--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/eclipse/jetty/util/security/Credential.java	Wed Sep 07 21:15:48 2016 -0600
@@ -0,0 +1,229 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util.security;
+
+import java.io.Serializable;
+import java.security.MessageDigest;
+
+import org.eclipse.jetty.util.StringUtil;
+import org.eclipse.jetty.util.TypeUtil;
+import org.eclipse.jetty.util.log.Log;
+import org.eclipse.jetty.util.log.Logger;
+
+/* ------------------------------------------------------------ */
+/**
+ * Credentials. The Credential class represents an abstract mechanism for
+ * checking authentication credentials. A credential instance either represents
+ * a secret, or some data that could only be derived from knowing the secret.
+ * <p>
+ * Often a Credential is related to a Password via a one way algorithm, so while
+ * a Password itself is a Credential, a UnixCrypt or MD5 digest of a a password
+ * is only a credential that can be checked against the password.
+ * <p>
+ * This class includes an implementation for unix Crypt an MD5 digest.
+ * 
+ * @see Password
+ * 
+ */
+public abstract class Credential implements Serializable
+{
+    private static final Logger LOG = Log.getLogger(Credential.class);
+
+    private static final long serialVersionUID = -7760551052768181572L;
+
+    /* ------------------------------------------------------------ */
+    /**
+     * Check a credential
+     * 
+     * @param credentials The credential to check against. This may either be
+     *                another Credential object, a Password object or a String
+     *                which is interpreted by this credential.
+     * @return True if the credentials indicated that the shared secret is known
+     *         to both this Credential and the passed credential.
+     */
+    public abstract boolean check(Object credentials);
+
+    /* ------------------------------------------------------------ */
+    /**
+     * Get a credential from a String. If the credential String starts with a
+     * known Credential type (eg "CRYPT:" or "MD5:" ) then a Credential of that
+     * type is returned. Else the credential is assumed to be a Password.
+     * 
+     * @param credential String representation of the credential
+     * @return A Credential or Password instance.
+     */
+    public static Credential getCredential(String credential)
+    {
+        if (credential.startsWith(Crypt.__TYPE)) return new Crypt(credential);
+        if (credential.startsWith(MD5.__TYPE)) return new MD5(credential);
+
+        return new Password(credential);
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * Unix Crypt Credentials
+     */
+    public static class Crypt extends Credential
+    {
+        private static final long serialVersionUID = -2027792997664744210L;
+
+        public static final String __TYPE = "CRYPT:";
+
+        private final String _cooked;
+
+        Crypt(String cooked)
+        {
+            _cooked = cooked.startsWith(Crypt.__TYPE) ? cooked.substring(__TYPE.length()) : cooked;
+        }
+
+        @Override
+        public boolean check(Object credentials)
+        {
+            if (credentials instanceof char[])
+                credentials=new String((char[])credentials);
+            if (!(credentials instanceof String) && !(credentials instanceof Password)) 
+                LOG.warn("Can't check " + credentials.getClass() + " against CRYPT");
+
+            String passwd = credentials.toString();
+            return _cooked.equals(UnixCrypt.crypt(passwd, _cooked));
+        }
+
+        public static String crypt(String user, String pw)
+        {
+            return "CRYPT:" + UnixCrypt.crypt(pw, user);
+        }
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * MD5 Credentials
+     */
+    public static class MD5 extends Credential
+    {
+        private static final long serialVersionUID = 5533846540822684240L;
+
+        public static final String __TYPE = "MD5:";
+
+        public static final Object __md5Lock = new Object();
+
+        private static MessageDigest __md;
+
+        private final byte[] _digest;
+
+        /* ------------------------------------------------------------ */
+        MD5(String digest)
+        {
+            digest = digest.startsWith(__TYPE) ? digest.substring(__TYPE.length()) : digest;
+            _digest = TypeUtil.parseBytes(digest, 16);
+        }
+
+        /* ------------------------------------------------------------ */
+        public byte[] getDigest()
+        {
+            return _digest;
+        }
+
+        /* ------------------------------------------------------------ */
+        @Override
+        public boolean check(Object credentials)
+        {
+            try
+            {
+                byte[] digest = null;
+
+                if (credentials instanceof char[])
+                    credentials=new String((char[])credentials);
+                if (credentials instanceof Password || credentials instanceof String)
+                {
+                    synchronized (__md5Lock)
+                    {
+                        if (__md == null) __md = MessageDigest.getInstance("MD5");
+                        __md.reset();
+                        __md.update(credentials.toString().getBytes(StringUtil.__ISO_8859_1));
+                        digest = __md.digest();
+                    }
+                    if (digest == null || digest.length != _digest.length) return false;
+                    for (int i = 0; i < digest.length; i++)
+                        if (digest[i] != _digest[i]) return false;
+                    return true;
+                }
+                else if (credentials instanceof MD5)
+                {
+                    MD5 md5 = (MD5) credentials;
+                    if (_digest.length != md5._digest.length) return false;
+                    for (int i = 0; i < _digest.length; i++)
+                        if (_digest[i] != md5._digest[i]) return false;
+                    return true;
+                }
+                else if (credentials instanceof Credential)
+                {
+                    // Allow credential to attempt check - i.e. this'll work
+                    // for DigestAuthModule$Digest credentials
+                    return ((Credential) credentials).check(this);
+                }
+                else
+                {
+                    LOG.warn("Can't check " + credentials.getClass() + " against MD5");
+                    return false;
+                }
+            }
+            catch (Exception e)
+            {
+                LOG.warn(e);
+                return false;
+            }
+        }
+
+        /* ------------------------------------------------------------ */
+        public static String digest(String password)
+        {
+            try
+            {
+                byte[] digest;
+                synchronized (__md5Lock)
+                {
+                    if (__md == null)
+                    {
+                        try
+                        {
+                            __md = MessageDigest.getInstance("MD5");
+                        }
+                        catch (Exception e)
+                        {
+                            LOG.warn(e);
+                            return null;
+                        }
+                    }
+
+                    __md.reset();
+                    __md.update(password.getBytes(StringUtil.__ISO_8859_1));
+                    digest = __md.digest();
+                }
+
+                return __TYPE + TypeUtil.toString(digest, 16);
+            }
+            catch (Exception e)
+            {
+                LOG.warn(e);
+                return null;
+            }
+        }
+    }
+}