1/* Xz.c - Xz
22009-04-15 : Igor Pavlov : Public domain */
3
4#include "7zCrc.h"
5#include "CpuArch.h"
6#include "Xz.h"
7#include "XzCrc64.h"
8
9Byte XZ_SIG[XZ_SIG_SIZE] = { 0xFD, '7', 'z', 'X', 'Z', 0 };
10Byte XZ_FOOTER_SIG[XZ_FOOTER_SIG_SIZE] = { 'Y', 'Z' };
11
12unsigned Xz_WriteVarInt(Byte *buf, UInt64 v)
13{
14  unsigned i = 0;
15  do
16  {
17    buf[i++] = (Byte)((v & 0x7F) | 0x80);
18    v >>= 7;
19  }
20  while (v != 0);
21  buf[i - 1] &= 0x7F;
22  return i;
23}
24
25void Xz_Construct(CXzStream *p)
26{
27  p->numBlocks = p->numBlocksAllocated = 0;
28  p->blocks = 0;
29  p->flags = 0;
30}
31
32void Xz_Free(CXzStream *p, ISzAlloc *alloc)
33{
34  alloc->Free(alloc, p->blocks);
35  p->numBlocks = p->numBlocksAllocated = 0;
36  p->blocks = 0;
37}
38
39unsigned XzFlags_GetCheckSize(CXzStreamFlags f)
40{
41  int t = XzFlags_GetCheckType(f);
42  return (t == 0) ? 0 : (4 << ((t - 1) / 3));
43}
44
45void XzCheck_Init(CXzCheck *p, int mode)
46{
47  p->mode = mode;
48  switch (mode)
49  {
50    case XZ_CHECK_CRC32: p->crc = CRC_INIT_VAL; break;
51    case XZ_CHECK_CRC64: p->crc64 = CRC64_INIT_VAL; break;
52    case XZ_CHECK_SHA256: Sha256_Init(&p->sha); break;
53  }
54}
55
56void XzCheck_Update(CXzCheck *p, const void *data, size_t size)
57{
58  switch (p->mode)
59  {
60    case XZ_CHECK_CRC32: p->crc = CrcUpdate(p->crc, data, size); break;
61    case XZ_CHECK_CRC64: p->crc64 = Crc64Update(p->crc64, data, size); break;
62    case XZ_CHECK_SHA256: Sha256_Update(&p->sha, (const Byte *)data, size); break;
63  }
64}
65
66int XzCheck_Final(CXzCheck *p, Byte *digest)
67{
68  switch (p->mode)
69  {
70    case XZ_CHECK_CRC32:
71      SetUi32(digest, CRC_GET_DIGEST(p->crc));
72      break;
73    case XZ_CHECK_CRC64:
74    {
75      int i;
76      UInt64 v = CRC64_GET_DIGEST(p->crc64);
77      for (i = 0; i < 8; i++, v >>= 8)
78        digest[i] = (Byte)(v & 0xFF);
79      break;
80    }
81    case XZ_CHECK_SHA256:
82      Sha256_Final(&p->sha, digest);
83      break;
84    default:
85      return 0;
86  }
87  return 1;
88}
89