diff --git a/phpseclib/System/SSH/Agent.php b/phpseclib/System/SSH/Agent.php
index d4555111..33e450bc 100644
--- a/phpseclib/System/SSH/Agent.php
+++ b/phpseclib/System/SSH/Agent.php
@@ -65,145 +65,8 @@ define('SYSTEM_SSH_AGENTC_SIGN_REQUEST', 13);
 define('SYSTEM_SSH_AGENT_SIGN_RESPONSE', 14);
 /**#@-*/
 
-/**
- * Pure-PHP ssh-agent client identity object
- *
- * Instantiation should only be performed by System_SSH_Agent class.
- * This could be thought of as implementing an interface that Crypt_RSA
- * implements. ie. maybe a Net_SSH_Auth_PublicKey interface or something.
- * The methods in this interface would be getPublicKey, setSignatureMode
- * and sign since those are the methods phpseclib looks for to perform
- * public key authentication.
- *
- * @package System_SSH_Agent
- * @author  Jim Wigginton <terrafrost@php.net>
- * @access  internal
- */
-class System_SSH_Agent_Identity
-{
-    /**
-     * Key Object
-     *
-     * @var Crypt_RSA
-     * @access private
-     * @see System_SSH_Agent_Identity::getPublicKey()
-     */
-    var $key;
-
-    /**
-     * Key Blob
-     *
-     * @var String
-     * @access private
-     * @see System_SSH_Agent_Identity::sign()
-     */
-    var $key_blob;
-
-    /**
-     * Socket Resource
-     *
-     * @var Resource
-     * @access private
-     * @see System_SSH_Agent_Identity::sign()
-     */
-    var $fsock;
-
-    /**
-     * Default Constructor.
-     *
-     * @param Resource $fsock
-     * @return System_SSH_Agent_Identity
-     * @access private
-     */
-    function __construct($fsock)
-    {
-        $this->fsock = $fsock;
-    }
-
-    /**
-     * Set Public Key
-     *
-     * Called by System_SSH_Agent::requestIdentities()
-     *
-     * @param Crypt_RSA $key
-     * @access private
-     */
-    function setPublicKey($key)
-    {
-        $this->key = $key;
-        $this->key->setPublicKey();
-    }
-
-    /**
-     * Set Public Key
-     *
-     * Called by System_SSH_Agent::requestIdentities(). The key blob could be extracted from $this->key
-     * but this saves a small amount of computation.
-     *
-     * @param String $key_blob
-     * @access private
-     */
-    function setPublicKeyBlob($key_blob)
-    {
-        $this->key_blob = $key_blob;
-    }
-
-    /**
-     * Get Public Key
-     *
-     * Wrapper for $this->key->getPublicKey()
-     *
-     * @param Integer $format optional
-     * @return Mixed
-     * @access public
-     */
-    function getPublicKey($format = null)
-    {
-        return !isset($format) ? $this->key->getPublicKey() : $this->key->getPublicKey($format);
-    }
-
-    /**
-     * Set Signature Mode
-     *
-     * Doesn't do anything as ssh-agent doesn't let you pick and choose the signature mode. ie.
-     * ssh-agent's only supported mode is CRYPT_RSA_SIGNATURE_PKCS1
-     *
-     * @param Integer $mode
-     * @access public
-     */
-    function setSignatureMode($mode)
-    {
-    }
-
-    /**
-     * Create a signature
-     *
-     * See "2.6.2 Protocol 2 private key signature request"
-     *
-     * @param String $message
-     * @return String
-     * @access public
-     */
-    function sign($message)
-    {
-        // the last parameter (currently 0) is for flags and ssh-agent only defines one flag (for ssh-dss): SSH_AGENT_OLD_SIGNATURE
-        $packet = pack('CNa*Na*N', SYSTEM_SSH_AGENTC_SIGN_REQUEST, strlen($this->key_blob), $this->key_blob, strlen($message), $message, 0);
-        $packet = pack('Na*', strlen($packet), $packet);
-        if (strlen($packet) != fputs($this->fsock, $packet)) {
-            user_error('Connection closed during signing');
-        }
-
-        $length = current(unpack('N', fread($this->fsock, 4)));
-        $type = ord(fread($this->fsock, 1));
-        if ($type != SYSTEM_SSH_AGENT_SIGN_RESPONSE) {
-            user_error('Unable to retreive signature');
-        }
-
-        $signature_blob = fread($this->fsock, $length - 1);
-        // the only other signature format defined - ssh-dss - is the same length as ssh-rsa
-        // the + 12 is for the other various SSH added length fields
-        return substr($signature_blob, strlen('ssh-rsa') + 12);
-    }
+if (!class_exists('System_SSH_Agent_Identity')) {
+    include_once 'Agent/Identity.php';
 }
 
 /**
diff --git a/phpseclib/System/SSH/Agent/Identity.php b/phpseclib/System/SSH/Agent/Identity.php
new file mode 100644
index 00000000..91a29282
--- /dev/null
+++ b/phpseclib/System/SSH/Agent/Identity.php
@@ -0,0 +1,173 @@
+<?php
+/**
+ * Pure-PHP ssh-agent client.
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @category  System
+ * @package   System_SSH_Agent
+ * @author    Jim Wigginton <terrafrost@php.net>
+ * @copyright MMXIV Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @link      http://phpseclib.sourceforge.net
+ * @internal  See http://api.libssh.org/rfc/PROTOCOL.agent
+ */
+
+/**
+ * Pure-PHP ssh-agent client identity object
+ *
+ * Instantiation should only be performed by System_SSH_Agent class.
+ * This could be thought of as implementing an interface that Crypt_RSA
+ * implements. ie. maybe a Net_SSH_Auth_PublicKey interface or something.
+ * The methods in this interface would be getPublicKey, setSignatureMode
+ * and sign since those are the methods phpseclib looks for to perform
+ * public key authentication.
+ *
+ * @package System_SSH_Agent
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @access  internal
+ */
+class System_SSH_Agent_Identity
+{
+    /**
+     * Key Object
+     *
+     * @var Crypt_RSA
+     * @access private
+     * @see System_SSH_Agent_Identity::getPublicKey()
+     */
+    var $key;
+
+    /**
+     * Key Blob
+     *
+     * @var String
+     * @access private
+     * @see System_SSH_Agent_Identity::sign()
+     */
+    var $key_blob;
+
+    /**
+     * Socket Resource
+     *
+     * @var Resource
+     * @access private
+     * @see System_SSH_Agent_Identity::sign()
+     */
+    var $fsock;
+
+    /**
+     * Default Constructor.
+     *
+     * @param Resource $fsock
+     * @return System_SSH_Agent_Identity
+     * @access private
+     */
+    function __construct($fsock)
+    {
+        $this->fsock = $fsock;
+    }
+
+    /**
+     * Set Public Key
+     *
+     * Called by System_SSH_Agent::requestIdentities()
+     *
+     * @param Crypt_RSA $key
+     * @access private
+     */
+    function setPublicKey($key)
+    {
+        $this->key = $key;
+        $this->key->setPublicKey();
+    }
+
+    /**
+     * Set Public Key
+     *
+     * Called by System_SSH_Agent::requestIdentities(). The key blob could be extracted from $this->key
+     * but this saves a small amount of computation.
+     *
+     * @param String $key_blob
+     * @access private
+     */
+    function setPublicKeyBlob($key_blob)
+    {
+        $this->key_blob = $key_blob;
+    }
+
+    /**
+     * Get Public Key
+     *
+     * Wrapper for $this->key->getPublicKey()
+     *
+     * @param Integer $format optional
+     * @return Mixed
+     * @access public
+     */
+    function getPublicKey($format = null)
+    {
+        return !isset($format) ? $this->key->getPublicKey() : $this->key->getPublicKey($format);
+    }
+
+    /**
+     * Set Signature Mode
+     *
+     * Doesn't do anything as ssh-agent doesn't let you pick and choose the signature mode. ie.
+     * ssh-agent's only supported mode is CRYPT_RSA_SIGNATURE_PKCS1
+     *
+     * @param Integer $mode
+     * @access public
+     */
+    function setSignatureMode($mode)
+    {
+    }
+
+    /**
+     * Create a signature
+     *
+     * See "2.6.2 Protocol 2 private key signature request"
+     *
+     * @param String $message
+     * @return String
+     * @access public
+     */
+    function sign($message)
+    {
+        // the last parameter (currently 0) is for flags and ssh-agent only defines one flag (for ssh-dss): SSH_AGENT_OLD_SIGNATURE
+        $packet = pack('CNa*Na*N', SYSTEM_SSH_AGENTC_SIGN_REQUEST, strlen($this->key_blob), $this->key_blob, strlen($message), $message, 0);
+        $packet = pack('Na*', strlen($packet), $packet);
+        if (strlen($packet) != fputs($this->fsock, $packet)) {
+            user_error('Connection closed during signing');
+        }
+
+        $length = current(unpack('N', fread($this->fsock, 4)));
+        $type = ord(fread($this->fsock, 1));
+        if ($type != SYSTEM_SSH_AGENT_SIGN_RESPONSE) {
+            user_error('Unable to retreive signature');
+        }
+
+        $signature_blob = fread($this->fsock, $length - 1);
+        // the only other signature format defined - ssh-dss - is the same length as ssh-rsa
+        // the + 12 is for the other various SSH added length fields
+        return substr($signature_blob, strlen('ssh-rsa') + 12);
+    }
+}