123 lines
4.8 KiB
Java
123 lines
4.8 KiB
Java
/**
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* $RCSfile$
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* $Revision: $
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* $Date: $
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*
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* Copyright 2003-2004 Jive Software.
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*
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* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.jivesoftware.smack.sasl;
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import org.jivesoftware.smack.SASLAuthentication;
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import org.jivesoftware.smack.util.StringUtils;
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import java.io.IOException;
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/**
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* Base class for SASL mechanisms. Subclasses must implement three methods:
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* <ul>
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* <li>{@link #getName()} -- returns the common name of the SASL mechanism.</li>
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* <li>{@link #getAuthenticationText(String, String, String)} -- authentication text to include
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* in the initial <tt>auth</tt> stanza.</li>
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* <li>{@link #getChallengeResponse(byte[])} -- to respond challenges made by the server.</li>
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* </ul>
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*
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* @author Gaston Dombiak
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*/
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public abstract class SASLMechanism {
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private SASLAuthentication saslAuthentication;
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public SASLMechanism(SASLAuthentication saslAuthentication) {
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super();
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this.saslAuthentication = saslAuthentication;
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}
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/**
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* Builds and sends the <tt>auth</tt> stanza to the server.
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*
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* @param username the username of the user being authenticated.
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* @param host the hostname where the user account resides.
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* @param password the password of the user.
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* @throws IOException If a network error occures while authenticating.
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*/
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public void authenticate(String username, String host, String password) throws IOException {
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// Build the authentication stanza encoding the authentication text
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StringBuilder stanza = new StringBuilder();
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stanza.append("<auth mechanism=\"").append(getName());
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stanza.append("\" xmlns=\"urn:ietf:params:xml:ns:xmpp-sasl\">");
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String authenticationText = getAuthenticationText(username, host, password);
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if (authenticationText != null) {
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stanza.append(StringUtils.encodeBase64(authenticationText));
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}
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stanza.append("</auth>");
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// Send the authentication to the server
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getSASLAuthentication().send(stanza.toString());
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}
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/**
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* The server is challenging the SASL mechanism for the stanza he just sent. Send a
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* response to the server's challenge.
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*
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* @param challenge a base64 encoded string representing the challenge.
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*/
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public void challengeReceived(String challenge) throws IOException {
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// Build the challenge response stanza encoding the response text
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StringBuilder stanza = new StringBuilder();
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stanza.append("<response xmlns=\"urn:ietf:params:xml:ns:xmpp-sasl\">");
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String authenticationText = getChallengeResponse(StringUtils.decodeBase64(challenge));
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if (authenticationText != null) {
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stanza.append(StringUtils.encodeBase64(authenticationText));
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}
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stanza.append("</response>");
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// Send the authentication to the server
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getSASLAuthentication().send(stanza.toString());
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}
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/**
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* Returns the response text to send answering the challenge sent by the server. Mechanisms
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* that will never receive a challenge may redefine this method returning <tt>null</tt>.
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*
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* @param bytes the challenge sent by the server.
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* @return the response text to send to answer the challenge sent by the server.
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*/
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protected abstract String getChallengeResponse(byte[] bytes);
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/**
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* Returns the common name of the SASL mechanism. E.g.: PLAIN, DIGEST-MD5 or KERBEROS_V4.
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*
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* @return the common name of the SASL mechanism.
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*/
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protected abstract String getName();
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/**
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* Returns the authentication text to include in the initial <tt>auth</tt> stanza
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* or <tt>null</tt> if nothing should be added.
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*
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* @param username the username of the user being authenticated.
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* @param host the hostname where the user account resides.
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* @param password the password of the user.
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* @return the authentication text to include in the initial <tt>auth</tt> stanza
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* or <tt>null</tt> if nothing should be added.
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*/
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protected abstract String getAuthenticationText(String username, String host, String password);
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protected SASLAuthentication getSASLAuthentication() {
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return saslAuthentication;
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}
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}
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