You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
72 lines
1.9 KiB
72 lines
1.9 KiB
package Common;
|
|
|
|
public class CRC {
|
|
public static final int[] Table = new int[256];
|
|
|
|
static {
|
|
for (int i = 0; i < 256; i++) {
|
|
int r = i;
|
|
for (int j = 0; j < 8; j++) {
|
|
if ((r & 1) != 0)
|
|
r = (r >>> 1) ^ 0xEDB88320;
|
|
else
|
|
r >>>= 1;
|
|
}
|
|
Table[i] = r;
|
|
}
|
|
}
|
|
|
|
int _value = -1;
|
|
|
|
public void Init() {
|
|
_value = -1;
|
|
}
|
|
|
|
public void UpdateByte(int b) {
|
|
_value = Table[(_value ^ b) & 0xFF] ^ (_value >>> 8);
|
|
}
|
|
|
|
public void UpdateUInt32(int v) {
|
|
for (int i = 0; i < 4; i++)
|
|
UpdateByte((v >> (8 * i)) & 0xFF );
|
|
}
|
|
|
|
public void UpdateUInt64(long v) {
|
|
for (int i = 0; i < 8; i++)
|
|
UpdateByte((int)((v >> (8 * i))) & 0xFF);
|
|
}
|
|
|
|
public int GetDigest() {
|
|
return _value ^ (-1);
|
|
}
|
|
|
|
public void Update(byte[] data, int size) {
|
|
for (int i = 0; i < size; i++)
|
|
_value = Table[(_value ^ data[i]) & 0xFF] ^ (_value >>> 8);
|
|
}
|
|
|
|
public void Update(byte[] data) {
|
|
for (int i = 0; i < data.length; i++)
|
|
_value = Table[(_value ^ data[i]) & 0xFF] ^ (_value >>> 8);
|
|
}
|
|
|
|
public void Update(byte[] data, int offset, int size) {
|
|
for (int i = 0; i < size; i++)
|
|
_value = Table[(_value ^ data[offset + i]) & 0xFF] ^ (_value >>> 8);
|
|
}
|
|
|
|
public static int CalculateDigest(byte [] data, int size) {
|
|
CRC crc = new CRC();
|
|
crc.Update(data, size);
|
|
return crc.GetDigest();
|
|
}
|
|
|
|
public static boolean VerifyDigest(int digest, byte [] data, int size) {
|
|
return (CalculateDigest(data, size) == digest);
|
|
}
|
|
|
|
public String toString() {
|
|
return Integer.toHexString(GetDigest());
|
|
}
|
|
}
|