--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/trilead/ssh2/transport/KexManager.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,568 @@
+
+package com.trilead.ssh2.transport;
+
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.security.interfaces.DSAPublicKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAPublicKey;
+import java.util.Set;
+import java.util.TreeSet;
+
+import com.trilead.ssh2.ConnectionInfo;
+import com.trilead.ssh2.DHGexParameters;
+import com.trilead.ssh2.ServerHostKeyVerifier;
+import com.trilead.ssh2.compression.CompressionFactory;
+import com.trilead.ssh2.compression.ICompressor;
+import com.trilead.ssh2.crypto.CryptoWishList;
+import com.trilead.ssh2.crypto.KeyMaterial;
+import com.trilead.ssh2.crypto.cipher.BlockCipher;
+import com.trilead.ssh2.crypto.cipher.BlockCipherFactory;
+import com.trilead.ssh2.crypto.dh.DhGroupExchange;
+import com.trilead.ssh2.crypto.dh.GenericDhExchange;
+import com.trilead.ssh2.crypto.digest.MAC;
+import com.trilead.ssh2.log.Logger;
+import com.trilead.ssh2.packets.PacketKexDHInit;
+import com.trilead.ssh2.packets.PacketKexDHReply;
+import com.trilead.ssh2.packets.PacketKexDhGexGroup;
+import com.trilead.ssh2.packets.PacketKexDhGexInit;
+import com.trilead.ssh2.packets.PacketKexDhGexReply;
+import com.trilead.ssh2.packets.PacketKexDhGexRequest;
+import com.trilead.ssh2.packets.PacketKexDhGexRequestOld;
+import com.trilead.ssh2.packets.PacketKexInit;
+import com.trilead.ssh2.packets.PacketNewKeys;
+import com.trilead.ssh2.packets.Packets;
+import com.trilead.ssh2.signature.DSASHA1Verify;
+import com.trilead.ssh2.signature.ECDSASHA2Verify;
+import com.trilead.ssh2.signature.RSASHA1Verify;
+
+
+/**
+ * KexManager.
+ *
+ * @author Christian Plattner, plattner@trilead.com
+ * @version $Id: KexManager.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $
+ */
+public class KexManager {
+    private static final Logger log = Logger.getLogger(KexManager.class);
+
+    private static final Set<String> HOSTKEY_ALGS = new TreeSet<String>();
+    static {
+        HOSTKEY_ALGS.add("ecdsa-sha2-nistp256");
+        HOSTKEY_ALGS.add("ecdsa-sha2-nistp384");
+        HOSTKEY_ALGS.add("ecdsa-sha2-nistp521");
+        HOSTKEY_ALGS.add("ssh-rsa");
+        HOSTKEY_ALGS.add("ssh-dsa");
+    }
+
+    private static final Set<String> KEX_ALGS = new TreeSet<String>();
+    static {
+        KEX_ALGS.add("ecdh-sha2-nistp256");
+        KEX_ALGS.add("ecdh-sha2-nistp384");
+        KEX_ALGS.add("ecdh-sha2-nistp521");
+        KEX_ALGS.add("diffie-hellman-group-exchange-sha256");
+        KEX_ALGS.add("diffie-hellman-group-exchange-sha1");
+        KEX_ALGS.add("diffie-hellman-group14-sha1");
+        KEX_ALGS.add("diffie-hellman-group1-sha1");
+    }
+
+    KexState kxs;
+    int kexCount = 0;
+    KeyMaterial km;
+    byte[] sessionId;
+    ClientServerHello csh;
+
+    final Object accessLock = new Object();
+    ConnectionInfo lastConnInfo = null;
+
+    boolean connectionClosed = false;
+
+    boolean ignore_next_kex_packet = false;
+
+    final TransportManager tm;
+
+    CryptoWishList nextKEXcryptoWishList;
+    DHGexParameters nextKEXdhgexParameters;
+
+    ServerHostKeyVerifier verifier;
+    final String hostname;
+    final int port;
+    final SecureRandom rnd;
+
+    public KexManager(TransportManager tm, ClientServerHello csh, CryptoWishList initialCwl, String hostname, int port,
+                      ServerHostKeyVerifier keyVerifier, SecureRandom rnd) {
+        this.tm = tm;
+        this.csh = csh;
+        this.nextKEXcryptoWishList = initialCwl;
+        this.nextKEXdhgexParameters = new DHGexParameters();
+        this.hostname = hostname;
+        this.port = port;
+        this.verifier = keyVerifier;
+        this.rnd = rnd;
+    }
+
+    public ConnectionInfo getOrWaitForConnectionInfo(int minKexCount) throws IOException {
+        synchronized (accessLock) {
+            while (true) {
+                if ((lastConnInfo != null) && (lastConnInfo.keyExchangeCounter >= minKexCount))
+                    return lastConnInfo;
+
+                if (connectionClosed)
+                    throw(IOException) new IOException("Key exchange was not finished, connection is closed.")
+                    .initCause(tm.getReasonClosedCause());
+
+                try {
+                    accessLock.wait();
+                }
+                catch (InterruptedException e) {
+                }
+            }
+        }
+    }
+
+    private String getFirstMatch(String[] client, String[] server) throws NegotiateException {
+        if (client == null || server == null)
+            throw new IllegalArgumentException();
+
+        if (client.length == 0)
+            return null;
+
+        for (int i = 0; i < client.length; i++) {
+            for (int j = 0; j < server.length; j++) {
+                if (client[i].equals(server[j]))
+                    return client[i];
+            }
+        }
+
+        throw new NegotiateException();
+    }
+
+    private boolean compareFirstOfNameList(String[] a, String[] b) {
+        if (a == null || b == null)
+            throw new IllegalArgumentException();
+
+        if ((a.length == 0) && (b.length == 0))
+            return true;
+
+        if ((a.length == 0) || (b.length == 0))
+            return false;
+
+        return (a[0].equals(b[0]));
+    }
+
+    private boolean isGuessOK(KexParameters cpar, KexParameters spar) {
+        if (cpar == null || spar == null)
+            throw new IllegalArgumentException();
+
+        if (compareFirstOfNameList(cpar.kex_algorithms, spar.kex_algorithms) == false) {
+            return false;
+        }
+
+        if (compareFirstOfNameList(cpar.server_host_key_algorithms, spar.server_host_key_algorithms) == false) {
+            return false;
+        }
+
+        /*
+         * We do NOT check here if the other algorithms can be agreed on, this
+         * is just a check if kex_algorithms and server_host_key_algorithms were
+         * guessed right!
+         */
+        return true;
+    }
+
+    private NegotiatedParameters mergeKexParameters(KexParameters client, KexParameters server) {
+        NegotiatedParameters np = new NegotiatedParameters();
+
+        try {
+            np.kex_algo = getFirstMatch(client.kex_algorithms, server.kex_algorithms);
+            log.log(20, "kex_algo=" + np.kex_algo);
+            np.server_host_key_algo = getFirstMatch(client.server_host_key_algorithms,
+                                                    server.server_host_key_algorithms);
+            log.log(20, "server_host_key_algo=" + np.server_host_key_algo);
+            np.enc_algo_client_to_server = getFirstMatch(client.encryption_algorithms_client_to_server,
+                                           server.encryption_algorithms_client_to_server);
+            np.enc_algo_server_to_client = getFirstMatch(client.encryption_algorithms_server_to_client,
+                                           server.encryption_algorithms_server_to_client);
+            log.log(20, "enc_algo_client_to_server=" + np.enc_algo_client_to_server);
+            log.log(20, "enc_algo_server_to_client=" + np.enc_algo_server_to_client);
+            np.mac_algo_client_to_server = getFirstMatch(client.mac_algorithms_client_to_server,
+                                           server.mac_algorithms_client_to_server);
+            np.mac_algo_server_to_client = getFirstMatch(client.mac_algorithms_server_to_client,
+                                           server.mac_algorithms_server_to_client);
+            log.log(20, "mac_algo_client_to_server=" + np.mac_algo_client_to_server);
+            log.log(20, "mac_algo_server_to_client=" + np.mac_algo_server_to_client);
+            np.comp_algo_client_to_server = getFirstMatch(client.compression_algorithms_client_to_server,
+                                            server.compression_algorithms_client_to_server);
+            np.comp_algo_server_to_client = getFirstMatch(client.compression_algorithms_server_to_client,
+                                            server.compression_algorithms_server_to_client);
+            log.log(20, "comp_algo_client_to_server=" + np.comp_algo_client_to_server);
+            log.log(20, "comp_algo_server_to_client=" + np.comp_algo_server_to_client);
+        }
+        catch (NegotiateException e) {
+            return null;
+        }
+
+        try {
+            np.lang_client_to_server = getFirstMatch(client.languages_client_to_server,
+                                       server.languages_client_to_server);
+        }
+        catch (NegotiateException e1) {
+            np.lang_client_to_server = null;
+        }
+
+        try {
+            np.lang_server_to_client = getFirstMatch(client.languages_server_to_client,
+                                       server.languages_server_to_client);
+        }
+        catch (NegotiateException e2) {
+            np.lang_server_to_client = null;
+        }
+
+        if (isGuessOK(client, server))
+            np.guessOK = true;
+
+        return np;
+    }
+
+    public synchronized void initiateKEX(CryptoWishList cwl, DHGexParameters dhgex) throws IOException {
+        nextKEXcryptoWishList = cwl;
+        nextKEXdhgexParameters = dhgex;
+
+        if (kxs == null) {
+            kxs = new KexState();
+            kxs.dhgexParameters = nextKEXdhgexParameters;
+            PacketKexInit kp = new PacketKexInit(nextKEXcryptoWishList);
+            kxs.localKEX = kp;
+            tm.sendKexMessage(kp.getPayload());
+        }
+    }
+
+    private boolean establishKeyMaterial() {
+        try {
+            int mac_cs_key_len = MAC.getKeyLen(kxs.np.mac_algo_client_to_server);
+            int enc_cs_key_len = BlockCipherFactory.getKeySize(kxs.np.enc_algo_client_to_server);
+            int enc_cs_block_len = BlockCipherFactory.getBlockSize(kxs.np.enc_algo_client_to_server);
+            int mac_sc_key_len = MAC.getKeyLen(kxs.np.mac_algo_server_to_client);
+            int enc_sc_key_len = BlockCipherFactory.getKeySize(kxs.np.enc_algo_server_to_client);
+            int enc_sc_block_len = BlockCipherFactory.getBlockSize(kxs.np.enc_algo_server_to_client);
+            km = KeyMaterial.create(kxs.hashAlgo, kxs.H, kxs.K, sessionId, enc_cs_key_len, enc_cs_block_len, mac_cs_key_len,
+                                    enc_sc_key_len, enc_sc_block_len, mac_sc_key_len);
+        }
+        catch (IllegalArgumentException e) {
+            return false;
+        }
+
+        return true;
+    }
+
+    private void finishKex() throws IOException {
+        if (sessionId == null)
+            sessionId = kxs.H;
+
+        establishKeyMaterial();
+        /* Tell the other side that we start using the new material */
+        PacketNewKeys ign = new PacketNewKeys();
+        tm.sendKexMessage(ign.getPayload());
+        BlockCipher cbc;
+        MAC mac;
+        ICompressor comp;
+
+        try {
+            cbc = BlockCipherFactory.createCipher(kxs.np.enc_algo_client_to_server, true, km.enc_key_client_to_server,
+                                                  km.initial_iv_client_to_server);
+            mac = new MAC(kxs.np.mac_algo_client_to_server, km.integrity_key_client_to_server);
+            comp = CompressionFactory.createCompressor(kxs.np.comp_algo_client_to_server);
+        }
+        catch (IllegalArgumentException e1) {
+            throw new IOException("Fatal error during MAC startup!");
+        }
+
+        tm.changeSendCipher(cbc, mac);
+        tm.changeSendCompression(comp);
+        tm.kexFinished();
+    }
+
+    public static final String[] getDefaultServerHostkeyAlgorithmList() {
+        return HOSTKEY_ALGS.toArray(new String[HOSTKEY_ALGS.size()]);
+    }
+
+    public static final void checkServerHostkeyAlgorithmsList(String[] algos) {
+        for (int i = 0; i < algos.length; i++) {
+            if (!HOSTKEY_ALGS.contains(algos[i]))
+                throw new IllegalArgumentException("Unknown server host key algorithm '" + algos[i] + "'");
+        }
+    }
+
+    public static final String[] getDefaultKexAlgorithmList() {
+        return KEX_ALGS.toArray(new String[KEX_ALGS.size()]);
+    }
+
+    public static final void checkKexAlgorithmList(String[] algos) {
+        for (int i = 0; i < algos.length; i++) {
+            if (!KEX_ALGS.contains(algos[i]))
+                throw new IllegalArgumentException("Unknown kex algorithm '" + algos[i] + "'");
+        }
+    }
+
+    private boolean verifySignature(byte[] sig, byte[] hostkey) throws IOException {
+        if (kxs.np.server_host_key_algo.startsWith("ecdsa-sha2-")) {
+            byte[] rs = ECDSASHA2Verify.decodeSSHECDSASignature(sig);
+            ECPublicKey epk = ECDSASHA2Verify.decodeSSHECDSAPublicKey(hostkey);
+            log.log(50, "Verifying ecdsa signature");
+            return ECDSASHA2Verify.verifySignature(kxs.H, rs, epk);
+        }
+
+        if (kxs.np.server_host_key_algo.equals("ssh-rsa")) {
+            byte[] rs = RSASHA1Verify.decodeSSHRSASignature(sig);
+            RSAPublicKey rpk = RSASHA1Verify.decodeSSHRSAPublicKey(hostkey);
+            log.log(50, "Verifying ssh-rsa signature");
+            return RSASHA1Verify.verifySignature(kxs.H, rs, rpk);
+        }
+
+        if (kxs.np.server_host_key_algo.equals("ssh-dss")) {
+            byte[] ds = DSASHA1Verify.decodeSSHDSASignature(sig);
+            DSAPublicKey dpk = DSASHA1Verify.decodeSSHDSAPublicKey(hostkey);
+            log.log(50, "Verifying ssh-dss signature");
+            return DSASHA1Verify.verifySignature(kxs.H, ds, dpk);
+        }
+
+        throw new IOException("Unknown server host key algorithm '" + kxs.np.server_host_key_algo + "'");
+    }
+
+    public synchronized void handleMessage(byte[] msg, int msglen) throws IOException {
+        PacketKexInit kip;
+
+        if (msg == null) {
+            synchronized (accessLock) {
+                connectionClosed = true;
+                accessLock.notifyAll();
+                return;
+            }
+        }
+
+        if ((kxs == null) && (msg[0] != Packets.SSH_MSG_KEXINIT))
+            throw new IOException("Unexpected KEX message (type " + msg[0] + ")");
+
+        if (ignore_next_kex_packet) {
+            ignore_next_kex_packet = false;
+            return;
+        }
+
+        if (msg[0] == Packets.SSH_MSG_KEXINIT) {
+            if ((kxs != null) && (kxs.state != 0))
+                throw new IOException("Unexpected SSH_MSG_KEXINIT message during on-going kex exchange!");
+
+            if (kxs == null) {
+                /*
+                 * Ah, OK, peer wants to do KEX. Let's be nice and play
+                 * together.
+                 */
+                kxs = new KexState();
+                kxs.dhgexParameters = nextKEXdhgexParameters;
+                kip = new PacketKexInit(nextKEXcryptoWishList);
+                kxs.localKEX = kip;
+                tm.sendKexMessage(kip.getPayload());
+            }
+
+            kip = new PacketKexInit(msg, 0, msglen);
+            kxs.remoteKEX = kip;
+            kxs.np = mergeKexParameters(kxs.localKEX.getKexParameters(), kxs.remoteKEX.getKexParameters());
+
+            if (kxs.np == null)
+                throw new IOException("Cannot negotiate, proposals do not match.");
+
+            if (kxs.remoteKEX.isFirst_kex_packet_follows() && (kxs.np.guessOK == false)) {
+                /*
+                 * Guess was wrong, we need to ignore the next kex packet.
+                 */
+                ignore_next_kex_packet = true;
+            }
+
+            if (kxs.np.kex_algo.equals("diffie-hellman-group-exchange-sha1")
+                    || kxs.np.kex_algo.equals("diffie-hellman-group-exchange-sha256")) {
+                if (kxs.dhgexParameters.getMin_group_len() == 0 || csh.server_versioncomment.matches("OpenSSH_2\\.([0-4]\\.|5\\.[0-2]).*")) {
+                    PacketKexDhGexRequestOld dhgexreq = new PacketKexDhGexRequestOld(kxs.dhgexParameters);
+                    tm.sendKexMessage(dhgexreq.getPayload());
+                }
+                else {
+                    PacketKexDhGexRequest dhgexreq = new PacketKexDhGexRequest(kxs.dhgexParameters);
+                    tm.sendKexMessage(dhgexreq.getPayload());
+                }
+
+                if (kxs.np.kex_algo.endsWith("sha1")) {
+                    kxs.hashAlgo = "SHA1";
+                }
+                else {
+                    kxs.hashAlgo = "SHA-256";
+                }
+
+                kxs.state = 1;
+                return;
+            }
+
+            if (kxs.np.kex_algo.equals("diffie-hellman-group1-sha1")
+                    || kxs.np.kex_algo.equals("diffie-hellman-group14-sha1")
+                    || kxs.np.kex_algo.equals("ecdh-sha2-nistp256")
+                    || kxs.np.kex_algo.equals("ecdh-sha2-nistp384")
+                    || kxs.np.kex_algo.equals("ecdh-sha2-nistp521")) {
+                kxs.dhx = GenericDhExchange.getInstance(kxs.np.kex_algo);
+                kxs.dhx.init(kxs.np.kex_algo);
+                kxs.hashAlgo = kxs.dhx.getHashAlgo();
+                PacketKexDHInit kp = new PacketKexDHInit(kxs.dhx.getE());
+                tm.sendKexMessage(kp.getPayload());
+                kxs.state = 1;
+                return;
+            }
+
+            throw new IllegalStateException("Unknown KEX method!");
+        }
+
+        if (msg[0] == Packets.SSH_MSG_NEWKEYS) {
+            if (km == null)
+                throw new IOException("Peer sent SSH_MSG_NEWKEYS, but I have no key material ready!");
+
+            BlockCipher cbc;
+            MAC mac;
+            ICompressor comp;
+
+            try {
+                cbc = BlockCipherFactory.createCipher(kxs.np.enc_algo_server_to_client, false,
+                                                      km.enc_key_server_to_client, km.initial_iv_server_to_client);
+                mac = new MAC(kxs.np.mac_algo_server_to_client, km.integrity_key_server_to_client);
+                comp = CompressionFactory.createCompressor(kxs.np.comp_algo_server_to_client);
+            }
+            catch (IllegalArgumentException e1) {
+                throw new IOException("Fatal error during MAC startup!");
+            }
+
+            tm.changeRecvCipher(cbc, mac);
+            tm.changeRecvCompression(comp);
+            ConnectionInfo sci = new ConnectionInfo();
+            kexCount++;
+            sci.keyExchangeAlgorithm = kxs.np.kex_algo;
+            sci.keyExchangeCounter = kexCount;
+            sci.clientToServerCryptoAlgorithm = kxs.np.enc_algo_client_to_server;
+            sci.serverToClientCryptoAlgorithm = kxs.np.enc_algo_server_to_client;
+            sci.clientToServerMACAlgorithm = kxs.np.mac_algo_client_to_server;
+            sci.serverToClientMACAlgorithm = kxs.np.mac_algo_server_to_client;
+            sci.serverHostKeyAlgorithm = kxs.np.server_host_key_algo;
+            sci.serverHostKey = kxs.hostkey;
+
+            synchronized (accessLock) {
+                lastConnInfo = sci;
+                accessLock.notifyAll();
+            }
+
+            kxs = null;
+            return;
+        }
+
+        if ((kxs == null) || (kxs.state == 0))
+            throw new IOException("Unexpected Kex submessage!");
+
+        if (kxs.np.kex_algo.equals("diffie-hellman-group-exchange-sha1")
+                || kxs.np.kex_algo.equals("diffie-hellman-group-exchange-sha256")) {
+            if (kxs.state == 1) {
+                PacketKexDhGexGroup dhgexgrp = new PacketKexDhGexGroup(msg, 0, msglen);
+                kxs.dhgx = new DhGroupExchange(dhgexgrp.getP(), dhgexgrp.getG());
+                kxs.dhgx.init(rnd);
+                PacketKexDhGexInit dhgexinit = new PacketKexDhGexInit(kxs.dhgx.getE());
+                tm.sendKexMessage(dhgexinit.getPayload());
+                kxs.state = 2;
+                return;
+            }
+
+            if (kxs.state == 2) {
+                PacketKexDhGexReply dhgexrpl = new PacketKexDhGexReply(msg, 0, msglen);
+                kxs.hostkey = dhgexrpl.getHostKey();
+
+                if (verifier != null) {
+                    boolean vres = false;
+
+                    try {
+                        vres = verifier.verifyServerHostKey(hostname, port, kxs.np.server_host_key_algo, kxs.hostkey);
+                    }
+                    catch (Exception e) {
+                        throw(IOException) new IOException(
+                            "The server hostkey was not accepted by the verifier callback.").initCause(e);
+                    }
+
+                    if (vres == false)
+                        throw new IOException("The server hostkey was not accepted by the verifier callback");
+                }
+
+                kxs.dhgx.setF(dhgexrpl.getF());
+
+                try {
+                    kxs.H = kxs.dhgx.calculateH(kxs.hashAlgo,
+                                                csh.getClientString(), csh.getServerString(),
+                                                kxs.localKEX.getPayload(), kxs.remoteKEX.getPayload(),
+                                                dhgexrpl.getHostKey(), kxs.dhgexParameters);
+                }
+                catch (IllegalArgumentException e) {
+                    throw(IOException) new IOException("KEX error.").initCause(e);
+                }
+
+                boolean res = verifySignature(dhgexrpl.getSignature(), kxs.hostkey);
+
+                if (res == false)
+                    throw new IOException("Hostkey signature sent by remote is wrong!");
+
+                kxs.K = kxs.dhgx.getK();
+                finishKex();
+                kxs.state = -1;
+                return;
+            }
+
+            throw new IllegalStateException("Illegal State in KEX Exchange!");
+        }
+
+        if (kxs.np.kex_algo.equals("diffie-hellman-group1-sha1")
+                || kxs.np.kex_algo.equals("diffie-hellman-group14-sha1")
+                || kxs.np.kex_algo.equals("ecdh-sha2-nistp256")
+                || kxs.np.kex_algo.equals("ecdh-sha2-nistp384")
+                || kxs.np.kex_algo.equals("ecdh-sha2-nistp521")) {
+            if (kxs.state == 1) {
+                PacketKexDHReply dhr = new PacketKexDHReply(msg, 0, msglen);
+                kxs.hostkey = dhr.getHostKey();
+
+                if (verifier != null) {
+                    boolean vres = false;
+
+                    try {
+                        vres = verifier.verifyServerHostKey(hostname, port, kxs.np.server_host_key_algo, kxs.hostkey);
+                    }
+                    catch (Exception e) {
+                        throw(IOException) new IOException(
+                            "The server hostkey was not accepted by the verifier callback.").initCause(e);
+                    }
+
+                    if (vres == false)
+                        throw new IOException("The server hostkey was not accepted by the verifier callback");
+                }
+
+                kxs.dhx.setF(dhr.getF());
+
+                try {
+                    kxs.H = kxs.dhx.calculateH(csh.getClientString(), csh.getServerString(), kxs.localKEX.getPayload(),
+                                               kxs.remoteKEX.getPayload(), dhr.getHostKey());
+                }
+                catch (IllegalArgumentException e) {
+                    throw(IOException) new IOException("KEX error.").initCause(e);
+                }
+
+                boolean res = verifySignature(dhr.getSignature(), kxs.hostkey);
+
+                if (res == false)
+                    throw new IOException("Hostkey signature sent by remote is wrong!");
+
+                kxs.K = kxs.dhx.getK();
+                finishKex();
+                kxs.state = -1;
+                return;
+            }
+        }
+
+        throw new IllegalStateException("Unkown KEX method! (" + kxs.np.kex_algo + ")");
+    }
+}