/* -*- c -*-
 * Copyright (C) 2000-2016 Free Software Foundation, Inc.
 * Copyright (C) 2015-2017 Red Hat, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS 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 program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

/* This file contains the types and prototypes for all the
 * high level functionality of the gnutls main library.
 *
 * If the optional C++ binding was built, it is available in
 * gnutls/gnutlsxx.h.
 *
 * The openssl compatibility layer (which is under the GNU GPL
 * license) is in gnutls/openssl.h.
 *
 * The low level cipher functionality is in gnutls/crypto.h.
 */

#ifndef GNUTLS_GNUTLS_H
#define GNUTLS_GNUTLS_H

/* Get ssize_t. */
#include <sys/types.h>

/* Get size_t. */
#include <stddef.h>

/* Get time_t. */
#include <time.h>

#ifdef __cplusplus
extern "C" {
#endif

#define GNUTLS_VERSION "3.8.4"

/* clang-format off */
#define GNUTLS_VERSION_MAJOR 3
#define GNUTLS_VERSION_MINOR 8
#define GNUTLS_VERSION_PATCH 4

#define GNUTLS_VERSION_NUMBER 0x030804
/* clang-format on */

#define GNUTLS_CIPHER_RIJNDAEL_128_CBC GNUTLS_CIPHER_AES_128_CBC
#define GNUTLS_CIPHER_RIJNDAEL_256_CBC GNUTLS_CIPHER_AES_256_CBC
#define GNUTLS_CIPHER_RIJNDAEL_CBC GNUTLS_CIPHER_AES_128_CBC
#define GNUTLS_CIPHER_ARCFOUR GNUTLS_CIPHER_ARCFOUR_128

#if !defined(GNUTLS_INTERNAL_BUILD) && defined(_WIN32)
#define _SYM_EXPORT __declspec(dllimport)
#else
#define _SYM_EXPORT
#endif

#ifdef __GNUC__
#define __GNUTLS_CONST__ __attribute__((const))
#define __GNUTLS_PURE__ __attribute__((pure))
#else
#define __GNUTLS_CONST__
#define __GNUTLS_PURE__
#endif

/* Use the following definition globally in your program to disable
 * implicit initialization of gnutls. */
#define GNUTLS_SKIP_GLOBAL_INIT             \
	int _gnutls_global_init_skip(void); \
	int _gnutls_global_init_skip(void)  \
	{                                   \
		return 1;                   \
	}

/**
 * gnutls_cipher_algorithm_t:
 * @GNUTLS_CIPHER_UNKNOWN: Value to identify an unknown/unsupported algorithm.
 * @GNUTLS_CIPHER_NULL: The NULL (identity) encryption algorithm.
 * @GNUTLS_CIPHER_ARCFOUR_128: ARCFOUR stream cipher with 128-bit keys.
 * @GNUTLS_CIPHER_3DES_CBC: 3DES in CBC mode.
 * @GNUTLS_CIPHER_AES_128_CBC: AES in CBC mode with 128-bit keys.
 * @GNUTLS_CIPHER_AES_192_CBC: AES in CBC mode with 192-bit keys.
 * @GNUTLS_CIPHER_AES_256_CBC: AES in CBC mode with 256-bit keys.
 * @GNUTLS_CIPHER_AES_128_CFB8: AES in CFB8 mode with 128-bit keys.
 * @GNUTLS_CIPHER_AES_192_CFB8: AES in CFB8 mode with 192-bit keys.
 * @GNUTLS_CIPHER_AES_256_CFB8: AES in CFB8 mode with 256-bit keys.
 * @GNUTLS_CIPHER_ARCFOUR_40: ARCFOUR stream cipher with 40-bit keys.
 * @GNUTLS_CIPHER_CAMELLIA_128_CBC: Camellia in CBC mode with 128-bit keys.
 * @GNUTLS_CIPHER_CAMELLIA_192_CBC: Camellia in CBC mode with 192-bit keys.
 * @GNUTLS_CIPHER_CAMELLIA_256_CBC: Camellia in CBC mode with 256-bit keys.
 * @GNUTLS_CIPHER_RC2_40_CBC: RC2 in CBC mode with 40-bit keys.
 * @GNUTLS_CIPHER_DES_CBC: DES in CBC mode (56-bit keys).
 * @GNUTLS_CIPHER_AES_128_GCM: AES in GCM mode with 128-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_256_GCM: AES in GCM mode with 256-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_128_CCM: AES in CCM mode with 128-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_256_CCM: AES in CCM mode with 256-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_128_CCM_8: AES in CCM mode with 64-bit tag and 128-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_256_CCM_8: AES in CCM mode with 64-bit tag and 256-bit keys (AEAD).
 * @GNUTLS_CIPHER_CAMELLIA_128_GCM: CAMELLIA in GCM mode with 128-bit keys (AEAD).
 * @GNUTLS_CIPHER_CAMELLIA_256_GCM: CAMELLIA in GCM mode with 256-bit keys (AEAD).
 * @GNUTLS_CIPHER_SALSA20_256: Salsa20 with 256-bit keys.
 * @GNUTLS_CIPHER_ESTREAM_SALSA20_256: Estream's Salsa20 variant with 256-bit keys.
 * @GNUTLS_CIPHER_CHACHA20_32: Chacha20 cipher with 96-bit nonces and 32-bit block counters.
 * @GNUTLS_CIPHER_CHACHA20_64: Chacha20 cipher with 64-bit nonces and 64-bit block counters.
 * @GNUTLS_CIPHER_CHACHA20_POLY1305: The Chacha20 cipher with the Poly1305 authenticator (AEAD).
 * @GNUTLS_CIPHER_GOST28147_TC26Z_CFB: GOST 28147-89 (Magma) cipher in CFB mode with TC26 Z S-box.
 * @GNUTLS_CIPHER_GOST28147_CPA_CFB: GOST 28147-89 (Magma) cipher in CFB mode with CryptoPro A S-box.
 * @GNUTLS_CIPHER_GOST28147_CPB_CFB: GOST 28147-89 (Magma) cipher in CFB mode with CryptoPro B S-box.
 * @GNUTLS_CIPHER_GOST28147_CPC_CFB: GOST 28147-89 (Magma) cipher in CFB mode with CryptoPro C S-box.
 * @GNUTLS_CIPHER_GOST28147_CPD_CFB: GOST 28147-89 (Magma) cipher in CFB mode with CryptoPro D S-box.
 * @GNUTLS_CIPHER_AES_128_XTS: AES in XTS mode with 128-bit key + 128bit tweak key.
 * @GNUTLS_CIPHER_AES_256_XTS: AES in XTS mode with 256-bit key + 256bit tweak key.
 *                             Note that the XTS ciphers are message oriented.
 *                             The whole message needs to be provided with a single call, because
 *                             cipher-stealing requires to know where the message actually terminates
 *                             in order to be able to compute where the stealing occurs.
 * @GNUTLS_CIPHER_GOST28147_TC26Z_CNT: GOST 28147-89 (Magma) cipher in CNT mode with TC26 Z S-box.
 * @GNUTLS_CIPHER_MAGMA_CTR_ACPKM: GOST R 34.12-2015 (Magma) cipher in CTR-ACPKM mode.
 * @GNUTLS_CIPHER_KUZNYECHIK_CTR_ACPKM: GOST R 34.12-2015 (Kuznyechik) cipher in CTR-ACPKM mode.
 * @GNUTLS_CIPHER_IDEA_PGP_CFB: IDEA in CFB mode (placeholder - unsupported).
 * @GNUTLS_CIPHER_3DES_PGP_CFB: 3DES in CFB mode (placeholder - unsupported).
 * @GNUTLS_CIPHER_CAST5_PGP_CFB: CAST5 in CFB mode (placeholder - unsupported).
 * @GNUTLS_CIPHER_BLOWFISH_PGP_CFB: Blowfish in CFB mode (placeholder - unsupported).
 * @GNUTLS_CIPHER_SAFER_SK128_PGP_CFB: Safer-SK in CFB mode with 128-bit keys (placeholder - unsupported).
 * @GNUTLS_CIPHER_AES128_PGP_CFB: AES in CFB mode with 128-bit keys (placeholder - unsupported).
 * @GNUTLS_CIPHER_AES192_PGP_CFB: AES in CFB mode with 192-bit keys (placeholder - unsupported).
 * @GNUTLS_CIPHER_AES256_PGP_CFB: AES in CFB mode with 256-bit keys (placeholder - unsupported).
 * @GNUTLS_CIPHER_TWOFISH_PGP_CFB: Twofish in CFB mode (placeholder - unsupported).
 * @GNUTLS_CIPHER_AES_128_SIV: AES in SIV mode with 128-bit key.
 * @GNUTLS_CIPHER_AES_256_SIV: AES in SIV mode with 256-bit key.
 *                             Note that the SIV ciphers can only be used with
 *                             the AEAD interface, and the IV plays a role as
 *                             the authentication tag while it is prepended to
 *                             the cipher text.
 * @GNUTLS_CIPHER_AES_192_GCM: AES in GCM mode with 192-bit keys (AEAD).
 * @GNUTLS_CIPHER_AES_128_SIV_GCM: AES in SIV-GCM mode with 128-bit key.
 * @GNUTLS_CIPHER_AES_256_SIV_GCM: AES in SIV-GCM mode with 256-bit key.
 *
 * Enumeration of different symmetric encryption algorithms.
 */
typedef enum gnutls_cipher_algorithm {
	GNUTLS_CIPHER_UNKNOWN = 0,
	GNUTLS_CIPHER_NULL = 1,
	GNUTLS_CIPHER_ARCFOUR_128 = 2,
	GNUTLS_CIPHER_3DES_CBC = 3,
	GNUTLS_CIPHER_AES_128_CBC = 4,
	GNUTLS_CIPHER_AES_256_CBC = 5,
	GNUTLS_CIPHER_ARCFOUR_40 = 6,
	GNUTLS_CIPHER_CAMELLIA_128_CBC = 7,
	GNUTLS_CIPHER_CAMELLIA_256_CBC = 8,
	GNUTLS_CIPHER_AES_192_CBC = 9,
	GNUTLS_CIPHER_AES_128_GCM = 10,
	GNUTLS_CIPHER_AES_256_GCM = 11,
	GNUTLS_CIPHER_CAMELLIA_192_CBC = 12,
	GNUTLS_CIPHER_SALSA20_256 = 13,
	GNUTLS_CIPHER_ESTREAM_SALSA20_256 = 14,
	GNUTLS_CIPHER_CAMELLIA_128_GCM = 15,
	GNUTLS_CIPHER_CAMELLIA_256_GCM = 16,
	GNUTLS_CIPHER_RC2_40_CBC = 17,
	GNUTLS_CIPHER_DES_CBC = 18,
	GNUTLS_CIPHER_AES_128_CCM = 19,
	GNUTLS_CIPHER_AES_256_CCM = 20,
	GNUTLS_CIPHER_AES_128_CCM_8 = 21,
	GNUTLS_CIPHER_AES_256_CCM_8 = 22,
	GNUTLS_CIPHER_CHACHA20_POLY1305 = 23,
	GNUTLS_CIPHER_GOST28147_TC26Z_CFB = 24,
	GNUTLS_CIPHER_GOST28147_CPA_CFB = 25,
	GNUTLS_CIPHER_GOST28147_CPB_CFB = 26,
	GNUTLS_CIPHER_GOST28147_CPC_CFB = 27,
	GNUTLS_CIPHER_GOST28147_CPD_CFB = 28,
	GNUTLS_CIPHER_AES_128_CFB8 = 29,
	GNUTLS_CIPHER_AES_192_CFB8 = 30,
	GNUTLS_CIPHER_AES_256_CFB8 = 31,
	GNUTLS_CIPHER_AES_128_XTS = 32,
	GNUTLS_CIPHER_AES_256_XTS = 33,
	GNUTLS_CIPHER_GOST28147_TC26Z_CNT = 34,
	GNUTLS_CIPHER_CHACHA20_64 = 35,
	GNUTLS_CIPHER_CHACHA20_32 = 36,
	GNUTLS_CIPHER_AES_128_SIV = 37,
	GNUTLS_CIPHER_AES_256_SIV = 38,
	GNUTLS_CIPHER_AES_192_GCM = 39,
	GNUTLS_CIPHER_MAGMA_CTR_ACPKM = 40,
	GNUTLS_CIPHER_KUZNYECHIK_CTR_ACPKM = 41,
	GNUTLS_CIPHER_AES_128_SIV_GCM = 42,
	GNUTLS_CIPHER_AES_256_SIV_GCM = 43,

	/* used only for PGP internals. Ignored in TLS/SSL
	 */
	GNUTLS_CIPHER_IDEA_PGP_CFB = 200,
	GNUTLS_CIPHER_3DES_PGP_CFB = 201,
	GNUTLS_CIPHER_CAST5_PGP_CFB = 202,
	GNUTLS_CIPHER_BLOWFISH_PGP_CFB = 203,
	GNUTLS_CIPHER_SAFER_SK128_PGP_CFB = 204,
	GNUTLS_CIPHER_AES128_PGP_CFB = 205,
	GNUTLS_CIPHER_AES192_PGP_CFB = 206,
	GNUTLS_CIPHER_AES256_PGP_CFB = 207,
	GNUTLS_CIPHER_TWOFISH_PGP_CFB = 208
} gnutls_cipher_algorithm_t;

/**
 * gnutls_kx_algorithm_t:
 * @GNUTLS_KX_UNKNOWN: Unknown key-exchange algorithm.
 * @GNUTLS_KX_RSA: RSA key-exchange algorithm.
 * @GNUTLS_KX_DHE_DSS: DHE-DSS key-exchange algorithm.
 * @GNUTLS_KX_DHE_RSA: DHE-RSA key-exchange algorithm.
 * @GNUTLS_KX_ECDHE_RSA: ECDHE-RSA key-exchange algorithm.
 * @GNUTLS_KX_ECDHE_ECDSA: ECDHE-ECDSA key-exchange algorithm.
 * @GNUTLS_KX_ANON_DH: Anon-DH key-exchange algorithm.
 * @GNUTLS_KX_ANON_ECDH: Anon-ECDH key-exchange algorithm.
 * @GNUTLS_KX_SRP: SRP key-exchange algorithm.
 * @GNUTLS_KX_RSA_EXPORT: RSA-EXPORT key-exchange algorithm (defunc).
 * @GNUTLS_KX_SRP_RSA: SRP-RSA key-exchange algorithm.
 * @GNUTLS_KX_SRP_DSS: SRP-DSS key-exchange algorithm.
 * @GNUTLS_KX_PSK: PSK key-exchange algorithm.
 * @GNUTLS_KX_DHE_PSK: DHE-PSK key-exchange algorithm.
 * @GNUTLS_KX_ECDHE_PSK: ECDHE-PSK key-exchange algorithm.
 * @GNUTLS_KX_RSA_PSK: RSA-PSK key-exchange algorithm.
 * @GNUTLS_KX_VKO_GOST_12: VKO GOST R 34.10-2012 key-exchange algorithm.
 *
 * Enumeration of different key exchange algorithms.
 */
typedef enum {
	GNUTLS_KX_UNKNOWN = 0,
	GNUTLS_KX_RSA = 1,
	GNUTLS_KX_DHE_DSS = 2,
	GNUTLS_KX_DHE_RSA = 3,
	GNUTLS_KX_ANON_DH = 4,
	GNUTLS_KX_SRP = 5,
	GNUTLS_KX_RSA_EXPORT = 6,
	GNUTLS_KX_SRP_RSA = 7,
	GNUTLS_KX_SRP_DSS = 8,
	GNUTLS_KX_PSK = 9,
	GNUTLS_KX_DHE_PSK = 10,
	GNUTLS_KX_ANON_ECDH = 11,
	GNUTLS_KX_ECDHE_RSA = 12,
	GNUTLS_KX_ECDHE_ECDSA = 13,
	GNUTLS_KX_ECDHE_PSK = 14,
	GNUTLS_KX_RSA_PSK = 15,
	GNUTLS_KX_VKO_GOST_12 = 16
} gnutls_kx_algorithm_t;

/**
 * gnutls_params_type_t:
 * @GNUTLS_PARAMS_RSA_EXPORT: Session RSA-EXPORT parameters (defunc).
 * @GNUTLS_PARAMS_DH: Session Diffie-Hellman parameters.
 * @GNUTLS_PARAMS_ECDH: Session Elliptic-Curve Diffie-Hellman parameters.
 *
 * Enumeration of different TLS session parameter types.
 */
typedef enum {
	GNUTLS_PARAMS_RSA_EXPORT = 1,
	GNUTLS_PARAMS_DH = 2,
	GNUTLS_PARAMS_ECDH = 3
} gnutls_params_type_t;

/**
 * gnutls_credentials_type_t:
 * @GNUTLS_CRD_CERTIFICATE: Certificate credential.
 * @GNUTLS_CRD_ANON: Anonymous credential.
 * @GNUTLS_CRD_SRP: SRP credential.
 * @GNUTLS_CRD_PSK: PSK credential.
 * @GNUTLS_CRD_IA: IA credential.
 *
 * Enumeration of different credential types.
 */
typedef enum {
	GNUTLS_CRD_CERTIFICATE = 1,
	GNUTLS_CRD_ANON,
	GNUTLS_CRD_SRP,
	GNUTLS_CRD_PSK,
	GNUTLS_CRD_IA
} gnutls_credentials_type_t;

#define GNUTLS_MAC_SHA GNUTLS_MAC_SHA1
#define GNUTLS_DIG_SHA GNUTLS_DIG_SHA1

/**
 * gnutls_mac_algorithm_t:
 * @GNUTLS_MAC_UNKNOWN: Unknown MAC algorithm.
 * @GNUTLS_MAC_NULL: NULL MAC algorithm (empty output).
 * @GNUTLS_MAC_MD5: HMAC-MD5 algorithm.
 * @GNUTLS_MAC_SHA1: HMAC-SHA-1 algorithm.
 * @GNUTLS_MAC_RMD160: HMAC-RMD160 algorithm.
 * @GNUTLS_MAC_MD2: HMAC-MD2 algorithm.
 * @GNUTLS_MAC_SHA256: HMAC-SHA-256 algorithm.
 * @GNUTLS_MAC_SHA384: HMAC-SHA-384 algorithm.
 * @GNUTLS_MAC_SHA512: HMAC-SHA-512 algorithm.
 * @GNUTLS_MAC_SHA224: HMAC-SHA-224 algorithm.
 * @GNUTLS_MAC_MD5_SHA1: Combined MD5+SHA1 MAC placeholder.
 * @GNUTLS_MAC_GOSTR_94: HMAC GOST R 34.11-94 algorithm.
 * @GNUTLS_MAC_STREEBOG_256: HMAC GOST R 34.11-2001 (Streebog) algorithm, 256 bit.
 * @GNUTLS_MAC_STREEBOG_512: HMAC GOST R 34.11-2001 (Streebog) algorithm, 512 bit.
 * @GNUTLS_MAC_AEAD: MAC implicit through AEAD cipher.
 * @GNUTLS_MAC_UMAC_96: The UMAC-96 MAC algorithm (requires nonce).
 * @GNUTLS_MAC_UMAC_128: The UMAC-128 MAC algorithm (requires nonce).
 * @GNUTLS_MAC_AES_CMAC_128: The AES-CMAC-128 MAC algorithm.
 * @GNUTLS_MAC_AES_CMAC_256: The AES-CMAC-256 MAC algorithm.
 * @GNUTLS_MAC_AES_GMAC_128: The AES-GMAC-128 MAC algorithm (requires nonce).
 * @GNUTLS_MAC_AES_GMAC_192: The AES-GMAC-192 MAC algorithm (requires nonce).
 * @GNUTLS_MAC_AES_GMAC_256: The AES-GMAC-256 MAC algorithm (requires nonce).
 * @GNUTLS_MAC_SHA3_224: Reserved; unimplemented.
 * @GNUTLS_MAC_SHA3_256: Reserved; unimplemented.
 * @GNUTLS_MAC_SHA3_384: Reserved; unimplemented.
 * @GNUTLS_MAC_SHA3_512: Reserved; unimplemented.
 * @GNUTLS_MAC_GOST28147_TC26Z_IMIT: The GOST 28147-89 working in IMIT mode with TC26 Z S-box.
 * @GNUTLS_MAC_SHAKE_128: Reserved; unimplemented.
 * @GNUTLS_MAC_SHAKE_256: Reserved; unimplemented.
 * @GNUTLS_MAC_MAGMA_OMAC: GOST R 34.12-2015 (Magma) in OMAC (CMAC) mode.
 * @GNUTLS_MAC_KUZNYECHIK_OMAC: GOST R 34.12-2015 (Kuznyechik) in OMAC (CMAC) mode.
 *
 * Enumeration of different Message Authentication Code (MAC)
 * algorithms.
 */
typedef enum {
	GNUTLS_MAC_UNKNOWN = 0,
	GNUTLS_MAC_NULL = 1,
	GNUTLS_MAC_MD5 = 2,
	GNUTLS_MAC_SHA1 = 3,
	GNUTLS_MAC_RMD160 = 4,
	GNUTLS_MAC_MD2 = 5,
	GNUTLS_MAC_SHA256 = 6,
	GNUTLS_MAC_SHA384 = 7,
	GNUTLS_MAC_SHA512 = 8,
	GNUTLS_MAC_SHA224 = 9,
	GNUTLS_MAC_SHA3_224 = 10, /* reserved: no implementation */
	GNUTLS_MAC_SHA3_256 = 11, /* reserved: no implementation */
	GNUTLS_MAC_SHA3_384 = 12, /* reserved: no implementation */
	GNUTLS_MAC_SHA3_512 = 13, /* reserved: no implementation */
	GNUTLS_MAC_MD5_SHA1 = 14, /* reserved: no implementation */
	GNUTLS_MAC_GOSTR_94 = 15,
	GNUTLS_MAC_STREEBOG_256 = 16,
	GNUTLS_MAC_STREEBOG_512 = 17,
	/* If you add anything here, make sure you align with
	   gnutls_digest_algorithm_t. */
	GNUTLS_MAC_AEAD = 200, /* indicates that MAC is on the cipher */
	GNUTLS_MAC_UMAC_96 = 201,
	GNUTLS_MAC_UMAC_128 = 202,
	GNUTLS_MAC_AES_CMAC_128 = 203,
	GNUTLS_MAC_AES_CMAC_256 = 204,
	GNUTLS_MAC_AES_GMAC_128 = 205,
	GNUTLS_MAC_AES_GMAC_192 = 206,
	GNUTLS_MAC_AES_GMAC_256 = 207,
	GNUTLS_MAC_GOST28147_TC26Z_IMIT = 208,
	GNUTLS_MAC_SHAKE_128 = 209,
	GNUTLS_MAC_SHAKE_256 = 210,
	GNUTLS_MAC_MAGMA_OMAC = 211,
	GNUTLS_MAC_KUZNYECHIK_OMAC = 212
} gnutls_mac_algorithm_t;

/**
 * gnutls_digest_algorithm_t:
 * @GNUTLS_DIG_UNKNOWN: Unknown hash algorithm.
 * @GNUTLS_DIG_NULL: NULL hash algorithm (empty output).
 * @GNUTLS_DIG_MD5: MD5 algorithm.
 * @GNUTLS_DIG_SHA1: SHA-1 algorithm.
 * @GNUTLS_DIG_RMD160: RMD160 algorithm.
 * @GNUTLS_DIG_MD2: MD2 algorithm.
 * @GNUTLS_DIG_SHA256: SHA-256 algorithm.
 * @GNUTLS_DIG_SHA384: SHA-384 algorithm.
 * @GNUTLS_DIG_SHA512: SHA-512 algorithm.
 * @GNUTLS_DIG_SHA224: SHA-224 algorithm.
 * @GNUTLS_DIG_SHA3_224: SHA3-224 algorithm.
 * @GNUTLS_DIG_SHA3_256: SHA3-256 algorithm.
 * @GNUTLS_DIG_SHA3_384: SHA3-384 algorithm.
 * @GNUTLS_DIG_SHA3_512: SHA3-512 algorithm.
 * @GNUTLS_DIG_MD5_SHA1: Combined MD5+SHA1 algorithm.
 * @GNUTLS_DIG_GOSTR_94: GOST R 34.11-94 algorithm.
 * @GNUTLS_DIG_STREEBOG_256: GOST R 34.11-2001 (Streebog) algorithm, 256 bit.
 * @GNUTLS_DIG_STREEBOG_512: GOST R 34.11-2001 (Streebog) algorithm, 512 bit.
 * @GNUTLS_DIG_SHAKE_128: Reserved; unimplemented.
 * @GNUTLS_DIG_SHAKE_256: Reserved; unimplemented.
 *
 * Enumeration of different digest (hash) algorithms.
 */
typedef enum {
	GNUTLS_DIG_UNKNOWN = GNUTLS_MAC_UNKNOWN,
	GNUTLS_DIG_NULL = GNUTLS_MAC_NULL,
	GNUTLS_DIG_MD5 = GNUTLS_MAC_MD5,
	GNUTLS_DIG_SHA1 = GNUTLS_MAC_SHA1,
	GNUTLS_DIG_RMD160 = GNUTLS_MAC_RMD160,
	GNUTLS_DIG_MD2 = GNUTLS_MAC_MD2,
	GNUTLS_DIG_SHA256 = GNUTLS_MAC_SHA256,
	GNUTLS_DIG_SHA384 = GNUTLS_MAC_SHA384,
	GNUTLS_DIG_SHA512 = GNUTLS_MAC_SHA512,
	GNUTLS_DIG_SHA224 = GNUTLS_MAC_SHA224,
	GNUTLS_DIG_SHA3_224 = GNUTLS_MAC_SHA3_224,
	GNUTLS_DIG_SHA3_256 = GNUTLS_MAC_SHA3_256,
	GNUTLS_DIG_SHA3_384 = GNUTLS_MAC_SHA3_384,
	GNUTLS_DIG_SHA3_512 = GNUTLS_MAC_SHA3_512,
	GNUTLS_DIG_MD5_SHA1 = GNUTLS_MAC_MD5_SHA1,
	GNUTLS_DIG_GOSTR_94 = GNUTLS_MAC_GOSTR_94,
	GNUTLS_DIG_STREEBOG_256 = GNUTLS_MAC_STREEBOG_256,
	GNUTLS_DIG_STREEBOG_512 = GNUTLS_MAC_STREEBOG_512,
	GNUTLS_DIG_SHAKE_128 = GNUTLS_MAC_SHAKE_128,
	GNUTLS_DIG_SHAKE_256 = GNUTLS_MAC_SHAKE_256
	/* If you add anything here, make sure you align with
	       gnutls_mac_algorithm_t. */
} gnutls_digest_algorithm_t;

/* exported for other gnutls headers. This is the maximum number of
   * algorithms (ciphers, kx or macs).
   */
#define GNUTLS_MAX_ALGORITHM_NUM 128
#define GNUTLS_MAX_SESSION_ID_SIZE 32

/**
 * gnutls_compression_method_t:
 * @GNUTLS_COMP_UNKNOWN: Unknown compression method.
 * @GNUTLS_COMP_NULL: The NULL compression method (no compression).
 * @GNUTLS_COMP_DEFLATE: The DEFLATE compression method from zlib.
 * @GNUTLS_COMP_ZLIB: Same as %GNUTLS_COMP_DEFLATE.
 * @GNUTLS_COMP_BROTLI: Brotli compression method.
 * @GNUTLS_COMP_ZSTD: Zstandard compression method.
 *
 * Enumeration of different TLS compression methods.
 */
typedef enum {
	GNUTLS_COMP_UNKNOWN = 0,
	GNUTLS_COMP_NULL = 1,
	GNUTLS_COMP_DEFLATE = 2,
	GNUTLS_COMP_ZLIB = GNUTLS_COMP_DEFLATE,
	GNUTLS_COMP_BROTLI = 3,
	GNUTLS_COMP_ZSTD = 4
} gnutls_compression_method_t;

/**
 * gnutls_init_flags_t:
 *
 * @GNUTLS_SERVER: Connection end is a server.
 * @GNUTLS_CLIENT: Connection end is a client.
 * @GNUTLS_DATAGRAM: Connection is datagram oriented (DTLS). Since 3.0.0.
 * @GNUTLS_NONBLOCK: Connection should not block. Since 3.0.0.
 * @GNUTLS_NO_SIGNAL: In systems where SIGPIPE is delivered on send, it will be disabled. That flag has effect in systems which support the MSG_NOSIGNAL sockets flag (since 3.4.2).
 * @GNUTLS_NO_DEFAULT_EXTENSIONS: Do not enable any TLS extensions by default such as session tickets and OCSP certificate status request (since 3.1.2). As TLS 1.2 and later require extensions this option is considered obsolete and should not be used.
 * @GNUTLS_NO_REPLAY_PROTECTION: Disable any replay protection in DTLS. This must only be used if  replay protection is achieved using other means. Since 3.2.2.
 * @GNUTLS_ALLOW_ID_CHANGE: Allow the peer to replace its certificate, or change its ID during a rehandshake. This change is often used in attacks and thus prohibited by default. Since 3.5.0.
 * @GNUTLS_ENABLE_FALSE_START: Enable the TLS false start on client side if the negotiated ciphersuites allow it. This will enable sending data prior to the handshake being complete, and may introduce a risk of crypto failure when combined with certain key exchanged; for that GnuTLS may not enable that option in ciphersuites that are known to be not safe for false start. Since 3.5.0.
 * @GNUTLS_ENABLE_EARLY_START: Under TLS1.3 allow the server to return earlier than the full handshake
 *   finish; similarly to false start the handshake will be completed once data are received by the
 *   client, while the server is able to transmit sooner. This is not enabled by default as it could
 *   break certain existing server assumptions and use-cases. Since 3.6.4.
 * @GNUTLS_ENABLE_EARLY_DATA: Under TLS1.3 allow the server to receive early data sent as part of the initial ClientHello (0-RTT).
 *   This can also be used to explicitly indicate that the client will send early data.
 *   This is not enabled by default as early data has weaker security properties than other data. Since 3.6.5.
 * @GNUTLS_FORCE_CLIENT_CERT: When in client side and only a single cert is specified, send that certificate irrespective of the issuers expected by the server. Since 3.5.0.
 * @GNUTLS_NO_TICKETS: Flag to indicate that the session should not use resumption with session tickets.
 * @GNUTLS_NO_TICKETS_TLS12: Flag to indicate that the session should not use resumption with session tickets. This flag only has effect if TLS 1.2 is used.
 * @GNUTLS_KEY_SHARE_TOP3: Generate key shares for the top-3 different groups which are enabled.
 *   That is, as each group is associated with a key type (EC, finite field, x25519), generate
 *   three keys using %GNUTLS_PK_DH, %GNUTLS_PK_EC, %GNUTLS_PK_ECDH_X25519 if all of them are enabled.
 * @GNUTLS_KEY_SHARE_TOP2: Generate key shares for the top-2 different groups which are enabled.
 *   For example (ECDH + x25519). This is the default.
 * @GNUTLS_KEY_SHARE_TOP: Generate key share for the first group which is enabled.
 *   For example x25519. This option is the most performant for client (less CPU spent
 *   generating keys), but if the server doesn't support the advertised option it may
 *   result to more roundtrips needed to discover the server's choice.
 * @GNUTLS_NO_AUTO_REKEY: Disable auto-rekeying under TLS1.3. If this option is not specified
 *   gnutls will force a rekey after 2^24 records have been sent.
 * @GNUTLS_POST_HANDSHAKE_AUTH: Enable post handshake authentication for server and client. When set and
 *   a server requests authentication after handshake %GNUTLS_E_REAUTH_REQUEST will be returned
 *   by gnutls_record_recv(). A client should then call gnutls_reauth() to re-authenticate.
 * @GNUTLS_SAFE_PADDING_CHECK: Flag to indicate that the TLS 1.3 padding check will be done in a
 *   safe way which doesn't leak the pad size based on GnuTLS processing time. This is of use to
 *   applications which hide the length of transferred data via the TLS1.3 padding mechanism and
 *   are already taking steps to hide the data processing time. This comes at a performance
 *   penalty.
 * @GNUTLS_AUTO_REAUTH: Enable transparent re-authentication in client side when the server
 *    requests to. That is, reauthentication is handled within gnutls_record_recv(), and
 *    the %GNUTLS_E_REHANDSHAKE or %GNUTLS_E_REAUTH_REQUEST are not returned. This must be
 *    enabled with %GNUTLS_POST_HANDSHAKE_AUTH for TLS1.3. Enabling this flag requires to restore
 *    interrupted calls to gnutls_record_recv() based on the output of gnutls_record_get_direction(),
 *    since gnutls_record_recv() could be interrupted when sending when this flag is enabled.
 *    Note this flag may not be used if you are using the same session for sending and receiving
 *    in different threads.
 * @GNUTLS_ENABLE_RAWPK: Allows raw public-keys to be negotiated during the handshake. Since 3.6.6.
 * @GNUTLS_NO_AUTO_SEND_TICKET: Under TLS1.3 disable auto-sending of
 *    session tickets during the handshake.
 * @GNUTLS_NO_END_OF_EARLY_DATA: Under TLS1.3 suppress sending EndOfEarlyData message. Since 3.7.2.
 * @GNUTLS_NO_STATUS_REQUEST: Prevents client from including the "status_request" TLS extension
 *    in the client hello, thus disabling the receival of certificate status information. Since 3.8.0.
 *
 * Enumeration of different flags for gnutls_init() function. All the flags
 * can be combined except @GNUTLS_SERVER and @GNUTLS_CLIENT which are mutually
 * exclusive.
 *
 * The key share options relate to the TLS 1.3 key share extension
 * which is a speculative key generation expecting that the server
 * would support the generated key.
 */
typedef enum {
	GNUTLS_SERVER = 1,
	GNUTLS_CLIENT = (1 << 1),
	GNUTLS_DATAGRAM = (1 << 2),
	GNUTLS_NONBLOCK = (1 << 3),
	GNUTLS_NO_DEFAULT_EXTENSIONS = (1 << 4),
	GNUTLS_NO_REPLAY_PROTECTION = (1 << 5),
	GNUTLS_NO_SIGNAL = (1 << 6),
	GNUTLS_ALLOW_ID_CHANGE = (1 << 7),
	GNUTLS_ENABLE_FALSE_START = (1 << 8),
	GNUTLS_FORCE_CLIENT_CERT = (1 << 9),
	GNUTLS_NO_TICKETS = (1 << 10),
	GNUTLS_KEY_SHARE_TOP = (1 << 11),
	GNUTLS_KEY_SHARE_TOP2 = (1 << 12),
	GNUTLS_KEY_SHARE_TOP3 = (1 << 13),
	GNUTLS_POST_HANDSHAKE_AUTH = (1 << 14),
	GNUTLS_NO_AUTO_REKEY = (1 << 15),
	GNUTLS_SAFE_PADDING_CHECK = (1 << 16),
	GNUTLS_ENABLE_EARLY_START = (1 << 17),
	GNUTLS_ENABLE_RAWPK = (1 << 18),
	GNUTLS_AUTO_REAUTH = (1 << 19),
	GNUTLS_ENABLE_EARLY_DATA = (1 << 20),
	GNUTLS_NO_AUTO_SEND_TICKET = (1 << 21),
	GNUTLS_NO_END_OF_EARLY_DATA = (1 << 22),
	GNUTLS_NO_TICKETS_TLS12 = (1 << 23),
	GNUTLS_NO_STATUS_REQUEST = (1 << 24)
} gnutls_init_flags_t;

/* compatibility defines (previous versions of gnutls
 * used defines instead of enumerated values). */
#define GNUTLS_SERVER (1)
#define GNUTLS_CLIENT (1 << 1)
#define GNUTLS_DATAGRAM (1 << 2)
#define GNUTLS_NONBLOCK (1 << 3)
#define GNUTLS_NO_DEFAULT_EXTENSIONS (1 << 4)
#define GNUTLS_NO_REPLAY_PROTECTION (1 << 5)
#define GNUTLS_NO_SIGNAL (1 << 6)
#define GNUTLS_ALLOW_ID_CHANGE (1 << 7)
#define GNUTLS_ENABLE_FALSE_START (1 << 8)
#define GNUTLS_FORCE_CLIENT_CERT (1 << 9)
#define GNUTLS_NO_TICKETS (1 << 10)
#define GNUTLS_ENABLE_CERT_TYPE_NEG 0
// Here for compatibility reasons

/* Keep backward compatibility */
#define GNUTLS_NO_EXTENSIONS GNUTLS_NO_DEFAULT_EXTENSIONS

/**
 * gnutls_alert_level_t:
 * @GNUTLS_AL_WARNING: Alert of warning severity.
 * @GNUTLS_AL_FATAL: Alert of fatal severity.
 *
 * Enumeration of different TLS alert severities.
 */
typedef enum {
	GNUTLS_AL_WARNING = 1,
	GNUTLS_AL_FATAL
} gnutls_alert_level_t;

/**
 * gnutls_alert_description_t:
 * @GNUTLS_A_CLOSE_NOTIFY: Close notify.
 * @GNUTLS_A_UNEXPECTED_MESSAGE: Unexpected message.
 * @GNUTLS_A_BAD_RECORD_MAC: Bad record MAC.
 * @GNUTLS_A_DECRYPTION_FAILED: Decryption failed.
 * @GNUTLS_A_RECORD_OVERFLOW: Record overflow.
 * @GNUTLS_A_DECOMPRESSION_FAILURE: Decompression failed.
 * @GNUTLS_A_HANDSHAKE_FAILURE: Handshake failed.
 * @GNUTLS_A_SSL3_NO_CERTIFICATE: No certificate.
 * @GNUTLS_A_BAD_CERTIFICATE: Certificate is bad.
 * @GNUTLS_A_UNSUPPORTED_CERTIFICATE: Certificate is not supported.
 * @GNUTLS_A_CERTIFICATE_REVOKED: Certificate was revoked.
 * @GNUTLS_A_CERTIFICATE_EXPIRED: Certificate is expired.
 * @GNUTLS_A_CERTIFICATE_UNKNOWN: Unknown certificate.
 * @GNUTLS_A_ILLEGAL_PARAMETER: Illegal parameter.
 * @GNUTLS_A_UNKNOWN_CA: CA is unknown.
 * @GNUTLS_A_ACCESS_DENIED: Access was denied.
 * @GNUTLS_A_DECODE_ERROR: Decode error.
 * @GNUTLS_A_DECRYPT_ERROR: Decrypt error.
 * @GNUTLS_A_EXPORT_RESTRICTION: Export restriction.
 * @GNUTLS_A_PROTOCOL_VERSION: Error in protocol version.
 * @GNUTLS_A_INSUFFICIENT_SECURITY: Insufficient security.
 * @GNUTLS_A_INTERNAL_ERROR: Internal error.
 * @GNUTLS_A_INAPPROPRIATE_FALLBACK: Inappropriate fallback,
 * @GNUTLS_A_USER_CANCELED: User canceled.
 * @GNUTLS_A_NO_RENEGOTIATION: No renegotiation is allowed.
 * @GNUTLS_A_MISSING_EXTENSION: An extension was expected but was not seen
 * @GNUTLS_A_UNSUPPORTED_EXTENSION: An unsupported extension was
 *   sent.
 * @GNUTLS_A_CERTIFICATE_UNOBTAINABLE: Could not retrieve the
 *   specified certificate.
 * @GNUTLS_A_UNRECOGNIZED_NAME: The server name sent was not
 *   recognized.
 * @GNUTLS_A_UNKNOWN_PSK_IDENTITY: The SRP/PSK username is missing
 *   or not known.
 * @GNUTLS_A_CERTIFICATE_REQUIRED: Certificate is required.
 * @GNUTLS_A_NO_APPLICATION_PROTOCOL: The ALPN protocol requested is
 *   not supported by the peer.
 *
 * Enumeration of different TLS alerts.
 */
typedef enum {
	GNUTLS_A_CLOSE_NOTIFY,
	GNUTLS_A_UNEXPECTED_MESSAGE = 10,
	GNUTLS_A_BAD_RECORD_MAC = 20,
	GNUTLS_A_DECRYPTION_FAILED,
	GNUTLS_A_RECORD_OVERFLOW,
	GNUTLS_A_DECOMPRESSION_FAILURE = 30,
	GNUTLS_A_HANDSHAKE_FAILURE = 40,
	GNUTLS_A_SSL3_NO_CERTIFICATE = 41,
	GNUTLS_A_BAD_CERTIFICATE = 42,
	GNUTLS_A_UNSUPPORTED_CERTIFICATE,
	GNUTLS_A_CERTIFICATE_REVOKED,
	GNUTLS_A_CERTIFICATE_EXPIRED,
	GNUTLS_A_CERTIFICATE_UNKNOWN,
	GNUTLS_A_ILLEGAL_PARAMETER,
	GNUTLS_A_UNKNOWN_CA,
	GNUTLS_A_ACCESS_DENIED,
	GNUTLS_A_DECODE_ERROR = 50,
	GNUTLS_A_DECRYPT_ERROR,
	GNUTLS_A_EXPORT_RESTRICTION = 60,
	GNUTLS_A_PROTOCOL_VERSION = 70,
	GNUTLS_A_INSUFFICIENT_SECURITY,
	GNUTLS_A_INTERNAL_ERROR = 80,
	GNUTLS_A_INAPPROPRIATE_FALLBACK = 86,
	GNUTLS_A_USER_CANCELED = 90,
	GNUTLS_A_NO_RENEGOTIATION = 100,
	GNUTLS_A_MISSING_EXTENSION = 109,
	GNUTLS_A_UNSUPPORTED_EXTENSION = 110,
	GNUTLS_A_CERTIFICATE_UNOBTAINABLE = 111,
	GNUTLS_A_UNRECOGNIZED_NAME = 112,
	GNUTLS_A_UNKNOWN_PSK_IDENTITY = 115,
	GNUTLS_A_CERTIFICATE_REQUIRED = 116,
	GNUTLS_A_NO_APPLICATION_PROTOCOL = 120,
	GNUTLS_A_MAX = GNUTLS_A_NO_APPLICATION_PROTOCOL
} gnutls_alert_description_t;

/**
 * gnutls_handshake_description_t:
 * @GNUTLS_HANDSHAKE_HELLO_REQUEST: Hello request.
 * @GNUTLS_HANDSHAKE_HELLO_VERIFY_REQUEST: DTLS Hello verify request.
 * @GNUTLS_HANDSHAKE_CLIENT_HELLO: Client hello.
 * @GNUTLS_HANDSHAKE_SERVER_HELLO: Server hello.
 * @GNUTLS_HANDSHAKE_END_OF_EARLY_DATA: End of early data.
 * @GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST: Hello retry request.
 * @GNUTLS_HANDSHAKE_NEW_SESSION_TICKET: New session ticket.
 * @GNUTLS_HANDSHAKE_CERTIFICATE_PKT: Certificate packet.
 * @GNUTLS_HANDSHAKE_SERVER_KEY_EXCHANGE: Server key exchange.
 * @GNUTLS_HANDSHAKE_CERTIFICATE_REQUEST: Certificate request.
 * @GNUTLS_HANDSHAKE_SERVER_HELLO_DONE: Server hello done.
 * @GNUTLS_HANDSHAKE_CERTIFICATE_VERIFY: Certificate verify.
 * @GNUTLS_HANDSHAKE_CLIENT_KEY_EXCHANGE: Client key exchange.
 * @GNUTLS_HANDSHAKE_FINISHED: Finished.
 * @GNUTLS_HANDSHAKE_CERTIFICATE_STATUS: Certificate status (OCSP).
 * @GNUTLS_HANDSHAKE_KEY_UPDATE: TLS1.3 key update message.
 * @GNUTLS_HANDSHAKE_COMPRESSED_CERTIFICATE_PKT: Compressed certificate packet.
 * @GNUTLS_HANDSHAKE_SUPPLEMENTAL: Supplemental.
 * @GNUTLS_HANDSHAKE_CHANGE_CIPHER_SPEC: Change Cipher Spec.
 * @GNUTLS_HANDSHAKE_CLIENT_HELLO_V2: SSLv2 Client Hello.
 * @GNUTLS_HANDSHAKE_ENCRYPTED_EXTENSIONS: Encrypted extensions message.
 *
 * Enumeration of different TLS handshake packets.
 */
typedef enum {
	GNUTLS_HANDSHAKE_HELLO_REQUEST = 0,
	GNUTLS_HANDSHAKE_CLIENT_HELLO = 1,
	GNUTLS_HANDSHAKE_SERVER_HELLO = 2,
	GNUTLS_HANDSHAKE_HELLO_VERIFY_REQUEST = 3,
	GNUTLS_HANDSHAKE_NEW_SESSION_TICKET = 4,
	GNUTLS_HANDSHAKE_END_OF_EARLY_DATA = 5,
	GNUTLS_HANDSHAKE_ENCRYPTED_EXTENSIONS = 8,
	GNUTLS_HANDSHAKE_CERTIFICATE_PKT = 11,
	GNUTLS_HANDSHAKE_SERVER_KEY_EXCHANGE = 12,
	GNUTLS_HANDSHAKE_CERTIFICATE_REQUEST = 13,
	GNUTLS_HANDSHAKE_SERVER_HELLO_DONE = 14,
	GNUTLS_HANDSHAKE_CERTIFICATE_VERIFY = 15,
	GNUTLS_HANDSHAKE_CLIENT_KEY_EXCHANGE = 16,
	GNUTLS_HANDSHAKE_FINISHED = 20,
	GNUTLS_HANDSHAKE_CERTIFICATE_STATUS = 22,
	GNUTLS_HANDSHAKE_SUPPLEMENTAL = 23,
	GNUTLS_HANDSHAKE_KEY_UPDATE = 24,
	GNUTLS_HANDSHAKE_COMPRESSED_CERTIFICATE_PKT = 25,
	GNUTLS_HANDSHAKE_CHANGE_CIPHER_SPEC = 254,
	GNUTLS_HANDSHAKE_CLIENT_HELLO_V2 = 1024,
	GNUTLS_HANDSHAKE_HELLO_RETRY_REQUEST = 1025,
} gnutls_handshake_description_t;

#define GNUTLS_HANDSHAKE_ANY ((unsigned int)-1)

const char *
gnutls_handshake_description_get_name(gnutls_handshake_description_t type);

/**
 * gnutls_certificate_status_t:
 * @GNUTLS_CERT_INVALID: The certificate is not signed by one of the
 *   known authorities or the signature is invalid (deprecated by the flags 
 *   %GNUTLS_CERT_SIGNATURE_FAILURE and %GNUTLS_CERT_SIGNER_NOT_FOUND).
 * @GNUTLS_CERT_SIGNATURE_FAILURE: The signature verification failed.
 * @GNUTLS_CERT_REVOKED: Certificate is revoked by its authority.  In X.509 this will be
 *   set only if CRLs are checked.
 * @GNUTLS_CERT_SIGNER_NOT_FOUND: The certificate's issuer is not known. 
 *   This is the case if the issuer is not included in the trusted certificate list.
 * @GNUTLS_CERT_SIGNER_NOT_CA: The certificate's signer was not a CA. This
 *   may happen if this was a version 1 certificate, which is common with
 *   some CAs, or a version 3 certificate without the basic constrains extension.
 * @GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE: The certificate's signer constraints were
 *   violated.
 * @GNUTLS_CERT_INSECURE_ALGORITHM:  The certificate was signed using an insecure
 *   algorithm such as MD2 or MD5. These algorithms have been broken and
 *   should not be trusted.
 * @GNUTLS_CERT_NOT_ACTIVATED: The certificate is not yet activated.
 * @GNUTLS_CERT_EXPIRED: The certificate has expired.
 * @GNUTLS_CERT_REVOCATION_DATA_SUPERSEDED: The revocation data are old and have been superseded.
 * @GNUTLS_CERT_REVOCATION_DATA_ISSUED_IN_FUTURE: The revocation data have a future issue date.
 * @GNUTLS_CERT_UNEXPECTED_OWNER: The owner is not the expected one.
 * @GNUTLS_CERT_MISMATCH: The certificate presented isn't the expected one (TOFU)
 * @GNUTLS_CERT_PURPOSE_MISMATCH: The certificate or an intermediate does not match the intended purpose (extended key usage).
 * @GNUTLS_CERT_MISSING_OCSP_STATUS: The certificate requires the server to send the certificate status, but no status was received.
 * @GNUTLS_CERT_INVALID_OCSP_STATUS: The received OCSP status response is invalid.
 * @GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS: The certificate has extensions marked as critical which are not supported.
 *
 * Enumeration of certificate status codes.  Note that the status
 * bits may have different meanings in OpenPGP keys and X.509
 * certificate verification.
 */
typedef enum {
	GNUTLS_CERT_INVALID = 1 << 1,
	GNUTLS_CERT_REVOKED = 1 << 5,
	GNUTLS_CERT_SIGNER_NOT_FOUND = 1 << 6,
	GNUTLS_CERT_SIGNER_NOT_CA = 1 << 7,
	GNUTLS_CERT_INSECURE_ALGORITHM = 1 << 8,
	GNUTLS_CERT_NOT_ACTIVATED = 1 << 9,
	GNUTLS_CERT_EXPIRED = 1 << 10,
	GNUTLS_CERT_SIGNATURE_FAILURE = 1 << 11,
	GNUTLS_CERT_REVOCATION_DATA_SUPERSEDED = 1 << 12,
	GNUTLS_CERT_UNEXPECTED_OWNER = 1 << 14,
	GNUTLS_CERT_REVOCATION_DATA_ISSUED_IN_FUTURE = 1 << 15,
	GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE = 1 << 16,
	GNUTLS_CERT_MISMATCH = 1 << 17,
	GNUTLS_CERT_PURPOSE_MISMATCH = 1 << 18,
	GNUTLS_CERT_MISSING_OCSP_STATUS = 1 << 19,
	GNUTLS_CERT_INVALID_OCSP_STATUS = 1 << 20,
	GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS = 1 << 21
} gnutls_certificate_status_t;

/**
 * gnutls_certificate_request_t:
 * @GNUTLS_CERT_IGNORE: Ignore certificate.
 * @GNUTLS_CERT_REQUEST: Request certificate.
 * @GNUTLS_CERT_REQUIRE: Require certificate.
 *
 * Enumeration of certificate request types.
 */
typedef enum {
	GNUTLS_CERT_IGNORE = 0,
	GNUTLS_CERT_REQUEST = 1,
	GNUTLS_CERT_REQUIRE = 2
} gnutls_certificate_request_t;

/**
 * gnutls_openpgp_crt_status_t:
 * @GNUTLS_OPENPGP_CERT: Send entire certificate.
 * @GNUTLS_OPENPGP_CERT_FINGERPRINT: Send only certificate fingerprint.
 *
 * Enumeration of ways to send OpenPGP certificate.
 */
typedef enum {
	GNUTLS_OPENPGP_CERT = 0,
	GNUTLS_OPENPGP_CERT_FINGERPRINT = 1
} gnutls_openpgp_crt_status_t;

/**
 * gnutls_close_request_t:
 * @GNUTLS_SHUT_RDWR: Disallow further receives/sends.
 * @GNUTLS_SHUT_WR: Disallow further sends.
 *
 * Enumeration of how TLS session should be terminated.  See gnutls_bye().
 */
typedef enum {
	GNUTLS_SHUT_RDWR = 0,
	GNUTLS_SHUT_WR = 1
} gnutls_close_request_t;

/**
 * gnutls_protocol_t:
 * @GNUTLS_SSL3: SSL version 3.0.
 * @GNUTLS_TLS1_0: TLS version 1.0.
 * @GNUTLS_TLS1: Same as %GNUTLS_TLS1_0.
 * @GNUTLS_TLS1_1: TLS version 1.1.
 * @GNUTLS_TLS1_2: TLS version 1.2.
 * @GNUTLS_TLS1_3: TLS version 1.3.
 * @GNUTLS_DTLS1_0: DTLS version 1.0.
 * @GNUTLS_DTLS1_2: DTLS version 1.2.
 * @GNUTLS_DTLS0_9: DTLS version 0.9 (Cisco AnyConnect / OpenSSL 0.9.8e).
 * @GNUTLS_TLS_VERSION_MAX: Maps to the highest supported TLS version.
 * @GNUTLS_DTLS_VERSION_MAX: Maps to the highest supported DTLS version.
 * @GNUTLS_VERSION_UNKNOWN: Unknown SSL/TLS version.
 *
 * Enumeration of different SSL/TLS protocol versions.
 */
typedef enum {
	GNUTLS_SSL3 = 1,
	GNUTLS_TLS1_0 = 2,
	GNUTLS_TLS1 = GNUTLS_TLS1_0,
	GNUTLS_TLS1_1 = 3,
	GNUTLS_TLS1_2 = 4,
	GNUTLS_TLS1_3 = 5,

	GNUTLS_DTLS0_9 = 200,
	GNUTLS_DTLS1_0 = 201, /* 201 */
	GNUTLS_DTLS1_2 = 202,
	GNUTLS_DTLS_VERSION_MIN = GNUTLS_DTLS0_9,
	GNUTLS_DTLS_VERSION_MAX = GNUTLS_DTLS1_2,
	GNUTLS_TLS_VERSION_MAX = GNUTLS_TLS1_3,
	GNUTLS_VERSION_UNKNOWN = 0xff /* change it to 0xffff */
} gnutls_protocol_t;

#define GNUTLS_CRT_RAW GNUTLS_CRT_RAWPK

/**
 * gnutls_certificate_type_t:
 * @GNUTLS_CRT_UNKNOWN: Unknown certificate type.
 * @GNUTLS_CRT_X509: X.509 Certificate.
 * @GNUTLS_CRT_OPENPGP: OpenPGP certificate.
 * @GNUTLS_CRT_RAWPK: Raw public-key (SubjectPublicKeyInfo)
 *
 * Enumeration of different certificate types.
 */
typedef enum {
	GNUTLS_CRT_UNKNOWN = 0,
	GNUTLS_CRT_X509 = 1,
	GNUTLS_CRT_OPENPGP = 2,
	GNUTLS_CRT_RAWPK = 3,
	GNUTLS_CRT_MAX = GNUTLS_CRT_RAWPK
} gnutls_certificate_type_t;

/**
 * gnutls_x509_crt_fmt_t:
 * @GNUTLS_X509_FMT_DER: X.509 certificate in DER format (binary).
 * @GNUTLS_X509_FMT_PEM: X.509 certificate in PEM format (text).
 *
 * Enumeration of different certificate encoding formats.
 */
typedef enum {
	GNUTLS_X509_FMT_DER = 0,
	GNUTLS_X509_FMT_PEM = 1
} gnutls_x509_crt_fmt_t;

/**
 * gnutls_certificate_print_formats_t:
 * @GNUTLS_CRT_PRINT_FULL: Full information about certificate.
 * @GNUTLS_CRT_PRINT_FULL_NUMBERS: Full information about certificate and include easy to parse public key parameters.
 * @GNUTLS_CRT_PRINT_COMPACT: Information about certificate name in one line, plus identification of the public key.
 * @GNUTLS_CRT_PRINT_ONELINE: Information about certificate in one line.
 * @GNUTLS_CRT_PRINT_UNSIGNED_FULL: All info for an unsigned certificate.
 *
 * Enumeration of different certificate printing variants.
 */
typedef enum gnutls_certificate_print_formats {
	GNUTLS_CRT_PRINT_FULL = 0,
	GNUTLS_CRT_PRINT_ONELINE = 1,
	GNUTLS_CRT_PRINT_UNSIGNED_FULL = 2,
	GNUTLS_CRT_PRINT_COMPACT = 3,
	GNUTLS_CRT_PRINT_FULL_NUMBERS = 4
} gnutls_certificate_print_formats_t;

#define GNUTLS_PK_ECC GNUTLS_PK_ECDSA
#define GNUTLS_PK_EC GNUTLS_PK_ECDSA

#define GNUTLS_PK_ECDHX GNUTLS_PK_ECDH_X25519
/**
 * gnutls_pk_algorithm_t:
 * @GNUTLS_PK_UNKNOWN: Unknown public-key algorithm.
 * @GNUTLS_PK_RSA: RSA public-key algorithm.
 * @GNUTLS_PK_RSA_OAEP: RSA public-key algorithm, with OAEP padding.
 * @GNUTLS_PK_RSA_PSS: RSA public-key algorithm, with PSS padding.
 * @GNUTLS_PK_DSA: DSA public-key algorithm.
 * @GNUTLS_PK_DH: Diffie-Hellman algorithm. Used to generate parameters.
 * @GNUTLS_PK_ECDSA: Elliptic curve algorithm. These parameters are compatible with the ECDSA and ECDH algorithm.
 * @GNUTLS_PK_ECDH_X25519: Elliptic curve algorithm, restricted to ECDH as per rfc7748.
 * @GNUTLS_PK_EDDSA_ED25519: Edwards curve Digital signature algorithm. Used with SHA512 on signatures.
 * @GNUTLS_PK_GOST_01: GOST R 34.10-2001 algorithm per rfc5832.
 * @GNUTLS_PK_GOST_12_256: GOST R 34.10-2012 algorithm, 256-bit key per rfc7091.
 * @GNUTLS_PK_GOST_12_512: GOST R 34.10-2012 algorithm, 512-bit key per rfc7091.
 * @GNUTLS_PK_ECDH_X448: Elliptic curve algorithm, restricted to ECDH as per rfc7748.
 * @GNUTLS_PK_EDDSA_ED448: Edwards curve Digital signature algorithm. Used with SHAKE256 on signatures.
 *
 * Enumeration of different public-key algorithms.
 */
typedef enum {
	GNUTLS_PK_UNKNOWN = 0,
	GNUTLS_PK_RSA = 1,
	GNUTLS_PK_DSA = 2,
	GNUTLS_PK_DH = 3,
	GNUTLS_PK_ECDSA = 4,
	GNUTLS_PK_ECDH_X25519 = 5,
	GNUTLS_PK_RSA_PSS = 6,
	GNUTLS_PK_EDDSA_ED25519 = 7,
	GNUTLS_PK_GOST_01 = 8,
	GNUTLS_PK_GOST_12_256 = 9,
	GNUTLS_PK_GOST_12_512 = 10,
	GNUTLS_PK_ECDH_X448 = 11,
	GNUTLS_PK_EDDSA_ED448 = 12,
	GNUTLS_PK_RSA_OAEP = 13,
	GNUTLS_PK_MAX = GNUTLS_PK_RSA_OAEP
} gnutls_pk_algorithm_t;

const char *gnutls_pk_algorithm_get_name(gnutls_pk_algorithm_t algorithm);

/**
 * gnutls_sign_algorithm_t:
 * @GNUTLS_SIGN_UNKNOWN: Unknown signature algorithm.
 * @GNUTLS_SIGN_RSA_RAW: Digital signature algorithm RSA with DigestInfo formatted data
 * @GNUTLS_SIGN_RSA_SHA1: Digital signature algorithm RSA with SHA-1
 * @GNUTLS_SIGN_RSA_SHA: Same as %GNUTLS_SIGN_RSA_SHA1.
 * @GNUTLS_SIGN_DSA_SHA1: Digital signature algorithm DSA with SHA-1
 * @GNUTLS_SIGN_DSA_SHA224: Digital signature algorithm DSA with SHA-224
 * @GNUTLS_SIGN_DSA_SHA256: Digital signature algorithm DSA with SHA-256
 * @GNUTLS_SIGN_DSA_SHA384: Digital signature algorithm DSA with SHA-384
 * @GNUTLS_SIGN_DSA_SHA512: Digital signature algorithm DSA with SHA-512
 * @GNUTLS_SIGN_DSA_SHA: Same as %GNUTLS_SIGN_DSA_SHA1.
 * @GNUTLS_SIGN_RSA_MD5: Digital signature algorithm RSA with MD5.
 * @GNUTLS_SIGN_RSA_MD2: Digital signature algorithm RSA with MD2.
 * @GNUTLS_SIGN_RSA_RMD160: Digital signature algorithm RSA with RMD-160.
 * @GNUTLS_SIGN_RSA_SHA256: Digital signature algorithm RSA with SHA-256.
 * @GNUTLS_SIGN_RSA_SHA384: Digital signature algorithm RSA with SHA-384.
 * @GNUTLS_SIGN_RSA_SHA512: Digital signature algorithm RSA with SHA-512.
 * @GNUTLS_SIGN_RSA_SHA224: Digital signature algorithm RSA with SHA-224.
 * @GNUTLS_SIGN_ECDSA_SHA1: ECDSA with SHA1.
 * @GNUTLS_SIGN_ECDSA_SHA224: Digital signature algorithm ECDSA with SHA-224.
 * @GNUTLS_SIGN_ECDSA_SHA256: Digital signature algorithm ECDSA with SHA-256.
 * @GNUTLS_SIGN_ECDSA_SHA384: Digital signature algorithm ECDSA with SHA-384.
 * @GNUTLS_SIGN_ECDSA_SHA512: Digital signature algorithm ECDSA with SHA-512.
 * @GNUTLS_SIGN_ECDSA_SECP256R1_SHA256: Digital signature algorithm ECDSA-SECP256R1 with SHA-256 (used in TLS 1.3 but not PKIX).
 * @GNUTLS_SIGN_ECDSA_SECP384R1_SHA384: Digital signature algorithm ECDSA-SECP384R1 with SHA-384 (used in TLS 1.3 but not PKIX).
 * @GNUTLS_SIGN_ECDSA_SECP521R1_SHA512: Digital signature algorithm ECDSA-SECP521R1 with SHA-512 (used in TLS 1.3 but not PKIX).
 * @GNUTLS_SIGN_ECDSA_SHA3_224: Digital signature algorithm ECDSA with SHA3-224.
 * @GNUTLS_SIGN_ECDSA_SHA3_256: Digital signature algorithm ECDSA with SHA3-256.
 * @GNUTLS_SIGN_ECDSA_SHA3_384: Digital signature algorithm ECDSA with SHA3-384.
 * @GNUTLS_SIGN_ECDSA_SHA3_512: Digital signature algorithm ECDSA with SHA3-512.
 * @GNUTLS_SIGN_DSA_SHA3_224: Digital signature algorithm DSA with SHA3-224.
 * @GNUTLS_SIGN_DSA_SHA3_256: Digital signature algorithm DSA with SHA3-256.
 * @GNUTLS_SIGN_DSA_SHA3_384: Digital signature algorithm DSA with SHA3-384.
 * @GNUTLS_SIGN_DSA_SHA3_512: Digital signature algorithm DSA with SHA3-512.
 * @GNUTLS_SIGN_RSA_SHA3_224: Digital signature algorithm RSA with SHA3-224.
 * @GNUTLS_SIGN_RSA_SHA3_256: Digital signature algorithm RSA with SHA3-256.
 * @GNUTLS_SIGN_RSA_SHA3_384: Digital signature algorithm RSA with SHA3-384.
 * @GNUTLS_SIGN_RSA_SHA3_512: Digital signature algorithm RSA with SHA3-512.
 * @GNUTLS_SIGN_RSA_PSS_RSAE_SHA256: Digital signature algorithm RSA with SHA-256,
 *      with PSS padding (RSA PKCS#1 1.5 certificate). This signature is identical
 *      to #GNUTLS_SIGN_RSA_PSS_SHA256, but they are distinct as the TLS1.3 protocol
 *      treats them differently.
 * @GNUTLS_SIGN_RSA_PSS_RSAE_SHA384: Digital signature algorithm RSA with SHA-384,
 *      with PSS padding (RSA PKCS#1 1.5 certificate). This signature is identical
 *      to #GNUTLS_SIGN_RSA_PSS_SHA384, but they are distinct as the TLS1.3 protocol
 *      treats them differently.
 * @GNUTLS_SIGN_RSA_PSS_RSAE_SHA512: Digital signature algorithm RSA with SHA-512,
 *      with PSS padding (RSA PKCS#1 1.5 certificate). This signature is identical
 *      to #GNUTLS_SIGN_RSA_PSS_SHA512, but they are distinct as the TLS1.3 protocol
 *      treats them differently.
 * @GNUTLS_SIGN_RSA_PSS_SHA256: Digital signature algorithm RSA with SHA-256, with PSS padding (RSA-PSS certificate).
 * @GNUTLS_SIGN_RSA_PSS_SHA384: Digital signature algorithm RSA with SHA-384, with PSS padding (RSA-PSS certificate).
 * @GNUTLS_SIGN_RSA_PSS_SHA512: Digital signature algorithm RSA with SHA-512, with PSS padding (RSA-PSS certificate).
 * @GNUTLS_SIGN_EDDSA_ED25519: Digital signature algorithm EdDSA with Ed25519 curve.
 * @GNUTLS_SIGN_GOST_94: Digital signature algorithm GOST R 34.10-2001 with GOST R 34.11-94
 * @GNUTLS_SIGN_GOST_256: Digital signature algorithm GOST R 34.10-2012 with GOST R 34.11-2012 256 bit
 * @GNUTLS_SIGN_GOST_512: Digital signature algorithm GOST R 34.10-2012 with GOST R 34.11-2012 512 bit
 * @GNUTLS_SIGN_EDDSA_ED448: Digital signature algorithm EdDSA with Ed448 curve.
 *
 * Enumeration of different digital signature algorithms.
 */
typedef enum {
	GNUTLS_SIGN_UNKNOWN = 0,
	GNUTLS_SIGN_RSA_SHA1 = 1,
	GNUTLS_SIGN_RSA_SHA = GNUTLS_SIGN_RSA_SHA1,
	GNUTLS_SIGN_DSA_SHA1 = 2,
	GNUTLS_SIGN_DSA_SHA = GNUTLS_SIGN_DSA_SHA1,
	GNUTLS_SIGN_RSA_MD5 = 3,
	GNUTLS_SIGN_RSA_MD2 = 4,
	GNUTLS_SIGN_RSA_RMD160 = 5,
	GNUTLS_SIGN_RSA_SHA256 = 6,
	GNUTLS_SIGN_RSA_SHA384 = 7,
	GNUTLS_SIGN_RSA_SHA512 = 8,
	GNUTLS_SIGN_RSA_SHA224 = 9,
	GNUTLS_SIGN_DSA_SHA224 = 10,
	GNUTLS_SIGN_DSA_SHA256 = 11,
	GNUTLS_SIGN_ECDSA_SHA1 = 12,
	GNUTLS_SIGN_ECDSA_SHA224 = 13,
	GNUTLS_SIGN_ECDSA_SHA256 = 14,
	GNUTLS_SIGN_ECDSA_SHA384 = 15,
	GNUTLS_SIGN_ECDSA_SHA512 = 16,
	GNUTLS_SIGN_DSA_SHA384 = 17,
	GNUTLS_SIGN_DSA_SHA512 = 18,
	GNUTLS_SIGN_ECDSA_SHA3_224 = 20,
	GNUTLS_SIGN_ECDSA_SHA3_256 = 21,
	GNUTLS_SIGN_ECDSA_SHA3_384 = 22,
	GNUTLS_SIGN_ECDSA_SHA3_512 = 23,

	GNUTLS_SIGN_DSA_SHA3_224 = 24,
	GNUTLS_SIGN_DSA_SHA3_256 = 25,
	GNUTLS_SIGN_DSA_SHA3_384 = 26,
	GNUTLS_SIGN_DSA_SHA3_512 = 27,
	GNUTLS_SIGN_RSA_SHA3_224 = 28,
	GNUTLS_SIGN_RSA_SHA3_256 = 29,
	GNUTLS_SIGN_RSA_SHA3_384 = 30,
	GNUTLS_SIGN_RSA_SHA3_512 = 31,

	GNUTLS_SIGN_RSA_PSS_SHA256 = 32,
	GNUTLS_SIGN_RSA_PSS_SHA384 = 33,
	GNUTLS_SIGN_RSA_PSS_SHA512 = 34,
	GNUTLS_SIGN_EDDSA_ED25519 = 35,
	GNUTLS_SIGN_RSA_RAW = 36,

	GNUTLS_SIGN_ECDSA_SECP256R1_SHA256 = 37,
	GNUTLS_SIGN_ECDSA_SECP384R1_SHA384 = 38,
	GNUTLS_SIGN_ECDSA_SECP521R1_SHA512 = 39,

	GNUTLS_SIGN_RSA_PSS_RSAE_SHA256 = 40,
	GNUTLS_SIGN_RSA_PSS_RSAE_SHA384 = 41,
	GNUTLS_SIGN_RSA_PSS_RSAE_SHA512 = 42,

	GNUTLS_SIGN_GOST_94 = 43,
	GNUTLS_SIGN_GOST_256 = 44,
	GNUTLS_SIGN_GOST_512 = 45,
	GNUTLS_SIGN_EDDSA_ED448 = 46,
	GNUTLS_SIGN_MAX = GNUTLS_SIGN_EDDSA_ED448
} gnutls_sign_algorithm_t;

/**
 * gnutls_ecc_curve_t:
 * @GNUTLS_ECC_CURVE_INVALID: Cannot be known
 * @GNUTLS_ECC_CURVE_SECP192R1: the SECP192R1 curve
 * @GNUTLS_ECC_CURVE_SECP224R1: the SECP224R1 curve
 * @GNUTLS_ECC_CURVE_SECP256R1: the SECP256R1 curve
 * @GNUTLS_ECC_CURVE_SECP384R1: the SECP384R1 curve
 * @GNUTLS_ECC_CURVE_SECP521R1: the SECP521R1 curve
 * @GNUTLS_ECC_CURVE_X25519: the X25519 curve (ECDH only)
 * @GNUTLS_ECC_CURVE_ED25519: the Ed25519 curve
 * @GNUTLS_ECC_CURVE_GOST256CPA: GOST R 34.10 CryptoPro 256 A curve
 * @GNUTLS_ECC_CURVE_GOST256CPB: GOST R 34.10 CryptoPro 256 B curve
 * @GNUTLS_ECC_CURVE_GOST256CPC: GOST R 34.10 CryptoPro 256 C curve
 * @GNUTLS_ECC_CURVE_GOST256CPXA: GOST R 34.10 CryptoPro 256 XchA curve
 * @GNUTLS_ECC_CURVE_GOST256CPXB: GOST R 34.10 CryptoPro 256 XchB curve
 * @GNUTLS_ECC_CURVE_GOST512A: GOST R 34.10 TC26 512 A curve
 * @GNUTLS_ECC_CURVE_GOST512B: GOST R 34.10 TC26 512 B curve
 * @GNUTLS_ECC_CURVE_GOST512C: GOST R 34.10 TC26 512 C curve
 * @GNUTLS_ECC_CURVE_GOST256A: GOST R 34.10 TC26 256 A curve
 * @GNUTLS_ECC_CURVE_GOST256B: GOST R 34.10 TC26 256 B curve
 * @GNUTLS_ECC_CURVE_GOST256C: GOST R 34.10 TC26 256 C curve
 * @GNUTLS_ECC_CURVE_GOST256D: GOST R 34.10 TC26 256 D curve
 * @GNUTLS_ECC_CURVE_X448: the X448 curve (ECDH only)
 * @GNUTLS_ECC_CURVE_ED448: the Ed448 curve
 *
 * Enumeration of ECC curves.
 */
typedef enum {
	GNUTLS_ECC_CURVE_INVALID = 0,
	GNUTLS_ECC_CURVE_SECP224R1,
	GNUTLS_ECC_CURVE_SECP256R1,
	GNUTLS_ECC_CURVE_SECP384R1,
	GNUTLS_ECC_CURVE_SECP521R1,
	GNUTLS_ECC_CURVE_SECP192R1,
	GNUTLS_ECC_CURVE_X25519,
	GNUTLS_ECC_CURVE_ED25519,
	GNUTLS_ECC_CURVE_GOST256CPA,
	GNUTLS_ECC_CURVE_GOST256CPB,
	GNUTLS_ECC_CURVE_GOST256CPC,
	GNUTLS_ECC_CURVE_GOST256CPXA,
	GNUTLS_ECC_CURVE_GOST256CPXB,
	GNUTLS_ECC_CURVE_GOST512A,
	GNUTLS_ECC_CURVE_GOST512B,
	GNUTLS_ECC_CURVE_GOST512C,
	GNUTLS_ECC_CURVE_GOST256A,
	GNUTLS_ECC_CURVE_GOST256B,
	GNUTLS_ECC_CURVE_GOST256C,
	GNUTLS_ECC_CURVE_GOST256D,
	GNUTLS_ECC_CURVE_X448,
	GNUTLS_ECC_CURVE_ED448,
	GNUTLS_ECC_CURVE_MAX = GNUTLS_ECC_CURVE_ED448
} gnutls_ecc_curve_t;

/**
 * gnutls_group_t:
 * @GNUTLS_GROUP_INVALID: Indicates unknown/invalid group
 * @GNUTLS_GROUP_SECP192R1: the SECP192R1 curve group (legacy, only for TLS 1.2 compatibility)
 * @GNUTLS_GROUP_SECP224R1: the SECP224R1 curve group (legacy, only for TLS 1.2 compatibility)
 * @GNUTLS_GROUP_SECP256R1: the SECP256R1 curve group
 * @GNUTLS_GROUP_SECP384R1: the SECP384R1 curve group
 * @GNUTLS_GROUP_SECP521R1: the SECP521R1 curve group
 * @GNUTLS_GROUP_X25519: the X25519 curve group
 * @GNUTLS_GROUP_GC256A: the GOST R 34.10 TC26 256 A curve group
 * @GNUTLS_GROUP_GC256B: the GOST R 34.10 TC26 256 B curve group
 * @GNUTLS_GROUP_GC256C: the GOST R 34.10 TC26 256 C curve group
 * @GNUTLS_GROUP_GC256D: the GOST R 34.10 TC26 256 D curve group
 * @GNUTLS_GROUP_GC512A: the GOST R 34.10 TC26 512 A curve group
 * @GNUTLS_GROUP_GC512B: the GOST R 34.10 TC26 512 B curve group
 * @GNUTLS_GROUP_GC512C: the GOST R 34.10 TC26 512 C curve group
 * @GNUTLS_GROUP_FFDHE2048: the FFDHE2048 group
 * @GNUTLS_GROUP_FFDHE3072: the FFDHE3072 group
 * @GNUTLS_GROUP_FFDHE4096: the FFDHE4096 group
 * @GNUTLS_GROUP_FFDHE6144: the FFDHE6144 group
 * @GNUTLS_GROUP_FFDHE8192: the FFDHE8192 group
 * @GNUTLS_GROUP_X448: the X448 curve group
 *
 * Enumeration of supported groups. It is intended to be backwards
 * compatible with the enumerations in %gnutls_ecc_curve_t for the groups
 * which are valid elliptic curves.
 */
typedef enum {
	GNUTLS_GROUP_INVALID = 0,
	GNUTLS_GROUP_SECP192R1 = GNUTLS_ECC_CURVE_SECP192R1,
	GNUTLS_GROUP_SECP224R1 = GNUTLS_ECC_CURVE_SECP224R1,
	GNUTLS_GROUP_SECP256R1 = GNUTLS_ECC_CURVE_SECP256R1,
	GNUTLS_GROUP_SECP384R1 = GNUTLS_ECC_CURVE_SECP384R1,
	GNUTLS_GROUP_SECP521R1 = GNUTLS_ECC_CURVE_SECP521R1,
	GNUTLS_GROUP_X25519 = GNUTLS_ECC_CURVE_X25519,
	GNUTLS_GROUP_X448 = GNUTLS_ECC_CURVE_X448,

	GNUTLS_GROUP_GC256A = GNUTLS_ECC_CURVE_GOST256A,
	GNUTLS_GROUP_GC256B = GNUTLS_ECC_CURVE_GOST256B,
	GNUTLS_GROUP_GC256C = GNUTLS_ECC_CURVE_GOST256C,
	GNUTLS_GROUP_GC256D = GNUTLS_ECC_CURVE_GOST256D,
	GNUTLS_GROUP_GC512A = GNUTLS_ECC_CURVE_GOST512A,
	GNUTLS_GROUP_GC512B = GNUTLS_ECC_CURVE_GOST512B,
	GNUTLS_GROUP_GC512C = GNUTLS_ECC_CURVE_GOST512C,

	GNUTLS_GROUP_FFDHE2048 = 256,
	GNUTLS_GROUP_FFDHE3072,
	GNUTLS_GROUP_FFDHE4096,
	GNUTLS_GROUP_FFDHE8192,
	GNUTLS_GROUP_FFDHE6144,
	GNUTLS_GROUP_MAX = GNUTLS_GROUP_FFDHE6144,
} gnutls_group_t;

/* macros to allow specifying a specific curve in gnutls_privkey_generate()
 * and gnutls_x509_privkey_generate() */
#define GNUTLS_CURVE_TO_BITS(curve) \
	(unsigned int)(((unsigned int)1 << 31) | ((unsigned int)(curve)))
#define GNUTLS_BITS_TO_CURVE(bits) (((unsigned int)(bits)) & 0x7FFFFFFF)
#define GNUTLS_BITS_ARE_CURVE(bits) (((unsigned int)(bits)) & 0x80000000)

/**
 * gnutls_sec_param_t:
 * @GNUTLS_SEC_PARAM_UNKNOWN: Cannot be known
 * @GNUTLS_SEC_PARAM_INSECURE: Less than 42 bits of security
 * @GNUTLS_SEC_PARAM_EXPORT: 42 bits of security
 * @GNUTLS_SEC_PARAM_VERY_WEAK: 64 bits of security
 * @GNUTLS_SEC_PARAM_WEAK: 72 bits of security
 * @GNUTLS_SEC_PARAM_LOW: 80 bits of security
 * @GNUTLS_SEC_PARAM_LEGACY: 96 bits of security
 * @GNUTLS_SEC_PARAM_MEDIUM: 112 bits of security (used to be %GNUTLS_SEC_PARAM_NORMAL)
 * @GNUTLS_SEC_PARAM_HIGH: 128 bits of security
 * @GNUTLS_SEC_PARAM_ULTRA: 192 bits of security
 * @GNUTLS_SEC_PARAM_FUTURE: 256 bits of security
 *
 * Enumeration of security parameters for passive attacks.
 */
typedef enum {
	GNUTLS_SEC_PARAM_UNKNOWN = 0,
	GNUTLS_SEC_PARAM_INSECURE = 5,
	GNUTLS_SEC_PARAM_EXPORT = 10,
	GNUTLS_SEC_PARAM_VERY_WEAK = 15,
	GNUTLS_SEC_PARAM_WEAK = 20,
	GNUTLS_SEC_PARAM_LOW = 25,
	GNUTLS_SEC_PARAM_LEGACY = 30,
	GNUTLS_SEC_PARAM_MEDIUM = 35,
	GNUTLS_SEC_PARAM_HIGH = 40,
	GNUTLS_SEC_PARAM_ULTRA = 45,
	GNUTLS_SEC_PARAM_FUTURE = 50,
	GNUTLS_SEC_PARAM_MAX = GNUTLS_SEC_PARAM_FUTURE
} gnutls_sec_param_t;

/* old name */
#define GNUTLS_SEC_PARAM_NORMAL GNUTLS_SEC_PARAM_MEDIUM

/**
 * gnutls_channel_binding_t:
 * @GNUTLS_CB_TLS_UNIQUE: "tls-unique" (RFC 5929) channel binding
 * @GNUTLS_CB_TLS_SERVER_END_POINT: "tls-server-end-point" (RFC 5929) channel binding
 * @GNUTLS_CB_TLS_EXPORTER: "tls-exporter" (RFC 9266) channel binding
 *
 * Enumeration of supported channel binding types.
 */
typedef enum {
	GNUTLS_CB_TLS_UNIQUE,
	GNUTLS_CB_TLS_SERVER_END_POINT,
	GNUTLS_CB_TLS_EXPORTER
} gnutls_channel_binding_t;

/**
 * gnutls_gost_paramset_t:
 * @GNUTLS_GOST_PARAMSET_UNKNOWN: Unknown/default parameter set
 * @GNUTLS_GOST_PARAMSET_TC26_Z: Specified by TC26, see rfc7836
 * @GNUTLS_GOST_PARAMSET_CP_A: CryptoPro-A, see rfc4357
 * @GNUTLS_GOST_PARAMSET_CP_B: CryptoPro-B, see rfc4357
 * @GNUTLS_GOST_PARAMSET_CP_C: CryptoPro-C, see rfc4357
 * @GNUTLS_GOST_PARAMSET_CP_D: CryptoPro-D, see rfc4357
 *
 * Enumeration of different GOST 28147 parameter sets.
 */
typedef enum {
	GNUTLS_GOST_PARAMSET_UNKNOWN = 0,
	GNUTLS_GOST_PARAMSET_TC26_Z,
	GNUTLS_GOST_PARAMSET_CP_A,
	GNUTLS_GOST_PARAMSET_CP_B,
	GNUTLS_GOST_PARAMSET_CP_C,
	GNUTLS_GOST_PARAMSET_CP_D
} gnutls_gost_paramset_t;

/**
 * gnutls_ctype_target_t:
 * @GNUTLS_CTYPE_CLIENT: for requesting client certificate type values.
 * @GNUTLS_CTYPE_SERVER: for requesting server certificate type values.
 * @GNUTLS_CTYPE_OURS: for requesting our certificate type values.
 * @GNUTLS_CTYPE_PEERS: for requesting the peers' certificate type values.
 *
 * Enumeration of certificate type targets with respect to asymmetric
 * certificate types as specified in RFC7250 and P2P connection set up
 * as specified in draft-vanrein-tls-symmetry-02.
 */
typedef enum {
	GNUTLS_CTYPE_CLIENT,
	GNUTLS_CTYPE_SERVER,
	GNUTLS_CTYPE_OURS,
	GNUTLS_CTYPE_PEERS
} gnutls_ctype_target_t;

/* If you want to change this, then also change the define in
 * gnutls_int.h, and recompile.
 */
typedef void *gnutls_transport_ptr_t;

struct gnutls_session_int;
typedef struct gnutls_session_int *gnutls_session_t;

struct gnutls_dh_params_int;
typedef struct gnutls_dh_params_int *gnutls_dh_params_t;

/* XXX ugly. */
struct gnutls_x509_privkey_int;
typedef struct gnutls_x509_privkey_int *gnutls_rsa_params_t;

struct gnutls_priority_st;
typedef struct gnutls_priority_st *gnutls_priority_t;

typedef struct {
	unsigned char *data;
	unsigned int size;
} gnutls_datum_t;

typedef struct gnutls_library_config_st {
	const char *name;
	const char *value;
} gnutls_library_config_st;

typedef struct gnutls_params_st {
	gnutls_params_type_t type;
	union params {
		gnutls_dh_params_t dh;
		gnutls_rsa_params_t rsa_export;
	} params;
	int deinit;
} gnutls_params_st;

typedef int gnutls_params_function(gnutls_session_t, gnutls_params_type_t,
				   gnutls_params_st *);

/* internal functions */

int gnutls_init(gnutls_session_t *session, unsigned int flags);
void gnutls_deinit(gnutls_session_t session);
#define _gnutls_deinit(x) gnutls_deinit(x)

int gnutls_bye(gnutls_session_t session, gnutls_close_request_t how);

int gnutls_handshake(gnutls_session_t session);

int gnutls_reauth(gnutls_session_t session, unsigned int flags);

#define GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT ((unsigned int)-1)
#define GNUTLS_INDEFINITE_TIMEOUT ((unsigned int)-2)
void gnutls_handshake_set_timeout(gnutls_session_t session, unsigned int ms);
int gnutls_rehandshake(gnutls_session_t session);

#define GNUTLS_KU_PEER 1
int gnutls_session_key_update(gnutls_session_t session, unsigned flags);

gnutls_alert_description_t gnutls_alert_get(gnutls_session_t session);
int gnutls_alert_send(gnutls_session_t session, gnutls_alert_level_t level,
		      gnutls_alert_description_t desc);
int gnutls_alert_send_appropriate(gnutls_session_t session, int err);
const char *gnutls_alert_get_name(gnutls_alert_description_t alert);
const char *gnutls_alert_get_strname(gnutls_alert_description_t alert);

gnutls_sec_param_t gnutls_pk_bits_to_sec_param(gnutls_pk_algorithm_t algo,
					       unsigned int bits);
const char *gnutls_sec_param_get_name(gnutls_sec_param_t param);
unsigned int gnutls_sec_param_to_pk_bits(gnutls_pk_algorithm_t algo,
					 gnutls_sec_param_t param);
unsigned int
gnutls_sec_param_to_symmetric_bits(gnutls_sec_param_t param) __GNUTLS_CONST__;

/* Elliptic curves */
const char *
gnutls_ecc_curve_get_name(gnutls_ecc_curve_t curve) __GNUTLS_CONST__;
const char *gnutls_ecc_curve_get_oid(gnutls_ecc_curve_t curve) __GNUTLS_CONST__;

const char *gnutls_group_get_name(gnutls_group_t group) __GNUTLS_CONST__;

int gnutls_ecc_curve_get_size(gnutls_ecc_curve_t curve) __GNUTLS_CONST__;
gnutls_ecc_curve_t gnutls_ecc_curve_get(gnutls_session_t session);

gnutls_group_t gnutls_group_get(gnutls_session_t session);

/* get information on the current session */
gnutls_cipher_algorithm_t gnutls_cipher_get(gnutls_session_t session);
gnutls_cipher_algorithm_t gnutls_early_cipher_get(gnutls_session_t session);
gnutls_kx_algorithm_t gnutls_kx_get(gnutls_session_t session);
gnutls_mac_algorithm_t gnutls_mac_get(gnutls_session_t session);
gnutls_digest_algorithm_t gnutls_prf_hash_get(const gnutls_session_t session);
gnutls_digest_algorithm_t
gnutls_early_prf_hash_get(const gnutls_session_t session);
gnutls_certificate_type_t gnutls_certificate_type_get(gnutls_session_t session);
gnutls_certificate_type_t
gnutls_certificate_type_get2(gnutls_session_t session,
			     gnutls_ctype_target_t target);

int gnutls_sign_algorithm_get(gnutls_session_t session);
int gnutls_sign_algorithm_get_client(gnutls_session_t session);

int gnutls_sign_algorithm_get_requested(gnutls_session_t session, size_t indx,
					gnutls_sign_algorithm_t *algo);

/* the name of the specified algorithms */
const char *
gnutls_cipher_get_name(gnutls_cipher_algorithm_t algorithm) __GNUTLS_CONST__;
const char *
gnutls_mac_get_name(gnutls_mac_algorithm_t algorithm) __GNUTLS_CONST__;

const char *
gnutls_digest_get_name(gnutls_digest_algorithm_t algorithm) __GNUTLS_CONST__;
const char *
gnutls_digest_get_oid(gnutls_digest_algorithm_t algorithm) __GNUTLS_CONST__;

const char *
gnutls_kx_get_name(gnutls_kx_algorithm_t algorithm) __GNUTLS_CONST__;
const char *gnutls_certificate_type_get_name(gnutls_certificate_type_t type)
	__GNUTLS_CONST__;
const char *
gnutls_pk_get_name(gnutls_pk_algorithm_t algorithm) __GNUTLS_CONST__;
const char *gnutls_pk_get_oid(gnutls_pk_algorithm_t algorithm) __GNUTLS_CONST__;

const char *
gnutls_sign_get_name(gnutls_sign_algorithm_t algorithm) __GNUTLS_CONST__;

const char *gnutls_sign_get_oid(gnutls_sign_algorithm_t sign) __GNUTLS_CONST__;

const char *
gnutls_gost_paramset_get_name(gnutls_gost_paramset_t param) __GNUTLS_CONST__;
const char *
gnutls_gost_paramset_get_oid(gnutls_gost_paramset_t param) __GNUTLS_CONST__;

size_t gnutls_cipher_get_key_size(gnutls_cipher_algorithm_t algorithm)
	__GNUTLS_CONST__;
size_t
gnutls_mac_get_key_size(gnutls_mac_algorithm_t algorithm) __GNUTLS_CONST__;

unsigned
gnutls_sign_is_secure(gnutls_sign_algorithm_t algorithm) __GNUTLS_CONST__;

/* It is possible that a signature algorithm is ok to use for short-lived
 * data (e.g., to sign a TLS session), but not for data that are long-lived
 * like certificates. This flag is about checking the security of the algorithm
 * for long-lived data. */
#define GNUTLS_SIGN_FLAG_SECURE_FOR_CERTS 1
unsigned gnutls_sign_is_secure2(gnutls_sign_algorithm_t algorithm,
				unsigned int flags) __GNUTLS_CONST__;

gnutls_digest_algorithm_t
gnutls_sign_get_hash_algorithm(gnutls_sign_algorithm_t sign) __GNUTLS_CONST__;
gnutls_pk_algorithm_t
gnutls_sign_get_pk_algorithm(gnutls_sign_algorithm_t sign) __GNUTLS_CONST__;
gnutls_sign_algorithm_t
gnutls_pk_to_sign(gnutls_pk_algorithm_t pk,
		  gnutls_digest_algorithm_t hash) __GNUTLS_CONST__;

unsigned
gnutls_sign_supports_pk_algorithm(gnutls_sign_algorithm_t sign,
				  gnutls_pk_algorithm_t pk) __GNUTLS_CONST__;

#define gnutls_sign_algorithm_get_name gnutls_sign_get_name

gnutls_mac_algorithm_t gnutls_mac_get_id(const char *name) __GNUTLS_CONST__;
gnutls_digest_algorithm_t
gnutls_digest_get_id(const char *name) __GNUTLS_CONST__;

gnutls_cipher_algorithm_t
gnutls_cipher_get_id(const char *name) __GNUTLS_CONST__;

gnutls_kx_algorithm_t gnutls_kx_get_id(const char *name) __GNUTLS_CONST__;
gnutls_protocol_t gnutls_protocol_get_id(const char *name) __GNUTLS_CONST__;
gnutls_certificate_type_t
gnutls_certificate_type_get_id(const char *name) __GNUTLS_CONST__;
gnutls_pk_algorithm_t gnutls_pk_get_id(const char *name) __GNUTLS_CONST__;
gnutls_sign_algorithm_t gnutls_sign_get_id(const char *name) __GNUTLS_CONST__;
gnutls_ecc_curve_t gnutls_ecc_curve_get_id(const char *name) __GNUTLS_CONST__;
gnutls_pk_algorithm_t
gnutls_ecc_curve_get_pk(gnutls_ecc_curve_t curve) __GNUTLS_CONST__;
gnutls_group_t gnutls_group_get_id(const char *name);

gnutls_digest_algorithm_t
gnutls_oid_to_digest(const char *oid) __GNUTLS_CONST__;
gnutls_mac_algorithm_t gnutls_oid_to_mac(const char *oid) __GNUTLS_CONST__;
gnutls_pk_algorithm_t gnutls_oid_to_pk(const char *oid) __GNUTLS_CONST__;
gnutls_sign_algorithm_t gnutls_oid_to_sign(const char *oid) __GNUTLS_CONST__;
gnutls_ecc_curve_t gnutls_oid_to_ecc_curve(const char *oid) __GNUTLS_CONST__;
gnutls_gost_paramset_t
gnutls_oid_to_gost_paramset(const char *oid) __GNUTLS_CONST__;

/* list supported algorithms */
const gnutls_ecc_curve_t *gnutls_ecc_curve_list(void) __GNUTLS_PURE__;
const gnutls_group_t *gnutls_group_list(void) __GNUTLS_PURE__;
const gnutls_cipher_algorithm_t *gnutls_cipher_list(void) __GNUTLS_PURE__;
const gnutls_mac_algorithm_t *gnutls_mac_list(void) __GNUTLS_PURE__;
const gnutls_digest_algorithm_t *gnutls_digest_list(void) __GNUTLS_PURE__;
const gnutls_protocol_t *gnutls_protocol_list(void) __GNUTLS_PURE__;
const gnutls_certificate_type_t *
gnutls_certificate_type_list(void) __GNUTLS_PURE__;
const gnutls_kx_algorithm_t *gnutls_kx_list(void) __GNUTLS_PURE__;
const gnutls_pk_algorithm_t *gnutls_pk_list(void) __GNUTLS_PURE__;
const gnutls_sign_algorithm_t *gnutls_sign_list(void) __GNUTLS_PURE__;
const char *gnutls_cipher_suite_info(size_t idx, unsigned char *cs_id,
				     gnutls_kx_algorithm_t *kx,
				     gnutls_cipher_algorithm_t *cipher,
				     gnutls_mac_algorithm_t *mac,
				     gnutls_protocol_t *min_version);

/* functions for run-time enablement of algorithms */
int gnutls_ecc_curve_set_enabled(gnutls_ecc_curve_t curve,
				 unsigned int enabled);
int gnutls_sign_set_secure(gnutls_sign_algorithm_t sign, unsigned int secure);
int gnutls_sign_set_secure_for_certs(gnutls_sign_algorithm_t sign,
				     unsigned int secure);
int gnutls_digest_set_secure(gnutls_digest_algorithm_t dig,
			     unsigned int secure);
int gnutls_protocol_set_enabled(gnutls_protocol_t version,
				unsigned int enabled);

/* error functions */
int gnutls_error_is_fatal(int error) __GNUTLS_CONST__;
int gnutls_error_to_alert(int err, int *level);

void gnutls_perror(int error);
const char *gnutls_strerror(int error) __GNUTLS_CONST__;
const char *gnutls_strerror_name(int error) __GNUTLS_CONST__;

/* Semi-internal functions.
 */
void gnutls_handshake_set_private_extensions(gnutls_session_t session,
					     int allow);
int gnutls_handshake_set_random(gnutls_session_t session,
				const gnutls_datum_t *random);

gnutls_handshake_description_t
gnutls_handshake_get_last_out(gnutls_session_t session);
gnutls_handshake_description_t
gnutls_handshake_get_last_in(gnutls_session_t session);

/* Record layer functions.
 */
#define GNUTLS_HEARTBEAT_WAIT 1
int gnutls_heartbeat_ping(gnutls_session_t session, size_t data_size,
			  unsigned int max_tries, unsigned int flags);
int gnutls_heartbeat_pong(gnutls_session_t session, unsigned int flags);

void gnutls_record_set_timeout(gnutls_session_t session, unsigned int ms);
void gnutls_record_disable_padding(gnutls_session_t session);

void gnutls_record_cork(gnutls_session_t session);
#define GNUTLS_RECORD_WAIT 1
int gnutls_record_uncork(gnutls_session_t session, unsigned int flags);
size_t gnutls_record_discard_queued(gnutls_session_t session);

int gnutls_record_get_state(gnutls_session_t session, unsigned read,
			    gnutls_datum_t *mac_key, gnutls_datum_t *IV,
			    gnutls_datum_t *cipher_key,
			    unsigned char seq_number[8]);

int gnutls_record_set_state(gnutls_session_t session, unsigned read,
			    const unsigned char seq_number[8]);

typedef struct {
	size_t low;
	size_t high;
} gnutls_range_st;

int gnutls_range_split(gnutls_session_t session, const gnutls_range_st *orig,
		       gnutls_range_st *small_range,
		       gnutls_range_st *rem_range);

ssize_t gnutls_record_send(gnutls_session_t session, const void *data,
			   size_t data_size);
ssize_t gnutls_record_send2(gnutls_session_t session, const void *data,
			    size_t data_size, size_t pad, unsigned flags);
ssize_t gnutls_record_send_range(gnutls_session_t session, const void *data,
				 size_t data_size,
				 const gnutls_range_st *range);
ssize_t gnutls_record_send_file(gnutls_session_t session, int fd, off_t *offset,
				size_t count);
ssize_t gnutls_record_recv(gnutls_session_t session, void *data,
			   size_t data_size);

typedef struct mbuffer_st *gnutls_packet_t;

ssize_t gnutls_record_recv_packet(gnutls_session_t session,
				  gnutls_packet_t *packet);

void gnutls_packet_get(gnutls_packet_t packet, gnutls_datum_t *data,
		       unsigned char *sequence);
void gnutls_packet_deinit(gnutls_packet_t packet);

#define gnutls_read gnutls_record_recv
#define gnutls_write gnutls_record_send
ssize_t gnutls_record_recv_seq(gnutls_session_t session, void *data,
			       size_t data_size, unsigned char *seq);

size_t gnutls_record_overhead_size(gnutls_session_t session);

size_t gnutls_est_record_overhead_size(gnutls_protocol_t version,
				       gnutls_cipher_algorithm_t cipher,
				       gnutls_mac_algorithm_t mac,
				       gnutls_compression_method_t comp,
				       unsigned int flags) __GNUTLS_CONST__;

void gnutls_session_enable_compatibility_mode(gnutls_session_t session);
#define gnutls_record_set_max_empty_records(session, x)

unsigned gnutls_record_can_use_length_hiding(gnutls_session_t session);

int gnutls_record_get_direction(gnutls_session_t session);

size_t gnutls_record_get_max_size(gnutls_session_t session);
ssize_t gnutls_record_set_max_size(gnutls_session_t session, size_t size);
ssize_t gnutls_record_set_max_recv_size(gnutls_session_t session, size_t size);

size_t gnutls_record_check_pending(gnutls_session_t session);
size_t gnutls_record_check_corked(gnutls_session_t session);

size_t gnutls_record_get_max_early_data_size(gnutls_session_t session);
int gnutls_record_set_max_early_data_size(gnutls_session_t session,
					  size_t size);
ssize_t gnutls_record_send_early_data(gnutls_session_t session,
				      const void *data, size_t length);
ssize_t gnutls_record_recv_early_data(gnutls_session_t session, void *data,
				      size_t data_size);

void gnutls_session_force_valid(gnutls_session_t session);

int gnutls_prf(gnutls_session_t session, size_t label_size, const char *label,
	       int server_random_first, size_t extra_size, const char *extra,
	       size_t outsize, char *out);
int gnutls_prf_rfc5705(gnutls_session_t session, size_t label_size,
		       const char *label, size_t context_size,
		       const char *context, size_t outsize, char *out);
int gnutls_prf_early(gnutls_session_t session, size_t label_size,
		     const char *label, size_t context_size,
		     const char *context, size_t outsize, char *out);

int gnutls_prf_raw(gnutls_session_t session, size_t label_size,
		   const char *label, size_t seed_size, const char *seed,
		   size_t outsize, char *out);

/**
 * gnutls_server_name_type_t:
 * @GNUTLS_NAME_DNS: Domain Name System name type.
 *
 * Enumeration of different server name types.
 */
typedef enum {
	GNUTLS_NAME_DNS = 1
} gnutls_server_name_type_t;

int gnutls_server_name_set(gnutls_session_t session,
			   gnutls_server_name_type_t type, const void *name,
			   size_t name_length);

int gnutls_server_name_get(gnutls_session_t session, void *data,
			   size_t *data_length, unsigned int *type,
			   unsigned int indx);

unsigned int gnutls_heartbeat_get_timeout(gnutls_session_t session);
void gnutls_heartbeat_set_timeouts(gnutls_session_t session,
				   unsigned int retrans_timeout,
				   unsigned int total_timeout);

#define GNUTLS_HB_PEER_ALLOWED_TO_SEND (1)
#define GNUTLS_HB_PEER_NOT_ALLOWED_TO_SEND (1 << 1)

/* Heartbeat */
void gnutls_heartbeat_enable(gnutls_session_t session, unsigned int type);

#define GNUTLS_HB_LOCAL_ALLOWED_TO_SEND (1 << 2)
unsigned gnutls_heartbeat_allowed(gnutls_session_t session, unsigned int type);

/* Safe renegotiation */
unsigned gnutls_safe_renegotiation_status(gnutls_session_t session);
unsigned gnutls_session_ext_master_secret_status(gnutls_session_t session);
unsigned gnutls_session_etm_status(gnutls_session_t session);

/**
 * gnutls_session_flags_t:
 * @GNUTLS_SFLAGS_SAFE_RENEGOTIATION: Safe renegotiation (RFC5746) was used
 * @GNUTLS_SFLAGS_EXT_MASTER_SECRET: The extended master secret (RFC7627) extension was used
 * @GNUTLS_SFLAGS_ETM: The encrypt then MAC (RFC7366) extension was used
 * @GNUTLS_SFLAGS_RFC7919: The RFC7919 Diffie-Hellman parameters were negotiated
 * @GNUTLS_SFLAGS_HB_LOCAL_SEND: The heartbeat negotiation allows the local side to send heartbeat messages
 * @GNUTLS_SFLAGS_HB_PEER_SEND: The heartbeat negotiation allows the peer to send heartbeat messages
 * @GNUTLS_SFLAGS_FALSE_START: False start was used in this client session.
 * @GNUTLS_SFLAGS_SESSION_TICKET: A session ticket has been received by the server.
 * @GNUTLS_SFLAGS_POST_HANDSHAKE_AUTH: Indicates client capability for post-handshake auth; set only on server side.
 * @GNUTLS_SFLAGS_EARLY_START: The TLS1.3 server session returned early.
 * @GNUTLS_SFLAGS_EARLY_DATA: The TLS1.3 early data has been received by the server.
 * @GNUTLS_SFLAGS_CLI_REQUESTED_OCSP: Set when the client has requested OCSP staple during handshake.
 * @GNUTLS_SFLAGS_SERV_REQUESTED_OCSP: Set when the server has requested OCSP staple during handshake.
 *
 * Enumeration of different session parameters.
 */
typedef enum {
	GNUTLS_SFLAGS_SAFE_RENEGOTIATION = 1,
	GNUTLS_SFLAGS_EXT_MASTER_SECRET = 1 << 1,
	GNUTLS_SFLAGS_ETM = 1 << 2,
	GNUTLS_SFLAGS_HB_LOCAL_SEND = 1 << 3,
	GNUTLS_SFLAGS_HB_PEER_SEND = 1 << 4,
	GNUTLS_SFLAGS_FALSE_START = 1 << 5,
	GNUTLS_SFLAGS_RFC7919 = 1 << 6,
	GNUTLS_SFLAGS_SESSION_TICKET = 1 << 7,
	GNUTLS_SFLAGS_POST_HANDSHAKE_AUTH = 1 << 8,
	GNUTLS_SFLAGS_EARLY_START = 1 << 9,
	GNUTLS_SFLAGS_EARLY_DATA = 1 << 10,
	GNUTLS_SFLAGS_CLI_REQUESTED_OCSP = 1 << 11,
	GNUTLS_SFLAGS_SERV_REQUESTED_OCSP = 1 << 12
} gnutls_session_flags_t;

unsigned gnutls_session_get_flags(gnutls_session_t session);

/**
 * gnutls_supplemental_data_format_type_t:
 * @GNUTLS_SUPPLEMENTAL_UNKNOWN: Unknown data format
 *
 * Enumeration of different supplemental data types (RFC 4680).
 */
typedef enum {
	GNUTLS_SUPPLEMENTAL_UNKNOWN = 0,
} gnutls_supplemental_data_format_type_t;

const char *
gnutls_supplemental_get_name(gnutls_supplemental_data_format_type_t type);

/* SessionTicket, RFC 5077. */
int gnutls_session_ticket_key_generate(gnutls_datum_t *key);
int gnutls_session_ticket_enable_client(gnutls_session_t session);
int gnutls_session_ticket_enable_server(gnutls_session_t session,
					const gnutls_datum_t *key);

int gnutls_session_ticket_send(gnutls_session_t session, unsigned nr,
			       unsigned flags);

/* SRTP, RFC 5764 */

/**
 * gnutls_srtp_profile_t:
 * @GNUTLS_SRTP_AES128_CM_HMAC_SHA1_80: 128 bit AES with a 80 bit HMAC-SHA1
 * @GNUTLS_SRTP_AES128_CM_HMAC_SHA1_32: 128 bit AES with a 32 bit HMAC-SHA1
 * @GNUTLS_SRTP_NULL_HMAC_SHA1_80: NULL cipher with a 80 bit HMAC-SHA1
 * @GNUTLS_SRTP_NULL_HMAC_SHA1_32: NULL cipher with a 32 bit HMAC-SHA1
 * @GNUTLS_SRTP_AEAD_AES_128_GCM: 128 bit AES with GCM
 * @GNUTLS_SRTP_AEAD_AES_256_GCM: 256 bit AES with GCM
 *
 * Enumeration of different SRTP protection profiles.
 */
typedef enum {
	GNUTLS_SRTP_AES128_CM_HMAC_SHA1_80 = 0x0001,
	GNUTLS_SRTP_AES128_CM_HMAC_SHA1_32 = 0x0002,
	GNUTLS_SRTP_NULL_HMAC_SHA1_80 = 0x0005,
	GNUTLS_SRTP_NULL_HMAC_SHA1_32 = 0x0006,
	GNUTLS_SRTP_AEAD_AES_128_GCM = 0x0007,
	GNUTLS_SRTP_AEAD_AES_256_GCM = 0x0008
} gnutls_srtp_profile_t;

int gnutls_srtp_set_profile(gnutls_session_t session,
			    gnutls_srtp_profile_t profile);
int gnutls_srtp_set_profile_direct(gnutls_session_t session,
				   const char *profiles, const char **err_pos);
int gnutls_srtp_get_selected_profile(gnutls_session_t session,
				     gnutls_srtp_profile_t *profile);

const char *gnutls_srtp_get_profile_name(gnutls_srtp_profile_t profile);
int gnutls_srtp_get_profile_id(const char *name,
			       gnutls_srtp_profile_t *profile);
int gnutls_srtp_get_keys(gnutls_session_t session, void *key_material,
			 unsigned int key_material_size,
			 gnutls_datum_t *client_key,
			 gnutls_datum_t *client_salt,
			 gnutls_datum_t *server_key,
			 gnutls_datum_t *server_salt);

int gnutls_srtp_set_mki(gnutls_session_t session, const gnutls_datum_t *mki);
int gnutls_srtp_get_mki(gnutls_session_t session, gnutls_datum_t *mki);

/* COMPRESS_CERTIFICATE extension, RFC8879 */
gnutls_compression_method_t
gnutls_compress_certificate_get_selected_method(gnutls_session_t session);
int gnutls_compress_certificate_set_methods(
	gnutls_session_t session, const gnutls_compression_method_t *methods,
	size_t methods_len);

/* ALPN TLS extension */

/**
 * gnutls_alpn_flags_t:
 * @GNUTLS_ALPN_MANDATORY: Require ALPN negotiation. The connection will be
 *   aborted if no matching ALPN protocol is found.
 * @GNUTLS_ALPN_SERVER_PRECEDENCE: The choices set by the server
 *   will take precedence over the client's.
 *
 * Enumeration of different ALPN flags. These are used by gnutls_alpn_set_protocols().
 */
typedef enum {
	GNUTLS_ALPN_MANDATORY = 1,
	GNUTLS_ALPN_SERVER_PRECEDENCE = (1 << 1)
} gnutls_alpn_flags_t;

#define GNUTLS_ALPN_MAND GNUTLS_ALPN_MANDATORY
int gnutls_alpn_get_selected_protocol(gnutls_session_t session,
				      gnutls_datum_t *protocol);
int gnutls_alpn_set_protocols(gnutls_session_t session,
			      const gnutls_datum_t *protocols,
			      unsigned protocols_size, unsigned flags);

int gnutls_key_generate(gnutls_datum_t *key, unsigned int key_size);

#define GNUTLS_PRIORITY_INIT_DEF_APPEND 1
int gnutls_priority_init(gnutls_priority_t *priority_cache,
			 const char *priorities, const char **err_pos);
int gnutls_priority_init2(gnutls_priority_t *priority_cache,
			  const char *priorities, const char **err_pos,
			  unsigned flags);
void gnutls_priority_deinit(gnutls_priority_t priority_cache);
int gnutls_priority_get_cipher_suite_index(gnutls_priority_t pcache,
					   unsigned int idx,
					   unsigned int *sidx);

#define GNUTLS_PRIORITY_LIST_INIT_KEYWORDS 1
#define GNUTLS_PRIORITY_LIST_SPECIAL 2
const char *gnutls_priority_string_list(unsigned iter, unsigned int flags);

int gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority);

int gnutls_priority_set_direct(gnutls_session_t session, const char *priorities,
			       const char **err_pos);

int gnutls_priority_certificate_type_list(gnutls_priority_t pcache,
					  const unsigned int **list);
int gnutls_priority_certificate_type_list2(gnutls_priority_t pcache,
					   const unsigned int **list,
					   gnutls_ctype_target_t target);
int gnutls_priority_sign_list(gnutls_priority_t pcache,
			      const unsigned int **list);
int gnutls_priority_protocol_list(gnutls_priority_t pcache,
				  const unsigned int **list);
int gnutls_priority_ecc_curve_list(gnutls_priority_t pcache,
				   const unsigned int **list);
int gnutls_priority_group_list(gnutls_priority_t pcache,
			       const unsigned int **list);

int gnutls_priority_kx_list(gnutls_priority_t pcache,
			    const unsigned int **list);
int gnutls_priority_cipher_list(gnutls_priority_t pcache,
				const unsigned int **list);
int gnutls_priority_mac_list(gnutls_priority_t pcache,
			     const unsigned int **list);

const char *gnutls_get_system_config_file(void);

int gnutls_set_default_priority(gnutls_session_t session);
int gnutls_set_default_priority_append(gnutls_session_t session,
				       const char *add_prio,
				       const char **err_pos, unsigned flags);

/* Returns the name of a cipher suite */
const char *gnutls_cipher_suite_get_name(
	gnutls_kx_algorithm_t kx_algorithm,
	gnutls_cipher_algorithm_t cipher_algorithm,
	gnutls_mac_algorithm_t mac_algorithm) __GNUTLS_CONST__;

const char *gnutls_ciphersuite_get(gnutls_session_t session) __GNUTLS_CONST__;

/* get the currently used protocol version */
gnutls_protocol_t gnutls_protocol_get_version(gnutls_session_t session);

const char *
gnutls_protocol_get_name(gnutls_protocol_t version) __GNUTLS_CONST__;

/* get/set session
 */
int gnutls_session_set_data(gnutls_session_t session, const void *session_data,
			    size_t session_data_size);
int gnutls_session_get_data(gnutls_session_t session, void *session_data,
			    size_t *session_data_size);
int gnutls_session_get_data2(gnutls_session_t session, gnutls_datum_t *data);
void gnutls_session_get_random(gnutls_session_t session, gnutls_datum_t *client,
			       gnutls_datum_t *server);

void gnutls_session_get_master_secret(gnutls_session_t session,
				      gnutls_datum_t *secret);

char *gnutls_session_get_desc(gnutls_session_t session);

typedef int gnutls_certificate_verify_function(gnutls_session_t);
void gnutls_session_set_verify_function(
	gnutls_session_t session, gnutls_certificate_verify_function *func);

/**
 * gnutls_vdata_types_t:
 * @GNUTLS_DT_UNKNOWN: Unknown data type.
 * @GNUTLS_DT_DNS_HOSTNAME: The data contain a null-terminated DNS hostname; the hostname will be 
 *   matched using the RFC6125 rules. If the data contain a textual IP (v4 or v6) address it will
 *   be marched against the IPAddress Alternative name, unless the verification flag %GNUTLS_VERIFY_DO_NOT_ALLOW_IP_MATCHES
 *   is specified.
 * @GNUTLS_DT_IP_ADDRESS: The data contain a raw IP address (4 or 16 bytes). If will be matched
 *   against the IPAddress Alternative name; option available since 3.6.0.
 * @GNUTLS_DT_RFC822NAME: The data contain a null-terminated email address; the email will be
 *   matched against the RFC822Name Alternative name of the certificate, or the EMAIL DN component if the
 *   former isn't available. Prior to matching the email address will be converted to ACE
 *   (ASCII-compatible-encoding).
 * @GNUTLS_DT_KEY_PURPOSE_OID: The data contain a null-terminated key purpose OID. It will be matched
 *   against the certificate's Extended Key Usage extension.
 *
 * Enumeration of different typed-data options. They are used as input to certificate
 * verification functions to provide information about the name and purpose of the
 * certificate. Only a single option of a type can be provided to the relevant functions
 * (i.e., options %GNUTLS_DT_DNS_HOSTNAME, %GNUTLS_DT_IP_ADDRESS and
 * %GNUTLS_DT_RFC822NAME cannot be combined).
 */
typedef enum {
	GNUTLS_DT_UNKNOWN = 0,
	GNUTLS_DT_DNS_HOSTNAME = 1,
	GNUTLS_DT_KEY_PURPOSE_OID = 2,
	GNUTLS_DT_RFC822NAME = 3,
	GNUTLS_DT_IP_ADDRESS = 4
} gnutls_vdata_types_t;

typedef struct {
	gnutls_vdata_types_t type;
	unsigned char *data;
	unsigned int size;
} gnutls_typed_vdata_st;

void gnutls_session_set_verify_cert(gnutls_session_t session,
				    const char *hostname, unsigned flags);

void gnutls_session_set_verify_cert2(gnutls_session_t session,
				     gnutls_typed_vdata_st *data,
				     unsigned elements, unsigned flags);

unsigned int gnutls_session_get_verify_cert_status(gnutls_session_t);

int gnutls_session_set_premaster(gnutls_session_t session, unsigned int entity,
				 gnutls_protocol_t version,
				 gnutls_kx_algorithm_t kx,
				 gnutls_cipher_algorithm_t cipher,
				 gnutls_mac_algorithm_t mac,
				 gnutls_compression_method_t comp,
				 const gnutls_datum_t *master,
				 const gnutls_datum_t *session_id);

/* returns the session ID */
#define GNUTLS_MAX_SESSION_ID 32
int gnutls_session_get_id(gnutls_session_t session, void *session_id,
			  size_t *session_id_size);
int gnutls_session_get_id2(gnutls_session_t session,
			   gnutls_datum_t *session_id);

int gnutls_session_set_id(gnutls_session_t session, const gnutls_datum_t *sid);

int gnutls_session_channel_binding(gnutls_session_t session,
				   gnutls_channel_binding_t cbtype,
				   gnutls_datum_t *cb);

/* checks if this session is a resumed one
 */
int gnutls_session_is_resumed(gnutls_session_t session);
int gnutls_session_resumption_requested(gnutls_session_t session);

typedef int (*gnutls_db_store_func)(void *, gnutls_datum_t key,
				    gnutls_datum_t data);
typedef int (*gnutls_db_remove_func)(void *, gnutls_datum_t key);
typedef gnutls_datum_t (*gnutls_db_retr_func)(void *, gnutls_datum_t key);

void gnutls_db_set_cache_expiration(gnutls_session_t session, int seconds);
unsigned gnutls_db_get_default_cache_expiration(void);

void gnutls_db_remove_session(gnutls_session_t session);
void gnutls_db_set_retrieve_function(gnutls_session_t session,
				     gnutls_db_retr_func retr_func);
void gnutls_db_set_remove_function(gnutls_session_t session,
				   gnutls_db_remove_func rem_func);
void gnutls_db_set_store_function(gnutls_session_t session,
				  gnutls_db_store_func store_func);
void gnutls_db_set_ptr(gnutls_session_t session, void *ptr);
void *gnutls_db_get_ptr(gnutls_session_t session);
int gnutls_db_check_entry(gnutls_session_t session,
			  gnutls_datum_t session_entry);
time_t gnutls_db_check_entry_time(gnutls_datum_t *entry);
time_t gnutls_db_check_entry_expire_time(gnutls_datum_t *entry);

#define GNUTLS_HOOK_POST (1)
#define GNUTLS_HOOK_PRE (0)
#define GNUTLS_HOOK_BOTH (-1)

/**
 * gnutls_handshake_hook_func:
 * @session: the current session
 * @htype: the type of the handshake message (%gnutls_handshake_description_t)
 * @when: non zero if this is a post-process/generation call and zero otherwise
 * @incoming: non zero if this is an incoming message and zero if this is an outgoing message
 * @msg: the (const) data of the handshake message without the handshake headers.
 *
 * Function prototype for handshake hooks. It is set using
 * gnutls_handshake_set_hook_function().
 *
 * Returns: Non zero on error.
 */
typedef int (*gnutls_handshake_hook_func)(gnutls_session_t, unsigned int htype,
					  unsigned when, unsigned int incoming,
					  const gnutls_datum_t *msg);
void gnutls_handshake_set_hook_function(gnutls_session_t session,
					unsigned int htype, int when,
					gnutls_handshake_hook_func func);

#define gnutls_handshake_post_client_hello_func \
	gnutls_handshake_simple_hook_func
typedef int (*gnutls_handshake_simple_hook_func)(gnutls_session_t);
void gnutls_handshake_set_post_client_hello_function(
	gnutls_session_t session, gnutls_handshake_simple_hook_func func);

void gnutls_handshake_set_max_packet_length(gnutls_session_t session,
					    size_t max);

/* returns libgnutls version (call it with a NULL argument)
 */
const char *gnutls_check_version(const char *req_version) __GNUTLS_CONST__;

/* A macro which will allow optimizing out calls to gnutls_check_version()
 * when the version being compiled with is sufficient.
 * Used as:
 *   if (gnutls_check_version_numerc(3,3,16)) {
 */
#define gnutls_check_version_numeric(a, b, c)                            \
	((GNUTLS_VERSION_MAJOR >= (a)) &&                                \
	 ((GNUTLS_VERSION_NUMBER >= (((a) << 16) + ((b) << 8) + (c))) || \
	  gnutls_check_version(#a "." #b "." #c)))

/* Functions for setting/clearing credentials
 */
void gnutls_credentials_clear(gnutls_session_t session);

/* cred is a structure defined by the kx algorithm
 */
int gnutls_credentials_set(gnutls_session_t session,
			   gnutls_credentials_type_t type, void *cred);
int gnutls_credentials_get(gnutls_session_t session,
			   gnutls_credentials_type_t type, void **cred);
#define gnutls_cred_set gnutls_credentials_set

/* x.509 types */

struct gnutls_pubkey_st;
typedef struct gnutls_pubkey_st *gnutls_pubkey_t;

struct gnutls_privkey_st;
typedef struct gnutls_privkey_st *gnutls_privkey_t;

struct gnutls_x509_privkey_int;
typedef struct gnutls_x509_privkey_int *gnutls_x509_privkey_t;

struct gnutls_x509_crl_int;
typedef struct gnutls_x509_crl_int *gnutls_x509_crl_t;

struct gnutls_x509_crt_int;
typedef struct gnutls_x509_crt_int *gnutls_x509_crt_t;

struct gnutls_x509_crq_int;
typedef struct gnutls_x509_crq_int *gnutls_x509_crq_t;

struct gnutls_openpgp_keyring_int;
typedef struct gnutls_openpgp_keyring_int *gnutls_openpgp_keyring_t;

/* Credential structures - used in gnutls_credentials_set(); */

struct gnutls_certificate_credentials_st;
typedef struct gnutls_certificate_credentials_st
	*gnutls_certificate_credentials_t;
typedef gnutls_certificate_credentials_t gnutls_certificate_server_credentials;
typedef gnutls_certificate_credentials_t gnutls_certificate_client_credentials;

typedef struct gnutls_anon_server_credentials_st
	*gnutls_anon_server_credentials_t;
typedef struct gnutls_anon_client_credentials_st
	*gnutls_anon_client_credentials_t;

void gnutls_anon_free_server_credentials(gnutls_anon_server_credentials_t sc);
int gnutls_anon_allocate_server_credentials(
	gnutls_anon_server_credentials_t *sc);

void gnutls_anon_set_server_dh_params(gnutls_anon_server_credentials_t res,
				      gnutls_dh_params_t dh_params);

int gnutls_anon_set_server_known_dh_params(gnutls_anon_server_credentials_t res,
					   gnutls_sec_param_t sec_param);

void gnutls_anon_set_server_params_function(
	gnutls_anon_server_credentials_t res, gnutls_params_function *func);

void gnutls_anon_free_client_credentials(gnutls_anon_client_credentials_t sc);
int gnutls_anon_allocate_client_credentials(
	gnutls_anon_client_credentials_t *sc);

/* CERTFILE is an x509 certificate in PEM form.
 * KEYFILE is a pkcs-1 private key in PEM form (for RSA keys).
 */
void gnutls_certificate_free_credentials(gnutls_certificate_credentials_t sc);
int gnutls_certificate_allocate_credentials(
	gnutls_certificate_credentials_t *res);

int gnutls_certificate_get_issuer(gnutls_certificate_credentials_t sc,
				  gnutls_x509_crt_t cert,
				  gnutls_x509_crt_t *issuer,
				  unsigned int flags);

int gnutls_certificate_get_crt_raw(gnutls_certificate_credentials_t sc,
				   unsigned idx1, unsigned idx2,
				   gnutls_datum_t *cert);

void gnutls_certificate_free_keys(gnutls_certificate_credentials_t sc);
void gnutls_certificate_free_cas(gnutls_certificate_credentials_t sc);
void gnutls_certificate_free_ca_names(gnutls_certificate_credentials_t sc);
void gnutls_certificate_free_crls(gnutls_certificate_credentials_t sc);

void gnutls_certificate_set_dh_params(gnutls_certificate_credentials_t res,
				      gnutls_dh_params_t dh_params);

int gnutls_certificate_set_known_dh_params(gnutls_certificate_credentials_t res,
					   gnutls_sec_param_t sec_param);
void gnutls_certificate_set_verify_flags(gnutls_certificate_credentials_t res,
					 unsigned int flags);
unsigned int
gnutls_certificate_get_verify_flags(gnutls_certificate_credentials_t res);

/**
 * gnutls_certificate_flags:
 * @GNUTLS_CERTIFICATE_SKIP_KEY_CERT_MATCH: Skip the key and certificate matching check.
 * @GNUTLS_CERTIFICATE_API_V2: If set the gnutls_certificate_set_*key* functions will return an index of the added key pair instead of zero.
 * @GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK: If set, the gnutls_certificate_set_ocsp_status_request_file
 *    function, will not check whether the response set matches any of the certificates.
 * @GNUTLS_CERTIFICATE_VERIFY_CRLS: This will enable CRL verification when added in the certificate structure.
 *    When used, it requires CAs to be added before CRLs.
 *
 * Enumeration of different certificate credentials flags.
 */
typedef enum gnutls_certificate_flags {
	GNUTLS_CERTIFICATE_SKIP_KEY_CERT_MATCH = 1,
	GNUTLS_CERTIFICATE_API_V2 = (1 << 1),
	GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK = (1 << 2),
	GNUTLS_CERTIFICATE_VERIFY_CRLS = (1 << 3)
} gnutls_certificate_flags;

void gnutls_certificate_set_flags(gnutls_certificate_credentials_t,
				  unsigned flags);

void gnutls_certificate_set_verify_limits(gnutls_certificate_credentials_t res,
					  unsigned int max_bits,
					  unsigned int max_depth);

int gnutls_certificate_set_x509_system_trust(
	gnutls_certificate_credentials_t cred);

int gnutls_certificate_set_x509_trust_file(gnutls_certificate_credentials_t cred,
					   const char *cafile,
					   gnutls_x509_crt_fmt_t type);
int gnutls_certificate_set_x509_trust_dir(gnutls_certificate_credentials_t cred,
					  const char *ca_dir,
					  gnutls_x509_crt_fmt_t type);

int gnutls_certificate_set_x509_trust_mem(gnutls_certificate_credentials_t res,
					  const gnutls_datum_t *ca,
					  gnutls_x509_crt_fmt_t type);

int gnutls_certificate_set_x509_crl_file(gnutls_certificate_credentials_t res,
					 const char *crlfile,
					 gnutls_x509_crt_fmt_t type);
int gnutls_certificate_set_x509_crl_mem(gnutls_certificate_credentials_t res,
					const gnutls_datum_t *CRL,
					gnutls_x509_crt_fmt_t type);

int gnutls_certificate_set_x509_key_file(gnutls_certificate_credentials_t res,
					 const char *certfile,
					 const char *keyfile,
					 gnutls_x509_crt_fmt_t type);

int gnutls_certificate_set_x509_key_file2(gnutls_certificate_credentials_t res,
					  const char *certfile,
					  const char *keyfile,
					  gnutls_x509_crt_fmt_t type,
					  const char *pass, unsigned int flags);

int gnutls_certificate_set_x509_key_mem(gnutls_certificate_credentials_t res,
					const gnutls_datum_t *cert,
					const gnutls_datum_t *key,
					gnutls_x509_crt_fmt_t type);

int gnutls_certificate_set_x509_key_mem2(gnutls_certificate_credentials_t res,
					 const gnutls_datum_t *cert,
					 const gnutls_datum_t *key,
					 gnutls_x509_crt_fmt_t type,
					 const char *pass, unsigned int flags);

void gnutls_certificate_send_x509_rdn_sequence(gnutls_session_t session,
					       int status);

int gnutls_certificate_set_x509_simple_pkcs12_file(
	gnutls_certificate_credentials_t res, const char *pkcs12file,
	gnutls_x509_crt_fmt_t type, const char *password);
int gnutls_certificate_set_x509_simple_pkcs12_mem(
	gnutls_certificate_credentials_t res, const gnutls_datum_t *p12blob,
	gnutls_x509_crt_fmt_t type, const char *password);

/* New functions to allow setting already parsed X.509 stuff.
 */

int gnutls_certificate_set_x509_key(gnutls_certificate_credentials_t res,
				    gnutls_x509_crt_t *cert_list,
				    int cert_list_size,
				    gnutls_x509_privkey_t key);
int gnutls_certificate_set_x509_trust(gnutls_certificate_credentials_t res,
				      gnutls_x509_crt_t *ca_list,
				      int ca_list_size);
int gnutls_certificate_set_x509_crl(gnutls_certificate_credentials_t res,
				    gnutls_x509_crl_t *crl_list,
				    int crl_list_size);

int gnutls_certificate_get_x509_key(gnutls_certificate_credentials_t res,
				    unsigned index, gnutls_x509_privkey_t *key);
int gnutls_certificate_get_x509_crt(gnutls_certificate_credentials_t res,
				    unsigned index,
				    gnutls_x509_crt_t **crt_list,
				    unsigned *crt_list_size);

/* OCSP status request extension, RFC 6066 */
typedef int (*gnutls_status_request_ocsp_func)(gnutls_session_t session,
					       void *ptr,
					       gnutls_datum_t *ocsp_response);

void gnutls_certificate_set_ocsp_status_request_function(
	gnutls_certificate_credentials_t res,
	gnutls_status_request_ocsp_func ocsp_func, void *ptr);

int gnutls_certificate_set_ocsp_status_request_function2(
	gnutls_certificate_credentials_t res, unsigned idx,
	gnutls_status_request_ocsp_func ocsp_func, void *ptr);

int gnutls_certificate_set_ocsp_status_request_file(
	gnutls_certificate_credentials_t res, const char *response_file,
	unsigned idx);

int gnutls_certificate_set_ocsp_status_request_file2(
	gnutls_certificate_credentials_t res, const char *response_file,
	unsigned idx, gnutls_x509_crt_fmt_t fmt);

int gnutls_certificate_set_ocsp_status_request_mem(
	gnutls_certificate_credentials_t res, const gnutls_datum_t *resp,
	unsigned idx, gnutls_x509_crt_fmt_t fmt);

typedef struct gnutls_ocsp_data_st {
	unsigned int version; /* must be zero */
	gnutls_datum_t response;
	time_t exptime;
	unsigned char padding[32];
} gnutls_ocsp_data_st;

time_t
gnutls_certificate_get_ocsp_expiration(gnutls_certificate_credentials_t sc,
				       unsigned idx, int oidx, unsigned flags);

int gnutls_ocsp_status_request_enable_client(
	gnutls_session_t session, gnutls_datum_t *responder_id,
	size_t responder_id_size, gnutls_datum_t *request_extensions);

int gnutls_ocsp_status_request_get(gnutls_session_t session,
				   gnutls_datum_t *response);

#define GNUTLS_OCSP_SR_IS_AVAIL 1
unsigned gnutls_ocsp_status_request_is_checked(gnutls_session_t session,
					       unsigned int flags);

int gnutls_ocsp_status_request_get2(gnutls_session_t session, unsigned idx,
				    gnutls_datum_t *response);

/* RAW public key functions (RFC7250) */
int gnutls_certificate_set_rawpk_key_mem(
	gnutls_certificate_credentials_t cred, const gnutls_datum_t *spki,
	const gnutls_datum_t *pkey, gnutls_x509_crt_fmt_t format,
	const char *pass, unsigned int key_usage, const char **names,
	unsigned int names_length, unsigned int flags);

int gnutls_certificate_set_rawpk_key_file(
	gnutls_certificate_credentials_t cred, const char *rawpkfile,
	const char *privkeyfile, gnutls_x509_crt_fmt_t format, const char *pass,
	unsigned int key_usage, const char **names, unsigned int names_length,
	unsigned int privkey_flags, unsigned int pkcs11_flags);

/* global state functions
 */
int gnutls_global_init(void);
void gnutls_global_deinit(void);

const gnutls_library_config_st *gnutls_get_library_config(void);

/**
 * gnutls_time_func:
 * @t: where to store time.
 *
 * Function prototype for time()-like function.  Set with
 * gnutls_global_set_time_function().
 *
 * Returns: Number of seconds since the epoch, or (time_t)-1 on errors.
 */
typedef time_t (*gnutls_time_func)(time_t *t);

typedef int (*mutex_init_func)(void **mutex);
typedef int (*mutex_lock_func)(void **mutex);
typedef int (*mutex_unlock_func)(void **mutex);
typedef int (*mutex_deinit_func)(void **mutex);

void gnutls_global_set_mutex(mutex_init_func init, mutex_deinit_func deinit,
			     mutex_lock_func lock, mutex_unlock_func unlock);

typedef void *(*gnutls_alloc_function)(size_t);
typedef void *(*gnutls_calloc_function)(size_t, size_t);
typedef int (*gnutls_is_secure_function)(const void *);
typedef void (*gnutls_free_function)(void *);
typedef void *(*gnutls_realloc_function)(void *, size_t);

void gnutls_global_set_time_function(gnutls_time_func time_func);

/* For use in callbacks */
extern _SYM_EXPORT gnutls_alloc_function gnutls_malloc;
extern _SYM_EXPORT gnutls_realloc_function gnutls_realloc;
extern _SYM_EXPORT gnutls_calloc_function gnutls_calloc;
extern _SYM_EXPORT gnutls_free_function gnutls_free;

#ifdef GNUTLS_INTERNAL_BUILD
#define gnutls_free(a) gnutls_free((void *)(a)), a = NULL
#endif

extern _SYM_EXPORT char *(*gnutls_strdup)(const char *);

/* a variant of memset that doesn't get optimized out */
void gnutls_memset(void *data, int c, size_t size);

/* constant time memcmp */
int gnutls_memcmp(const void *s1, const void *s2, size_t n);

typedef void (*gnutls_log_func)(int, const char *);
typedef void (*gnutls_audit_log_func)(gnutls_session_t, const char *);
void gnutls_global_set_log_function(gnutls_log_func log_func);
void gnutls_global_set_audit_log_function(gnutls_audit_log_func log_func);
void gnutls_global_set_log_level(int level);

/**
 * gnutls_keylog_func:
 * @session: the current session
 * @label: the keylog label
 * @secret: the (const) data of the derived secret.
 *
 * Function prototype for keylog hooks. It is set using
 * gnutls_session_set_keylog_function().
 *
 * Returns: Non zero on error.
 * Since: 3.6.13
 */
typedef int (*gnutls_keylog_func)(gnutls_session_t session, const char *label,
				  const gnutls_datum_t *secret);
gnutls_keylog_func
gnutls_session_get_keylog_function(const gnutls_session_t session);
void gnutls_session_set_keylog_function(gnutls_session_t session,
					gnutls_keylog_func func);

/* Diffie-Hellman parameter handling.
 */
int gnutls_dh_params_init(gnutls_dh_params_t *dh_params);
void gnutls_dh_params_deinit(gnutls_dh_params_t dh_params);
int gnutls_dh_params_import_raw(gnutls_dh_params_t dh_params,
				const gnutls_datum_t *prime,
				const gnutls_datum_t *generator);
int gnutls_dh_params_import_dsa(gnutls_dh_params_t dh_params,
				gnutls_x509_privkey_t key);
int gnutls_dh_params_import_raw2(gnutls_dh_params_t dh_params,
				 const gnutls_datum_t *prime,
				 const gnutls_datum_t *generator,
				 unsigned key_bits);
int gnutls_dh_params_import_raw3(gnutls_dh_params_t dh_params,
				 const gnutls_datum_t *prime,
				 const gnutls_datum_t *q,
				 const gnutls_datum_t *generator);
int gnutls_dh_params_import_pkcs3(gnutls_dh_params_t params,
				  const gnutls_datum_t *pkcs3_params,
				  gnutls_x509_crt_fmt_t format);
int gnutls_dh_params_generate2(gnutls_dh_params_t params, unsigned int bits);
int gnutls_dh_params_export_pkcs3(gnutls_dh_params_t params,
				  gnutls_x509_crt_fmt_t format,
				  unsigned char *params_data,
				  size_t *params_data_size);
int gnutls_dh_params_export2_pkcs3(gnutls_dh_params_t params,
				   gnutls_x509_crt_fmt_t format,
				   gnutls_datum_t *out);
int gnutls_dh_params_export_raw(gnutls_dh_params_t params,
				gnutls_datum_t *prime,
				gnutls_datum_t *generator, unsigned int *bits);
int gnutls_dh_params_cpy(gnutls_dh_params_t dst, gnutls_dh_params_t src);

/* Session stuff
 */
/* clang-format off */
typedef struct {
    void *iov_base;
    size_t iov_len;
} giovec_t;
	/* clang-format on */

	typedef ssize_t (*gnutls_pull_func)(gnutls_transport_ptr_t, void *,
					    size_t);
typedef ssize_t (*gnutls_push_func)(gnutls_transport_ptr_t, const void *,
				    size_t);

int gnutls_system_recv_timeout(gnutls_transport_ptr_t ptr, unsigned int ms);
typedef int (*gnutls_pull_timeout_func)(gnutls_transport_ptr_t,
					unsigned int ms);

typedef ssize_t (*gnutls_vec_push_func)(gnutls_transport_ptr_t,
					const giovec_t *iov, int iovcnt);

typedef int (*gnutls_errno_func)(gnutls_transport_ptr_t);

#if 0
 /* This will be defined as macro. */
void gnutls_transport_set_int(gnutls_session_t session, int r);
#endif

void gnutls_transport_set_int2(gnutls_session_t session, int r, int s);
#define gnutls_transport_set_int(s, i) gnutls_transport_set_int2(s, i, i)

void gnutls_transport_get_int2(gnutls_session_t session, int *r, int *s);
int gnutls_transport_get_int(gnutls_session_t session);

void gnutls_transport_set_ptr(gnutls_session_t session,
			      gnutls_transport_ptr_t ptr);
void gnutls_transport_set_ptr2(gnutls_session_t session,
			       gnutls_transport_ptr_t recv_ptr,
			       gnutls_transport_ptr_t send_ptr);

gnutls_transport_ptr_t gnutls_transport_get_ptr(gnutls_session_t session);
void gnutls_transport_get_ptr2(gnutls_session_t session,
			       gnutls_transport_ptr_t *recv_ptr,
			       gnutls_transport_ptr_t *send_ptr);

void gnutls_transport_set_vec_push_function(gnutls_session_t session,
					    gnutls_vec_push_func vec_func);
void gnutls_transport_set_push_function(gnutls_session_t session,
					gnutls_push_func push_func);
void gnutls_transport_set_pull_function(gnutls_session_t session,
					gnutls_pull_func pull_func);

void gnutls_transport_set_pull_timeout_function(gnutls_session_t session,
						gnutls_pull_timeout_func func);

void gnutls_transport_set_errno_function(gnutls_session_t session,
					 gnutls_errno_func errno_func);

void gnutls_transport_set_errno(gnutls_session_t session, int err);

/* session specific
 */
void gnutls_session_set_ptr(gnutls_session_t session, void *ptr);
void *gnutls_session_get_ptr(gnutls_session_t session);

void gnutls_openpgp_send_cert(gnutls_session_t session,
			      gnutls_openpgp_crt_status_t status);

/* This function returns the hash of the given data.
 */
int gnutls_fingerprint(gnutls_digest_algorithm_t algo,
		       const gnutls_datum_t *data, void *result,
		       size_t *result_size);

/**
 * gnutls_random_art_t:
 * @GNUTLS_RANDOM_ART_OPENSSH: OpenSSH-style random art.
 *
 * Enumeration of different random art types.
 */
typedef enum gnutls_random_art {
	GNUTLS_RANDOM_ART_OPENSSH = 1
} gnutls_random_art_t;

int gnutls_random_art(gnutls_random_art_t type, const char *key_type,
		      unsigned int key_size, void *fpr, size_t fpr_size,
		      gnutls_datum_t *art);

/* IDNA */
#define GNUTLS_IDNA_FORCE_2008 (1 << 1)
int gnutls_idna_map(const char *input, unsigned ilen, gnutls_datum_t *out,
		    unsigned flags);
int gnutls_idna_reverse_map(const char *input, unsigned ilen,
			    gnutls_datum_t *out, unsigned flags);

/* SRP
 */

typedef struct gnutls_srp_server_credentials_st *gnutls_srp_server_credentials_t;
typedef struct gnutls_srp_client_credentials_st *gnutls_srp_client_credentials_t;

void gnutls_srp_free_client_credentials(gnutls_srp_client_credentials_t sc);
int gnutls_srp_allocate_client_credentials(gnutls_srp_client_credentials_t *sc);
int gnutls_srp_set_client_credentials(gnutls_srp_client_credentials_t res,
				      const char *username,
				      const char *password);

void gnutls_srp_free_server_credentials(gnutls_srp_server_credentials_t sc);
int gnutls_srp_allocate_server_credentials(gnutls_srp_server_credentials_t *sc);
int gnutls_srp_set_server_credentials_file(gnutls_srp_server_credentials_t res,
					   const char *password_file,
					   const char *password_conf_file);

const char *gnutls_srp_server_get_username(gnutls_session_t session);

void gnutls_srp_set_prime_bits(gnutls_session_t session, unsigned int bits);

int gnutls_srp_verifier(const char *username, const char *password,
			const gnutls_datum_t *salt,
			const gnutls_datum_t *generator,
			const gnutls_datum_t *prime, gnutls_datum_t *res);

/* The static parameters defined in draft-ietf-tls-srp-05
 * Those should be used as input to gnutls_srp_verifier().
 */
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_8192_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_8192_group_generator;

extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_4096_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_4096_group_generator;

extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_3072_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_3072_group_generator;

extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_2048_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_2048_group_generator;

extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_1536_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_1536_group_generator;

extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_1024_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_srp_1024_group_generator;

/* The static parameters defined in rfc7919
 */

extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_8192_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_8192_group_q;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_8192_group_generator;
extern _SYM_EXPORT const unsigned int gnutls_ffdhe_8192_key_bits;

extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_6144_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_6144_group_q;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_6144_group_generator;
extern _SYM_EXPORT const unsigned int gnutls_ffdhe_6144_key_bits;

extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_4096_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_4096_group_q;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_4096_group_generator;
extern _SYM_EXPORT const unsigned int gnutls_ffdhe_4096_key_bits;

extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_3072_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_3072_group_q;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_3072_group_generator;
extern _SYM_EXPORT const unsigned int gnutls_ffdhe_3072_key_bits;

extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_2048_group_prime;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_2048_group_q;
extern _SYM_EXPORT const gnutls_datum_t gnutls_ffdhe_2048_group_generator;
extern _SYM_EXPORT const unsigned int gnutls_ffdhe_2048_key_bits;

typedef int gnutls_srp_server_credentials_function(gnutls_session_t,
						   const char *username,
						   gnutls_datum_t *salt,
						   gnutls_datum_t *verifier,
						   gnutls_datum_t *generator,
						   gnutls_datum_t *prime);
void gnutls_srp_set_server_credentials_function(
	gnutls_srp_server_credentials_t cred,
	gnutls_srp_server_credentials_function *func);

typedef int gnutls_srp_client_credentials_function(gnutls_session_t, char **,
						   char **);
void gnutls_srp_set_client_credentials_function(
	gnutls_srp_client_credentials_t cred,
	gnutls_srp_client_credentials_function *func);

int gnutls_srp_base64_encode(const gnutls_datum_t *data, char *result,
			     size_t *result_size);
int gnutls_srp_base64_encode2(const gnutls_datum_t *data,
			      gnutls_datum_t *result);

int gnutls_srp_base64_decode(const gnutls_datum_t *b64_data, char *result,
			     size_t *result_size);
int gnutls_srp_base64_decode2(const gnutls_datum_t *b64_data,
			      gnutls_datum_t *result);

#define gnutls_srp_base64_encode_alloc gnutls_srp_base64_encode2
#define gnutls_srp_base64_decode_alloc gnutls_srp_base64_decode2

void gnutls_srp_set_server_fake_salt_seed(gnutls_srp_server_credentials_t sc,
					  const gnutls_datum_t *seed,
					  unsigned int salt_length);

/* PSK stuff */
typedef struct gnutls_psk_server_credentials_st *gnutls_psk_server_credentials_t;
typedef struct gnutls_psk_client_credentials_st *gnutls_psk_client_credentials_t;

/**
 * gnutls_psk_key_flags:
 * @GNUTLS_PSK_KEY_RAW: PSK-key in raw format.
 * @GNUTLS_PSK_KEY_HEX: PSK-key in hex format.
 * @GNUTLS_PSK_KEY_EXT: PSK-key is external and to be imported.
 *
 * Enumeration of different PSK key flags.
 */
typedef enum gnutls_psk_key_flags {
	GNUTLS_PSK_KEY_RAW = 0,
	GNUTLS_PSK_KEY_HEX = 1 << 0,
	GNUTLS_PSK_KEY_EXT = 1 << 1
} gnutls_psk_key_flags;

void gnutls_psk_free_client_credentials(gnutls_psk_client_credentials_t sc);
int gnutls_psk_allocate_client_credentials(gnutls_psk_client_credentials_t *sc);
int gnutls_psk_set_client_credentials(gnutls_psk_client_credentials_t res,
				      const char *username,
				      const gnutls_datum_t *key,
				      gnutls_psk_key_flags flags);
int gnutls_psk_set_client_credentials2(gnutls_psk_client_credentials_t res,
				       const gnutls_datum_t *username,
				       const gnutls_datum_t *key,
				       gnutls_psk_key_flags flags);

void gnutls_psk_free_server_credentials(gnutls_psk_server_credentials_t sc);
int gnutls_psk_allocate_server_credentials(gnutls_psk_server_credentials_t *sc);
int gnutls_psk_set_server_credentials_file(gnutls_psk_server_credentials_t res,
					   const char *password_file);

int gnutls_psk_set_server_credentials_hint(gnutls_psk_server_credentials_t res,
					   const char *hint);

const char *gnutls_psk_server_get_username(gnutls_session_t session);
int gnutls_psk_server_get_username2(gnutls_session_t session,
				    gnutls_datum_t *out);
const char *gnutls_psk_client_get_hint(gnutls_session_t session);

typedef int gnutls_psk_server_credentials_function(gnutls_session_t,
						   const char *username,
						   gnutls_datum_t *key);
typedef int gnutls_psk_server_credentials_function2(
	gnutls_session_t, const gnutls_datum_t *username, gnutls_datum_t *key);
typedef int gnutls_psk_server_credentials_function3(
	gnutls_session_t, const gnutls_datum_t *username, gnutls_datum_t *key,
	gnutls_psk_key_flags *flags);
void gnutls_psk_set_server_credentials_function(
	gnutls_psk_server_credentials_t cred,
	gnutls_psk_server_credentials_function *func);
void gnutls_psk_set_server_credentials_function2(
	gnutls_psk_server_credentials_t cred,
	gnutls_psk_server_credentials_function2 *func);
void gnutls_psk_set_server_credentials_function3(
	gnutls_psk_server_credentials_t cred,
	gnutls_psk_server_credentials_function3 *func);

int gnutls_psk_format_imported_identity(const gnutls_datum_t *identity,
					const gnutls_datum_t *context,
					gnutls_protocol_t version,
					gnutls_digest_algorithm_t hash,
					gnutls_datum_t *imported_identity);

typedef int gnutls_psk_client_credentials_function(gnutls_session_t,
						   char **username,
						   gnutls_datum_t *key);
typedef int gnutls_psk_client_credentials_function2(gnutls_session_t,
						    gnutls_datum_t *username,
						    gnutls_datum_t *key);
typedef int gnutls_psk_client_credentials_function3(
	gnutls_session_t, gnutls_datum_t *username, gnutls_datum_t *key,
	gnutls_psk_key_flags *flags);
void gnutls_psk_set_client_credentials_function(
	gnutls_psk_client_credentials_t cred,
	gnutls_psk_client_credentials_function *func);
void gnutls_psk_set_client_credentials_function2(
	gnutls_psk_client_credentials_t cred,
	gnutls_psk_client_credentials_function2 *func);
void gnutls_psk_set_client_credentials_function3(
	gnutls_psk_client_credentials_t cred,
	gnutls_psk_client_credentials_function3 *func);

int gnutls_hex_encode(const gnutls_datum_t *data, char *result,
		      size_t *result_size);
int gnutls_hex_decode(const gnutls_datum_t *hex_data, void *result,
		      size_t *result_size);

int gnutls_hex_encode2(const gnutls_datum_t *data, gnutls_datum_t *result);
int gnutls_hex_decode2(const gnutls_datum_t *data, gnutls_datum_t *result);

void gnutls_psk_set_server_dh_params(gnutls_psk_server_credentials_t res,
				     gnutls_dh_params_t dh_params);

int gnutls_psk_set_server_known_dh_params(gnutls_psk_server_credentials_t res,
					  gnutls_sec_param_t sec_param);

void gnutls_psk_set_server_params_function(gnutls_psk_server_credentials_t res,
					   gnutls_params_function *func);

/**
 * gnutls_x509_subject_alt_name_t:
 * @GNUTLS_SAN_DNSNAME: DNS-name SAN.
 * @GNUTLS_SAN_RFC822NAME: E-mail address SAN.
 * @GNUTLS_SAN_URI: URI SAN.
 * @GNUTLS_SAN_IPADDRESS: IP address SAN.
 * @GNUTLS_SAN_OTHERNAME: OtherName SAN.
 * @GNUTLS_SAN_DN: DN SAN.
 * @GNUTLS_SAN_REGISTERED_ID: RegisteredID.
 * @GNUTLS_SAN_OTHERNAME_XMPP: Virtual SAN, used by certain functions for convenience.
 * @GNUTLS_SAN_OTHERNAME_KRB5PRINCIPAL: Virtual SAN, used by certain functions for convenience.
 * @GNUTLS_SAN_OTHERNAME_MSUSERPRINCIPAL: Virtual SAN, used by certain functions for convenience.
 *
 * Enumeration of different subject alternative names types.
 */
typedef enum gnutls_x509_subject_alt_name_t {
	GNUTLS_SAN_DNSNAME = 1,
	GNUTLS_SAN_RFC822NAME = 2,
	GNUTLS_SAN_URI = 3,
	GNUTLS_SAN_IPADDRESS = 4,
	GNUTLS_SAN_OTHERNAME = 5,
	GNUTLS_SAN_DN = 6,
	GNUTLS_SAN_REGISTERED_ID = 7,
	GNUTLS_SAN_MAX = GNUTLS_SAN_REGISTERED_ID,
	/* The following are "virtual" subject alternative name types, in
	   that they are represented by an otherName value and an OID.
	   Used by gnutls_x509_crt_get_subject_alt_othername_oid.  */
	GNUTLS_SAN_OTHERNAME_XMPP = 1000,
	GNUTLS_SAN_OTHERNAME_KRB5PRINCIPAL,
	GNUTLS_SAN_OTHERNAME_MSUSERPRINCIPAL
} gnutls_x509_subject_alt_name_t;

struct gnutls_openpgp_crt_int;
typedef struct gnutls_openpgp_crt_int *gnutls_openpgp_crt_t;

struct gnutls_openpgp_privkey_int;
typedef struct gnutls_openpgp_privkey_int *gnutls_openpgp_privkey_t;

struct gnutls_pkcs11_privkey_st;
typedef struct gnutls_pkcs11_privkey_st *gnutls_pkcs11_privkey_t;

/**
 * gnutls_privkey_type_t:
 * @GNUTLS_PRIVKEY_X509: X.509 private key, #gnutls_x509_privkey_t.
 * @GNUTLS_PRIVKEY_OPENPGP: OpenPGP private key, #gnutls_openpgp_privkey_t.
 * @GNUTLS_PRIVKEY_PKCS11: PKCS11 private key, #gnutls_pkcs11_privkey_t.
 * @GNUTLS_PRIVKEY_EXT: External private key, operating using callbacks.
 *
 * Enumeration of different private key types.
 */
typedef enum {
	GNUTLS_PRIVKEY_X509,
	GNUTLS_PRIVKEY_OPENPGP,
	GNUTLS_PRIVKEY_PKCS11,
	GNUTLS_PRIVKEY_EXT
} gnutls_privkey_type_t;

typedef struct gnutls_retr2_st {
	gnutls_certificate_type_t cert_type;
	gnutls_privkey_type_t key_type;

	union {
		gnutls_x509_crt_t *x509;
		gnutls_openpgp_crt_t pgp;
	} cert;
	unsigned int ncerts; /* one for pgp keys */

	union {
		gnutls_x509_privkey_t x509;
		gnutls_openpgp_privkey_t pgp;
		gnutls_pkcs11_privkey_t pkcs11;
	} key;

	unsigned int deinit_all; /* if non zero all keys will be deinited */
} gnutls_retr2_st;

/* Functions that allow auth_info_t structures handling
   */

gnutls_credentials_type_t gnutls_auth_get_type(gnutls_session_t session);
gnutls_credentials_type_t gnutls_auth_server_get_type(gnutls_session_t session);
gnutls_credentials_type_t gnutls_auth_client_get_type(gnutls_session_t session);

/* DH */

void gnutls_dh_set_prime_bits(gnutls_session_t session, unsigned int bits);
int gnutls_dh_get_secret_bits(gnutls_session_t session);
int gnutls_dh_get_peers_public_bits(gnutls_session_t session);
int gnutls_dh_get_prime_bits(gnutls_session_t session);

int gnutls_dh_get_group(gnutls_session_t session, gnutls_datum_t *raw_gen,
			gnutls_datum_t *raw_prime);
int gnutls_dh_get_pubkey(gnutls_session_t session, gnutls_datum_t *raw_key);

/* X509PKI */

/* These are set on the credentials structure.
   */

/* use gnutls_certificate_set_retrieve_function2() in abstract.h
   * instead. It's much more efficient.
   */

typedef int gnutls_certificate_retrieve_function(
	gnutls_session_t, const gnutls_datum_t *req_ca_rdn, int nreqs,
	const gnutls_pk_algorithm_t *pk_algos, int pk_algos_length,
	gnutls_retr2_st *);

void gnutls_certificate_set_retrieve_function(
	gnutls_certificate_credentials_t cred,
	gnutls_certificate_retrieve_function *func);

void gnutls_certificate_set_verify_function(
	gnutls_certificate_credentials_t cred,
	gnutls_certificate_verify_function *func);

void gnutls_certificate_server_set_request(gnutls_session_t session,
					   gnutls_certificate_request_t req);

/* get data from the session
   */
const gnutls_datum_t *gnutls_certificate_get_peers(gnutls_session_t session,
						   unsigned int *list_size);
const gnutls_datum_t *gnutls_certificate_get_ours(gnutls_session_t session);

int gnutls_certificate_get_peers_subkey_id(gnutls_session_t session,
					   gnutls_datum_t *id);

time_t gnutls_certificate_activation_time_peers(gnutls_session_t session);
time_t gnutls_certificate_expiration_time_peers(gnutls_session_t session);

unsigned gnutls_certificate_client_get_request_status(gnutls_session_t session);
int gnutls_certificate_verify_peers2(gnutls_session_t session,
				     unsigned int *status);
int gnutls_certificate_verify_peers3(gnutls_session_t session,
				     const char *hostname,
				     unsigned int *status);

int gnutls_certificate_verify_peers(gnutls_session_t session,
				    gnutls_typed_vdata_st *data,
				    unsigned int elements,
				    unsigned int *status);

int gnutls_certificate_verification_status_print(unsigned int status,
						 gnutls_certificate_type_t type,
						 gnutls_datum_t *out,
						 unsigned int flags);

int gnutls_pem_base64_encode(const char *msg, const gnutls_datum_t *data,
			     char *result, size_t *result_size);
int gnutls_pem_base64_decode(const char *header, const gnutls_datum_t *b64_data,
			     unsigned char *result, size_t *result_size);

int gnutls_pem_base64_encode2(const char *msg, const gnutls_datum_t *data,
			      gnutls_datum_t *result);
int gnutls_pem_base64_decode2(const char *header,
			      const gnutls_datum_t *b64_data,
			      gnutls_datum_t *result);

int gnutls_base64_encode2(const gnutls_datum_t *data, gnutls_datum_t *result);
int gnutls_base64_decode2(const gnutls_datum_t *b64_data,
			  gnutls_datum_t *result);

#define gnutls_pem_base64_encode_alloc gnutls_pem_base64_encode2
#define gnutls_pem_base64_decode_alloc gnutls_pem_base64_decode2

/* key_usage will be an OR of the following values:
   */

/* when the key is to be used for signing: */
#define GNUTLS_KEY_DIGITAL_SIGNATURE 128
#define GNUTLS_KEY_NON_REPUDIATION 64
/* when the key is to be used for encryption: */
#define GNUTLS_KEY_KEY_ENCIPHERMENT 32
#define GNUTLS_KEY_DATA_ENCIPHERMENT 16
#define GNUTLS_KEY_KEY_AGREEMENT 8
#define GNUTLS_KEY_KEY_CERT_SIGN 4
#define GNUTLS_KEY_CRL_SIGN 2
#define GNUTLS_KEY_ENCIPHER_ONLY 1
#define GNUTLS_KEY_DECIPHER_ONLY 32768

void gnutls_certificate_set_params_function(
	gnutls_certificate_credentials_t res, gnutls_params_function *func);
void gnutls_anon_set_params_function(gnutls_anon_server_credentials_t res,
				     gnutls_params_function *func);
void gnutls_psk_set_params_function(gnutls_psk_server_credentials_t res,
				    gnutls_params_function *func);

int gnutls_hex2bin(const char *hex_data, size_t hex_size, void *bin_data,
		   size_t *bin_size);

/* Trust on first use (or ssh like) functions */

/* stores the provided information to a database
   */
typedef int (*gnutls_tdb_store_func)(const char *db_name, const char *host,
				     const char *service, time_t expiration,
				     const gnutls_datum_t *pubkey);

typedef int (*gnutls_tdb_store_commitment_func)(
	const char *db_name, const char *host, const char *service,
	time_t expiration, gnutls_digest_algorithm_t hash_algo,
	const gnutls_datum_t *hash);

/* searches for the provided host/service pair that match the
   * provided public key in the database. */
typedef int (*gnutls_tdb_verify_func)(const char *db_name, const char *host,
				      const char *service,
				      const gnutls_datum_t *pubkey);

struct gnutls_tdb_int;
typedef struct gnutls_tdb_int *gnutls_tdb_t;

int gnutls_tdb_init(gnutls_tdb_t *tdb);
void gnutls_tdb_set_store_func(gnutls_tdb_t tdb, gnutls_tdb_store_func store);
void gnutls_tdb_set_store_commitment_func(
	gnutls_tdb_t tdb, gnutls_tdb_store_commitment_func cstore);
void gnutls_tdb_set_verify_func(gnutls_tdb_t tdb,
				gnutls_tdb_verify_func verify);
void gnutls_tdb_deinit(gnutls_tdb_t tdb);

int gnutls_verify_stored_pubkey(const char *db_name, gnutls_tdb_t tdb,
				const char *host, const char *service,
				gnutls_certificate_type_t cert_type,
				const gnutls_datum_t *cert, unsigned int flags);

#define GNUTLS_SCOMMIT_FLAG_ALLOW_BROKEN 1
int gnutls_store_commitment(const char *db_name, gnutls_tdb_t tdb,
			    const char *host, const char *service,
			    gnutls_digest_algorithm_t hash_algo,
			    const gnutls_datum_t *hash, time_t expiration,
			    unsigned int flags);

int gnutls_store_pubkey(const char *db_name, gnutls_tdb_t tdb, const char *host,
			const char *service,
			gnutls_certificate_type_t cert_type,
			const gnutls_datum_t *cert, time_t expiration,
			unsigned int flags);

/* Other helper functions */
int gnutls_load_file(const char *filename, gnutls_datum_t *data);

unsigned gnutls_url_is_supported(const char *url);

/* PIN callback */

/**
 * gnutls_pin_flag_t:
 * @GNUTLS_PIN_USER: The PIN for the user.
 * @GNUTLS_PIN_SO: The PIN for the security officer (admin).
 * @GNUTLS_PIN_CONTEXT_SPECIFIC: The PIN is for a specific action and key like signing.
 * @GNUTLS_PIN_FINAL_TRY: This is the final try before blocking.
 * @GNUTLS_PIN_COUNT_LOW: Few tries remain before token blocks.
 * @GNUTLS_PIN_WRONG: Last given PIN was not correct.
 *
 * Enumeration of different flags that are input to the PIN function.
 */
typedef enum {
	GNUTLS_PIN_USER = (1 << 0),
	GNUTLS_PIN_SO = (1 << 1),
	GNUTLS_PIN_FINAL_TRY = (1 << 2),
	GNUTLS_PIN_COUNT_LOW = (1 << 3),
	GNUTLS_PIN_CONTEXT_SPECIFIC = (1 << 4),
	GNUTLS_PIN_WRONG = (1 << 5)
} gnutls_pin_flag_t;

#define GNUTLS_PKCS11_PIN_USER GNUTLS_PIN_USER
#define GNUTLS_PKCS11_PIN_SO GNUTLS_PIN_SO
#define GNUTLS_PKCS11_PIN_FINAL_TRY GNUTLS_PIN_FINAL_TRY
#define GNUTLS_PKCS11_PIN_COUNT_LOW GNUTLS_PIN_COUNT_LOW
#define GNUTLS_PKCS11_PIN_CONTEXT_SPECIFIC GNUTLS_PIN_CONTEXT_SPECIFIC
#define GNUTLS_PKCS11_PIN_WRONG GNUTLS_PIN_WRONG

/**
 * gnutls_pin_callback_t:
 * @userdata: user-controlled data from gnutls_pkcs11_set_pin_function().
 * @attempt: pin-attempt counter, initially 0.
 * @token_url: URL of token.
 * @token_label: label of token.
 * @flags: a #gnutls_pin_flag_t flag.
 * @pin: buffer to hold PIN, of size @pin_max.
 * @pin_max: size of @pin buffer.
 *
 * Callback function type for PKCS#11 or TPM PIN entry.  It is set by
 * functions like gnutls_pkcs11_set_pin_function().
 *
 * The callback should provides the PIN code to unlock the token with
 * label @token_label, specified by the URL @token_url.
 *
 * The PIN code, as a NUL-terminated ASCII string, should be copied
 * into the @pin buffer (of maximum size @pin_max), and return 0 to
 * indicate success.  Alternatively, the callback may return a
 * negative gnutls error code to indicate failure and cancel PIN entry
 * (in which case, the contents of the @pin parameter are ignored).
 *
 * When a PIN is required, the callback will be invoked repeatedly
 * (and indefinitely) until either the returned PIN code is correct,
 * the callback returns failure, or the token refuses login (e.g. when
 * the token is locked due to too many incorrect PINs!).  For the
 * first such invocation, the @attempt counter will have value zero;
 * it will increase by one for each subsequent attempt.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success or a negative error code on error.
 *
 * Since: 2.12.0
 **/
typedef int (*gnutls_pin_callback_t)(void *userdata, int attempt,
				     const char *token_url,
				     const char *token_label,
				     unsigned int flags, char *pin,
				     size_t pin_max);

void gnutls_certificate_set_pin_function(gnutls_certificate_credentials_t,
					 gnutls_pin_callback_t fn,
					 void *userdata);

/* Public string related functions */
typedef struct gnutls_buffer_st *gnutls_buffer_t;

int gnutls_buffer_append_data(gnutls_buffer_t, const void *data,
			      size_t data_size);

#define GNUTLS_UTF8_IGNORE_ERRS 1
int gnutls_utf8_password_normalize(const unsigned char *password,
				   unsigned password_len, gnutls_datum_t *out,
				   unsigned flags);

/* Public extensions related functions */

typedef void *gnutls_ext_priv_data_t;

void gnutls_ext_set_data(gnutls_session_t session, unsigned type,
			 gnutls_ext_priv_data_t);
int gnutls_ext_get_data(gnutls_session_t session, unsigned type,
			gnutls_ext_priv_data_t *);

unsigned gnutls_ext_get_current_msg(gnutls_session_t session);

typedef int (*gnutls_ext_recv_func)(gnutls_session_t session,
				    const unsigned char *data, size_t len);

typedef int (*gnutls_ext_send_func)(gnutls_session_t session,
				    gnutls_buffer_t extdata);

typedef void (*gnutls_ext_deinit_data_func)(gnutls_ext_priv_data_t data);

typedef int (*gnutls_ext_pack_func)(gnutls_ext_priv_data_t data,
				    gnutls_buffer_t packed_data);

typedef int (*gnutls_ext_unpack_func)(gnutls_buffer_t packed_data,
				      gnutls_ext_priv_data_t *data);

#define GNUTLS_EXT_RAW_FLAG_TLS_CLIENT_HELLO 1
#define GNUTLS_EXT_RAW_FLAG_DTLS_CLIENT_HELLO (1 << 1)
typedef int (*gnutls_ext_raw_process_func)(void *ctx, unsigned tls_id,
					   const unsigned char *data,
					   unsigned data_size);
int gnutls_ext_raw_parse(void *ctx, gnutls_ext_raw_process_func cb,
			 const gnutls_datum_t *data, unsigned int flags);

/**
 * gnutls_ext_parse_type_t:
 * @GNUTLS_EXT_NONE: Never to be parsed
 * @GNUTLS_EXT_ANY: Any extension type (should not be used as it is used only internally).
 * @GNUTLS_EXT_VERSION_NEG: Extensions to be parsed first for TLS version negotiation.
 * @GNUTLS_EXT_MANDATORY: Parsed after @GNUTLS_EXT_VERSION_NEG and even when resuming.
 * @GNUTLS_EXT_APPLICATION: Parsed after @GNUTLS_EXT_MANDATORY
 * @GNUTLS_EXT_TLS: TLS-internal extensions, parsed after @GNUTLS_EXT_APPLICATION.
 *
 * Enumeration of different TLS extension parsing phases.  The @gnutls_ext_parse_type_t
 * indicates the time/phase an extension is parsed during Client or Server hello parsing.
 *
 */
typedef enum {
	GNUTLS_EXT_ANY = 0,
	GNUTLS_EXT_APPLICATION = 1,
	GNUTLS_EXT_TLS = 2,
	GNUTLS_EXT_MANDATORY = 3,
	GNUTLS_EXT_NONE = 4,
	GNUTLS_EXT_VERSION_NEG = 5
} gnutls_ext_parse_type_t;

/**
 * gnutls_ext_flags_t:
 * @GNUTLS_EXT_FLAG_OVERRIDE_INTERNAL: If specified the extension registered will override the internal; this does not work with extensions existing prior to 3.6.0.
 * @GNUTLS_EXT_FLAG_CLIENT_HELLO: This extension can be present in a client hello
 * @GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO: This extension can be present in a TLS1.2 or earlier server hello
 * @GNUTLS_EXT_FLAG_TLS13_SERVER_HELLO: This extension can be present in a TLS1.3 server hello
 * @GNUTLS_EXT_FLAG_EE: This extension can be present in encrypted extensions message
 * @GNUTLS_EXT_FLAG_HRR: This extension can be present in hello retry request message
 * @GNUTLS_EXT_FLAG_IGNORE_CLIENT_REQUEST: When flag is present, this extension will be send even if the client didn't advertise it. An extension of this type is the Cookie TLS1.3 extension.
 * @GNUTLS_EXT_FLAG_DTLS: This extension can be present under DTLS; otherwise ignored.
 * @GNUTLS_EXT_FLAG_TLS: This extension can be present under TLS; otherwise ignored.
 *
 * Enumeration of different TLS extension registration flags.
 */
typedef enum {
	GNUTLS_EXT_FLAG_OVERRIDE_INTERNAL = 1,
	GNUTLS_EXT_FLAG_CLIENT_HELLO = (1 << 1),
	GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO = (1 << 2),
	GNUTLS_EXT_FLAG_TLS13_SERVER_HELLO = (1 << 3),
	GNUTLS_EXT_FLAG_EE = (1 << 4), /* ENCRYPTED */
	GNUTLS_EXT_FLAG_HRR = (1 << 5),
	GNUTLS_EXT_FLAG_IGNORE_CLIENT_REQUEST = (1 << 6),
	GNUTLS_EXT_FLAG_TLS = (1 << 7),
	GNUTLS_EXT_FLAG_DTLS = (1 << 8)
} gnutls_ext_flags_t;

/* Register a custom tls extension
 */
int gnutls_ext_register(const char *name, int type,
			gnutls_ext_parse_type_t parse_point,
			gnutls_ext_recv_func recv_func,
			gnutls_ext_send_func send_func,
			gnutls_ext_deinit_data_func deinit_func,
			gnutls_ext_pack_func pack_func,
			gnutls_ext_unpack_func unpack_func);

int gnutls_session_ext_register(gnutls_session_t, const char *name, int type,
				gnutls_ext_parse_type_t parse_point,
				gnutls_ext_recv_func recv_func,
				gnutls_ext_send_func send_func,
				gnutls_ext_deinit_data_func deinit_func,
				gnutls_ext_pack_func pack_func,
				gnutls_ext_unpack_func unpack_func,
				unsigned flags);

const char *gnutls_ext_get_name(unsigned int ext);
const char *gnutls_ext_get_name2(gnutls_session_t session, unsigned int tls_id,
				 gnutls_ext_parse_type_t parse_point);

/* Public supplemental data related functions */

typedef int (*gnutls_supp_recv_func)(gnutls_session_t session,
				     const unsigned char *data,
				     size_t data_size);
typedef int (*gnutls_supp_send_func)(gnutls_session_t session,
				     gnutls_buffer_t buf);

int gnutls_supplemental_register(const char *name,
				 gnutls_supplemental_data_format_type_t type,
				 gnutls_supp_recv_func supp_recv_func,
				 gnutls_supp_send_func supp_send_func);

int gnutls_session_supplemental_register(
	gnutls_session_t session, const char *name,
	gnutls_supplemental_data_format_type_t type,
	gnutls_supp_recv_func supp_recv_func,
	gnutls_supp_send_func supp_send_func, unsigned int flags);

void gnutls_supplemental_recv(gnutls_session_t session,
			      unsigned do_recv_supplemental);

void gnutls_supplemental_send(gnutls_session_t session,
			      unsigned do_send_supplemental);

/* Anti-replay related functions */

typedef struct gnutls_anti_replay_st *gnutls_anti_replay_t;

int gnutls_anti_replay_init(gnutls_anti_replay_t *anti_replay);
void gnutls_anti_replay_deinit(gnutls_anti_replay_t anti_replay);
void gnutls_anti_replay_set_window(gnutls_anti_replay_t anti_replay,
				   unsigned int window);
void gnutls_anti_replay_enable(gnutls_session_t session,
			       gnutls_anti_replay_t anti_replay);

typedef int (*gnutls_db_add_func)(void *, time_t exp_time,
				  const gnutls_datum_t *key,
				  const gnutls_datum_t *data);

void gnutls_anti_replay_set_add_function(gnutls_anti_replay_t,
					 gnutls_db_add_func add_func);

void gnutls_anti_replay_set_ptr(gnutls_anti_replay_t, void *ptr);

/**
 * gnutls_record_encryption_level_t:
 * @GNUTLS_ENCRYPTION_LEVEL_INITIAL: initial level that doesn't involve any
 *    encryption
 * @GNUTLS_ENCRYPTION_LEVEL_EARLY: early traffic secret is installed
 * @GNUTLS_ENCRYPTION_LEVEL_HANDSHAKE: handshake traffic secret is installed
 * @GNUTLS_ENCRYPTION_LEVEL_APPLICATION: application traffic secret is installed
 *
 * Enumeration of different levels of record encryption currently in place.
 * This is used by gnutls_handshake_set_read_function() and
 * gnutls_handshake_write().
 *
 * Since: 3.7.0
 */
typedef enum {
	GNUTLS_ENCRYPTION_LEVEL_INITIAL,
	GNUTLS_ENCRYPTION_LEVEL_EARLY,
	GNUTLS_ENCRYPTION_LEVEL_HANDSHAKE,
	GNUTLS_ENCRYPTION_LEVEL_APPLICATION
} gnutls_record_encryption_level_t;

/**
 * gnutls_handshake_read_func:
 * @session: the current session
 * @htype: the type of the handshake message (#gnutls_handshake_description_t)
 * @level: #gnutls_record_encryption_level_t
 * @data: the (const) data that was being sent
 * @data_size: the size of data
 *
 * Function prototype for handshake intercepting hooks. It is set using
 * gnutls_handshake_set_read_function().
 *
 * Returns: Non zero on error.
 * Since: 3.7.0
 */
typedef int (*gnutls_handshake_read_func)(gnutls_session_t session,
					  gnutls_record_encryption_level_t level,
					  gnutls_handshake_description_t htype,
					  const void *data, size_t data_size);

void gnutls_handshake_set_read_function(gnutls_session_t session,
					gnutls_handshake_read_func func);

int gnutls_handshake_write(gnutls_session_t session,
			   gnutls_record_encryption_level_t level,
			   const void *data, size_t data_size);

/**
 * gnutls_handshake_secret_func:
 * @session: the current session
 * @level: the encryption level
 * @secret_read: the secret used for reading, can be %NULL if not set
 * @secret_write: the secret used for writing, can be %NULL if not set
 * @secret_size: the size of the secrets
 *
 * Function prototype for secret hooks. It is set using
 * gnutls_handshake_set_secret_function().
 *
 * Returns: Non zero on error.
 * Since: 3.7.0
 */
typedef int (*gnutls_handshake_secret_func)(
	gnutls_session_t session, gnutls_record_encryption_level_t level,
	const void *secret_read, const void *secret_write, size_t secret_size);

void gnutls_handshake_set_secret_function(gnutls_session_t session,
					  gnutls_handshake_secret_func func);

/**
 * gnutls_alert_read_func:
 * @session: the current session
 * @level: #gnutls_record_encryption_level_t
 * @alert_level: the level of the alert
 * @alert_desc: the alert description
 *
 * Function prototype for alert intercepting hooks. It is set using
 * gnutls_alert_set_read_function().
 *
 * Returns: Non zero on error.
 * Since: 3.7.0
 */
typedef int (*gnutls_alert_read_func)(gnutls_session_t session,
				      gnutls_record_encryption_level_t level,
				      gnutls_alert_level_t alert_level,
				      gnutls_alert_description_t alert_desc);

void gnutls_alert_set_read_function(gnutls_session_t session,
				    gnutls_alert_read_func func);

/* FIPS140-2 related functions */
unsigned gnutls_fips140_mode_enabled(void);

/**
 * gnutls_fips_mode_t:
 * @GNUTLS_FIPS140_DISABLED: The FIPS140-2 mode is disabled.
 * @GNUTLS_FIPS140_STRICT: The default mode; all forbidden operations will cause an
 *                         operation failure via error code.
 * @GNUTLS_FIPS140_LAX: The library still uses the FIPS140-2 relevant algorithms but all
 *                      forbidden by FIPS140-2 operations are allowed; this is useful when the
 *                      application is aware of the followed security policy, and needs
 *                      to utilize disallowed operations for other reasons (e.g., compatibility).
 * @GNUTLS_FIPS140_LOG: Similarly to %GNUTLS_FIPS140_LAX, it allows forbidden operations; any use of them results
 *                      to a message to the audit callback functions.
 * @GNUTLS_FIPS140_SELFTESTS: A transient state during library initialization. That state
 *			cannot be set or seen by applications.
 *
 * Enumeration of different operational modes under FIPS140-2.
 */
typedef enum gnutls_fips_mode_t {
	GNUTLS_FIPS140_DISABLED = 0,
	GNUTLS_FIPS140_STRICT = 1,
	GNUTLS_FIPS140_SELFTESTS = 2,
	GNUTLS_FIPS140_LAX = 3,
	GNUTLS_FIPS140_LOG = 4
} gnutls_fips_mode_t;

#define GNUTLS_FIPS140_SET_MODE_THREAD 1

void gnutls_fips140_set_mode(gnutls_fips_mode_t mode, unsigned flags);

#define GNUTLS_FIPS140_SET_LAX_MODE()                            \
	do {                                                     \
		if (gnutls_fips140_mode_enabled())               \
			gnutls_fips140_set_mode(                 \
				GNUTLS_FIPS140_LAX,              \
				GNUTLS_FIPS140_SET_MODE_THREAD); \
	} while (0)

#define GNUTLS_FIPS140_SET_STRICT_MODE()                         \
	do {                                                     \
		if (gnutls_fips140_mode_enabled())               \
			gnutls_fips140_set_mode(                 \
				GNUTLS_FIPS140_STRICT,           \
				GNUTLS_FIPS140_SET_MODE_THREAD); \
	} while (0)

typedef struct gnutls_fips140_context_st *gnutls_fips140_context_t;

int gnutls_fips140_context_init(gnutls_fips140_context_t *context);
void gnutls_fips140_context_deinit(gnutls_fips140_context_t context);

/**
 * gnutls_fips140_operation_state_t:
 * @GNUTLS_FIPS140_OP_INITIAL: no previous operation has done
 * @GNUTLS_FIPS140_OP_APPROVED: the previous operation was FIPS approved
 * @GNUTLS_FIPS140_OP_NOT_APPROVED: the previous operation was not FIPS approved
 * @GNUTLS_FIPS140_OP_ERROR: the previous operation caused an error regardless of FIPS
 *
 * The FIPS operation state set by the preceding operation.
 *
 * There are state transition rules among the enum values:
 * - When the context is attached to a thread, it will be set to reset
 *   to the %GNUTLS_FIPS140_OP_INITIAL state
 * - From the %GNUTLS_FIPS140_OP_INITIAL state, the context can
 *   transition to either %GNUTLS_FIPS140_OP_APPROVED,
 *   %GNUTLS_FIPS140_OP_NOT_APPROVED, or %GNUTLS_FIPS140_OP_ERROR
 * - From the %GNUTLS_FIPS140_OP_APPROVED state, the context can
 *   transition to %GNUTLS_FIPS140_OP_NOT_APPROVED
 * - All other transitions are prohibited.
 *
 * Since: 3.7.3
 */
typedef enum {
	GNUTLS_FIPS140_OP_INITIAL,
	GNUTLS_FIPS140_OP_APPROVED,
	GNUTLS_FIPS140_OP_NOT_APPROVED,
	GNUTLS_FIPS140_OP_ERROR
} gnutls_fips140_operation_state_t;

gnutls_fips140_operation_state_t
gnutls_fips140_get_operation_state(gnutls_fips140_context_t context);

int gnutls_fips140_push_context(gnutls_fips140_context_t context);
int gnutls_fips140_pop_context(void);

int gnutls_fips140_run_self_tests(void);

/**
 * gnutls_transport_ktls_enable_flags_t:
 * @GNUTLS_KTLS_RECV: ktls enabled for recv function.
 * @GNUTLS_KTLS_SEND: ktls enabled for send function.
 * @GNUTLS_KTLS_DUPLEX: ktls enabled for both recv and send functions.
 *
 * Flag enumeration of ktls enable status for recv and send functions.
 * This is used by gnutls_transport_is_ktls_enabled().
 *
 * Since: 3.7.3
 */
typedef enum {
	GNUTLS_KTLS_RECV = 1 << 0,
	GNUTLS_KTLS_SEND = 1 << 1,
	GNUTLS_KTLS_DUPLEX = GNUTLS_KTLS_RECV | GNUTLS_KTLS_SEND,
} gnutls_transport_ktls_enable_flags_t;

gnutls_transport_ktls_enable_flags_t
gnutls_transport_is_ktls_enabled(gnutls_session_t session);

/* Gnutls error codes. The mapping to a TLS alert is also shown in
   * comments.
   */

#define GNUTLS_E_SUCCESS 0
#define GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM -3
#define GNUTLS_E_UNKNOWN_CIPHER_TYPE -6
#define GNUTLS_E_LARGE_PACKET -7
#define GNUTLS_E_UNSUPPORTED_VERSION_PACKET -8 /* GNUTLS_A_PROTOCOL_VERSION */
#define GNUTLS_E_TLS_PACKET_DECODING_ERROR GNUTLS_E_UNEXPECTED_PACKET_LENGTH
#define GNUTLS_E_UNEXPECTED_PACKET_LENGTH -9 /* GNUTLS_A_DECODE_ERROR */
#define GNUTLS_E_INVALID_SESSION -10
#define GNUTLS_E_FATAL_ALERT_RECEIVED -12
#define GNUTLS_E_UNEXPECTED_PACKET -15 /* GNUTLS_A_UNEXPECTED_MESSAGE */
#define GNUTLS_E_WARNING_ALERT_RECEIVED -16
#define GNUTLS_E_ERROR_IN_FINISHED_PACKET -18
#define GNUTLS_E_UNEXPECTED_HANDSHAKE_PACKET -19
#define GNUTLS_E_UNKNOWN_CIPHER_SUITE -21
/* GNUTLS_A_HANDSHAKE_FAILURE */
#define GNUTLS_E_UNWANTED_ALGORITHM -22
#define GNUTLS_E_MPI_SCAN_FAILED -23
#define GNUTLS_E_DECRYPTION_FAILED \
	-24 /* GNUTLS_A_DECRYPTION_FAILED, GNUTLS_A_BAD_RECORD_MAC */
#define GNUTLS_E_MEMORY_ERROR -25
#define GNUTLS_E_DECOMPRESSION_FAILED -26 /* GNUTLS_A_DECOMPRESSION_FAILURE */
#define GNUTLS_E_COMPRESSION_FAILED -27
#define GNUTLS_E_AGAIN -28
#define GNUTLS_E_EXPIRED -29
#define GNUTLS_E_DB_ERROR -30
#define GNUTLS_E_SRP_PWD_ERROR GNUTLS_E_KEYFILE_ERROR
#define GNUTLS_E_KEYFILE_ERROR -31
#define GNUTLS_E_INSUFFICIENT_CREDENTIALS -32
#define GNUTLS_E_INSUFICIENT_CREDENTIALS \
	GNUTLS_E_INSUFFICIENT_CREDENTIALS /* for backwards compatibility only */
#define GNUTLS_E_INSUFFICIENT_CRED GNUTLS_E_INSUFFICIENT_CREDENTIALS
#define GNUTLS_E_INSUFICIENT_CRED \
	GNUTLS_E_INSUFFICIENT_CREDENTIALS /* for backwards compatibility only */

#define GNUTLS_E_HASH_FAILED -33
#define GNUTLS_E_BASE64_DECODING_ERROR -34

#define GNUTLS_E_MPI_PRINT_FAILED -35
#define GNUTLS_E_REHANDSHAKE -37 /* GNUTLS_A_NO_RENEGOTIATION */
#define GNUTLS_E_GOT_APPLICATION_DATA -38
#define GNUTLS_E_RECORD_LIMIT_REACHED -39
#define GNUTLS_E_ENCRYPTION_FAILED -40

#define GNUTLS_E_PK_ENCRYPTION_FAILED -44
#define GNUTLS_E_PK_DECRYPTION_FAILED -45
#define GNUTLS_E_PK_SIGN_FAILED -46
#define GNUTLS_E_X509_UNSUPPORTED_CRITICAL_EXTENSION -47
#define GNUTLS_E_KEY_USAGE_VIOLATION -48
#define GNUTLS_E_NO_CERTIFICATE_FOUND -49 /* GNUTLS_A_BAD_CERTIFICATE */
#define GNUTLS_E_INVALID_REQUEST -50
#define GNUTLS_E_SHORT_MEMORY_BUFFER -51
#define GNUTLS_E_INTERRUPTED -52
#define GNUTLS_E_PUSH_ERROR -53
#define GNUTLS_E_PULL_ERROR -54
#define GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER -55 /* GNUTLS_A_ILLEGAL_PARAMETER */
#define GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE -56
#define GNUTLS_E_PKCS1_WRONG_PAD -57
#define GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION -58
#define GNUTLS_E_INTERNAL_ERROR -59
#define GNUTLS_E_DH_PRIME_UNACCEPTABLE -63
#define GNUTLS_E_FILE_ERROR -64
#define GNUTLS_E_TOO_MANY_EMPTY_PACKETS -78
#define GNUTLS_E_UNKNOWN_PK_ALGORITHM -80
#define GNUTLS_E_TOO_MANY_HANDSHAKE_PACKETS -81
#define GNUTLS_E_RECEIVED_DISALLOWED_NAME -82 /* GNUTLS_A_ILLEGAL_PARAMETER */
#define GNUTLS_E_CERTIFICATE_REQUIRED -112 /* GNUTLS_A_CERTIFICATE_REQUIRED */

/* returned if you need to generate temporary RSA
   * parameters. These are needed for export cipher suites.
   */
#define GNUTLS_E_NO_TEMPORARY_RSA_PARAMS -84

#define GNUTLS_E_NO_COMPRESSION_ALGORITHMS -86
#define GNUTLS_E_NO_CIPHER_SUITES -87

#define GNUTLS_E_OPENPGP_GETKEY_FAILED -88
#define GNUTLS_E_PK_SIG_VERIFY_FAILED -89

#define GNUTLS_E_ILLEGAL_SRP_USERNAME -90
#define GNUTLS_E_SRP_PWD_PARSING_ERROR GNUTLS_E_KEYFILE_PARSING_ERROR
#define GNUTLS_E_KEYFILE_PARSING_ERROR -91
#define GNUTLS_E_NO_TEMPORARY_DH_PARAMS -93

/* For certificate and key stuff
   */
#define GNUTLS_E_ASN1_ELEMENT_NOT_FOUND -67
#define GNUTLS_E_ASN1_IDENTIFIER_NOT_FOUND -68
#define GNUTLS_E_ASN1_DER_ERROR -69
#define GNUTLS_E_ASN1_VALUE_NOT_FOUND -70
#define GNUTLS_E_ASN1_GENERIC_ERROR -71
#define GNUTLS_E_ASN1_VALUE_NOT_VALID -72
#define GNUTLS_E_ASN1_TAG_ERROR -73
#define GNUTLS_E_ASN1_TAG_IMPLICIT -74
#define GNUTLS_E_ASN1_TYPE_ANY_ERROR -75
#define GNUTLS_E_ASN1_SYNTAX_ERROR -76
#define GNUTLS_E_ASN1_DER_OVERFLOW -77
#define GNUTLS_E_OPENPGP_UID_REVOKED -79
#define GNUTLS_E_CERTIFICATE_ERROR -43
#define GNUTLS_E_X509_CERTIFICATE_ERROR GNUTLS_E_CERTIFICATE_ERROR
#define GNUTLS_E_CERTIFICATE_KEY_MISMATCH -60
#define GNUTLS_E_UNSUPPORTED_CERTIFICATE_TYPE \
	-61 /* GNUTLS_A_UNSUPPORTED_CERTIFICATE */
#define GNUTLS_E_X509_UNKNOWN_SAN -62
#define GNUTLS_E_OPENPGP_FINGERPRINT_UNSUPPORTED -94
#define GNUTLS_E_X509_UNSUPPORTED_ATTRIBUTE -95
#define GNUTLS_E_UNKNOWN_HASH_ALGORITHM -96
#define GNUTLS_E_UNKNOWN_PKCS_CONTENT_TYPE -97
#define GNUTLS_E_UNKNOWN_PKCS_BAG_TYPE -98
#define GNUTLS_E_INVALID_PASSWORD -99
#define GNUTLS_E_MAC_VERIFY_FAILED -100 /* for PKCS #12 MAC */
#define GNUTLS_E_CONSTRAINT_ERROR -101

#define GNUTLS_E_WARNING_IA_IPHF_RECEIVED -102
#define GNUTLS_E_WARNING_IA_FPHF_RECEIVED -103

#define GNUTLS_E_IA_VERIFY_FAILED -104
#define GNUTLS_E_UNKNOWN_ALGORITHM -105
#define GNUTLS_E_UNSUPPORTED_SIGNATURE_ALGORITHM -106
#define GNUTLS_E_SAFE_RENEGOTIATION_FAILED -107
#define GNUTLS_E_UNSAFE_RENEGOTIATION_DENIED -108
#define GNUTLS_E_UNKNOWN_SRP_USERNAME -109
#define GNUTLS_E_PREMATURE_TERMINATION -110

#define GNUTLS_E_MALFORMED_CIDR -111

#define GNUTLS_E_BASE64_ENCODING_ERROR -201
#define GNUTLS_E_INCOMPATIBLE_GCRYPT_LIBRARY -202 /* obsolete */
#define GNUTLS_E_INCOMPATIBLE_CRYPTO_LIBRARY -202
#define GNUTLS_E_INCOMPATIBLE_LIBTASN1_LIBRARY -203

#define GNUTLS_E_OPENPGP_KEYRING_ERROR -204
#define GNUTLS_E_X509_UNSUPPORTED_OID -205

#define GNUTLS_E_RANDOM_FAILED -206
#define GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR -207

#define GNUTLS_E_OPENPGP_SUBKEY_ERROR -208

#define GNUTLS_E_CRYPTO_ALREADY_REGISTERED GNUTLS_E_ALREADY_REGISTERED
#define GNUTLS_E_ALREADY_REGISTERED -209

#define GNUTLS_E_HANDSHAKE_TOO_LARGE -210

#define GNUTLS_E_CRYPTODEV_IOCTL_ERROR -211
#define GNUTLS_E_CRYPTODEV_DEVICE_ERROR -212

#define GNUTLS_E_CHANNEL_BINDING_NOT_AVAILABLE -213
#define GNUTLS_E_BAD_COOKIE -214
#define GNUTLS_E_OPENPGP_PREFERRED_KEY_ERROR -215
#define GNUTLS_E_INCOMPAT_DSA_KEY_WITH_TLS_PROTOCOL -216
#define GNUTLS_E_INSUFFICIENT_SECURITY -217

#define GNUTLS_E_HEARTBEAT_PONG_RECEIVED -292
#define GNUTLS_E_HEARTBEAT_PING_RECEIVED -293

#define GNUTLS_E_UNRECOGNIZED_NAME -294

/* PKCS11 related */
#define GNUTLS_E_PKCS11_ERROR -300
#define GNUTLS_E_PKCS11_LOAD_ERROR -301
#define GNUTLS_E_PARSING_ERROR -302
#define GNUTLS_E_PKCS11_PIN_ERROR -303

#define GNUTLS_E_PKCS11_SLOT_ERROR -305
#define GNUTLS_E_LOCKING_ERROR -306
#define GNUTLS_E_PKCS11_ATTRIBUTE_ERROR -307
#define GNUTLS_E_PKCS11_DEVICE_ERROR -308
#define GNUTLS_E_PKCS11_DATA_ERROR -309
#define GNUTLS_E_PKCS11_UNSUPPORTED_FEATURE_ERROR -310
#define GNUTLS_E_PKCS11_KEY_ERROR -311
#define GNUTLS_E_PKCS11_PIN_EXPIRED -312
#define GNUTLS_E_PKCS11_PIN_LOCKED -313
#define GNUTLS_E_PKCS11_SESSION_ERROR -314
#define GNUTLS_E_PKCS11_SIGNATURE_ERROR -315
#define GNUTLS_E_PKCS11_TOKEN_ERROR -316
#define GNUTLS_E_PKCS11_USER_ERROR -317

#define GNUTLS_E_CRYPTO_INIT_FAILED -318
#define GNUTLS_E_TIMEDOUT -319
#define GNUTLS_E_USER_ERROR -320
#define GNUTLS_E_ECC_NO_SUPPORTED_CURVES -321
#define GNUTLS_E_ECC_UNSUPPORTED_CURVE -322
#define GNUTLS_E_PKCS11_REQUESTED_OBJECT_NOT_AVAILBLE -323
#define GNUTLS_E_CERTIFICATE_LIST_UNSORTED -324
#define GNUTLS_E_ILLEGAL_PARAMETER -325 /* GNUTLS_A_ILLEGAL_PARAMETER */
#define GNUTLS_E_NO_PRIORITIES_WERE_SET -326
#define GNUTLS_E_X509_UNSUPPORTED_EXTENSION -327
#define GNUTLS_E_SESSION_EOF -328

#define GNUTLS_E_TPM_ERROR -329
#define GNUTLS_E_TPM_KEY_PASSWORD_ERROR -330
#define GNUTLS_E_TPM_SRK_PASSWORD_ERROR -331
#define GNUTLS_E_TPM_SESSION_ERROR -332
#define GNUTLS_E_TPM_KEY_NOT_FOUND -333
#define GNUTLS_E_TPM_UNINITIALIZED -334
#define GNUTLS_E_TPM_NO_LIB -335

#define GNUTLS_E_NO_CERTIFICATE_STATUS -340
#define GNUTLS_E_OCSP_RESPONSE_ERROR -341
#define GNUTLS_E_RANDOM_DEVICE_ERROR -342
#define GNUTLS_E_AUTH_ERROR -343
#define GNUTLS_E_NO_APPLICATION_PROTOCOL -344
#define GNUTLS_E_SOCKETS_INIT_ERROR -345
#define GNUTLS_E_KEY_IMPORT_FAILED -346
#define GNUTLS_E_INAPPROPRIATE_FALLBACK \
	-347 /*GNUTLS_A_INAPPROPRIATE_FALLBACK */
#define GNUTLS_E_CERTIFICATE_VERIFICATION_ERROR -348
#define GNUTLS_E_PRIVKEY_VERIFICATION_ERROR -349
#define GNUTLS_E_UNEXPECTED_EXTENSIONS_LENGTH -350 /*GNUTLS_A_DECODE_ERROR */
#define GNUTLS_E_ASN1_EMBEDDED_NULL_IN_STRING -351

#define GNUTLS_E_SELF_TEST_ERROR -400
#define GNUTLS_E_NO_SELF_TEST -401
#define GNUTLS_E_LIB_IN_ERROR_STATE -402
#define GNUTLS_E_PK_GENERATION_ERROR -403
#define GNUTLS_E_IDNA_ERROR -404

#define GNUTLS_E_NEED_FALLBACK -405
#define GNUTLS_E_SESSION_USER_ID_CHANGED -406
#define GNUTLS_E_HANDSHAKE_DURING_FALSE_START -407
#define GNUTLS_E_UNAVAILABLE_DURING_HANDSHAKE -408
#define GNUTLS_E_PK_INVALID_PUBKEY -409
#define GNUTLS_E_PK_INVALID_PRIVKEY -410
#define GNUTLS_E_NOT_YET_ACTIVATED -411
#define GNUTLS_E_INVALID_UTF8_STRING -412
#define GNUTLS_E_NO_EMBEDDED_DATA -413
#define GNUTLS_E_INVALID_UTF8_EMAIL -414
#define GNUTLS_E_INVALID_PASSWORD_STRING -415
#define GNUTLS_E_CERTIFICATE_TIME_ERROR -416
#define GNUTLS_E_RECORD_OVERFLOW -417 /* GNUTLS_A_RECORD_OVERFLOW */
#define GNUTLS_E_ASN1_TIME_ERROR -418
#define GNUTLS_E_INCOMPATIBLE_SIG_WITH_KEY -419
#define GNUTLS_E_PK_INVALID_PUBKEY_PARAMS -420
#define GNUTLS_E_PK_NO_VALIDATION_PARAMS -421
#define GNUTLS_E_OCSP_MISMATCH_WITH_CERTS -422

#define GNUTLS_E_NO_COMMON_KEY_SHARE -423
#define GNUTLS_E_REAUTH_REQUEST -424
#define GNUTLS_E_TOO_MANY_MATCHES -425
#define GNUTLS_E_CRL_VERIFICATION_ERROR -426
#define GNUTLS_E_MISSING_EXTENSION -427
#define GNUTLS_E_DB_ENTRY_EXISTS -428
#define GNUTLS_E_EARLY_DATA_REJECTED -429
#define GNUTLS_E_X509_DUPLICATE_EXTENSION -430

#define GNUTLS_E_UNIMPLEMENTED_FEATURE -1250

/* Internal errors of the library; will never be returned
 * to a calling application */
#define GNUTLS_E_INT_RET_0 -1251
#define GNUTLS_E_INT_CHECK_AGAIN -1252

#define GNUTLS_E_APPLICATION_ERROR_MAX -65000
#define GNUTLS_E_APPLICATION_ERROR_MIN -65500

#ifdef __cplusplus
}
#endif

#include <gnutls/compat.h>

#endif /* GNUTLS_GNUTLS_H */
