1 /* Xz.c - Xz 2 2009-04-15 : Igor Pavlov : Public domain */ 3 4 #include "Precomp.h" 5 6 #include "7zCrc.h" 7 #include "CpuArch.h" 8 #include "Xz.h" 9 #include "XzCrc64.h" 10 11 Byte XZ_SIG[XZ_SIG_SIZE] = { 0xFD, '7', 'z', 'X', 'Z', 0 }; 12 Byte XZ_FOOTER_SIG[XZ_FOOTER_SIG_SIZE] = { 'Y', 'Z' }; 13 14 unsigned Xz_WriteVarInt(Byte *buf, UInt64 v) 15 { 16 unsigned i = 0; 17 do 18 { 19 buf[i++] = (Byte)((v & 0x7F) | 0x80); 20 v >>= 7; 21 } 22 while (v != 0); 23 buf[i - 1] &= 0x7F; 24 return i; 25 } 26 27 void Xz_Construct(CXzStream *p) 28 { 29 p->numBlocks = p->numBlocksAllocated = 0; 30 p->blocks = 0; 31 p->flags = 0; 32 } 33 34 void Xz_Free(CXzStream *p, ISzAlloc *alloc) 35 { 36 alloc->Free(alloc, p->blocks); 37 p->numBlocks = p->numBlocksAllocated = 0; 38 p->blocks = 0; 39 } 40 41 unsigned XzFlags_GetCheckSize(CXzStreamFlags f) 42 { 43 int t = XzFlags_GetCheckType(f); 44 return (t == 0) ? 0 : (4 << ((t - 1) / 3)); 45 } 46 47 void XzCheck_Init(CXzCheck *p, int mode) 48 { 49 p->mode = mode; 50 switch (mode) 51 { 52 case XZ_CHECK_CRC32: p->crc = CRC_INIT_VAL; break; 53 case XZ_CHECK_CRC64: p->crc64 = CRC64_INIT_VAL; break; 54 case XZ_CHECK_SHA256: Sha256_Init(&p->sha); break; 55 } 56 } 57 58 void XzCheck_Update(CXzCheck *p, const void *data, size_t size) 59 { 60 switch (p->mode) 61 { 62 case XZ_CHECK_CRC32: p->crc = CrcUpdate(p->crc, data, size); break; 63 case XZ_CHECK_CRC64: p->crc64 = Crc64Update(p->crc64, data, size); break; 64 case XZ_CHECK_SHA256: Sha256_Update(&p->sha, (const Byte *)data, size); break; 65 } 66 } 67 68 int XzCheck_Final(CXzCheck *p, Byte *digest) 69 { 70 switch (p->mode) 71 { 72 case XZ_CHECK_CRC32: 73 SetUi32(digest, CRC_GET_DIGEST(p->crc)); 74 break; 75 case XZ_CHECK_CRC64: 76 { 77 int i; 78 UInt64 v = CRC64_GET_DIGEST(p->crc64); 79 for (i = 0; i < 8; i++, v >>= 8) 80 digest[i] = (Byte)(v & 0xFF); 81 break; 82 } 83 case XZ_CHECK_SHA256: 84 Sha256_Final(&p->sha, digest); 85 break; 86 default: 87 return 0; 88 } 89 return 1; 90 } 91
