Added support for HTTP CONNECT proxies by implementing custom Socket (Fixes #170)

src/main/java/com/hierynomus/sshj/backport/JavaVersion.java

@@ -0,0 +1,13 @@
+package com.hierynomus.sshj.backport;
+
+import java.math.BigDecimal;
+
+public class JavaVersion {
+    public static boolean isJava7OrEarlier() {
+        String property = System.getProperty("java.specification.version");
+        float diff = Float.parseFloat(property) - 1.7f;
+
+        return diff < 0.01;
+    }
+
+}

src/main/java/com/hierynomus/sshj/backport/Jdk7HttpProxySocket.java

@@ -0,0 +1,62 @@
+package com.hierynomus.sshj.backport;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.*;
+import java.nio.charset.Charset;
+
+public class Jdk7HttpProxySocket extends Socket {
+
+    private Proxy httpProxy = null;
+
+    public Jdk7HttpProxySocket(Proxy proxy) {
+        super(proxy.type() == Proxy.Type.HTTP ? Proxy.NO_PROXY : proxy);
+        if (proxy.type() == Proxy.Type.HTTP) {
+            this.httpProxy = proxy;
+        }
+    }
+
+    @Override
+    public void connect(SocketAddress endpoint, int timeout) throws IOException {
+        if (httpProxy != null) {
+            connectHttpProxy(endpoint, timeout);
+        } else {
+            super.connect(endpoint, timeout);
+        }
+    }
+
+    private void connectHttpProxy(SocketAddress endpoint, int timeout) throws IOException {
+        super.connect(httpProxy.address(), timeout);
+
+        if (!(endpoint instanceof InetSocketAddress)) {
+            throw new SocketException("Expected an InetSocketAddress to connect to, got: " + endpoint);
+        }
+        InetSocketAddress isa = (InetSocketAddress) endpoint;
+        String httpConnect = "CONNECT " + isa.getHostName() + ":" + isa.getPort() + " HTTP/1.0\n\n";
+        getOutputStream().write(httpConnect.getBytes(Charset.forName("UTF-8")));
+        checkAndFlushProxyResponse();
+    }
+
+    private void checkAndFlushProxyResponse()throws IOException {
+        InputStream socketInput = 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);
+        }
+    }
+}

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

@@ -15,6 +15,9 @@
  */
 package net.schmizz.sshj;
 
+import com.hierynomus.sshj.backport.JavaVersion;
+import com.hierynomus.sshj.backport.Jdk7HttpProxySocket;
+
 import javax.net.SocketFactory;
 import java.io.IOException;
 import java.io.InputStream;
@@ -45,34 +48,35 @@ public abstract class SocketClient {
         this.defaultPort = defaultPort;
     }
 
-    public void connect(InetAddress host, int port)
-            throws IOException {
+    public void connect(InetAddress host, int port) throws IOException {
         socket = socketFactory.createSocket();
         socket.connect(new InetSocketAddress(host, port), connectTimeout);
         onConnect();
     }
 
-    public void connect(InetAddress host, int port, Proxy proxy)
-            throws IOException {
-        socket = new Socket(proxy);
+
+    public void connect(InetAddress host, int port, Proxy proxy) throws IOException {
+        if (JavaVersion.isJava7OrEarlier() && proxy.type() == Proxy.Type.HTTP) {
+            // Java7 and earlier have no support for HTTP Connect proxies, return our custom socket.
+            socket = new Jdk7HttpProxySocket(proxy);
+        } else {
+            socket = new Socket(proxy);
+        }
         socket.connect(new InetSocketAddress(host, port), connectTimeout);
         onConnect();
     }
 
-    public void connect(String hostname, int port)
-            throws IOException {
+    public void connect(String hostname, int port) throws IOException {
         this.hostname = hostname;
         connect(InetAddress.getByName(hostname), port);
     }
 
-    public void connect(String hostname, int port, Proxy proxy)
-            throws IOException {
+    public void connect(String hostname, int port, Proxy proxy) throws IOException {
         this.hostname = hostname;
         connect(InetAddress.getByName(hostname), port, proxy);
     }
 
-    public void connect(InetAddress host, int port,
-                        InetAddress localAddr, int localPort)
+    public void connect(InetAddress host, int port, InetAddress localAddr, int localPort)
             throws IOException {
         socket = socketFactory.createSocket();
         socket.bind(new InetSocketAddress(localAddr, localPort));
@@ -80,35 +84,28 @@ public abstract class SocketClient {
         onConnect();
     }
 
-    public void connect(String hostname, int port,
-                        InetAddress localAddr, int localPort)
-            throws IOException {
+    public void connect(String hostname, int port, InetAddress localAddr, int localPort) throws IOException {
         this.hostname = hostname;
         connect(InetAddress.getByName(hostname), port, localAddr, localPort);
     }
 
-    public void connect(InetAddress host)
-            throws IOException {
+    public void connect(InetAddress host) throws IOException {
         connect(host, defaultPort);
     }
 
-    public void connect(String hostname)
-            throws IOException {
+    public void connect(String hostname) throws IOException {
         connect(hostname, defaultPort);
     }
 
-    public void connect(InetAddress host, Proxy proxy)
-            throws IOException {
+    public void connect(InetAddress host, Proxy proxy) throws IOException {
         connect(host, defaultPort, proxy);
     }
 
-    public void connect(String hostname, Proxy proxy)
-            throws IOException {
+    public void connect(String hostname, Proxy proxy) throws IOException {
         connect(hostname, defaultPort, proxy);
     }
 
-    public void disconnect()
-            throws IOException {
+    public void disconnect() throws IOException {
         if (socket != null) {
             socket.close();
             socket = null;
@@ -131,7 +128,6 @@ public abstract class SocketClient {
         return socket.getLocalPort();
     }
 
-
     public InetAddress getLocalAddress() {
         return socket.getLocalAddress();
     }
@@ -149,10 +145,11 @@ public abstract class SocketClient {
     }
 
     public void setSocketFactory(SocketFactory factory) {
-        if (factory == null)
+        if (factory == null) {
             socketFactory = SocketFactory.getDefault();
-        else
+        } else {
             socketFactory = factory;
+        }
     }
 
     public SocketFactory getSocketFactory() {
@@ -187,8 +184,7 @@ public abstract class SocketClient {
         return output;
     }
 
-    void onConnect()
-            throws IOException {
+    void onConnect() throws IOException {
         socket.setSoTimeout(timeout);
         input = socket.getInputStream();
         output = socket.getOutputStream();