tls_crypto_t *this);

	/**
	 * Destroy a tls_crypto_t.
	 */
	void (*destroy)(tls_crypto_t *this);
};

/**
 * Create a tls_crypto instance.
 *
 * @param tls			TLS stack
 * @param cache			TLS session cache
 * @return				TLS crypto helper
 */
tls_crypto_t *tls_crypto_create(tls_t *tls, tls_cache_t *cache);

/**
 * Get a list of all supported TLS cipher suites.
 *
 * @param null			include supported NULL encryption suites
 * @param suites		pointer to allocated suites array, to free(), or NULL
 * @return				number of suites supported
 */
int tls_crypto_get_supported_suites(bool null, tls_cipher_suite_t **suites);

#endif /** TLS_CRYPTO_H_ @}*/