Google
Edit File: hmac.h
/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ /*! * \file isc/hmac.h * \brief This is the header for for message authentication code. */ #pragma once #include <isc/lang.h> #include <isc/md.h> #include <isc/platform.h> #include <isc/result.h> #include <isc/types.h> typedef void isc_hmac_t; /** * isc_hmac: * @type: the digest type * @key: the key * @keylen: the length of the key * @buf: data to hash * @len: length of the data to hash * @digest: the output buffer * @digestlen: the length of the data written to @digest * * This function computes the message authentication code using a digest type * @type with key @key which is @keylen bytes long from data in @buf which is * @len bytes long, and places the output into @digest, which must have space * for the hash function output (use ISC_MAX_MD_SIZE if unsure). If the * @digestlen parameter is not NULL then the number of bytes of data written * (i.e. the length of the digest) will be written to the @digestlen. */ isc_result_t isc_hmac(const isc_md_type_t *type, const void *key, const int keylen, const unsigned char *buf, const size_t len, unsigned char *digest, unsigned int *digestlen); /** * isc_hmac_new: * * This function allocates, initializes and returns HMAC context. */ isc_hmac_t * isc_hmac_new(void); /** * isc_hmac_free: * @md: HMAC context * * This function cleans up HMAC context and frees up the space allocated to it. */ void isc_hmac_free(isc_hmac_t *hmac); /** * isc_hmac_init: * @md: HMAC context * @key: HMAC key * @keylen: HMAC key length * @type: digest type * * This function sets up HMAC context to use a hash function of @type and key * @key which is @keylen bytes long. */ isc_result_t isc_hmac_init(isc_hmac_t *hmac, const void *key, size_t keylen, const isc_md_type_t *type); /** * isc_hmac_reset: * @hmac: HMAC context * * This function resets the HMAC context. This can be used to reuse an already * existing context. */ isc_result_t isc_hmac_reset(isc_hmac_t *hmac); /** * isc_hmac_update: * @hmac: HMAC context * @buf: data to hash * @len: length of the data to hash * * This function can be called repeatedly with chunks of the message @buf to be * authenticated which is @len bytes long. */ isc_result_t isc_hmac_update(isc_hmac_t *hmac, const unsigned char *buf, const size_t len); /** * isc_hmac_final: * @hmac: HMAC context * @digest: the output buffer * @digestlen: the length of the data written to @digest * * This function retrieves the message authentication code from @hmac and places * it in @digest, which must have space for the hash function output. If the * @digestlen parameter is not NULL then the number of bytes of data written * (i.e. the length of the digest) will be written to the @digestlen. After * calling this function no additional calls to isc_hmac_update() can be made. */ isc_result_t isc_hmac_final(isc_hmac_t *hmac, unsigned char *digest, unsigned int *digestlen); /** * isc_hmac_md_type: * @hmac: HMAC context * * This function return the isc_md_type_t previously set for the supplied * HMAC context or NULL if no isc_md_type_t has been set. */ const isc_md_type_t * isc_hmac_get_md_type(isc_hmac_t *hmac); /** * isc_hmac_get_size: * * This function return the size of the message digest when passed an isc_hmac_t * structure, i.e. the size of the hash. */ size_t isc_hmac_get_size(isc_hmac_t *hmac); /** * isc_hmac_get_block_size: * * This function return the block size of the message digest when passed an * isc_hmac_t structure. */ int isc_hmac_get_block_size(isc_hmac_t *hmac);