Created
January 23, 2011 00:42
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Adjust parity
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public class Util { | |
/** | |
* DES Keys use the LSB as the odd parity bit. This method can | |
* be used enforce correct parity. | |
* | |
* @param bytes the byte array to set the odd parity on. | |
*/ | |
public static void adjustDESParity (byte[] bytes) { | |
for (int i = 0; i < bytes.length; i++) { | |
int b = bytes[i]; | |
bytes[i] = (byte)((b & 0xfe) | ((((b >> 1) ^ (b >> 2) ^ (b >> 3) ^ (b >> 4) ^ (b >> 5) ^ (b >> 6) ^ (b >> 7)) ^ 0x01) & 0x01)); | |
} | |
} | |
/** | |
* DES Keys use the LSB as the odd parity bit. This method checks | |
* whether the parity is adjusted or not | |
* | |
* @param bytes the byte[] to be checked | |
* @return true if parity is adjusted else returns false | |
*/ | |
public static boolean isDESParityAdjusted (byte[] bytes) { | |
byte[] correct = (byte[])bytes.clone(); | |
adjustDESParity(correct); | |
return Arrays.equals(bytes, correct); | |
} | |
} | |
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