Added support for (unauthenticated) HTTP proxies (fixes #170)

src/main/java/com/hierynomus/sshj/socket/SocketFactory.java

@@ -0,0 +1,92 @@
+package com.hierynomus.sshj.socket;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.net.Socket;
+import java.net.SocketException;
+
+import static java.lang.String.format;
+
+/**
+ * https://code.google.com/p/java-socket-over-http-proxy-connect/source/browse/trunk/src/sg/com/en/SocketFactory.java
+ */
+public class SocketFactory {
+
+    private static final int DEFAULT_CONNECT_TIMEOUT = 0;
+    private int connectTimeout = DEFAULT_CONNECT_TIMEOUT;
+
+    private final javax.net.SocketFactory delegateSocketFactory = javax.net.SocketFactory.getDefault();
+
+    public static SocketFactory getDefault() {
+        return new SocketFactory();
+    }
+
+    public Socket createSocket(String address, int port) throws IOException {
+        return createSocket(new InetSocketAddress(address, port));
+    }
+
+    public Socket createSocket(InetSocketAddress inetSocketAddress) throws IOException {
+        Socket socket = delegateSocketFactory.createSocket();
+        socket.connect(inetSocketAddress, connectTimeout);
+        return socket;
+    }
+
+    public Socket createSocket(InetSocketAddress inetSocketAddress, Proxy proxy) throws IOException {
+        if (proxy.type() == Proxy.Type.HTTP) {
+            return createHttpProxySocket(inetSocketAddress, proxy);
+        }
+        Socket socket = new Socket(proxy);
+        socket.connect(inetSocketAddress, connectTimeout);
+        return socket;
+    }
+
+    private Socket createHttpProxySocket(InetSocketAddress inetSocketAddress, Proxy proxy) throws IOException {
+        Socket socket = delegateSocketFactory.createSocket();
+        socket.connect(proxy.address());
+
+        String connect = format("CONNECT %s:%d\n\n", inetSocketAddress.getHostName(), inetSocketAddress.getPort());
+        socket.getOutputStream().write(connect.getBytes());
+        checkAndFlushProxyResponse(socket);
+        return socket;
+    }
+
+    private void checkAndFlushProxyResponse(Socket socket)throws IOException {
+        InputStream socketInput = socket.getInputStream();
+        byte[] tmpBuffer = new byte[512];
+        int len = socketInput.read(tmpBuffer, 0, tmpBuffer.length);
+
+        if (len == 0) {
+            throw new SocketException("Empty response from proxy");
+        }
+
+        String proxyResponse = new String(tmpBuffer, 0, len, "UTF-8");
+
+        // Expecting HTTP/1.x 200 OK
+        if (proxyResponse.contains("200")) {
+            // Flush any outstanding message in buffer
+            if (socketInput.available() > 0)
+                socketInput.skip(socketInput.available());
+            // Proxy Connect Successful
+        } else {
+            throw new SocketException("Fail to create Socket\nResponse was:" + proxyResponse);
+        }
+    }
+
+    public Socket createSocket(InetSocketAddress bindpoint, InetSocketAddress endpoint) throws IOException {
+        Socket socket = delegateSocketFactory.createSocket();
+        socket.bind(bindpoint);
+        socket.connect(endpoint, connectTimeout);
+        return socket;
+    }
+
+    public int getConnectTimeout() {
+        return connectTimeout;
+    }
+
+    public void setConnectTimeout(int connectTimeout) {
+        this.connectTimeout = connectTimeout;
+    }
+
+}

src/main/java/net/schmizz/sshj/SocketClient.java

@@ -15,7 +15,8 @@
  */
 package net.schmizz.sshj;
 
-import javax.net.SocketFactory;
+import com.hierynomus.sshj.socket.SocketFactory;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -32,10 +33,7 @@ public abstract class SocketClient {
     private InputStream input;
     private OutputStream output;
 
-    private SocketFactory socketFactory = SocketFactory.getDefault();
-
-    private static final int DEFAULT_CONNECT_TIMEOUT = 0;
-    private int connectTimeout = DEFAULT_CONNECT_TIMEOUT;
+    private SocketFactory socketFactory = new SocketFactory();
 
     private int timeout = 0;
 
@@ -47,15 +45,13 @@ public abstract class SocketClient {
 
     public void connect(InetAddress host, int port)
             throws IOException {
-        socket = socketFactory.createSocket();
-        socket.connect(new InetSocketAddress(host, port), connectTimeout);
+        socket = socketFactory.createSocket(new InetSocketAddress(host, port));
         onConnect();
     }
 
     public void connect(InetAddress host, int port, Proxy proxy)
             throws IOException {
-        socket = new Socket(proxy);
-        socket.connect(new InetSocketAddress(host, port), connectTimeout);
+        socket = socketFactory.createSocket(new InetSocketAddress(host, port), proxy);
         onConnect();
     }
 
@@ -74,9 +70,9 @@ public abstract class SocketClient {
     public void connect(InetAddress host, int port,
                         InetAddress localAddr, int localPort)
             throws IOException {
-        socket = socketFactory.createSocket();
-        socket.bind(new InetSocketAddress(localAddr, localPort));
-        socket.connect(new InetSocketAddress(host, port), connectTimeout);
+        InetSocketAddress bindpoint = new InetSocketAddress(localAddr, localPort);
+        InetSocketAddress endpoint = new InetSocketAddress(host, port);
+        socket = socketFactory.createSocket(bindpoint, endpoint);
         onConnect();
     }
 
@@ -160,11 +156,11 @@ public abstract class SocketClient {
     }
 
     public int getConnectTimeout() {
-        return connectTimeout;
+        return socketFactory.getConnectTimeout();
     }
 
     public void setConnectTimeout(int connectTimeout) {
-        this.connectTimeout = connectTimeout;
+        socketFactory.setConnectTimeout(connectTimeout);
     }
 
     public int getTimeout() {