package org.jboss.seam.security.crypto;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
/**
* Copied from Matthias Gartner's PKCS#5 implementation - see
* http://rtner.de/software/PBKDF2.html
* <p/>
* Default PRF implementation based on standard javax.crypt.Mac mechanisms.
* <p/>
* <hr />
* <p>
* A free Java implementation of Password Based Key Derivation Function 2 as
* defined by RFC 2898. Copyright (c) 2007 Matthias Gärtner
* </p>
* <p>
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
* </p>
* <p>
* This library 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 Lesser General Public License for more
* details.
* </p>
* <p>
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* </p>
* <p>
* For Details, see <a
* href="http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html">http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html</a>.
* </p>
*
* @author Matthias Gärtner
* @version 1.0
*/
public class MacBasedPRF implements PRF {
protected Mac mac;
protected int hLen;
protected String macAlgorithm;
/**
* Create Mac-based Pseudo Random Function.
*
* @param macAlgorithm Mac algorithm to use, i.e. HMacSHA1 or HMacMD5.
*/
public MacBasedPRF(String macAlgorithm) {
this.macAlgorithm = macAlgorithm;
try {
mac = Mac.getInstance(macAlgorithm);
hLen = mac.getMacLength();
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
}
}
public MacBasedPRF(String macAlgorithm, String provider) {
this.macAlgorithm = macAlgorithm;
try {
mac = Mac.getInstance(macAlgorithm, provider);
hLen = mac.getMacLength();
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
} catch (NoSuchProviderException e) {
throw new RuntimeException(e);
}
}
public byte[] doFinal(byte[] M) {
byte[] r = mac.doFinal(M);
return r;
}
public int getHLen() {
return hLen;
}
public void init(byte[] P) {
try {
mac.init(new SecretKeySpec(P, macAlgorithm));
} catch (InvalidKeyException e) {
throw new RuntimeException(e);
}
}
}