银联mac算法, 示例

SampleSM.java

// 示例代码
class SampleSM {
	
	...

	public byte[] generateUnpayMACImpl(byte[] data, SecureDESKey kd)
			throws SMException {
		data = ISOUtil.concat(data, new byte[8]);
		int len = data.length - data.length % 8;
		if (data.length != len) {
			data = ISOUtil.trim(data, len);
		} else {
			data = ISOUtil.trim(data, len - 8);
		}
		byte[] mac = new byte[8];
		byte[] tmp = new byte[8];
		byte[] block = new byte[8];

		for (int i = 0; i < data.length / 8; i++) {
			System.arraycopy(data, i * 8, tmp, 0, 8);
			block = ISOUtil.xor(block, tmp);
		}

		block = ISOUtil.hexString(block).getBytes();
		System.arraycopy(block, 0, tmp, 0, 8);

		Key mak = decryptFromLMK(kd);

		mac = this.jceHandler.encryptData(tmp, mak);

		System.arraycopy(block, 8, tmp, 0, 8);
		tmp = ISOUtil.xor(mac, tmp);
		mac = this.jceHandler.encryptData(tmp, mak);

		block = ISOUtil.hexString(mac).getBytes();
		System.arraycopy(block, 0, mac, 0, 8);

		return mac;
	}


	...

}