java/org/rivoreo/crypto/ECIES_XTEA.java

/*
 * Copyright 2015-2016 Rivoreo
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 */

package org.rivoreo.crypto;

public class ECIES_XTEA extends ECIES {
	public ECIES_XTEA(SECTDomainParameters dp) {
		super(dp);
	}

	private void debug_print_integers(int[] a, int len) {
		for(int i=0; i<a.length; i++) System.err.printf("0x%x\n", a[i]);
	}

/*
	private void init_key(int[] k, int offset, final byte[] key) {
		System.err.printf("method: org.rivoreo.crypto.ECIES_XTEA::init_key(int[%d], %d, final byte[%d])\n", k.length, offset, key.length);
		k[offset] = unsigned_bytes_to_int(key, 0);
		k[offset + 1] = unsigned_bytes_to_int(key, 4);
		k[offset + 2] = unsigned_bytes_to_int(key, 8);
		k[offset + 3] = unsigned_bytes_to_int(key, 12);
	}
*/

	private void init_key(int[] k, final byte[] key) {
		//init_key(k, 0, key);
		k[0] = unsigned_bytes_to_int(key, 0);
		k[1] = unsigned_bytes_to_int(key, 4);
		k[2] = unsigned_bytes_to_int(key, 8);
		k[3] = unsigned_bytes_to_int(key, 12);
	}

/*
	private void encipher_block(byte[] data, final int[] k) {
		System.err.printf("method: org.rivoreo.crypto.ECIES_XTEA::encipher_block(byte[%d], final int[%d])\n", data.length, k.length);
		long sum = 0, delta = 0x9e3779b9l;
		long y = unsigned_bytes_to_int(data, 0), z = unsigned_bytes_to_int(data, 4);
		//System.err.printf("encipher_block: y = %d, z = %d\n", y, z);
		System.err.printf("encipher_block: delta = %d\n", delta);
		for(int i = 0; i < 32; i++) {
			y += ((z << 4 ^ z >>> 5) + z) ^ (sum + k[(int)(sum & 3)]);
			System.err.printf("encipher_block: y = %d\n", y);
			sum += delta;
			System.err.printf("encipher_block: sum = %d\n", sum);
			z += ((y << 4 ^ y >>> 5) + y) ^ (sum + k[(int)(sum >>> 11 & 3)]);
			System.err.printf("encipher_block: z = %d\n", z);
		}
		int_to_bytes(data, 0, (int)y);
		int_to_bytes(data, 4, (int)z);
	}
*/

	private void encipher_block(byte[] data, final int[] k) {
		System.err.printf("method: org.rivoreo.crypto.ECIES_XTEA::encipher_block(byte[%d], final int[%d])\n", data.length, k.length);
		long sum = 0, delta = 0x9e3779b9l;
		int y = unsigned_bytes_to_int(data, 0), z = unsigned_bytes_to_int(data, 4);
		//System.err.printf("encipher_block: y = %d, z = %d\n", y, z);
		//System.err.printf("encipher_block: delta = %d\n", delta);
		for(int i = 0; i < 32; i++) {
			//y += ((z << 4 ^ z >>> 5) + z) ^ (sum + k[(int)(sum & 3)]);
			y = (int)((long)y + (((z << 4 ^ z >>> 5) + unsigned_int_to_long(z)) ^ (sum + unsigned_int_to_long(k[(int)(sum & 3)]))));
		//	System.err.printf("encipher_block: y = %d\n", y);
			sum += delta;
		//	System.err.printf("encipher_block: sum = %d\n", sum);
			z += ((y << 4 ^ y >>> 5) + y) ^ (sum + unsigned_int_to_long(k[(int)(sum >>> 11 & 3)]));
		//	System.err.printf("encipher_block: z = %d\n", z);
		}
		int_to_bytes(data, 0, (int)y);
		int_to_bytes(data, 4, (int)z);
	}

	protected int get_symmetric_key_bytes() {
		return 16;
	}

	protected void ctr_crypt(byte[] data, int len, final byte[] key) {
		System.err.printf("method: org.rivoreo.crypto.ECIES_XTEA::ctr_crypt(int[%d], %d, final byte[%d])\n", data.length, len, key.length);
		int[] k = new int[4];
		int ctr = 0;
		int blen, i, di = 0;
		byte[] buf = new byte[8];
		init_key(k, key);
		while(len > 0) {
			int_to_bytes(buf, 0, 0);
			int_to_bytes(buf, 4, ctr++);
			encipher_block(buf, k);
			blen = Math.min(8, len);
			for(i = 0; i < blen; i++) {
				//*data++ ^= buf[i];
				data[di++] ^= buf[i];
			}
			len -= blen;
		}
	}

	protected void cbc_mac(byte[] mac, final byte[] data, int len, final byte[] key) {
		int[] k = new int[4];
		int blen, i, di = 0;
		init_key(k, key);
		int_to_bytes(mac, 0, 0);
		int_to_bytes(mac, 4, len);
		encipher_block(mac, k);
		while(len > 0) {
			blen = Math.min(ECIES_CHUNK_OVERHEAD, len);
			for(i = 0; i < blen; i++) {
				//mac[i] ^= *data++;
				mac[i] ^= data[di++];
			}
			encipher_block(mac, k);
			len -= blen;
		}
	}

	protected void davies_meyer(byte[] out, final byte[] in, int ilen) {
		System.err.printf("method: org.rivoreo.crypto.ECIES_XTEA::davies_meyer(byte[%d], final byte[%d], %d)\n", out.length, in.length, ilen);
		int[] k = new int[4];
		byte[] buf = new byte[8];
		int i, offset = 0;
		//memset(out, 0, 8);
		for(i = 0; i < 8; i++) out[i] = 0;
		while(ilen-- > 0) {
			//System.err.printf("davies_meyer: ilen = %d\n", ilen);
			//init_key(k, in, offset);
			init_key(k, sub_byte_array(in, offset));
			//debug_print_integers(k, 4);
			//System.err.println();
			//memcpy(buf, out, 8);
			for(i = 0; i < 8; i++) buf[i] = out[i];
			encipher_block(buf, k);
			//debug_print_bytes(buf, 8);
			for(i = 0; i < 8; i++) out[i] ^= buf[i];
			offset += 16;
		}
	}
}