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- fixed xorend function
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- SIV implementation now satisfies all official test vectors
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Sebastian Stenzel committed Feb 15, 2015
1 parent 3187520 commit 5aaee7b
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Showing 2 changed files with 82 additions and 22 deletions.
33 changes: 11 additions & 22 deletions main/crypto-aes/src/main/java/org/cryptomator/crypto/aes256/AesSivCipherUtil.java
View file
Expand Up @@ -13,7 +13,6 @@
import java.security.MessageDigest;
import java.util.Arrays;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.ArrayUtils;
import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.CipherParameters;
Expand Down Expand Up @@ -61,7 +60,7 @@ static byte[] sivEncrypt(byte[] key, byte[] plaintext, byte[]... additionalData)
aes.reset();
}

final byte[] ciphertext = xorbegin(plaintext, x);
final byte[] ciphertext = xor(plaintext, x);

return ArrayUtils.addAll(iv, ciphertext);
}
Expand Down Expand Up @@ -96,9 +95,7 @@ static byte[] sivDecrypt(byte[] key, byte[] ciphertext, byte[]... additionalData
aes.reset();
}

final byte[] plaintext = xorbegin(actualCiphertext, x);

Hex.encodeHexString(actualCiphertext);
final byte[] plaintext = xor(actualCiphertext, x);

final byte[] control = s2v(k1, plaintext, additionalData);

Expand Down Expand Up @@ -178,34 +175,26 @@ private static byte[] dbl(byte[] in) {
}

private static byte[] xor(byte[] in1, byte[] in2) {
if (in1 == null || in2 == null || in1.length != in2.length) {
throw new IllegalArgumentException("Inputs must equal in length.");
if (in1 == null || in2 == null || in1.length > in2.length) {
throw new IllegalArgumentException("Length of first input must be <= length of second input.");
}

return xorbegin(in1, in2);
final byte[] result = new byte[in1.length];
for (int i = 0; i < result.length; i++) {
result[i] = (byte) (in1[i] ^ in2[i]);
}
return result;
}

private static byte[] xorend(byte[] in1, byte[] in2) {
if (in1 == null || in2 == null || in1.length < in2.length) {
throw new IllegalArgumentException("Length of first input must be >= length of second input.");
}

final byte[] result = new byte[in2.length];
final byte[] result = Arrays.copyOf(in1, in1.length);
final int diff = in1.length - in2.length;
for (int i = 0; i < in2.length; i++) {
result[i] = (byte) (in1[i + diff] ^ in2[i]);
}
return result;
}

private static byte[] xorbegin(byte[] in1, byte[] in2) {
if (in1 == null || in2 == null || in1.length > in2.length) {
throw new IllegalArgumentException("Length of first input must be <= length of second input.");
}

final byte[] result = new byte[in1.length];
for (int i = 0; i < result.length; i++) {
result[i] = (byte) (in1[i] ^ in2[i]);
result[i + diff] = (byte) (result[i + diff] ^ in2[i]);
}
return result;
}
Expand Down
71 changes: 71 additions & 0 deletions main/crypto-aes/src/test/java/org/cryptomator/crypto/aes256/AesSivCipherUtilTest.java
View file
Expand Up @@ -147,4 +147,75 @@ public void testSivDecryptWithInvalidKey() throws DecryptFailedException, Invali
final byte[] result = AesSivCipherUtil.sivDecrypt(key, ciphertext, ad);
Assert.assertArrayEquals(expected, result);
}

/**
* https://tools.ietf.org/html/rfc5297#appendix-A.2
*/
@Test
public void testNonceBasedAuthenticatedEncryption() throws InvalidKeyException {

final byte[] key = {(byte) 0x7f, (byte) 0x7e, (byte) 0x7d, (byte) 0x7c, //
(byte) 0x7b, (byte) 0x7a, (byte) 0x79, (byte) 0x78, //
(byte) 0x77, (byte) 0x76, (byte) 0x75, (byte) 0x74, //
(byte) 0x73, (byte) 0x72, (byte) 0x71, (byte) 0x70, //
(byte) 0x40, (byte) 0x41, (byte) 0x42, (byte) 0x43, //
(byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, //
(byte) 0x48, (byte) 0x49, (byte) 0x4a, (byte) 0x4b, //
(byte) 0x4c, (byte) 0x4d, (byte) 0x4e, (byte) 0x4f};

final byte[] ad1 = {(byte) 0x00, (byte) 0x11, (byte) 0x22, (byte) 0x33, //
(byte) 0x44, (byte) 0x55, (byte) 0x66, (byte) 0x77, //
(byte) 0x88, (byte) 0x99, (byte) 0xaa, (byte) 0xbb, //
(byte) 0xcc, (byte) 0xdd, (byte) 0xee, (byte) 0xff, //
(byte) 0xde, (byte) 0xad, (byte) 0xda, (byte) 0xda, //
(byte) 0xde, (byte) 0xad, (byte) 0xda, (byte) 0xda, //
(byte) 0xff, (byte) 0xee, (byte) 0xdd, (byte) 0xcc, //
(byte) 0xbb, (byte) 0xaa, (byte) 0x99, (byte) 0x88, //
(byte) 0x77, (byte) 0x66, (byte) 0x55, (byte) 0x44, //
(byte) 0x33, (byte) 0x22, (byte) 0x11, (byte) 0x00};

final byte[] ad2 = {(byte) 0x10, (byte) 0x20, (byte) 0x30, (byte) 0x40, //
(byte) 0x50, (byte) 0x60, (byte) 0x70, (byte) 0x80, //
(byte) 0x90, (byte) 0xa0};

final byte[] nonce = {(byte) 0x09, (byte) 0xf9, (byte) 0x11, (byte) 0x02, //
(byte) 0x9d, (byte) 0x74, (byte) 0xe3, (byte) 0x5b, //
(byte) 0xd8, (byte) 0x41, (byte) 0x56, (byte) 0xc5, //
(byte) 0x63, (byte) 0x56, (byte) 0x88, (byte) 0xc0};

final byte[] plaintext = {(byte) 0x74, (byte) 0x68, (byte) 0x69, (byte) 0x73, //
(byte) 0x20, (byte) 0x69, (byte) 0x73, (byte) 0x20, //
(byte) 0x73, (byte) 0x6f, (byte) 0x6d, (byte) 0x65, //
(byte) 0x20, (byte) 0x70, (byte) 0x6c, (byte) 0x61, //
(byte) 0x69, (byte) 0x6e, (byte) 0x74, (byte) 0x65, //
(byte) 0x78, (byte) 0x74, (byte) 0x20, (byte) 0x74, //
(byte) 0x6f, (byte) 0x20, (byte) 0x65, (byte) 0x6e, //
(byte) 0x63, (byte) 0x72, (byte) 0x79, (byte) 0x70, //
(byte) 0x74, (byte) 0x20, (byte) 0x75, (byte) 0x73, //
(byte) 0x69, (byte) 0x6e, (byte) 0x67, (byte) 0x20, //
(byte) 0x53, (byte) 0x49, (byte) 0x56, (byte) 0x2d, //
(byte) 0x41, (byte) 0x45, (byte) 0x53};

final byte[] result = AesSivCipherUtil.sivEncrypt(key, plaintext, ad1, ad2, nonce);

final byte[] expected = {(byte) 0x7b, (byte) 0xdb, (byte) 0x6e, (byte) 0x3b, //
(byte) 0x43, (byte) 0x26, (byte) 0x67, (byte) 0xeb, //
(byte) 0x06, (byte) 0xf4, (byte) 0xd1, (byte) 0x4b, //
(byte) 0xff, (byte) 0x2f, (byte) 0xbd, (byte) 0x0f, //
(byte) 0xcb, (byte) 0x90, (byte) 0x0f, (byte) 0x2f, //
(byte) 0xdd, (byte) 0xbe, (byte) 0x40, (byte) 0x43, //
(byte) 0x26, (byte) 0x60, (byte) 0x19, (byte) 0x65, //
(byte) 0xc8, (byte) 0x89, (byte) 0xbf, (byte) 0x17, //
(byte) 0xdb, (byte) 0xa7, (byte) 0x7c, (byte) 0xeb, //
(byte) 0x09, (byte) 0x4f, (byte) 0xa6, (byte) 0x63, //
(byte) 0xb7, (byte) 0xa3, (byte) 0xf7, (byte) 0x48, //
(byte) 0xba, (byte) 0x8a, (byte) 0xf8, (byte) 0x29, //
(byte) 0xea, (byte) 0x64, (byte) 0xad, (byte) 0x54, //
(byte) 0x4a, (byte) 0x27, (byte) 0x2e, (byte) 0x9c, //
(byte) 0x48, (byte) 0x5b, (byte) 0x62, (byte) 0xa3, //
(byte) 0xfd, (byte) 0x5c, (byte) 0x0d};

Assert.assertArrayEquals(expected, result);

}
}

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