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Diffstat (limited to 'src/liblzma/api/lzma/check.h')
| -rw-r--r-- | src/liblzma/api/lzma/check.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/liblzma/api/lzma/check.h b/src/liblzma/api/lzma/check.h new file mode 100644 index 00000000..4a2a453b --- /dev/null +++ b/src/liblzma/api/lzma/check.h @@ -0,0 +1,128 @@ +/** + * \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 <lzma.h> 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 = 3, + /**< + * CRC64 using the polynomial from the ECMA-182 standard + * + * Size of the Check field: 8 bytes + */ + + LZMA_CHECK_SHA256 = 5 + /**< + * SHA-256 + * + * Size of the Check field: 32 bytes + */ +} lzma_check_type; + + +/** + * \brief Maximum valid Check ID + * + * The .lzma file format specification specifies eight Check IDs (0-7). 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 7 + + +/** + * \brief Check IDs supported by this liblzma build + * + * If lzma_available_checks[n] is true, the Check ID n is supported by this + * liblzma build. You can assume that LZMA_CHECK_NONE and LZMA_CHECK_CRC32 + * are always available. + */ +extern const lzma_bool lzma_available_checks[LZMA_CHECK_ID_MAX + 1]; + + +/** + * \brief Size of the Check field with different Check IDs + * + * Although not all Check IDs have a check algorithm associated, the size of + * every Check is already frozen. This array contains the size (in bytes) of + * the Check field with specified Check ID. The values are taken from the + * section 2.2.2 of the .lzma file format specification: + * { 0, 4, 4, 8, 16, 32, 32, 64 } + */ +extern const uint32_t lzma_check_sizes[LZMA_CHECK_ID_MAX + 1]; + + +/** + * \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); + + +/** + * \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); + + +/* + * SHA256 functions are currently not exported to public API. + * Contact the author if you think it should be. + */ |