libjava/classpath/gnu/javax/crypto/sasl/crammd5/CramMD5Server.java

   1 /* CramMD5Server.java --
   2    Copyright (C) 2003, 2006 Free Software Foundation, Inc.
   3
   4 This file is a part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or (at
   9 your option) any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; if not, write to the Free Software
  18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19 USA
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version.  */
  37
  38
  39 package gnu.javax.crypto.sasl.crammd5;
  40
  41 import gnu.java.security.Registry;
  42 import gnu.java.security.util.Util;
  43 import gnu.javax.crypto.sasl.NoSuchUserException;
  44 import gnu.javax.crypto.sasl.ServerMechanism;
  45
  46 import java.io.IOException;
  47 import java.io.UnsupportedEncodingException;
  48 import java.security.InvalidKeyException;
  49 import java.util.Arrays;
  50 import java.util.HashMap;
  51 import java.util.Map;
  52
  53 import javax.security.sasl.AuthenticationException;
  54 import javax.security.sasl.SaslException;
  55 import javax.security.sasl.SaslServer;
  56
  57 /**
  58  * <p>The CRAM-MD5 SASL server-side mechanism.</p>
  59  */
  60 public class CramMD5Server extends ServerMechanism implements SaslServer
  61 {
  62
  63   // Constants and variables
  64   // -------------------------------------------------------------------------
  65
  66   private byte[] msgID;
  67
  68   // Constructor(s)
  69   // -------------------------------------------------------------------------
  70
  71   public CramMD5Server()
  72   {
  73     super(Registry.SASL_CRAM_MD5_MECHANISM);
  74   }
  75
  76   // Class methods
  77   // -------------------------------------------------------------------------
  78
  79   // abstract methods implementation -----------------------------------------
  80
  81   protected void initMechanism() throws SaslException
  82   {
  83   }
  84
  85   protected void resetMechanism() throws SaslException
  86   {
  87   }
  88
  89   // javax.security.sasl.SaslServer interface implementation -----------------
  90
  91   public byte[] evaluateResponse(final byte[] response) throws SaslException
  92   {
  93     if (state == 0)
  94       {
  95         msgID = CramMD5Util.createMsgID();
  96         state++;
  97         return msgID;
  98       }
  99
 100     final String responseStr = new String(response);
 101     final int index = responseStr.lastIndexOf(" ");
 102     final String username = responseStr.substring(0, index);
 103     final byte[] responseDigest;
 104     try
 105       {
 106         responseDigest = responseStr.substring(index + 1).getBytes("UTF-8");
 107       }
 108     catch (UnsupportedEncodingException x)
 109       {
 110         throw new AuthenticationException("evaluateResponse()", x);
 111       }
 112
 113     // Look up the password
 114     final char[] password = lookupPassword(username);
 115
 116     // Compute the digest
 117     byte[] digest;
 118     try
 119       {
 120         digest = CramMD5Util.createHMac(password, msgID);
 121       }
 122     catch (InvalidKeyException x)
 123       {
 124         throw new AuthenticationException("evaluateResponse()", x);
 125       }
 126     try
 127       {
 128         //         digest = (new String(Util.toString(digest).toLowerCase())).getBytes("UTF-8");
 129         digest = Util.toString(digest).toLowerCase().getBytes("UTF-8");
 130       }
 131     catch (UnsupportedEncodingException x)
 132       {
 133         throw new AuthenticationException("evaluateResponse()", x);
 134       }
 135
 136     // Compare the received and computed digests
 137     if (!Arrays.equals(digest, responseDigest))
 138       {
 139         throw new AuthenticationException("Digest mismatch");
 140       }
 141     state++;
 142     return null;
 143   }
 144
 145   public boolean isComplete()
 146   {
 147     return (state == 2);
 148   }
 149
 150   protected String getNegotiatedQOP()
 151   {
 152     return Registry.QOP_AUTH;
 153   }
 154
 155   // Other instance methods --------------------------------------------------
 156
 157   private char[] lookupPassword(final String userName) throws SaslException
 158   {
 159     try
 160       {
 161         if (!authenticator.contains(userName))
 162           {
 163             throw new NoSuchUserException(userName);
 164           }
 165         final Map userID = new HashMap();
 166         userID.put(Registry.SASL_USERNAME, userName);
 167         final Map credentials = authenticator.lookup(userID);
 168         final String password = (String) credentials.get(Registry.SASL_PASSWORD);
 169         if (password == null)
 170           {
 171             throw new AuthenticationException("lookupPassword()",
 172                                               new InternalError());
 173           }
 174         return password.toCharArray();
 175       }
 176     catch (IOException x)
 177       {
 178         if (x instanceof SaslException)
 179           {
 180             throw (SaslException) x;
 181           }
 182         throw new AuthenticationException("lookupPassword()", x);
 183       }
 184   }
 185 }