/** * \file lzma/check.h * \brief Integrity checks * * \author Copyright (C) 1999-2006 Igor Pavlov * \author Copyright (C) 2007 Lasse Collin * * This library 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. */ #ifndef LZMA_H_INTERNAL # error Never include this file directly. Use instead. #endif /** * \brief Type of the Check * * The .lzma format supports multiple types of Checks that are calculated * from the uncompressed data (unless it is empty; then it's calculated * from Block Header). */ typedef enum { LZMA_CHECK_NONE = 0, /**< * No Check is calculated. * * Size of the Check field: 0 bytes */ LZMA_CHECK_CRC32 = 1, /**< * CRC32 using the polynomial from the IEEE 802.3 standard * * Size of the Check field: 4 bytes */ LZMA_CHECK_CRC64 = 4, /**< * CRC64 using the polynomial from the ECMA-182 standard * * Size of the Check field: 8 bytes */ LZMA_CHECK_SHA256 = 10 /**< * SHA-256 * * Size of the Check field: 32 bytes */ } lzma_check; /** * \brief Maximum valid Check ID * * The .lzma file format specification specifies eight Check IDs (0-15). Some * of them are only reserved i.e. no actual Check algorithm has been assigned. * Still liblzma accepts any of these eight IDs for future compatibility * when decoding files. If a valid but unsupported Check ID is detected, * liblzma indicates a warning with LZMA_UNSUPPORTED_CHECK. * * FIXME bad desc */ #define LZMA_CHECK_ID_MAX 15 /** * \brief Maximum size of a Check field */ #define LZMA_CHECK_SIZE_MAX 64 /** * \brief Test if the given Check ID is supported * * Returns true if the given Check ID is supported by this liblzma build. * Otherwise false is returned. It is safe to call this with a value that * is not in the range [0, 15]; in that case the return value is always false. */ extern lzma_bool lzma_check_is_supported(lzma_check check) lzma_attr_const; /** * \brief Get the size of the Check field with given Check ID * * Although not all Check IDs have a check algorithm associated, the size of * every Check is already frozen. This function returns the size (in bytes) of * the Check field with the specified Check ID. The values are taken from the * section 2.1.1.2 of the .lzma file format specification: * { 0, 4, 4, 4, 8, 8, 8, 16, 16, 16, 32, 32, 32, 64, 64, 64 } * * If the argument is not in the range [0, 15], UINT32_MAX is returned. */ extern uint32_t lzma_check_size(lzma_check check) lzma_attr_const; /** * \brief Calculate CRC32 * * Calculates CRC32 using the polynomial from the IEEE 802.3 standard. * * \param buf Pointer to the input buffer * \param size Size of the input buffer * \param crc Previously returned CRC value. This is used to * calculate the CRC of a big buffer in smaller chunks. * Set to zero when there is no previous value. * * \return Updated CRC value, which can be passed to this function * again to continue CRC calculation. */ extern uint32_t lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) lzma_attr_pure; /** * \brief Calculate CRC64 * * Calculates CRC64 using the polynomial from the ECMA-182 standard. * * This function is used similarly to lzma_crc32(). See its documentation. */ extern uint64_t lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc) lzma_attr_pure; /* * SHA256 functions are currently not exported to public API. * Contact the author if you think it should be. */ /** * \brief Get the type of the integrity check * * This function can be called only immediatelly after lzma_code() has * returned LZMA_NO_CHECK, LZMA_UNSUPPORTED_CHECK, or LZMA_GET_CHECK. * Calling this function in any other situation has undefined behavior. */ extern lzma_check lzma_get_check(const lzma_stream *strm);