1/* Xz.c - Xz
 22017-05-12 : 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
11const 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
14unsigned 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
27void Xz_Construct(CXzStream *p)
28{
29  p->numBlocks = 0;
30  p->blocks = NULL;
31  p->flags = 0;
32}
33
34void Xz_Free(CXzStream *p, ISzAllocPtr alloc)
35{
36  ISzAlloc_Free(alloc, p->blocks);
37  p->numBlocks = 0;
38  p->blocks = NULL;
39}
40
41unsigned XzFlags_GetCheckSize(CXzStreamFlags f)
42{
43  unsigned t = XzFlags_GetCheckType(f);
44  return (t == 0) ? 0 : (4 << ((t - 1) / 3));
45}
46
47void 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
58void 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
68int 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}