blob: 62bb8478ba9a754dc504388da7f2fce676ce7ee3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
// Common/CRC.cs
namespace SevenZip
{
class CRC
{
public static readonly uint[] Table;
static CRC()
{
Table = new uint[256];
const uint kPoly = 0xEDB88320;
for (uint i = 0; i < 256; i++)
{
uint r = i;
for (int j = 0; j < 8; j++)
if ((r & 1) != 0)
r = (r >> 1) ^ kPoly;
else
r >>= 1;
Table[i] = r;
}
}
uint _value = 0xFFFFFFFF;
public void Init() { _value = 0xFFFFFFFF; }
public void UpdateByte(byte b)
{
_value = Table[(((byte)(_value)) ^ b)] ^ (_value >> 8);
}
public void Update(byte[] data, uint offset, uint size)
{
for (uint i = 0; i < size; i++)
_value = Table[(((byte)(_value)) ^ data[offset + i])] ^ (_value >> 8);
}
public uint GetDigest() { return _value ^ 0xFFFFFFFF; }
static uint CalculateDigest(byte[] data, uint offset, uint size)
{
CRC crc = new CRC();
// crc.Init();
crc.Update(data, offset, size);
return crc.GetDigest();
}
static bool VerifyDigest(uint digest, byte[] data, uint offset, uint size)
{
return (CalculateDigest(data, offset, size) == digest);
}
}
}
|
