public void verify(char[] password) {
if (!isMasked() || payload == null) {
return;
}
IMac m = null;
try {
m = getMac(password);
} catch (Exception x) {
throw new IllegalArgumentException(x.toString());
}
m.update(payload, 0, payload.length - m.macSize());
byte[] macValue = new byte[m.macSize()];
System.arraycopy(payload, payload.length - macValue.length, macValue, 0, macValue.length);
if (!Arrays.equals(macValue, m.digest())) {
throw new IllegalArgumentException("MAC verification failed");
}
try {
DataInputStream in =
new DataInputStream(new ByteArrayInputStream(payload, 0, payload.length - m.macSize()));
decodeEnvelope(in);
} catch (IOException ioe) {
throw new IllegalArgumentException("malformed keyring fragment");
}
setMasked(false);
payload = null;
}
/*
* The PRF is defined as:
*
* PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
* P_SHA-1(S2, label + seed);
*
* P_hash is defined as:
*
* P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
* HMAC_hash(secret, A(2) + seed) +
* HMAC_hash(secret, A(3) + seed) + ...
*
* And A() is defined as:
*
* A(0) = seed
* A(i) = HMAC_hash(secret, A(i-1))
*
* For simplicity, we compute an 80-byte block on each call, which
* corresponds to five iterations of MD5, and four of SHA-1.
*/
private synchronized void fillBuffer() {
int len = hmac_md5.macSize();
for (int i = 0; i < buffer.length; i += len) {
hmac_md5.update(md5_a, 0, md5_a.length);
hmac_md5.update(seed, 0, seed.length);
byte[] b = hmac_md5.digest();
hmac_md5.reset();
System.arraycopy(b, 0, buffer, i, len);
hmac_md5.update(md5_a, 0, md5_a.length);
md5_a = hmac_md5.digest();
hmac_md5.reset();
}
len = hmac_sha.macSize();
for (int i = 0; i < buffer.length; i += len) {
hmac_sha.update(sha_a, 0, sha_a.length);
hmac_sha.update(seed, 0, seed.length);
byte[] b = hmac_sha.digest();
hmac_sha.reset();
for (int j = 0; j < len; j++) {
buffer[j + i] ^= b[j];
}
hmac_sha.update(sha_a, 0, sha_a.length);
sha_a = hmac_sha.digest();
hmac_sha.reset();
}
idx = 0;
}
public void init(Map attributes) {
HashMap sha_attr = new HashMap();
HashMap md5_attr = new HashMap();
byte[] secret = (byte[]) attributes.get(SECRET);
if (secret != null) {
int l = (secret.length >>> 1) + (secret.length & 1);
byte[] s1 = Util.trim(secret, 0, l);
byte[] s2 = Util.trim(secret, secret.length - l, l);
md5_attr.put(IMac.MAC_KEY_MATERIAL, s1);
sha_attr.put(IMac.MAC_KEY_MATERIAL, s2);
try {
hmac_md5.init(md5_attr);
hmac_sha.init(sha_attr);
} catch (InvalidKeyException ike) {
throw new Error(ike.toString());
}
} else if (!init) {
throw new IllegalArgumentException("no secret supplied");
}
// else re-use
byte[] seeed = (byte[]) attributes.get(SEED);
if (seeed != null) {
seed = (byte[]) seeed.clone();
} else if (!init) {
throw new IllegalArgumentException("no seed supplied");
}
// else re-use
// A(0) is the seed, A(1) = HMAC_hash(secret, A(0)).
hmac_md5.update(seed, 0, seed.length);
md5_a = hmac_md5.digest();
hmac_md5.reset();
hmac_sha.update(seed, 0, seed.length);
sha_a = hmac_sha.digest();
hmac_sha.reset();
fillBuffer();
init = true;
}
public void test(TestHarness harness) {
harness.checkPoint("TestOfTMMH16");
/*
KEY_LENGTH: 10
TAG_LENGTH: 2
key: { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc }
message: { 0xca, 0xfe, 0xba, 0xbe, 0xba, 0xde }
output: { 0x9d, 0x6a }
*/
try {
attributes.clear();
keystream = new DummyKeystream();
keystream.init(null);
output = new byte[] {(byte) 0x9d, (byte) 0x6a};
mac = new TMMH16();
attributes.put(TMMH16.KEYSTREAM, keystream);
attributes.put(TMMH16.TAG_LENGTH, new Integer(2));
mac.init(attributes);
message =
new byte[] {(byte) 0xca, (byte) 0xfe, (byte) 0xba, (byte) 0xbe, (byte) 0xba, (byte) 0xde};
for (int i = 0; i < message.length; i++) {
mac.update(message[i]);
}
result = mac.digest();
harness.check(Arrays.equals(result, output), "testVector1");
} catch (Exception x) {
harness.debug(x);
harness.fail("TestOfTMMH16.testVector1");
}
/*
KEY_LENGTH: 10
TAG_LENGTH: 2
key: { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc }
message: { 0xca, 0xfe, 0xba }
output: { 0xc8, 0x8e }
*/
try {
attributes.clear();
keystream = new DummyKeystream();
keystream.init(null);
output = new byte[] {(byte) 0xc8, (byte) 0x8e};
mac = new TMMH16();
attributes.put(TMMH16.KEYSTREAM, keystream);
attributes.put(TMMH16.TAG_LENGTH, new Integer(2));
mac.init(attributes);
message = new byte[] {(byte) 0xca, (byte) 0xfe, (byte) 0xba};
for (int i = 0; i < message.length; i++) {
mac.update(message[i]);
}
result = mac.digest();
harness.check(Arrays.equals(result, output), "testVector2");
} catch (Exception x) {
harness.debug(x);
harness.fail("TestOfTMMH16.testVector2");
}
/*
KEY_LENGTH: 10
TAG_LENGTH: 4
key: { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc }
message: { 0xca, 0xfe, 0xba, 0xbe, 0xba, 0xde }
output: { 0x9d, 0x6a, 0xc0, 0xd3 }
*/
try {
attributes.clear();
keystream = new DummyKeystream();
keystream.init(null);
output = new byte[] {(byte) 0x9d, (byte) 0x6a, (byte) 0xc0, (byte) 0xd3};
mac = new TMMH16();
attributes.put(TMMH16.KEYSTREAM, keystream);
attributes.put(TMMH16.TAG_LENGTH, new Integer(4));
mac.init(attributes);
message =
new byte[] {(byte) 0xca, (byte) 0xfe, (byte) 0xba, (byte) 0xbe, (byte) 0xba, (byte) 0xde};
for (int i = 0; i < message.length; i++) {
mac.update(message[i]);
}
result = mac.digest();
harness.check(Arrays.equals(result, output), "testVector3");
} catch (Exception x) {
harness.debug(x);
harness.fail("TestOfTMMH16.testVector3");
}
}