private void testBlockCiphers() {
for (String algorithm : new String[] {"AES", "XTEA", "FOG"}) {
byte[] test = new byte[4096];
BlockCipher cipher = CipherFactory.getBlockCipher(algorithm);
cipher.setKey("abcdefghijklmnop".getBytes());
for (int i = 0; i < 10; i++) {
cipher.encrypt(test, 0, test.length);
}
assertFalse(isCompressible(test));
for (int i = 0; i < 10; i++) {
cipher.decrypt(test, 0, test.length);
}
assertEquals(new byte[test.length], test);
assertTrue(isCompressible(test));
}
}
private byte[] initTweak(long id) {
byte[] tweak = new byte[CIPHER_BLOCK_SIZE];
for (int j = 0; j < CIPHER_BLOCK_SIZE; j++, id >>>= 8) {
tweak[j] = (byte) (id & 0xff);
}
cipher.encrypt(tweak, 0, CIPHER_BLOCK_SIZE);
return tweak;
}
/**
* Encrypt the data.
*
* @param id the (sector) id
* @param len the number of bytes
* @param data the data
* @param offset the offset within the data
*/
void encrypt(long id, int len, byte[] data, int offset) {
byte[] tweak = initTweak(id);
int i = 0;
for (; i + CIPHER_BLOCK_SIZE <= len; i += CIPHER_BLOCK_SIZE) {
if (i > 0) {
updateTweak(tweak);
}
xorTweak(data, i + offset, tweak);
cipher.encrypt(data, i + offset, CIPHER_BLOCK_SIZE);
xorTweak(data, i + offset, tweak);
}
if (i < len) {
updateTweak(tweak);
swap(data, i + offset, i - CIPHER_BLOCK_SIZE + offset, len - i);
xorTweak(data, i - CIPHER_BLOCK_SIZE + offset, tweak);
cipher.encrypt(data, i - CIPHER_BLOCK_SIZE + offset, CIPHER_BLOCK_SIZE);
xorTweak(data, i - CIPHER_BLOCK_SIZE + offset, tweak);
}
}
/**
* Decrypt the data.
*
* @param id the (sector) id
* @param len the number of bytes
* @param data the data
* @param offset the offset within the data
*/
void decrypt(long id, int len, byte[] data, int offset) {
byte[] tweak = initTweak(id), tweakEnd = tweak;
int i = 0;
for (; i + CIPHER_BLOCK_SIZE <= len; i += CIPHER_BLOCK_SIZE) {
if (i > 0) {
updateTweak(tweak);
if (i + CIPHER_BLOCK_SIZE + CIPHER_BLOCK_SIZE > len && i + CIPHER_BLOCK_SIZE < len) {
tweakEnd = Arrays.copyOf(tweak, CIPHER_BLOCK_SIZE);
updateTweak(tweak);
}
}
xorTweak(data, i + offset, tweak);
cipher.decrypt(data, i + offset, CIPHER_BLOCK_SIZE);
xorTweak(data, i + offset, tweak);
}
if (i < len) {
swap(data, i, i - CIPHER_BLOCK_SIZE + offset, len - i + offset);
xorTweak(data, i - CIPHER_BLOCK_SIZE + offset, tweakEnd);
cipher.decrypt(data, i - CIPHER_BLOCK_SIZE + offset, CIPHER_BLOCK_SIZE);
xorTweak(data, i - CIPHER_BLOCK_SIZE + offset, tweakEnd);
}
}
private void testAES() {
BlockCipher test = CipherFactory.getBlockCipher("AES");
String r;
byte[] data;
// test vector from
// http://csrc.nist.gov/groups/STM/cavp/documents/aes/KAT_AES.zip
// ECBVarTxt128e.txt
// COUNT = 0
test.setKey(StringUtils.convertHexToBytes("00000000000000000000000000000000"));
data = StringUtils.convertHexToBytes("80000000000000000000000000000000");
test.encrypt(data, 0, data.length);
r = StringUtils.convertBytesToHex(data);
assertEquals("3ad78e726c1ec02b7ebfe92b23d9ec34", r);
// COUNT = 127
test.setKey(StringUtils.convertHexToBytes("00000000000000000000000000000000"));
data = StringUtils.convertHexToBytes("ffffffffffffffffffffffffffffffff");
test.encrypt(data, 0, data.length);
r = StringUtils.convertBytesToHex(data);
assertEquals("3f5b8cc9ea855a0afa7347d23e8d664e", r);
// test vector
test.setKey(StringUtils.convertHexToBytes("2b7e151628aed2a6abf7158809cf4f3c"));
data = StringUtils.convertHexToBytes("6bc1bee22e409f96e93d7e117393172a");
test.encrypt(data, 0, data.length);
r = StringUtils.convertBytesToHex(data);
assertEquals("3ad77bb40d7a3660a89ecaf32466ef97", r);
test.setKey(StringUtils.convertHexToBytes("000102030405060708090A0B0C0D0E0F"));
byte[] in = new byte[128];
byte[] enc = new byte[128];
test.encrypt(enc, 0, 128);
test.decrypt(enc, 0, 128);
if (!Arrays.equals(in, enc)) {
throw new AssertionError();
}
for (int i = 0; i < 10; i++) {
test.encrypt(in, 0, 128);
test.decrypt(enc, 0, 128);
}
}