diff options
Diffstat (limited to 'src/liblzma/api/lzma/check.h')
| -rw-r--r-- | src/liblzma/api/lzma/check.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/liblzma/api/lzma/check.h b/src/liblzma/api/lzma/check.h new file mode 100644 index 0000000..b37197d --- /dev/null +++ b/src/liblzma/api/lzma/check.h @@ -0,0 +1,164 @@ +/** + * \file lzma/check.h + * \brief Integrity checks + * \note Never include this file directly. Use <lzma.h> instead. + */ + +/* + * Author: Lasse Collin + * + * This file has been put into the public domain. + * You can do whatever you want with this file. + */ + +#ifndef LZMA_H_INTERNAL +# error Never include this file directly. Use <lzma.h> instead. +#endif + + +/** + * \brief Type of the integrity check (Check ID) + * + * The .xz format supports multiple types of checks that are calculated + * from the uncompressed data. They vary in both speed and ability to + * detect errors. + */ +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 .xz file format specification specifies 16 Check IDs (0-15). Some + * of them are only reserved, that is, no actual Check algorithm has been + * assigned. When decoding, liblzma still accepts unknown Check IDs for + * future compatibility. If a valid but unsupported Check ID is detected, + * liblzma can indicate a warning; see the flags LZMA_TELL_NO_CHECK, + * LZMA_TELL_UNSUPPORTED_CHECK, and LZMA_TELL_ANY_CHECK in container.h. + */ +#define LZMA_CHECK_ID_MAX 15 + + +/** + * \brief Test if the given Check ID is supported + * + * LZMA_CHECK_NONE and LZMA_CHECK_CRC32 are always supported (even if + * liblzma is built with limited features). + * + * \note 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. + * + * \param check Check ID + * + * \return lzma_bool: + * - true if Check ID is supported by this liblzma build. + * - false otherwise. + */ +extern LZMA_API(lzma_bool) lzma_check_is_supported(lzma_check check) + lzma_nothrow lzma_attr_const; + + +/** + * \brief Get the size of the Check field with the 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: + * { 0, 4, 4, 4, 8, 8, 8, 16, 16, 16, 32, 32, 32, 64, 64, 64 } + * + * \param check Check ID + * + * \return Size of the Check field in bytes. If the argument is not in + * the range [0, 15], UINT32_MAX is returned. + */ +extern LZMA_API(uint32_t) lzma_check_size(lzma_check check) + lzma_nothrow lzma_attr_const; + + +/** + * \brief Maximum size of a Check field + */ +#define LZMA_CHECK_SIZE_MAX 64 + + +/** + * \brief Calculate CRC32 + * + * Calculate 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 starting a new calculation. + * + * \return Updated CRC value, which can be passed to this function + * again to continue CRC calculation. + */ +extern LZMA_API(uint32_t) lzma_crc32( + const uint8_t *buf, size_t size, uint32_t crc) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Calculate CRC64 + * + * Calculate CRC64 using the polynomial from the ECMA-182 standard. + * + * This function is used similarly to lzma_crc32(). + * + * \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 starting a new calculation. + * + * \return Updated CRC value, which can be passed to this function + * again to continue CRC calculation. + */ +extern LZMA_API(uint64_t) lzma_crc64( + const uint8_t *buf, size_t size, uint64_t crc) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Get the type of the integrity check + * + * This function can be called only immediately 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. + * + * \param strm Pointer to lzma_stream meeting the above conditions. + * + * \return Check ID in the lzma_stream, or undefined if called improperly. + */ +extern LZMA_API(lzma_check) lzma_get_check(const lzma_stream *strm) + lzma_nothrow; |