check.h revision 213700 
1///////////////////////////////////////////////////////////////////////////////
2//
3/// \file       check.h
4/// \brief      Internal API to different integrity check functions
5//
6//  Author:     Lasse Collin
7//
8//  This file has been put into the public domain.
9//  You can do whatever you want with this file.
10//
11///////////////////////////////////////////////////////////////////////////////
12
13#ifndef LZMA_CHECK_H
14#define LZMA_CHECK_H
15
16#include "common.h"
17
18
19// Index hashing needs the best possible hash function (preferably
20// a cryptographic hash) for maximum reliability.
21#if defined(HAVE_CHECK_SHA256)
22#	define LZMA_CHECK_BEST LZMA_CHECK_SHA256
23#elif defined(HAVE_CHECK_CRC64)
24#	define LZMA_CHECK_BEST LZMA_CHECK_CRC64
25#else
26#	define LZMA_CHECK_BEST LZMA_CHECK_CRC32
27#endif
28
29
30/// \brief      Structure to hold internal state of the check being calculated
31///
32/// \note       This is not in the public API because this structure may
33///             change in future if new integrity check algorithms are added.
34typedef struct {
35	/// Buffer to hold the final result and a temporary buffer for SHA256.
36	union {
37		uint8_t u8[64];
38		uint32_t u32[16];
39		uint64_t u64[8];
40	} buffer;
41
42	/// Check-specific data
43	union {
44		uint32_t crc32;
45		uint64_t crc64;
46
47		struct {
48			/// Internal state
49			uint32_t state[8];
50
51			/// Size of the message excluding padding
52			uint64_t size;
53		} sha256;
54	} state;
55
56} lzma_check_state;
57
58
59/// lzma_crc32_table[0] is needed by LZ encoder so we need to keep
60/// the array two-dimensional.
61#ifdef HAVE_SMALL
62extern uint32_t lzma_crc32_table[1][256];
63extern void lzma_crc32_init(void);
64#else
65extern const uint32_t lzma_crc32_table[8][256];
66extern const uint64_t lzma_crc64_table[4][256];
67#endif
68
69
70/// \brief      Initialize *check depending on type
71///
72/// \return     LZMA_OK on success. LZMA_UNSUPPORTED_CHECK if the type is not
73///             supported by the current version or build of liblzma.
74///             LZMA_PROG_ERROR if type > LZMA_CHECK_ID_MAX.
75extern void lzma_check_init(lzma_check_state *check, lzma_check type);
76
77/// Update the check state
78extern void lzma_check_update(lzma_check_state *check, lzma_check type,
79		const uint8_t *buf, size_t size);
80
81/// Finish the check calculation and store the result to check->buffer.u8.
82extern void lzma_check_finish(lzma_check_state *check, lzma_check type);
83
84
85/// Prepare SHA-256 state for new input.
86extern void lzma_sha256_init(lzma_check_state *check);
87
88/// Update the SHA-256 hash state
89extern void lzma_sha256_update(
90		const uint8_t *buf, size_t size, lzma_check_state *check);
91
92/// Finish the SHA-256 calculation and store the result to check->buffer.u8.
93extern void lzma_sha256_finish(lzma_check_state *check);
94
95#endif
96