1 /* Xz.c - Xz
2 2017-05-12 : 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 const Byte XZ_SIG[XZ_SIG_SIZE] = { 0xFD, '7', 'z', 'X', 'Z', 0 };
12 /* const Byte XZ_FOOTER_SIG[XZ_FOOTER_SIG_SIZE] = { 'Y', 'Z' }; */
13
Xz_WriteVarInt(Byte * buf,UInt64 v)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[(size_t)i - 1] &= 0x7F;
24 return i;
25 }
26
Xz_Construct(CXzStream * p)27 void Xz_Construct(CXzStream *p)
28 {
29 p->numBlocks = 0;
30 p->blocks = NULL;
31 p->flags = 0;
32 }
33
Xz_Free(CXzStream * p,ISzAllocPtr alloc)34 void Xz_Free(CXzStream *p, ISzAllocPtr alloc)
35 {
36 ISzAlloc_Free(alloc, p->blocks);
37 p->numBlocks = 0;
38 p->blocks = NULL;
39 }
40
XzFlags_GetCheckSize(CXzStreamFlags f)41 unsigned XzFlags_GetCheckSize(CXzStreamFlags f)
42 {
43 unsigned t = XzFlags_GetCheckType(f);
44 return (t == 0) ? 0 : (4 << ((t - 1) / 3));
45 }
46
XzCheck_Init(CXzCheck * p,unsigned mode)47 void XzCheck_Init(CXzCheck *p, unsigned 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
XzCheck_Update(CXzCheck * p,const void * data,size_t size)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
XzCheck_Final(CXzCheck * p,Byte * digest)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