merged branch improve_bytestreams in trunk

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@11821 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smackx/bytestreams/socks5/Socks5Utils.java

@@ -0,0 +1,73 @@
+/**
+ * All rights reserved. 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 org.jivesoftware.smackx.bytestreams.socks5;
+
+import java.io.DataInputStream;
+import java.io.IOException;
+
+import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smack.util.StringUtils;
+
+/**
+ * A collection of utility methods for SOcKS5 messages.
+ * 
+ * @author Henning Staib
+ */
+class Socks5Utils {
+
+    /**
+     * Returns a SHA-1 digest of the given parameters as specified in <a
+     * href="http://xmpp.org/extensions/xep-0065.html#impl-socks5">XEP-0065</a>.
+     * 
+     * @param sessionID for the SOCKS5 Bytestream
+     * @param initiatorJID JID of the initiator of a SOCKS5 Bytestream
+     * @param targetJID JID of the target of a SOCKS5 Bytestream
+     * @return SHA-1 digest of the given parameters
+     */
+    public static String createDigest(String sessionID, String initiatorJID, String targetJID) {
+        StringBuilder b = new StringBuilder();
+        b.append(sessionID).append(initiatorJID).append(targetJID);
+        return StringUtils.hash(b.toString());
+    }
+
+    /**
+     * Reads a SOCKS5 message from the given InputStream. The message can either be a SOCKS5 request
+     * message or a SOCKS5 response message.
+     * <p>
+     * (see <a href="http://tools.ietf.org/html/rfc1928">RFC1928</a>)
+     * 
+     * @param in the DataInputStream to read the message from
+     * @return the SOCKS5 message
+     * @throws IOException if a network error occurred
+     * @throws XMPPException if the SOCKS5 message contains an unsupported address type
+     */
+    public static byte[] receiveSocks5Message(DataInputStream in) throws IOException, XMPPException {
+        byte[] header = new byte[5];
+        in.readFully(header, 0, 5);
+
+        if (header[3] != (byte) 0x03) {
+            throw new XMPPException("Unsupported SOCKS5 address type");
+        }
+
+        int addressLength = header[4];
+
+        byte[] response = new byte[7 + addressLength];
+        System.arraycopy(header, 0, response, 0, header.length);
+
+        in.readFully(response, header.length, addressLength + 2);
+
+        return response;
+    }
+
+}