changeset 10556:104c06bb638c

8044860: Vectors and fixed length fields should be verified for allowed sizes. Reviewed-by: xuelei
author igerasim
date Thu, 19 Mar 2015 19:03:38 +0300
parents 3c875265a334
children 478602cc17e2 9a7d2535db72
files src/share/classes/sun/security/ssl/HandshakeMessage.java src/share/classes/sun/security/ssl/SessionId.java test/sun/security/ssl/com/sun/net/ssl/internal/ssl/ClientHandshaker/LengthCheckTest.java
diffstat 3 files changed, 834 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/classes/sun/security/ssl/HandshakeMessage.java	Thu Mar 19 17:39:52 2015 +0300
+++ b/src/share/classes/sun/security/ssl/HandshakeMessage.java	Thu Mar 19 19:03:38 2015 +0300
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2015, 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
@@ -243,6 +243,7 @@
         protocolVersion = ProtocolVersion.valueOf(s.getInt8(), s.getInt8());
         clnt_random = new RandomCookie(s);
         sessionId = new SessionId(s.getBytes8());
+        sessionId.checkLength(protocolVersion);
         cipherSuites = new CipherSuiteList(s);
         compression_methods = s.getBytes8();
         if (messageLength() != messageLength) {
@@ -355,6 +356,7 @@
                                                   input.getInt8());
         svr_random = new RandomCookie(input);
         sessionId = new SessionId(input.getBytes8());
+        sessionId.checkLength(protocolVersion);
         cipherSuite = CipherSuite.valueOf(input.getInt8(), input.getInt8());
         compression_method = (byte)input.getInt8();
         if (messageLength() != messageLength) {
--- a/src/share/classes/sun/security/ssl/SessionId.java	Thu Mar 19 17:39:52 2015 +0300
+++ b/src/share/classes/sun/security/ssl/SessionId.java	Thu Mar 19 19:03:38 2015 +0300
@@ -27,6 +27,7 @@
 package sun.security.ssl;
 
 import java.security.SecureRandom;
+import javax.net.ssl.SSLProtocolException;
 
 /**
  * Encapsulates an SSL session ID.  SSL Session IDs are not reused by
@@ -41,6 +42,7 @@
 final
 class SessionId
 {
+    static int MAX_LENGTH = 32;
     private byte sessionId [];          // max 32 bytes
 
     /** Constructs a new session ID ... perhaps for a rejoinable session */
@@ -114,4 +116,19 @@
         }
         return true;
     }
+
+    /**
+     * Checks the length of the session ID to make sure it sits within
+     * the range called out in the specification
+     */
+    void checkLength(ProtocolVersion pv) throws SSLProtocolException {
+        // As of today all versions of TLS have a 32-byte maximum length.
+        // In the future we can do more here to support protocol versions
+        // that may have longer max lengths.
+        if (sessionId.length > MAX_LENGTH) {
+            throw new SSLProtocolException("Invalid session ID length (" +
+                    sessionId.length + " bytes)");
+        }
+    }
+
 }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/sun/security/ssl/com/sun/net/ssl/internal/ssl/ClientHandshaker/LengthCheckTest.java	Thu Mar 19 19:03:38 2015 +0300
@@ -0,0 +1,814 @@
+/*
+ * Copyright (c) 2015, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8044860
+ * @summary Vectors and fixed length fields should be verified
+ *          for allowed sizes.
+ * @run main/othervm LengthCheckTest
+ */
+
+/**
+ * A SSLEngine usage example which simplifies the presentation
+ * by removing the I/O and multi-threading concerns.
+ *
+ * The test creates two SSLEngines, simulating a client and server.
+ * The "transport" layer consists two byte buffers:  think of them
+ * as directly connected pipes.
+ *
+ * Note, this is a *very* simple example: real code will be much more
+ * involved.  For example, different threading and I/O models could be
+ * used, transport mechanisms could close unexpectedly, and so on.
+ *
+ * When this application runs, notice that several messages
+ * (wrap/unwrap) pass before any application data is consumed or
+ * produced.  (For more information, please see the SSL/TLS
+ * specifications.)  There may several steps for a successful handshake,
+ * so it's typical to see the following series of operations:
+ *
+ *      client          server          message
+ *      ======          ======          =======
+ *      wrap()          ...             ClientHello
+ *      ...             unwrap()        ClientHello
+ *      ...             wrap()          ServerHello/Certificate
+ *      unwrap()        ...             ServerHello/Certificate
+ *      wrap()          ...             ClientKeyExchange
+ *      wrap()          ...             ChangeCipherSpec
+ *      wrap()          ...             Finished
+ *      ...             unwrap()        ClientKeyExchange
+ *      ...             unwrap()        ChangeCipherSpec
+ *      ...             unwrap()        Finished
+ *      ...             wrap()          ChangeCipherSpec
+ *      ...             wrap()          Finished
+ *      unwrap()        ...             ChangeCipherSpec
+ *      unwrap()        ...             Finished
+ */
+
+import javax.net.ssl.*;
+import javax.net.ssl.SSLEngineResult.*;
+import java.io.*;
+import java.security.*;
+import java.nio.*;
+import java.util.List;
+import java.util.ArrayList;
+import sun.security.ssl.ProtocolVersion;
+
+public class LengthCheckTest {
+
+    /*
+     * Enables logging of the SSLEngine operations.
+     */
+    private static final boolean logging = true;
+
+    /*
+     * Enables the JSSE system debugging system property:
+     *
+     *     -Djavax.net.debug=all
+     *
+     * This gives a lot of low-level information about operations underway,
+     * including specific handshake messages, and might be best examined
+     * after gaining some familiarity with this application.
+     */
+    private static final boolean debug = false;
+    private static final boolean dumpBufs = true;
+
+    private final SSLContext sslc;
+
+    private SSLEngine clientEngine;     // client Engine
+    private ByteBuffer clientOut;       // write side of clientEngine
+    private ByteBuffer clientIn;        // read side of clientEngine
+
+    private SSLEngine serverEngine;     // server Engine
+    private ByteBuffer serverOut;       // write side of serverEngine
+    private ByteBuffer serverIn;        // read side of serverEngine
+
+    private HandshakeTest handshakeTest;
+
+    /*
+     * For data transport, this example uses local ByteBuffers.  This
+     * isn't really useful, but the purpose of this example is to show
+     * SSLEngine concepts, not how to do network transport.
+     */
+    private ByteBuffer cTOs;            // "reliable" transport client->server
+    private ByteBuffer sTOc;            // "reliable" transport server->client
+
+    /*
+     * The following is to set up the keystores.
+     */
+    private static final String pathToStores = "/../../../../../../../etc";
+    private static final String keyStoreFile = "keystore";
+    private static final String trustStoreFile = "truststore";
+    private static final String passwd = "passphrase";
+
+    private static final String keyFilename =
+            System.getProperty("test.src", ".") + "/" + pathToStores +
+                "/" + keyStoreFile;
+    private static final String trustFilename =
+            System.getProperty("test.src", ".") + "/" + pathToStores +
+                "/" + trustStoreFile;
+
+    // Define a few basic TLS record and message types we might need
+    private static final int TLS_RECTYPE_CCS = 0x14;
+    private static final int TLS_RECTYPE_ALERT = 0x15;
+    private static final int TLS_RECTYPE_HANDSHAKE = 0x16;
+    private static final int TLS_RECTYPE_APPDATA = 0x17;
+
+    private static final int TLS_HS_HELLO_REQUEST = 0x00;
+    private static final int TLS_HS_CLIENT_HELLO = 0x01;
+    private static final int TLS_HS_SERVER_HELLO = 0x02;
+    private static final int TLS_HS_CERTIFICATE = 0x0B;
+    private static final int TLS_HS_SERVER_KEY_EXCHG = 0x0C;
+    private static final int TLS_HS_CERT_REQUEST = 0x0D;
+    private static final int TLS_HS_SERVER_HELLO_DONE = 0x0E;
+    private static final int TLS_HS_CERT_VERIFY = 0x0F;
+    private static final int TLS_HS_CLIENT_KEY_EXCHG = 0x10;
+    private static final int TLS_HS_FINISHED = 0x14;
+
+    // We're not going to define all the alert types in TLS, just
+    // the ones we think we'll need to reference by name.
+    private static final int TLS_ALERT_LVL_WARNING = 0x01;
+    private static final int TLS_ALERT_LVL_FATAL = 0x02;
+
+    private static final int TLS_ALERT_UNEXPECTED_MSG = 0x0A;
+    private static final int TLS_ALERT_HANDSHAKE_FAILURE = 0x28;
+    private static final int TLS_ALERT_INTERNAL_ERROR = 0x50;
+
+    public interface HandshakeTest {
+        void execTest() throws Exception;
+    }
+
+    public final HandshakeTest servSendLongID = new HandshakeTest() {
+        @Override
+        public void execTest() throws Exception {
+            boolean gotException = false;
+            SSLEngineResult clientResult;   // results from client's last op
+            SSLEngineResult serverResult;   // results from server's last op
+
+            log("\n==== Test: Client receives 64-byte session ID ====");
+
+            // Send Client Hello
+            clientResult = clientEngine.wrap(clientOut, cTOs);
+            log("client wrap: ", clientResult);
+            runDelegatedTasks(clientResult, clientEngine);
+            cTOs.flip();
+            dumpByteBuffer("CLIENT-TO-SERVER", cTOs);
+
+            // Server consumes Client Hello
+            serverResult = serverEngine.unwrap(cTOs, serverIn);
+            log("server unwrap: ", serverResult);
+            runDelegatedTasks(serverResult, serverEngine);
+            cTOs.compact();
+
+            // Server generates ServerHello/Cert/Done record
+            serverResult = serverEngine.wrap(serverOut, sTOc);
+            log("server wrap: ", serverResult);
+            runDelegatedTasks(serverResult, serverEngine);
+            sTOc.flip();
+
+            // Intercept the ServerHello messages and instead send
+            // one that has a 64-byte session ID.
+            if (isTlsMessage(sTOc, TLS_RECTYPE_HANDSHAKE,
+                        TLS_HS_SERVER_HELLO)) {
+                ArrayList<ByteBuffer> recList = splitRecord(sTOc);
+
+                // Use the original ServerHello as a template to craft one
+                // with a longer-than-allowed session ID.
+                ByteBuffer servHelloBuf =
+                        createEvilServerHello(recList.get(0), 64);
+
+                recList.set(0, servHelloBuf);
+
+                // Now send each ByteBuffer (each being a complete
+                // TLS record) into the client-side unwrap.
+                for (ByteBuffer bBuf : recList) {
+                    dumpByteBuffer("SERVER-TO-CLIENT", bBuf);
+                    try {
+                        clientResult = clientEngine.unwrap(bBuf, clientIn);
+                    } catch (SSLProtocolException e) {
+                        log("Received expected SSLProtocolException: " + e);
+                        gotException = true;
+                    }
+                    log("client unwrap: ", clientResult);
+                    runDelegatedTasks(clientResult, clientEngine);
+                }
+            } else {
+                dumpByteBuffer("SERVER-TO-CLIENT", sTOc);
+                log("client unwrap: ", clientResult);
+                runDelegatedTasks(clientResult, clientEngine);
+            }
+            sTOc.compact();
+
+            // The Client should now send a TLS Alert
+            clientResult = clientEngine.wrap(clientOut, cTOs);
+            log("client wrap: ", clientResult);
+            runDelegatedTasks(clientResult, clientEngine);
+            cTOs.flip();
+            dumpByteBuffer("CLIENT-TO-SERVER", cTOs);
+
+            // At this point we can verify that both an exception
+            // was thrown and the proper action (a TLS alert) was
+            // sent back to the server.
+            if (gotException == false ||
+                !isTlsMessage(cTOs, TLS_RECTYPE_ALERT, TLS_ALERT_LVL_FATAL,
+                        TLS_ALERT_INTERNAL_ERROR)) {
+                throw new SSLException(
+                    "Client failed to throw Alert:fatal:internal_error");
+            }
+        }
+    };
+
+    public final HandshakeTest clientSendLongID = new HandshakeTest() {
+        @Override
+        public void execTest() throws Exception {
+            boolean gotException = false;
+            SSLEngineResult clientResult;   // results from client's last op
+            SSLEngineResult serverResult;   // results from server's last op
+
+            log("\n==== Test: Server receives 64-byte session ID ====");
+
+            // Send Client Hello
+            ByteBuffer evilClientHello = createEvilClientHello(64);
+            dumpByteBuffer("CLIENT-TO-SERVER", evilClientHello);
+
+            try {
+                // Server consumes Client Hello
+                serverResult = serverEngine.unwrap(evilClientHello, serverIn);
+                log("server unwrap: ", serverResult);
+                runDelegatedTasks(serverResult, serverEngine);
+                evilClientHello.compact();
+
+                // Under normal circumstances this should be a ServerHello
+                // But should throw an exception instead due to the invalid
+                // session ID.
+                serverResult = serverEngine.wrap(serverOut, sTOc);
+                log("server wrap: ", serverResult);
+                runDelegatedTasks(serverResult, serverEngine);
+                sTOc.flip();
+                dumpByteBuffer("SERVER-TO-CLIENT", sTOc);
+            } catch (SSLProtocolException ssle) {
+                log("Received expected SSLProtocolException: " + ssle);
+                gotException = true;
+            }
+
+            // We expect to see the server generate an alert here
+            serverResult = serverEngine.wrap(serverOut, sTOc);
+            log("server wrap: ", serverResult);
+            runDelegatedTasks(serverResult, serverEngine);
+            sTOc.flip();
+            dumpByteBuffer("SERVER-TO-CLIENT", sTOc);
+
+            // At this point we can verify that both an exception
+            // was thrown and the proper action (a TLS alert) was
+            // sent back to the client.
+            if (gotException == false ||
+                !isTlsMessage(sTOc, TLS_RECTYPE_ALERT, TLS_ALERT_LVL_FATAL,
+                        TLS_ALERT_INTERNAL_ERROR)) {
+                throw new SSLException(
+                    "Server failed to throw Alert:fatal:internal_error");
+            }
+        }
+    };
+
+
+    /*
+     * Main entry point for this test.
+     */
+    public static void main(String args[]) throws Exception {
+        List<LengthCheckTest> ccsTests = new ArrayList<>();
+
+        if (debug) {
+            System.setProperty("javax.net.debug", "ssl");
+        }
+
+        ccsTests.add(new LengthCheckTest("ServSendLongID"));
+        ccsTests.add(new LengthCheckTest("ClientSendLongID"));
+
+        for (LengthCheckTest test : ccsTests) {
+            test.runTest();
+        }
+
+        System.out.println("Test Passed.");
+    }
+
+    /*
+     * Create an initialized SSLContext to use for these tests.
+     */
+    public LengthCheckTest(String testName) throws Exception {
+
+        KeyStore ks = KeyStore.getInstance("JKS");
+        KeyStore ts = KeyStore.getInstance("JKS");
+
+        char[] passphrase = "passphrase".toCharArray();
+
+        ks.load(new FileInputStream(keyFilename), passphrase);
+        ts.load(new FileInputStream(trustFilename), passphrase);
+
+        KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
+        kmf.init(ks, passphrase);
+
+        TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
+        tmf.init(ts);
+
+        SSLContext sslCtx = SSLContext.getInstance("TLS");
+
+        sslCtx.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
+
+        sslc = sslCtx;
+
+        switch (testName) {
+            case "ServSendLongID":
+                handshakeTest = servSendLongID;
+                break;
+            case "ClientSendLongID":
+                handshakeTest = clientSendLongID;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown test name: " +
+                        testName);
+        }
+    }
+
+    /*
+     * Run the test.
+     *
+     * Sit in a tight loop, both engines calling wrap/unwrap regardless
+     * of whether data is available or not.  We do this until both engines
+     * report back they are closed.
+     *
+     * The main loop handles all of the I/O phases of the SSLEngine's
+     * lifetime:
+     *
+     *     initial handshaking
+     *     application data transfer
+     *     engine closing
+     *
+     * One could easily separate these phases into separate
+     * sections of code.
+     */
+    private void runTest() throws Exception {
+        boolean dataDone = false;
+
+        createSSLEngines();
+        createBuffers();
+
+        handshakeTest.execTest();
+    }
+
+    /*
+     * Using the SSLContext created during object creation,
+     * create/configure the SSLEngines we'll use for this test.
+     */
+    private void createSSLEngines() throws Exception {
+        /*
+         * Configure the serverEngine to act as a server in the SSL/TLS
+         * handshake.  Also, require SSL client authentication.
+         */
+        serverEngine = sslc.createSSLEngine();
+        serverEngine.setUseClientMode(false);
+        serverEngine.setNeedClientAuth(false);
+
+        /*
+         * Similar to above, but using client mode instead.
+         */
+        clientEngine = sslc.createSSLEngine("client", 80);
+        clientEngine.setUseClientMode(true);
+
+        // In order to make a test that will be backwards compatible
+        // going back to JDK 5, force the handshake to be TLS 1.0 and
+        // use one of the older cipher suites.
+        clientEngine.setEnabledProtocols(new String[]{"TLSv1"});
+        clientEngine.setEnabledCipherSuites(
+                new String[]{"TLS_RSA_WITH_AES_128_CBC_SHA"});
+    }
+
+    /*
+     * Create and size the buffers appropriately.
+     */
+    private void createBuffers() {
+
+        /*
+         * We'll assume the buffer sizes are the same
+         * between client and server.
+         */
+        SSLSession session = clientEngine.getSession();
+        int appBufferMax = session.getApplicationBufferSize();
+        int netBufferMax = session.getPacketBufferSize();
+
+        /*
+         * We'll make the input buffers a bit bigger than the max needed
+         * size, so that unwrap()s following a successful data transfer
+         * won't generate BUFFER_OVERFLOWS.
+         *
+         * We'll use a mix of direct and indirect ByteBuffers for
+         * tutorial purposes only.  In reality, only use direct
+         * ByteBuffers when they give a clear performance enhancement.
+         */
+        clientIn = ByteBuffer.allocate(appBufferMax + 50);
+        serverIn = ByteBuffer.allocate(appBufferMax + 50);
+
+        cTOs = ByteBuffer.allocateDirect(netBufferMax);
+        sTOc = ByteBuffer.allocateDirect(netBufferMax);
+
+        clientOut = ByteBuffer.wrap("Hi Server, I'm Client".getBytes());
+        serverOut = ByteBuffer.wrap("Hello Client, I'm Server".getBytes());
+    }
+
+    /*
+     * If the result indicates that we have outstanding tasks to do,
+     * go ahead and run them in this thread.
+     */
+    private static void runDelegatedTasks(SSLEngineResult result,
+            SSLEngine engine) throws Exception {
+
+        if (result.getHandshakeStatus() == HandshakeStatus.NEED_TASK) {
+            Runnable runnable;
+            while ((runnable = engine.getDelegatedTask()) != null) {
+                log("\trunning delegated task...");
+                runnable.run();
+            }
+            HandshakeStatus hsStatus = engine.getHandshakeStatus();
+            if (hsStatus == HandshakeStatus.NEED_TASK) {
+                throw new Exception(
+                    "handshake shouldn't need additional tasks");
+            }
+            log("\tnew HandshakeStatus: " + hsStatus);
+        }
+    }
+
+    private static boolean isEngineClosed(SSLEngine engine) {
+        return (engine.isOutboundDone() && engine.isInboundDone());
+    }
+
+    /*
+     * Simple check to make sure everything came across as expected.
+     */
+    private static void checkTransfer(ByteBuffer a, ByteBuffer b)
+            throws Exception {
+        a.flip();
+        b.flip();
+
+        if (!a.equals(b)) {
+            throw new Exception("Data didn't transfer cleanly");
+        } else {
+            log("\tData transferred cleanly");
+        }
+
+        a.position(a.limit());
+        b.position(b.limit());
+        a.limit(a.capacity());
+        b.limit(b.capacity());
+    }
+
+    /*
+     * Logging code
+     */
+    private static boolean resultOnce = true;
+
+    private static void log(String str, SSLEngineResult result) {
+        if (!logging) {
+            return;
+        }
+        if (resultOnce) {
+            resultOnce = false;
+            System.out.println("The format of the SSLEngineResult is: \n" +
+                "\t\"getStatus() / getHandshakeStatus()\" +\n" +
+                "\t\"bytesConsumed() / bytesProduced()\"\n");
+        }
+        HandshakeStatus hsStatus = result.getHandshakeStatus();
+        log(str +
+            result.getStatus() + "/" + hsStatus + ", " +
+            result.bytesConsumed() + "/" + result.bytesProduced() +
+            " bytes");
+        if (hsStatus == HandshakeStatus.FINISHED) {
+            log("\t...ready for application data");
+        }
+    }
+
+    private static void log(String str) {
+        if (logging) {
+            System.out.println(str);
+        }
+    }
+
+    /**
+     * Split a record consisting of multiple TLS handshake messages
+     * into individual TLS records, each one in a ByteBuffer of its own.
+     *
+     * @param tlsRecord A ByteBuffer containing the tls record data.
+     *        The position of the buffer should be at the first byte
+     *        in the TLS record data.
+     *
+     * @return An ArrayList consisting of one or more ByteBuffers.  Each
+     *         ByteBuffer will contain a single TLS record with one message.
+     *         That message will be taken from the input record.  The order
+     *         of the messages in the ArrayList will be the same as they
+     *         were in the input record.
+     */
+    private ArrayList<ByteBuffer> splitRecord(ByteBuffer tlsRecord) {
+        SSLSession session = clientEngine.getSession();
+        int netBufferMax = session.getPacketBufferSize();
+        ArrayList<ByteBuffer> recordList = new ArrayList<>();
+
+        if (tlsRecord.hasRemaining()) {
+            int type = Byte.toUnsignedInt(tlsRecord.get());
+            byte ver_major = tlsRecord.get();
+            byte ver_minor = tlsRecord.get();
+            int recLen = Short.toUnsignedInt(tlsRecord.getShort());
+            byte[] newMsgData = null;
+            while (tlsRecord.hasRemaining()) {
+                ByteBuffer newRecord = ByteBuffer.allocateDirect(netBufferMax);
+                switch (type) {
+                    case TLS_RECTYPE_CCS:
+                    case TLS_RECTYPE_ALERT:
+                    case TLS_RECTYPE_APPDATA:
+                        // None of our tests have multiple non-handshake
+                        // messages coalesced into a single record.
+                        break;
+                    case TLS_RECTYPE_HANDSHAKE:
+                        newMsgData = getHandshakeMessage(tlsRecord);
+                        break;
+                }
+
+                // Put a new TLS record on the destination ByteBuffer
+                newRecord.put((byte)type);
+                newRecord.put(ver_major);
+                newRecord.put(ver_minor);
+                newRecord.putShort((short)newMsgData.length);
+
+                // Now add the message content itself and attach to the
+                // returned ArrayList
+                newRecord.put(newMsgData);
+                newRecord.flip();
+                recordList.add(newRecord);
+            }
+        }
+
+        return recordList;
+    }
+
+    private static ByteBuffer createEvilClientHello(int sessIdLen) {
+        ByteBuffer newRecord = ByteBuffer.allocateDirect(4096);
+
+        // Lengths will initially be place holders until we determine the
+        // finished length of the ByteBuffer.  Then we'll go back and scribble
+        // in the correct lengths.
+
+        newRecord.put((byte)TLS_RECTYPE_HANDSHAKE);     // Record type
+        newRecord.putShort((short)0x0301);              // Protocol (TLS 1.0)
+        newRecord.putShort((short)0);                   // Length place holder
+
+        newRecord.putInt(TLS_HS_CLIENT_HELLO << 24);    // HS type and length
+        newRecord.putShort((short)0x0301);
+        newRecord.putInt((int)(System.currentTimeMillis() / 1000));
+        SecureRandom sr = new SecureRandom();
+        byte[] randBuf = new byte[28];
+        sr.nextBytes(randBuf);
+        newRecord.put(randBuf);                         // Client Random
+        newRecord.put((byte)sessIdLen);                 // Session ID length
+        if (sessIdLen > 0) {
+            byte[] sessId = new byte[sessIdLen];
+            sr.nextBytes(sessId);
+            newRecord.put(sessId);                      // Session ID
+        }
+        newRecord.putShort((short)2);                   // 2 bytes of ciphers
+        newRecord.putShort((short)0x002F);              // TLS_RSA_AES_CBC_SHA
+        newRecord.putShort((short)0x0100);              // only null compression
+        newRecord.putShort((short)5);                   // 5 bytes of extensions
+        newRecord.putShort((short)0xFF01);              // Renegotiation info
+        newRecord.putShort((short)1);
+        newRecord.put((byte)0);                         // No reneg info exts
+
+        // Go back and fill in the correct length values for the record
+        // and handshake message headers.
+        int recordLength = newRecord.position();
+        newRecord.putShort(3, (short)(recordLength - 5));
+        int newTypeAndLen = (newRecord.getInt(5) & 0xFF000000) |
+                ((recordLength - 9) & 0x00FFFFFF);
+        newRecord.putInt(5, newTypeAndLen);
+
+        newRecord.flip();
+        return newRecord;
+    }
+
+    private static ByteBuffer createEvilServerHello(ByteBuffer origHello,
+            int newSessIdLen) {
+        if (newSessIdLen < 0 || newSessIdLen > Byte.MAX_VALUE) {
+            throw new RuntimeException("Length must be 0 <= X <= 127");
+        }
+
+        ByteBuffer newRecord = ByteBuffer.allocateDirect(4096);
+        // Copy the bytes from the old hello to the new up to the session ID
+        // field.  We will go back later and fill in a new length field in
+        // the record header.  This includes the record header (5 bytes), the
+        // Handshake message header (4 bytes), protocol version (2 bytes),
+        // and the random (32 bytes).
+        ByteBuffer scratchBuffer = origHello.slice();
+        scratchBuffer.limit(43);
+        newRecord.put(scratchBuffer);
+
+        // Advance the position in the originial hello buffer past the
+        // session ID.
+        origHello.position(43);
+        int origIDLen = Byte.toUnsignedInt(origHello.get());
+        if (origIDLen > 0) {
+            // Skip over the session ID
+            origHello.position(origHello.position() + origIDLen);
+        }
+
+        // Now add our own sessionID to the new record
+        SecureRandom sr = new SecureRandom();
+        byte[] sessId = new byte[newSessIdLen];
+        sr.nextBytes(sessId);
+        newRecord.put((byte)newSessIdLen);
+        newRecord.put(sessId);
+
+        // Create another slice in the original buffer, based on the position
+        // past the session ID.  Copy the remaining bytes into the new
+        // hello buffer.  Then go back and fix up the length
+        newRecord.put(origHello.slice());
+
+        // Go back and fill in the correct length values for the record
+        // and handshake message headers.
+        int recordLength = newRecord.position();
+        newRecord.putShort(3, (short)(recordLength - 5));
+        int newTypeAndLen = (newRecord.getInt(5) & 0xFF000000) |
+                ((recordLength - 9) & 0x00FFFFFF);
+        newRecord.putInt(5, newTypeAndLen);
+
+        newRecord.flip();
+        return newRecord;
+    }
+
+    /**
+     * Look at an incoming TLS record and see if it is the desired
+     * record type, and where appropriate the correct subtype.
+     *
+     * @param srcRecord The input TLS record to be evaluated.  This
+     *        method will only look at the leading message if multiple
+     *        TLS handshake messages are coalesced into a single record.
+     * @param reqRecType The requested TLS record type
+     * @param recParams Zero or more integer sub type fields.  For CCS
+     *        and ApplicationData, no params are used.  For handshake records,
+     *        one value corresponding to the HandshakeType is required.
+     *        For Alerts, two values corresponding to AlertLevel and
+     *        AlertDescription are necessary.
+     *
+     * @return true if the proper handshake message is the first one
+     *         in the input record, false otherwise.
+     */
+    private boolean isTlsMessage(ByteBuffer srcRecord, int reqRecType,
+            int... recParams) {
+        boolean foundMsg = false;
+
+        if (srcRecord.hasRemaining()) {
+            srcRecord.mark();
+
+            // Grab the fields from the TLS Record
+            int recordType = Byte.toUnsignedInt(srcRecord.get());
+            byte ver_major = srcRecord.get();
+            byte ver_minor = srcRecord.get();
+            int recLen = Short.toUnsignedInt(srcRecord.getShort());
+
+            if (recordType == reqRecType) {
+                // For any zero-length recParams, making sure the requested
+                // type is sufficient.
+                if (recParams.length == 0) {
+                    foundMsg = true;
+                } else {
+                    switch (recordType) {
+                        case TLS_RECTYPE_CCS:
+                        case TLS_RECTYPE_APPDATA:
+                            // We really shouldn't find ourselves here, but
+                            // if someone asked for these types and had more
+                            // recParams we can ignore them.
+                            foundMsg = true;
+                            break;
+                        case TLS_RECTYPE_ALERT:
+                            // Needs two params, AlertLevel and AlertDescription
+                            if (recParams.length != 2) {
+                                throw new RuntimeException(
+                                    "Test for Alert requires level and desc.");
+                            } else {
+                                int level = Byte.toUnsignedInt(srcRecord.get());
+                                int desc = Byte.toUnsignedInt(srcRecord.get());
+                                if (level == recParams[0] &&
+                                        desc == recParams[1]) {
+                                    foundMsg = true;
+                                }
+                            }
+                            break;
+                        case TLS_RECTYPE_HANDSHAKE:
+                            // Needs one parameter, HandshakeType
+                            if (recParams.length != 1) {
+                                throw new RuntimeException(
+                                    "Test for Handshake requires only HS type");
+                            } else {
+                                // Go into the first handhshake message in the
+                                // record and grab the handshake message header.
+                                // All we need to do is parse out the leading
+                                // byte.
+                                int msgHdr = srcRecord.getInt();
+                                int msgType = (msgHdr >> 24) & 0x000000FF;
+                                if (msgType == recParams[0]) {
+                                foundMsg = true;
+                            }
+                        }
+                        break;
+                    }
+                }
+            }
+
+            srcRecord.reset();
+        }
+
+        return foundMsg;
+    }
+
+    private byte[] getHandshakeMessage(ByteBuffer srcRecord) {
+        // At the start of this routine, the position should be lined up
+        // at the first byte of a handshake message.  Mark this location
+        // so we can return to it after reading the type and length.
+        srcRecord.mark();
+        int msgHdr = srcRecord.getInt();
+        int type = (msgHdr >> 24) & 0x000000FF;
+        int length = msgHdr & 0x00FFFFFF;
+
+        // Create a byte array that has enough space for the handshake
+        // message header and body.
+        byte[] data = new byte[length + 4];
+        srcRecord.reset();
+        srcRecord.get(data, 0, length + 4);
+
+        return (data);
+    }
+
+    /**
+     * Hex-dumps a ByteBuffer to stdout.
+     */
+    private static void dumpByteBuffer(String header, ByteBuffer bBuf) {
+        if (dumpBufs == false) {
+            return;
+        }
+
+        int bufLen = bBuf.remaining();
+        if (bufLen > 0) {
+            bBuf.mark();
+
+            // We expect the position of the buffer to be at the
+            // beginning of a TLS record.  Get the type, version and length.
+            int type = Byte.toUnsignedInt(bBuf.get());
+            int ver_major = Byte.toUnsignedInt(bBuf.get());
+            int ver_minor = Byte.toUnsignedInt(bBuf.get());
+            int recLen = Short.toUnsignedInt(bBuf.getShort());
+            ProtocolVersion pv = ProtocolVersion.valueOf(ver_major, ver_minor);
+
+            log("===== " + header + " (" + tlsRecType(type) + " / " +
+                pv + " / " + bufLen + " bytes) =====");
+            bBuf.reset();
+            for (int i = 0; i < bufLen; i++) {
+                if (i != 0 && i % 16 == 0) {
+                    System.out.print("\n");
+                }
+                System.out.format("%02X ", bBuf.get(i));
+            }
+            log("\n===============================================");
+            bBuf.reset();
+        }
+    }
+
+    private static String tlsRecType(int type) {
+        switch (type) {
+            case 20:
+                return "Change Cipher Spec";
+            case 21:
+                return "Alert";
+            case 22:
+                return "Handshake";
+            case 23:
+                return "Application Data";
+            default:
+                return ("Unknown (" + type + ")");
+        }
+    }
+}