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/* * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.security.sasl; import javax.security.sasl.*;import javax.security.auth.callback.*;import java.util.Random;import java.util.Map;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.security.NoSuchAlgorithmException; import java.util.logging.Logger;import java.util.logging.Level; /**  * Implements the CRAM-MD5 SASL server-side mechanism.  * (<A HREF="http://www.ietf.org/rfc/rfc2195.txt">RFC 2195</A>).  * CRAM-MD5 has no initial response.  *  * client <---- M={random, timestamp, server-fqdn} ------- server  * client ----- {username HMAC_MD5(pw, M)} --------------> server  *  * CallbackHandler must be able to handle the following callbacks:  * - NameCallback: default name is name of user for whom to get password  * - PasswordCallback: must fill in password; if empty, no pw  * - AuthorizeCallback: must setAuthorized() and canonicalized authorization id  *      - auth id == authzid, but needed to get canonicalized authzid  *  * @author Rosanna Lee  */final class CramMD5Server extends CramMD5Base implements SaslServer {    private String fqdn;    private byte[] challengeData = null;    private String authzid;    private CallbackHandler cbh;     /**     * Creates a SASL mechanism with client credentials that it needs     * to participate in CRAM-MD5 authentication exchange with the server.     *     * @param authID A  non-null string representing the principal     * being authenticated.     *     * @param pw A non-null String or byte[]     * containing the password. If it is an array, it is first cloned.     */    CramMD5Server(String protocol, String serverFqdn, Map props,        CallbackHandler cbh) throws SaslException {        if (serverFqdn == null) {            throw new SaslException(                "CRAM-MD5: fully qualified server name must be specified");        }         fqdn = serverFqdn;        this.cbh = cbh;    }     /**     * Generates challenge based on response sent by client.     *     * CRAM-MD5 has no initial response.     * First call generates challenge.     * Second call verifies client response. If authentication fails, throws     * SaslException.     *     * @param responseData A non-null byte array containing the response     *        data from the client.     * @return A non-null byte array containing the challenge to be sent to     *        the client for the first call; null when 2nd call is successful.     * @throws SaslException If authentication fails.     */    public byte[] evaluateResponse(byte[] responseData)        throws SaslException {         // See if we've been here before        if (completed) {            throw new IllegalStateException(                "CRAM-MD5 authentication already completed");        }         if (aborted) {            throw new IllegalStateException(                "CRAM-MD5 authentication previously aborted due to error");        }         try {            if (challengeData == null) {                if (responseData.length != 0) {                    aborted = true;                    throw new SaslException(                        "CRAM-MD5 does not expect any initial response");                }                 // Generate challenge {random, timestamp, fqdn}                Random random = new Random();                long rand = random.nextLong();                long timestamp = System.currentTimeMillis();                 StringBuffer buf = new StringBuffer();                buf.append('<');                buf.append(rand);                buf.append('.');                buf.append(timestamp);                buf.append('@');                buf.append(fqdn);                buf.append('>');                String challengeStr = buf.toString();                 logger.log(Level.FINE,                    "CRAMSRV01:Generated challenge: {0}", challengeStr);                 challengeData = challengeStr.getBytes("UTF8");                return challengeData.clone();             } else {                // Examine response to see if correctly encrypted challengeData                if(logger.isLoggable(Level.FINE)) {                    logger.log(Level.FINE,                        "CRAMSRV02:Received response: {0}",                        new String(responseData, "UTF8"));                }                 // Extract username from response                int ulen = 0;                for (int i = 0; i < responseData.length; i++) {                    if (responseData[i] == ' ') {                        ulen = i;                        break;                    }                }                if (ulen == 0) {                    aborted = true;                    throw new SaslException(                        "CRAM-MD5: Invalid response; space missing");                }                String username = new String(responseData, 0, ulen, "UTF8");                 logger.log(Level.FINE,                    "CRAMSRV03:Extracted username: {0}", username);                 // Get user's password                NameCallback ncb =                    new NameCallback("CRAM-MD5 authentication ID: ", username);                PasswordCallback pcb =                    new PasswordCallback("CRAM-MD5 password: ", false);                cbh.handle(new Callback[]{ncb,pcb});                char pwChars[] = pcb.getPassword();                if (pwChars == null || pwChars.length == 0) {                    // user has no password; OK to disclose to server                    aborted = true;                    throw new SaslException(                        "CRAM-MD5: username not found: " + username);                }                pcb.clearPassword();                String pwStr = new String(pwChars);                for (int i = 0; i < pwChars.length; i++) {                    pwChars[i] = 0;                }                pw = pwStr.getBytes("UTF8");                 // Generate a keyed-MD5 digest from the user's password and                // original challenge.                String digest = HMAC_MD5(pw, challengeData);                 logger.log(Level.FINE,                    "CRAMSRV04:Expecting digest: {0}", digest);                 // clear pw when we no longer need it                clearPassword();                 // Check whether digest is as expected                byte [] expectedDigest = digest.getBytes("UTF8");                int digestLen = responseData.length - ulen - 1;                if (expectedDigest.length != digestLen) {                    aborted = true;                    throw new SaslException("Invalid response");                }                int j = 0;                for (int i = ulen + 1; i < responseData.length ; i++) {                    if (expectedDigest[j++] != responseData[i]) {                        aborted = true;                        throw new SaslException("Invalid response");                    }                }                 // All checks out, use AuthorizeCallback to canonicalize name                AuthorizeCallback acb = new AuthorizeCallback(username, username);                cbh.handle(new Callback[]{acb});                if (acb.isAuthorized()) {                    authzid = acb.getAuthorizedID();                } else {                    // Not authorized                    aborted = true;                    throw new SaslException(                        "CRAM-MD5: user not authorized: " + username);                }                 logger.log(Level.FINE,                    "CRAMSRV05:Authorization id: {0}", authzid);                 completed = true;                return null;            }        } catch (UnsupportedEncodingException e) {            aborted = true;            throw new SaslException("UTF8 not available on platform", e);        } catch (NoSuchAlgorithmException e) {            aborted = true;            throw new SaslException("MD5 algorithm not available on platform", e);        } catch (UnsupportedCallbackException e) {            aborted = true;            throw new SaslException("CRAM-MD5 authentication failed", e);        } catch (SaslException e) {            throw e; // rethrow        } catch (IOException e) {            aborted = true;            throw new SaslException("CRAM-MD5 authentication failed", e);        }    }     public String getAuthorizationID() {        if (completed) {            return authzid;        } else {            throw new IllegalStateException(                "CRAM-MD5 authentication not completed");        }    }}