org.apache.wss4j.common.derivedKey.P_SHA1 Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.wss4j.common.derivedKey;
/**
*
P_SHA-1 DEFINITION
==================
P_SHA-1(secret, seed) =
HMAC_SHA-1(secret, A(1) + seed) +
HMAC_SHA-1(secret, A(2) + seed) +
HMAC_SHA-1(secret, A(3) + seed) + ...
Where + indicates concatenation.
A() is defined as:
A(0) = seed
A(i) = HMAC_SHA-1(secret, A(i-1))
Source : RFC 2246 - The TLS Protocol Version 1.0
Section 5. HMAC and the pseudorandom function
*/
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
public class P_SHA1 implements DerivationAlgorithm {
@Override
public byte[] createKey(byte[] secret, byte[] seed, int offset, long length)
throws ConversationException {
try {
Mac mac = Mac.getInstance("HmacSHA1");
byte[] tempBytes = P_hash(secret, seed, mac, offset + (int) length);
byte[] key = new byte[(int) length];
System.arraycopy(tempBytes, offset, key, 0, key.length);
return key;
} catch (NoSuchAlgorithmException e) {
throw new ConversationException("errorInKeyDerivation", null, e);
} catch (InvalidKeyException e) {
throw new ConversationException("errorInKeyDerivation", null, e);
}
}
/**
* P_hash as defined in RFC 2246 for TLS.
*
* @param secret is the key for the HMAC
* @param seed the seed value to start the generation - A(0)
* @param mac the HMAC algorithm
* @param required number of bytes to generate
* @return a byte array that contains a secret key
* @throws InvalidKeyException
*/
private static byte[] P_hash(byte[] secret, byte[] seed, Mac mac, int required)
throws InvalidKeyException {
byte[] out = new byte[required];
int offset = 0, tocpy;
byte[] a = seed; // a(0) is the seed
byte[] tmp;
SecretKeySpec key = new SecretKeySpec(secret, "HMACSHA1");
mac.init(key);
while (required > 0) {
mac.update(a);
a = mac.doFinal();
mac.update(a);
mac.update(seed);
tmp = mac.doFinal();
tocpy = Math.min(required, tmp.length);
System.arraycopy(tmp, 0, out, offset, tocpy);
offset += tocpy;
required -= tocpy;
}
return out;
}
}