--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/trilead/ssh2/channel/AuthAgentForwardThread.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,542 @@
+/*
+ * ConnectBot: simple, powerful, open-source SSH client for Android
+ * Copyright 2007 Kenny Root, Jeffrey Sharkey
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.trilead.ssh2.channel;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.math.BigInteger;
+import java.security.KeyFactory;
+import java.security.KeyPair;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.SecureRandom;
+import java.security.interfaces.DSAPrivateKey;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.spec.DSAPrivateKeySpec;
+import java.security.spec.DSAPublicKeySpec;
+import java.security.spec.ECParameterSpec;
+import java.security.spec.ECPoint;
+import java.security.spec.ECPrivateKeySpec;
+import java.security.spec.ECPublicKeySpec;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+import java.security.spec.RSAPrivateCrtKeySpec;
+import java.security.spec.RSAPublicKeySpec;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import com.trilead.ssh2.AuthAgentCallback;
+import com.trilead.ssh2.log.Logger;
+import com.trilead.ssh2.packets.TypesReader;
+import com.trilead.ssh2.packets.TypesWriter;
+import com.trilead.ssh2.signature.DSASHA1Verify;
+import com.trilead.ssh2.signature.ECDSASHA2Verify;
+import com.trilead.ssh2.signature.RSASHA1Verify;
+
+/**
+ * AuthAgentForwardThread.
+ *
+ * @author Kenny Root
+ * @version $Id$
+ */
+public class AuthAgentForwardThread extends Thread implements IChannelWorkerThread {
+    private static final byte[] SSH_AGENT_FAILURE = {0, 0, 0, 1, 5}; // 5
+    private static final byte[] SSH_AGENT_SUCCESS = {0, 0, 0, 1, 6}; // 6
+
+    private static final int SSH2_AGENTC_REQUEST_IDENTITIES = 11;
+    private static final int SSH2_AGENT_IDENTITIES_ANSWER = 12;
+
+    private static final int SSH2_AGENTC_SIGN_REQUEST = 13;
+    private static final int SSH2_AGENT_SIGN_RESPONSE = 14;
+
+    private static final int SSH2_AGENTC_ADD_IDENTITY = 17;
+    private static final int SSH2_AGENTC_REMOVE_IDENTITY = 18;
+    private static final int SSH2_AGENTC_REMOVE_ALL_IDENTITIES = 19;
+
+//  private static final int SSH_AGENTC_ADD_SMARTCARD_KEY = 20;
+//  private static final int SSH_AGENTC_REMOVE_SMARTCARD_KEY = 21;
+
+    private static final int SSH_AGENTC_LOCK = 22;
+    private static final int SSH_AGENTC_UNLOCK = 23;
+
+    private static final int SSH2_AGENTC_ADD_ID_CONSTRAINED = 25;
+//  private static final int SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED = 26;
+
+    // Constraints for adding keys
+    private static final int SSH_AGENT_CONSTRAIN_LIFETIME = 1;
+    private static final int SSH_AGENT_CONSTRAIN_CONFIRM = 2;
+
+    // Flags for signature requests
+//  private static final int SSH_AGENT_OLD_SIGNATURE = 1;
+
+    private static final Logger log = Logger.getLogger(RemoteAcceptThread.class);
+
+    AuthAgentCallback authAgent;
+    OutputStream os;
+    InputStream is;
+    Channel c;
+
+    byte[] buffer = new byte[Channel.CHANNEL_BUFFER_SIZE];
+
+    public AuthAgentForwardThread(Channel c, AuthAgentCallback authAgent) {
+        this.c = c;
+        this.authAgent = authAgent;
+
+        if (log.isEnabled())
+            log.log(20, "AuthAgentForwardThread started");
+    }
+
+    @Override
+    public void run() {
+        try {
+            c.cm.registerThread(this);
+        }
+        catch (IOException e) {
+            stopWorking();
+            return;
+        }
+
+        try {
+            c.cm.sendOpenConfirmation(c);
+            is = c.getStdoutStream();
+            os = c.getStdinStream();
+            int totalSize = 4;
+            int readSoFar = 0;
+
+            while (true) {
+                int len;
+
+                try {
+                    len = is.read(buffer, readSoFar, buffer.length - readSoFar);
+                }
+                catch (IOException e) {
+                    stopWorking();
+                    return;
+                }
+
+                if (len <= 0)
+                    break;
+
+                readSoFar += len;
+
+                if (readSoFar >= 4) {
+                    TypesReader tr = new TypesReader(buffer, 0, 4);
+                    totalSize = tr.readUINT32() + 4;
+                }
+
+                if (totalSize == readSoFar) {
+                    TypesReader tr = new TypesReader(buffer, 4, readSoFar - 4);
+                    int messageType = tr.readByte();
+
+                    switch (messageType) {
+                        case SSH2_AGENTC_REQUEST_IDENTITIES:
+                            sendIdentities();
+                            break;
+
+                        case SSH2_AGENTC_ADD_IDENTITY:
+                            addIdentity(tr, false);
+                            break;
+
+                        case SSH2_AGENTC_ADD_ID_CONSTRAINED:
+                            addIdentity(tr, true);
+                            break;
+
+                        case SSH2_AGENTC_REMOVE_IDENTITY:
+                            removeIdentity(tr);
+                            break;
+
+                        case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
+                            removeAllIdentities(tr);
+                            break;
+
+                        case SSH2_AGENTC_SIGN_REQUEST:
+                            processSignRequest(tr);
+                            break;
+
+                        case SSH_AGENTC_LOCK:
+                            processLockRequest(tr);
+                            break;
+
+                        case SSH_AGENTC_UNLOCK:
+                            processUnlockRequest(tr);
+                            break;
+
+                        default:
+                            os.write(SSH_AGENT_FAILURE);
+                            break;
+                    }
+
+                    readSoFar = 0;
+                }
+            }
+
+            c.cm.closeChannel(c, "EOF on both streams reached.", true);
+        }
+        catch (IOException e) {
+            log.log(50, "IOException in agent forwarder: " + e.getMessage());
+
+            try {
+                is.close();
+            }
+            catch (IOException e1) {
+            }
+
+            try {
+                os.close();
+            }
+            catch (IOException e2) {
+            }
+
+            try {
+                c.cm.closeChannel(c, "IOException in agent forwarder (" + e.getMessage() + ")", true);
+            }
+            catch (IOException e3) {
+            }
+        }
+    }
+
+    public void stopWorking() {
+        try {
+            /* This will lead to an IOException in the is.read() call */
+            is.close();
+        }
+        catch (IOException e) {
+        }
+    }
+
+    /**
+     * @return whether the agent is locked
+     */
+    private boolean failWhenLocked() throws IOException {
+        if (authAgent.isAgentLocked()) {
+            os.write(SSH_AGENT_FAILURE);
+            return true;
+        }
+        else
+            return false;
+    }
+
+    private void sendIdentities() throws IOException {
+        Map<String, byte[]> keys = null;
+        TypesWriter tw = new TypesWriter();
+        tw.writeByte(SSH2_AGENT_IDENTITIES_ANSWER);
+        int numKeys = 0;
+
+        if (!authAgent.isAgentLocked())
+            keys = authAgent.retrieveIdentities();
+
+        if (keys != null)
+            numKeys = keys.size();
+
+        tw.writeUINT32(numKeys);
+
+        if (keys != null) {
+            for (Entry<String, byte[]> entry : keys.entrySet()) {
+                byte[] keyBytes = entry.getValue();
+                tw.writeString(keyBytes, 0, keyBytes.length);
+                tw.writeString(entry.getKey());
+            }
+        }
+
+        sendPacket(tw.getBytes());
+    }
+
+    /**
+     * @param tr
+     */
+    private void addIdentity(TypesReader tr, boolean checkConstraints) {
+        try {
+            if (failWhenLocked())
+                return;
+
+            String type = tr.readString();
+            String comment;
+            String keyType;
+            KeySpec pubSpec;
+            KeySpec privSpec;
+
+            if (type.equals("ssh-rsa")) {
+                keyType = "RSA";
+                BigInteger n = tr.readMPINT();
+                BigInteger e = tr.readMPINT();
+                BigInteger d = tr.readMPINT();
+                BigInteger iqmp = tr.readMPINT();
+                BigInteger p = tr.readMPINT();
+                BigInteger q = tr.readMPINT();
+                comment = tr.readString();
+                // Derive the extra values Java needs.
+                BigInteger dmp1 = d.mod(p.subtract(BigInteger.ONE));
+                BigInteger dmq1 = d.mod(q.subtract(BigInteger.ONE));
+                pubSpec = new RSAPublicKeySpec(n, e);
+                privSpec = new RSAPrivateCrtKeySpec(n, e, d, p, q, dmp1, dmq1, iqmp);
+            }
+            else if (type.equals("ssh-dss")) {
+                keyType = "DSA";
+                BigInteger p = tr.readMPINT();
+                BigInteger q = tr.readMPINT();
+                BigInteger g = tr.readMPINT();
+                BigInteger y = tr.readMPINT();
+                BigInteger x = tr.readMPINT();
+                comment = tr.readString();
+                pubSpec = new DSAPublicKeySpec(y, p, q, g);
+                privSpec = new DSAPrivateKeySpec(x, p, q, g);
+            }
+            else if (type.equals("ecdsa-sha2-nistp256")) {
+                keyType = "EC";
+                String curveName = tr.readString();
+                byte[] groupBytes = tr.readByteString();
+                BigInteger exponent = tr.readMPINT();
+                comment = tr.readString();
+
+                if (!"nistp256".equals(curveName)) {
+                    log.log(2, "Invalid curve name for ecdsa-sha2-nistp256: " + curveName);
+                    os.write(SSH_AGENT_FAILURE);
+                    return;
+                }
+
+                ECParameterSpec nistp256 = ECDSASHA2Verify.EllipticCurves.nistp256;
+                ECPoint group = ECDSASHA2Verify.decodeECPoint(groupBytes, nistp256.getCurve());
+
+                if (group == null) {
+                    // TODO log error
+                    os.write(SSH_AGENT_FAILURE);
+                    return;
+                }
+
+                pubSpec = new ECPublicKeySpec(group, nistp256);
+                privSpec = new ECPrivateKeySpec(exponent, nistp256);
+            }
+            else {
+                log.log(2, "Unknown key type: " + type);
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+
+            PublicKey pubKey;
+            PrivateKey privKey;
+
+            try {
+                KeyFactory kf = KeyFactory.getInstance(keyType);
+                pubKey = kf.generatePublic(pubSpec);
+                privKey = kf.generatePrivate(privSpec);
+            }
+            catch (NoSuchAlgorithmException ex) {
+                // TODO: log error
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+            catch (InvalidKeySpecException ex) {
+                // TODO: log error
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+
+            KeyPair pair = new KeyPair(pubKey, privKey);
+            boolean confirmUse = false;
+            int lifetime = 0;
+
+            if (checkConstraints) {
+                while (tr.remain() > 0) {
+                    int constraint = tr.readByte();
+
+                    if (constraint == SSH_AGENT_CONSTRAIN_CONFIRM)
+                        confirmUse = true;
+                    else if (constraint == SSH_AGENT_CONSTRAIN_LIFETIME)
+                        lifetime = tr.readUINT32();
+                    else {
+                        // Unknown constraint. Bail.
+                        os.write(SSH_AGENT_FAILURE);
+                        return;
+                    }
+                }
+            }
+
+            if (authAgent.addIdentity(pair, comment, confirmUse, lifetime))
+                os.write(SSH_AGENT_SUCCESS);
+            else
+                os.write(SSH_AGENT_FAILURE);
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    /**
+     * @param tr
+     */
+    private void removeIdentity(TypesReader tr) {
+        try {
+            if (failWhenLocked())
+                return;
+
+            byte[] publicKey = tr.readByteString();
+
+            if (authAgent.removeIdentity(publicKey))
+                os.write(SSH_AGENT_SUCCESS);
+            else
+                os.write(SSH_AGENT_FAILURE);
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    /**
+     * @param tr
+     */
+    private void removeAllIdentities(TypesReader tr) {
+        try {
+            if (failWhenLocked())
+                return;
+
+            if (authAgent.removeAllIdentities())
+                os.write(SSH_AGENT_SUCCESS);
+            else
+                os.write(SSH_AGENT_FAILURE);
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    private void processSignRequest(TypesReader tr) {
+        try {
+            if (failWhenLocked())
+                return;
+
+            byte[] publicKeyBytes = tr.readByteString();
+            byte[] challenge = tr.readByteString();
+            int flags = tr.readUINT32();
+
+            if (flags != 0) {
+                // We don't understand any flags; abort!
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+
+            KeyPair pair = authAgent.getKeyPair(publicKeyBytes);
+
+            if (pair == null) {
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+
+            byte[] response;
+            PrivateKey privKey = pair.getPrivate();
+
+            if (privKey instanceof RSAPrivateKey) {
+                byte[] signature = RSASHA1Verify.generateSignature(challenge,
+                                   (RSAPrivateKey) privKey);
+                response = RSASHA1Verify.encodeSSHRSASignature(signature);
+            }
+            else if (privKey instanceof DSAPrivateKey) {
+                byte[] signature = DSASHA1Verify.generateSignature(challenge,
+                                   (DSAPrivateKey) privKey, new SecureRandom());
+                response = DSASHA1Verify.encodeSSHDSASignature(signature);
+            }
+            else {
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+
+            TypesWriter tw = new TypesWriter();
+            tw.writeByte(SSH2_AGENT_SIGN_RESPONSE);
+            tw.writeString(response, 0, response.length);
+            sendPacket(tw.getBytes());
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    /**
+     * @param tr
+     */
+    private void processLockRequest(TypesReader tr) {
+        try {
+            if (failWhenLocked())
+                return;
+
+            String lockPassphrase = tr.readString();
+
+            if (!authAgent.setAgentLock(lockPassphrase)) {
+                os.write(SSH_AGENT_FAILURE);
+                return;
+            }
+            else
+                os.write(SSH_AGENT_SUCCESS);
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    /**
+     * @param tr
+     */
+    private void processUnlockRequest(TypesReader tr) {
+        try {
+            String unlockPassphrase = tr.readString();
+
+            if (authAgent.requestAgentUnlock(unlockPassphrase))
+                os.write(SSH_AGENT_SUCCESS);
+            else
+                os.write(SSH_AGENT_FAILURE);
+        }
+        catch (IOException e) {
+            try {
+                os.write(SSH_AGENT_FAILURE);
+            }
+            catch (IOException e1) {
+            }
+        }
+    }
+
+    /**
+     * @param tw
+     * @throws IOException
+     */
+    private void sendPacket(byte[] message) throws IOException {
+        TypesWriter packet = new TypesWriter();
+        packet.writeUINT32(message.length);
+        packet.writeBytes(message);
+        os.write(packet.getBytes());
+    }
+}