The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 package org.mozilla.gecko.background.fxa;

 import java.io.UnsupportedEncodingException;

 import java.security.GeneralSecurityException;

 import java.util.HashMap;

 import java.util.Map;

 import org.mozilla.gecko.sync.Utils;

 public class QuickPasswordStretcher implements PasswordStretcher {

   protected final String password;

   protected final Map<String, String> cache = new HashMap<String, String>();

   public QuickPasswordStretcher(String password) {

     this.password = password;

   }

   public synchronized byte[] getQuickStretchedPW(byte[] emailUTF8) throws UnsupportedEncodingException, GeneralSecurityException {

     if (emailUTF8 == null) {

       throw new IllegalArgumentException("emailUTF8 must not be null");

     }

     String key = Utils.byte2Hex(emailUTF8);

     if (!cache.containsKey(key)) {

       byte[] value = FxAccountUtils.generateQuickStretchedPW(emailUTF8, password.getBytes("UTF-8"));

       cache.put(key, Utils.byte2Hex(value));

       return value;

     }

     return Utils.hex2Byte(cache.get(key));

   }

 }