| /* SRP6SaslClient.java -- |
| Copyright (C) 2003, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath 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 |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
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| exception statement from your version. */ |
| |
| |
| package gnu.javax.crypto.key.srp6; |
| |
| import gnu.java.security.hash.IMessageDigest; |
| import gnu.java.security.util.Util; |
| |
| import gnu.javax.crypto.key.KeyAgreementException; |
| import gnu.javax.crypto.key.IncomingMessage; |
| import gnu.javax.crypto.key.OutgoingMessage; |
| |
| import java.math.BigInteger; |
| |
| /** |
| * A variation of the SRP-6 protocol as used in the SASL-SRP mechanism, for the |
| * User (client side). |
| * <p> |
| * In this alternative, the exchange goes as follows: |
| * |
| * <pre> |
| * C -> S: I (identifies self) |
| * S -> C: N, g, s, B = 3v + gˆb (sends salt, b = random number) |
| * C -> S: A = gˆa (a = random number) |
| * </pre> |
| * |
| * <p> |
| * All elements are computed the same way as in the standard version. |
| * <p> |
| * Reference: |
| * <ol> |
| * <li><a |
| * href="http://www.ietf.org/internet-drafts/draft-burdis-cat-srp-sasl-09.txt"> |
| * Secure Remote Password Authentication Mechanism</a><br> |
| * K. Burdis, R. Naffah.</li> |
| * <li><a href="http://srp.stanford.edu/design.html">SRP Protocol Design</a><br> |
| * Thomas J. Wu.</li> |
| * </ol> |
| */ |
| public class SRP6SaslClient |
| extends SRP6TLSClient |
| { |
| // default 0-arguments constructor |
| |
| protected OutgoingMessage computeSharedSecret(final IncomingMessage in) |
| throws KeyAgreementException |
| { |
| final OutgoingMessage result = super.computeSharedSecret(in); |
| final byte[] sBytes = Util.trim(K); |
| final IMessageDigest hash = srp.newDigest(); |
| hash.update(sBytes, 0, sBytes.length); |
| K = new BigInteger(1, hash.digest()); |
| return result; |
| } |
| } |