Method crcHeader

java/src/cx/fbn/encrypt/EnCrypt.java:323–336

(byte[] bytes)

	// Utility function to return the CRC header of an encoded string.  This is
	// used to verify good decryption and put in front of a new encrypted string
	private String crcHeader(byte[] bytes) {
		CRC32 crc = new CRC32();
		crc.update(bytes);
		int realCRC = (int)crc.getValue();
		
		// The first 4 chars of the hex string will equal the first
		// 4 chars of the decyphered text.  If they match we have a
		// good password.  This is what we return
		realCRC = realCRC ^ (-1);
		realCRC = realCRC >>> 0;
		String hexCRC = Integer.toHexString(realCRC).substring(0,4);
		return hexCRC.toString().toUpperCase();

	}

}