diff options
| author | John Schoenick <[email protected]> | 2015-09-09 18:35:41 -0700 |
|---|---|---|
| committer | John Schoenick <[email protected]> | 2015-09-09 18:35:41 -0700 |
| commit | 0d8dceea4310fde5706b3ce1c70609d72a38efdf (patch) | |
| tree | c831ef32c2c801a5c5a80401736b52c7b5a528ec /sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c | |
| parent | Updated the SDK with the latest code from the TF and HL2 branches. (diff) | |
| download | source-sdk-2013-master.tar.xz source-sdk-2013-master.zip | |
Diffstat (limited to 'sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c')
| -rw-r--r-- | sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c b/sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c new file mode 100644 index 00000000..97738404 --- /dev/null +++ b/sp/src/utils/lzma/C/7zip/Archive/7z_C/7zCrc.c @@ -0,0 +1,76 @@ +/* 7zCrc.c */ + +#include "7zCrc.h" + +#define kCrcPoly 0xEDB88320 + +UInt32 g_CrcTable[256]; + +void InitCrcTable() +{ + UInt32 i; + for (i = 0; i < 256; i++) + { + UInt32 r = i; + int j; + for (j = 0; j < 8; j++) + if (r & 1) + r = (r >> 1) ^ kCrcPoly; + else + r >>= 1; + g_CrcTable[i] = r; + } +} + +void CrcInit(UInt32 *crc) { *crc = 0xFFFFFFFF; } +UInt32 CrcGetDigest(UInt32 *crc) { return *crc ^ 0xFFFFFFFF; } + +void CrcUpdateByte(UInt32 *crc, Byte b) +{ + *crc = g_CrcTable[((Byte)(*crc)) ^ b] ^ (*crc >> 8); +} + +void CrcUpdateUInt16(UInt32 *crc, UInt16 v) +{ + CrcUpdateByte(crc, (Byte)v); + CrcUpdateByte(crc, (Byte)(v >> 8)); +} + +void CrcUpdateUInt32(UInt32 *crc, UInt32 v) +{ + int i; + for (i = 0; i < 4; i++) + CrcUpdateByte(crc, (Byte)(v >> (8 * i))); +} + +void CrcUpdateUInt64(UInt32 *crc, UInt64 v) +{ + int i; + for (i = 0; i < 8; i++) + { + CrcUpdateByte(crc, (Byte)(v)); + v >>= 8; + } +} + +void CrcUpdate(UInt32 *crc, const void *data, size_t size) +{ + UInt32 v = *crc; + const Byte *p = (const Byte *)data; + for (; size > 0 ; size--, p++) + v = g_CrcTable[((Byte)(v)) ^ *p] ^ (v >> 8); + *crc = v; +} + +UInt32 CrcCalculateDigest(const void *data, size_t size) +{ + UInt32 crc; + CrcInit(&crc); + CrcUpdate(&crc, data, size); + return CrcGetDigest(&crc); +} + +int CrcVerifyDigest(UInt32 digest, const void *data, size_t size) +{ + return (CrcCalculateDigest(data, size) == digest); +} |