Make 'zlib' compression work.

Previously all compression was the equivalent of zlib@openssh.com
since TransportConnection enforced that.

5 files changed, 55 insertions, 7 deletions

diff --git a/lib/src/main/java/com/trilead/ssh2/compression/CompressionFactory.java b/lib/src/main/java/com/trilead/ssh2/compression/CompressionFactory.java
index a846f58..9f8d7ef 100644
--- a/lib/src/main/java/com/trilead/ssh2/compression/CompressionFactory.java
+++ b/lib/src/main/java/com/trilead/ssh2/compression/CompressionFactory.java
@@ -43,7 +43,7 @@ public class CompressionFactory {
 		/* Higher Priority First */
 
 		compressors.addElement(new CompressorEntry("zlib", "com.trilead.ssh2.compression.Zlib"));
-		compressors.addElement(new CompressorEntry("zlib@openssh.com", "com.trilead.ssh2.compression.Zlib"));
+		compressors.addElement(new CompressorEntry("zlib@openssh.com", "com.trilead.ssh2.compression.ZlibOpenSSH"));
 		compressors.addElement(new CompressorEntry("none", ""));
 	}
 
diff --git a/lib/src/main/java/com/trilead/ssh2/compression/ICompressor.java b/lib/src/main/java/com/trilead/ssh2/compression/ICompressor.java
index 3f76326..0b435b9 100644
--- a/lib/src/main/java/com/trilead/ssh2/compression/ICompressor.java
+++ b/lib/src/main/java/com/trilead/ssh2/compression/ICompressor.java
@@ -27,4 +27,6 @@ public interface ICompressor {
 	int compress(byte[] buf, int start, int len, byte[] output);
 
 	byte[] uncompress(byte[] buf, int start, int[] len);
+
+	boolean canCompressPreauth();
 }
diff --git a/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java b/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
index e9cc017..c1203a3 100644
--- a/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
+++ b/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
@@ -47,6 +47,10 @@ public class Zlib implements ICompressor {
 		inflated_buf = new byte[DEFAULT_BUF_SIZE];
 	}
 
+	public boolean canCompressPreauth() {
+		return true;
+	}
+
 	public int getBufferSize() {
 		return DEFAULT_BUF_SIZE;
 	}
diff --git a/lib/src/main/java/com/trilead/ssh2/compression/ZlibOpenSSH.java b/lib/src/main/java/com/trilead/ssh2/compression/ZlibOpenSSH.java
new file mode 100644
index 0000000..266fff9
--- /dev/null
+++ b/lib/src/main/java/com/trilead/ssh2/compression/ZlibOpenSSH.java
@@ -0,0 +1,35 @@
+/*
+ * 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.compression;
+
+/**
+ * Defines how zlib@openssh.org compression works.
+ * See 
+ * http://www.openssh.org/txt/draft-miller-secsh-compression-delayed-00.txt
+ * compression is disabled until userauth has occurred.
+ *
+ * @author Matt Johnston
+ *
+ */
+public class ZlibOpenSSH extends Zlib {
+
+	public boolean canCompressPreauth() {
+		return false;
+	}
+
+}
diff --git a/lib/src/main/java/com/trilead/ssh2/transport/TransportConnection.java b/lib/src/main/java/com/trilead/ssh2/transport/TransportConnection.java
index 77eaded..2c04ce4 100644
--- a/lib/src/main/java/com/trilead/ssh2/transport/TransportConnection.java
+++ b/lib/src/main/java/com/trilead/ssh2/transport/TransportConnection.java
@@ -56,7 +56,9 @@ public class TransportConnection
 	

 	ICompressor send_comp = null;

 	

-	boolean can_compress = false;

+	boolean can_recv_compress = false;

+

+	boolean can_send_compress = false;

 

 	byte[] recv_comp_buffer;

 	

@@ -117,16 +119,20 @@ public class TransportConnection
 	{

 		recv_comp = comp;

 		

-		if (comp != null)

+		if (comp != null) {

 			recv_comp_buffer = new byte[comp.getBufferSize()];

+			can_recv_compress |= recv_comp.canCompressPreauth();

+		}

 	}

 

 	public void changeSendCompression(ICompressor comp)

 	{

 		send_comp = comp;

 		

-		if (comp != null)

+		if (comp != null) {

 			send_comp_buffer = new byte[comp.getBufferSize()];

+			can_send_compress |= send_comp.canCompressPreauth();

+		}

 	}

 	

 	public void sendMessage(byte[] message) throws IOException

@@ -152,7 +158,7 @@ public class TransportConnection
 		else if (padd > 64)

 			padd = 64;

 		

-		if (send_comp != null && can_compress) {

+		if (send_comp != null && can_send_compress) {

 			if (send_comp_buffer.length < message.length + 1024)

 				send_comp_buffer = new byte[message.length + 1024];

 			len = send_comp.compress(message, off, len, send_comp_buffer);

@@ -313,7 +319,7 @@ public class TransportConnection
 					+ " bytes payload");

 		}

 

-		if (recv_comp != null && can_compress) {

+		if (recv_comp != null && can_recv_compress) {

 			int[] uncomp_len = new int[] { payload_length };

 			buffer = recv_comp.uncompress(buffer, off, uncomp_len);

 			

@@ -331,6 +337,7 @@ public class TransportConnection
 	 * 

 	 */

 	public void startCompression() {

-		can_compress = true;

+		can_recv_compress = true;

+		can_send_compress = true;

 	}

 }