diff --git a/README.md b/README.md
index 01550575..4e1330e8 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ MIT-licensed pure-PHP implementations of an arbitrary-precision integer
 arithmetic library, fully PKCS#1 (v2.1) compliant RSA, DES, 3DES, RC4, Rijndael,
 AES, SSH-1, SSH-2, SFTP, and X.509
 
-* [Download (0.3.0)](http://sourceforge.net/projects/phpseclib/files/phpseclib0.3.0.zip/download)
+* [Download (0.3.1)](http://sourceforge.net/projects/phpseclib/files/phpseclib0.3.1.zip/download)
 * [Browse Git](https://github.com/phpseclib/phpseclib)
 * [Documentation](http://phpseclib.sourceforge.net/)
 * [Support](http://www.frostjedi.com/phpbb/viewforum.php?f=46)
diff --git a/phpseclib/Crypt/DES.php b/phpseclib/Crypt/DES.php
index f6c1f301..6a6d3389 100644
--- a/phpseclib/Crypt/DES.php
+++ b/phpseclib/Crypt/DES.php
@@ -723,7 +723,7 @@ class Crypt_DES {
                 mcrypt_generic_init($this->demcrypt, $this->keys, $this->decryptIV);
             }
 
-            return $this->mode != 'ctr' ? $this->_unpad($plaintext) : $plaintext;
+            return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
         }
 
         if (!is_array($this->keys)) {
@@ -937,7 +937,7 @@ class Crypt_DES {
             if (($length & 7) == 0) {
                 return $text;
             } else {
-                user_error("The plaintext's length ($length) is not a multiple of the block size (8)", E_USER_NOTICE);
+                $this->_handle_error("The plaintext's length ($length) is not a multiple of the block size (8)");
                 $this->padding = true;
             }
         }
@@ -1289,6 +1289,24 @@ class Crypt_DES {
         $string = substr($string, $index);
         return $substr;
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
 
 // vim: ts=4:sw=4:et:
diff --git a/phpseclib/Crypt/RSA.php b/phpseclib/Crypt/RSA.php
index 52ab883a..cd3d2bae 100644
--- a/phpseclib/Crypt/RSA.php
+++ b/phpseclib/Crypt/RSA.php
@@ -1166,7 +1166,8 @@ class Crypt_RSA {
                 xml_set_object($xml, $this);
                 xml_set_element_handler($xml, '_start_element_handler', '_stop_element_handler');
                 xml_set_character_data_handler($xml, '_data_handler');
-                if (!xml_parse($xml, $key)) {
+                // add <xml></xml> to account for "dangling" tags like <BitStrength>...</BitStrength> that are sometimes added
+                if (!xml_parse($xml, '<xml>' . $key . '</xml>')) {
                     return false;
                 }
 
@@ -1763,7 +1764,7 @@ class Crypt_RSA {
     {
         $x = $x->toBytes();
         if (strlen($x) > $xLen) {
-            user_error('Integer too large', E_USER_NOTICE);
+            $this->_handle_error('Integer too large');
             return false;
         }
         return str_pad($x, $xLen, chr(0), STR_PAD_LEFT);
@@ -1925,7 +1926,7 @@ class Crypt_RSA {
     function _rsaep($m)
     {
         if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
-            user_error('Message representative out of range', E_USER_NOTICE);
+            $this->_handle_error('Message representative out of range');
             return false;
         }
         return $this->_exponentiate($m);
@@ -1943,7 +1944,7 @@ class Crypt_RSA {
     function _rsadp($c)
     {
         if ($c->compare($this->zero) < 0 || $c->compare($this->modulus) > 0) {
-            user_error('Ciphertext representative out of range', E_USER_NOTICE);
+            $this->_handle_error('Ciphertext representative out of range');
             return false;
         }
         return $this->_exponentiate($c);
@@ -1961,7 +1962,7 @@ class Crypt_RSA {
     function _rsasp1($m)
     {
         if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
-            user_error('Message representative out of range', E_USER_NOTICE);
+            $this->_handle_error('Message representative out of range');
             return false;
         }
         return $this->_exponentiate($m);
@@ -1979,7 +1980,7 @@ class Crypt_RSA {
     function _rsavp1($s)
     {
         if ($s->compare($this->zero) < 0 || $s->compare($this->modulus) > 0) {
-            user_error('Signature representative out of range', E_USER_NOTICE);
+            $this->_handle_error('Signature representative out of range');
             return false;
         }
         return $this->_exponentiate($s);
@@ -2030,7 +2031,7 @@ class Crypt_RSA {
         // be output.
 
         if ($mLen > $this->k - 2 * $this->hLen - 2) {
-            user_error('Message too long', E_USER_NOTICE);
+            $this->_handle_error('Message too long');
             return false;
         }
 
@@ -2091,7 +2092,7 @@ class Crypt_RSA {
         // be output.
 
         if (strlen($c) != $this->k || $this->k < 2 * $this->hLen + 2) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
 
@@ -2100,7 +2101,7 @@ class Crypt_RSA {
         $c = $this->_os2ip($c);
         $m = $this->_rsadp($c);
         if ($m === false) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
         $em = $this->_i2osp($m, $this->k);
@@ -2118,12 +2119,12 @@ class Crypt_RSA {
         $lHash2 = substr($db, 0, $this->hLen);
         $m = substr($db, $this->hLen);
         if ($lHash != $lHash2) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
         $m = ltrim($m, chr(0));
         if (ord($m[0]) != 1) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
 
@@ -2148,7 +2149,7 @@ class Crypt_RSA {
         // Length checking
 
         if ($mLen > $this->k - 11) {
-            user_error('Message too long', E_USER_NOTICE);
+            $this->_handle_error('Message too long');
             return false;
         }
 
@@ -2192,7 +2193,7 @@ class Crypt_RSA {
         // Length checking
 
         if (strlen($c) != $this->k) { // or if k < 11
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
 
@@ -2202,7 +2203,7 @@ class Crypt_RSA {
         $m = $this->_rsadp($c);
 
         if ($m === false) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
         $em = $this->_i2osp($m, $this->k);
@@ -2210,7 +2211,7 @@ class Crypt_RSA {
         // EME-PKCS1-v1_5 decoding
 
         if (ord($em[0]) != 0 || ord($em[1]) > 2) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
 
@@ -2218,7 +2219,7 @@ class Crypt_RSA {
         $m = substr($em, strlen($ps) + 3);
 
         if (strlen($ps) < 8) {
-            user_error('Decryption error', E_USER_NOTICE);
+            $this->_handle_error('Decryption error');
             return false;
         }
 
@@ -2246,7 +2247,7 @@ class Crypt_RSA {
 
         $mHash = $this->hash->hash($m);
         if ($emLen < $this->hLen + $sLen + 2) {
-            user_error('Encoding error', E_USER_NOTICE);
+            $this->_handle_error('Encoding error');
             return false;
         }
 
@@ -2351,7 +2352,7 @@ class Crypt_RSA {
         // Length checking
 
         if (strlen($s) != $this->k) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
 
@@ -2362,12 +2363,12 @@ class Crypt_RSA {
         $s2 = $this->_os2ip($s);
         $m2 = $this->_rsavp1($s2);
         if ($m2 === false) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
         $em = $this->_i2osp($m2, $modBits >> 3);
         if ($em === false) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
 
@@ -2417,7 +2418,7 @@ class Crypt_RSA {
         $tLen = strlen($t);
 
         if ($emLen < $tLen + 11) {
-            user_error('Intended encoded message length too short', E_USER_NOTICE);
+            $this->_handle_error('Intended encoded message length too short');
             return false;
         }
 
@@ -2443,7 +2444,7 @@ class Crypt_RSA {
 
         $em = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
         if ($em === false) {
-            user_error('RSA modulus too short', E_USER_NOTICE);
+            $this->_handle_error('RSA modulus too short');
             return false;
         }
 
@@ -2472,7 +2473,7 @@ class Crypt_RSA {
         // Length checking
 
         if (strlen($s) != $this->k) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
 
@@ -2481,12 +2482,12 @@ class Crypt_RSA {
         $s = $this->_os2ip($s);
         $m2 = $this->_rsavp1($s);
         if ($m2 === false) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
         $em = $this->_i2osp($m2, $this->k);
         if ($em === false) {
-            user_error('Invalid signature', E_USER_NOTICE);
+            $this->_handle_error('Invalid signature');
             return false;
         }
 
@@ -2494,12 +2495,11 @@ class Crypt_RSA {
 
         $em2 = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
         if ($em2 === false) {
-            user_error('RSA modulus too short', E_USER_NOTICE);
+            $this->_handle_error('RSA modulus too short');
             return false;
         }
 
         // Compare
-
         return $this->_equals($em, $em2);
     }
 
@@ -2587,6 +2587,8 @@ class Crypt_RSA {
         }
 
         $ciphertext = str_split($ciphertext, $this->k);
+        $ciphertext[count($ciphertext) - 1] = str_pad($ciphertext[count($ciphertext) - 1], $this->k, chr(0), STR_PAD_LEFT);
+
         $plaintext = '';
 
         switch ($this->encryptionMode) {
@@ -2655,4 +2657,22 @@ class Crypt_RSA {
                 return $this->_rsassa_pss_verify($message, $signature);
         }
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
diff --git a/phpseclib/Crypt/Rijndael.php b/phpseclib/Crypt/Rijndael.php
index e7f17a6f..71155c89 100644
--- a/phpseclib/Crypt/Rijndael.php
+++ b/phpseclib/Crypt/Rijndael.php
@@ -582,7 +582,7 @@ class Crypt_Rijndael {
      *
      * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
      *     {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
-     *         $hash, $salt, $count
+     *         $hash, $salt, $method
      *     Set $dkLen by calling setKeyLength()
      *
      * @param String $password
@@ -601,7 +601,7 @@ class Crypt_Rijndael {
                 }
                 // WPA and WPA use the SSID as the salt
                 if (!isset($salt)) {
-                    $salt = 'phpseclib/salt';
+                    $salt = 'phpseclib';
                 }
                 // RFC2898#section-4.2 uses 1,000 iterations by default
                 // WPA and WPA2 use 4,096.
@@ -1365,7 +1365,7 @@ class Crypt_Rijndael {
             if ($length % $this->block_size == 0) {
                 return $text;
             } else {
-                user_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})", E_USER_NOTICE);
+                $this->_handle_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})");
                 $this->padding = true;
             }
         }
@@ -1472,7 +1472,25 @@ class Crypt_Rijndael {
         $string = substr($string, $index);
         return $substr;
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
 
 // vim: ts=4:sw=4:et:
-// vim6: fdl=1:
+// vim6: fdl=1:
\ No newline at end of file
diff --git a/phpseclib/Crypt/TripleDES.php b/phpseclib/Crypt/TripleDES.php
index bbabf169..faf8c18a 100644
--- a/phpseclib/Crypt/TripleDES.php
+++ b/phpseclib/Crypt/TripleDES.php
@@ -265,6 +265,7 @@ class Crypt_TripleDES {
                 new Crypt_DES(CRYPT_DES_MODE_CBC),
                 new Crypt_DES(CRYPT_DES_MODE_CBC)
             );
+            $this->paddable = true;
 
             // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
             $this->des[0]->disablePadding();
diff --git a/phpseclib/File/ANSI.php b/phpseclib/File/ANSI.php
index 29ad949e..4f500f9b 100644
--- a/phpseclib/File/ANSI.php
+++ b/phpseclib/File/ANSI.php
@@ -409,7 +409,7 @@ class File_ANSI {
                                                 case 47: $back = 'white'; break;
 
                                                 default:
-                                                    user_error('Unsupported attribute: ' . $mod);
+                                                    $this->_handle_error('Unsupported attribute: ' . $mod);
                                                     $this->ansi = '';
                                                     break 2;
                                             }
@@ -537,4 +537,22 @@ class File_ANSI {
 
         return '<pre style="color: white; background: black" width="' . ($this->max_x + 1) . '">' . $scrollback . '</pre>';
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 4f101efe..201af908 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -959,7 +959,7 @@ class File_ASN1 {
             case FILE_ASN1_TYPE_OBJECT_IDENTIFIER:
                 $oid = preg_match('#(?:\d+\.)+#', $source) ? $source : array_search($source, $this->oids);
                 if ($oid === false) {
-                    user_error('Invalid OID', E_USER_NOTICE);
+                    $this->_handle_error('Invalid OID');
                     return false;
                 }
                 $value = '';
@@ -1012,7 +1012,7 @@ class File_ASN1 {
                     $filters = $filters[$part];
                 }
                 if ($filters === false) {
-                    user_error('No filters defined for ' . implode('/', $loc), E_USER_NOTICE);
+                    $this->_handle_error('No filters defined for ' . implode('/', $loc));
                     return false;
                 }
                 return $this->_encode_der($source, $filters + $mapping);
@@ -1036,7 +1036,7 @@ class File_ASN1 {
                 $value = $source ? "\xFF" : "\x00";
                 break;
             default:
-                user_error('Mapping provides no type definition for ' . implode('/', $this->location), E_USER_NOTICE);
+                $this->_handle_error('Mapping provides no type definition for ' . implode('/', $this->location));
                 return false;
         }
 
@@ -1188,7 +1188,6 @@ class File_ASN1 {
      * @return String
      * @access public
      */
-
     function convert($in, $from = FILE_ASN1_TYPE_UTF8_STRING, $to = FILE_ASN1_TYPE_UTF8_STRING)
     {
         if (!isset($this->stringTypeSize[$from]) || !isset($this->stringTypeSize[$to])) {
@@ -1275,4 +1274,22 @@ class File_ASN1 {
         }
         return $out;
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index 4f022dfd..2dd68dfb 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -59,15 +59,59 @@ if (!class_exists('File_ASN1')) {
  */
 define('FILE_X509_VALIDATE_SIGNATURE_BY_CA', 1);
 
-/**
- * Name format tokens for the getDN() method.
+/**#@+
+ * @access public
+ * @see File_X509::getDN()
  */
-define('FILE_X509_DN_ARRAY', 0); // Internal array representation.
-define('FILE_X509_DN_STRING', 1); // String.
-define('FILE_X509_DN_ASN1', 2); // ASN.1 Name string.
-define('FILE_X509_DN_OPENSSL', 3); // OpenSSL compatible array.
-define('FILE_X509_DN_CANON', 4); // Canonical ASN.1 RDNs string.
-define('FILE_X509_DN_HASH', 5); // Name hash for file indexing.
+/**
+ * Return internal array representation
+ */
+define('FILE_X509_DN_ARRAY', 0);
+/**
+ * Return string
+ */
+define('FILE_X509_DN_STRING', 1);
+/**
+ * Return ASN.1 name string
+ */
+define('FILE_X509_DN_ASN1', 2);
+/**
+ * Return OpenSSL compatible array
+ */
+define('FILE_X509_DN_OPENSSL', 3);
+/**
+ * Return canonical ASN.1 RDNs string
+ */
+define('FILE_X509_DN_CANON', 4);
+/**
+ * Return name hash for file indexing
+ */
+define('FILE_X509_DN_HASH', 5);
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see File_X509::saveX509()
+ * @see File_X509::saveCSR()
+ * @see File_X509::saveCRL()
+ */
+/**
+ * Save as PEM
+ *
+ * ie. a base64-encoded PEM with a header and a footer
+ */
+define('FILE_X509_FORMAT_PEM', 0);
+/**
+ * Save as DER
+ */
+define('FILE_X509_FORMAT_DER', 1);
+/**
+ * Save as a SPKAC
+ *
+ * Only works on CSRs. Not currently supported.
+ */
+define('FILE_X509_FORMAT_SPKAC', 2);
+/**#@-*/
 
 /**
  * Attribute value disposition.
@@ -81,7 +125,7 @@ define('FILE_X509_ATTR_REPLACE', -3); // Clear first, then add a value.
  * Pure-PHP X.509 Parser
  *
  * @author  Jim Wigginton <terrafrost@php.net>
- * @version 0.3.0
+ * @version 0.3.1
  * @access  public
  * @package File_X509
  */
@@ -1356,9 +1400,20 @@ class File_X509 {
     function loadX509($cert)
     {
         if (is_array($cert) && isset($cert['tbsCertificate'])) {
+            unset($this->currentCert);
+            unset($this->currentKeyIdentifier);
+            $this->dn = $cert['tbsCertificate']['subject'];
+            if (!isset($this->dn)) {
+                return false;
+            }
             $this->currentCert = $cert;
+
+            $currentKeyIdentifier = $this->getExtension('id-ce-subjectKeyIdentifier');
+            $this->currentKeyIdentifier = is_string($currentKeyIdentifier) ? $currentKeyIdentifier : NULL;
+
             unset($this->signatureSubject);
-            return false;
+
+            return $cert;
         }
 
         $asn1 = new File_ASN1();
@@ -1370,8 +1425,11 @@ class File_X509 {
             subject=/O=organization/OU=org unit/CN=common name
             issuer=/O=organization/CN=common name
         */
-        $cert = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]| #', '', $cert);
-        $cert = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $cert) ? base64_decode($cert) : false;
+        $temp = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]| #', '', $cert);
+        $temp = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $temp) ? base64_decode($temp) : false;
+        if ($temp != false) {
+            $cert = $temp;
+        }
 
         if ($cert === false) {
             $this->currentCert = false;
@@ -1409,21 +1467,27 @@ class File_X509 {
      * Save X.509 certificate
      *
      * @param Array $cert
+     * @param Integer $format optional
      * @access public
      * @return String
      */
-    function saveX509($cert)
+    function saveX509($cert, $format = FILE_X509_FORMAT_PEM)
     {
         if (!is_array($cert) || !isset($cert['tbsCertificate'])) {
             return false;
         }
 
-        if (is_array($cert['tbsCertificate']['subjectPublicKeyInfo'])) {
-            switch ($cert['tbsCertificate']['subjectPublicKeyInfo']['algorithm']['algorithm']) {
-                case 'rsaEncryption':
-                    $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'] = 
-                        base64_encode("\0" . base64_decode(preg_replace('#-.+-|[\r\n]#', '', $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'])));
-            }
+        switch (true) {
+            // "case !$a: case !$b: break; default: whatever();" is the same thing as "if ($a && $b) whatever()"
+            case !($algorithm = $this->_subArray($cert, 'tbsCertificate/subjectPublicKeyInfo/algorithm/algorithm')):
+            case is_object($cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey']):
+                break;
+            default:
+                switch ($algorithm) {
+                    case 'rsaEncryption':
+                        $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'] = 
+                            base64_encode("\0" . base64_decode(preg_replace('#-.+-|[\r\n]#', '', $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'])));
+                }
         }
 
         $asn1 = new File_ASN1();
@@ -1455,7 +1519,13 @@ class File_X509 {
 
         $cert = $asn1->encodeDER($cert, $this->Certificate);
 
-        return "-----BEGIN CERTIFICATE-----\r\n" . chunk_split(base64_encode($cert)) . '-----END CERTIFICATE-----';
+        switch ($format) {
+            case FILE_X509_FORMAT_DER:
+                return $cert;
+            // case FILE_X509_FORMAT_PEM:
+            default:
+                return "-----BEGIN CERTIFICATE-----\r\n" . chunk_split(base64_encode($cert)) . '-----END CERTIFICATE-----';
+        }
     }
 
     /**
@@ -1559,7 +1629,7 @@ class File_X509 {
                 $map = $this->_getMapping($id);
                 if (is_bool($map)) {
                     if (!$map) {
-                        user_error($id . ' is not a currently supported extension', E_USER_NOTICE);
+                        $this->_handle_error($id . ' is not a currently supported extension');
                         unset($extensions[$i]);
                     }
                 } else {
@@ -1664,6 +1734,10 @@ class File_X509 {
      */
     function _getMapping($extnId)
     {
+        if (!is_string($extnId)) { // eg. if it's a File_ASN1_Element object
+            return true;
+        }
+
         switch ($extnId) {
             case 'id-ce-keyUsage':
                 return $this->KeyUsage;
@@ -1756,8 +1830,18 @@ class File_X509 {
      */
     function loadCA($cert)
     {
+        $olddn = $this->dn;
+        $oldcert = $this->currentCert;
+        $oldsigsubj = $this->signatureSubject;
+        $oldkeyid = $this->currentKeyIdentifier;
+
         $cert = $this->loadX509($cert);
         if (!$cert) {
+            $this->dn = $olddn;
+            $this->currentCert = $oldcert;
+            $this->signatureSubject = $oldsigsubj;
+            $this->currentKeyIdentifier = $oldkeyid;
+
             return false;
         }
 
@@ -1786,8 +1870,10 @@ class File_X509 {
         //}
 
         $this->CAs[] = $cert;
-        unset($this->currentCert);
-        unset($this->signatureSubject);
+
+        $this->dn = $olddn;
+        $this->currentCert = $oldcert;
+        $this->signatureSubject = $oldsigsubj;
 
         return true;
     }
@@ -1895,9 +1981,7 @@ class File_X509 {
      * Validate a signature
      *
      * Works on X.509 certs, CSR's and CRL's.
-     * Returns 1 if the signature is verified, 0 if it is not correct or -1 on error
-     *
-     * To know if a signature is valid one should do validateSignature() === 1
+     * Returns true if the signature is verified, false if it is not correct or NULL on error
      *
      * The behavior of this function is inspired by {@link http://php.net/openssl-verify openssl_verify}.
      *
@@ -1947,10 +2031,10 @@ class File_X509 {
                         }
                     }
                     if (count($this->CAs) == $i && ($options & FILE_X509_VALIDATE_SIGNATURE_BY_CA)) {
-                        return 0;
+                        return false;
                     }
                 } elseif (!isset($signingCert) || ($options & FILE_X509_VALIDATE_SIGNATURE_BY_CA)) {
-                    return 0;
+                    return false;
                 }
                 return $this->_validateSignature(
                     $signingCert['tbsCertificate']['subjectPublicKeyInfo']['algorithm']['algorithm'],
@@ -1984,7 +2068,7 @@ class File_X509 {
                     }
                 }
                 if (!isset($signingCert)) {
-                    return 0;
+                    return false;
                 }
                 return $this->_validateSignature(
                     $signingCert['tbsCertificate']['subjectPublicKeyInfo']['algorithm']['algorithm'],
@@ -1994,14 +2078,14 @@ class File_X509 {
                     $this->signatureSubject
                 );
             default:
-                return 0;
+                return false;
         }
     }
 
     /**
      * Validates a signature
      *
-     * Returns 1 if the signature is verified, 0 if it is not correct or -1 on error
+     * Returns true if the signature is verified, false if it is not correct or NULL on error
      *
      * @param String $publicKeyAlgorithm
      * @param String $publicKey
@@ -2033,18 +2117,18 @@ class File_X509 {
                         $rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
 
                         if (!@$rsa->verify($signatureSubject, $signature)) {
-                            return 0;
+                            return false;
                         }
                         break;
                     default:
-                        return -1;
+                        return NULL;
                 }
                 break;
             default:
-                return -1;
+                return NULL;
         }
 
-        return 1;
+        return true;
     }
 
     /**
@@ -2328,7 +2412,7 @@ class File_X509 {
     function getDN($format = FILE_X509_DN_ARRAY, $dn = NULL)
     {
         if (!isset($dn)) {
-            $dn = $this->dn;
+            $dn = isset($this->currentCert['tbsCertList']) ? $this->currentCert['tbsCertList']['issuer'] : $this->dn;
         }
 
         switch ((int) $format) {
@@ -2480,7 +2564,7 @@ class File_X509 {
                 return $this->getDN($format, $this->currentCert['tbsCertList']['issuer']);
         }
 
-    return false;
+        return false;
     }
 
     /**
@@ -2504,7 +2588,7 @@ class File_X509 {
                 return $this->getDN($format, $this->currentCert['certificationRequestInfo']['subject']);
         }
 
-    return false;
+        return false;
     }
 
     /**
@@ -2526,7 +2610,7 @@ class File_X509 {
                 return $this->getDNProp($propname, $this->currentCert['tbsCertList']['issuer'], $withType);
         }
 
-    return false;
+        return false;
     }
 
     /**
@@ -2550,7 +2634,52 @@ class File_X509 {
                 return $this->getDNProp($propname, $this->currentCert['certificationRequestInfo']['subject'], $withType);
         }
 
-    return false;
+        return false;
+    }
+
+    /**
+     * Get the certificate chain for the current cert
+     *
+     * @access public
+     * @return Mixed
+     */
+    function getChain()
+    {
+        $chain = array($this->currentCert);
+
+        if (!is_array($this->currentCert) || !isset($this->currentCert['tbsCertificate'])) {
+            return false;
+        }
+        if (empty($this->CAs)) {
+            return $chain;
+        }
+        while (true) {
+            $currentCert = $chain[count($chain) - 1];
+            for ($i = 0; $i < count($this->CAs); $i++) {
+                $ca = $this->CAs[$i];
+                if ($currentCert['tbsCertificate']['issuer'] === $ca['tbsCertificate']['subject']) {
+                    $authorityKey = $this->getExtension('id-ce-authorityKeyIdentifier', $currentCert);
+                    $subjectKeyID = $this->getExtension('id-ce-subjectKeyIdentifier', $ca);
+                    switch (true) {
+                        case !is_array($authorityKey):
+                        case is_array($authorityKey) && isset($authorityKey['keyIdentifier']) && $authorityKey['keyIdentifier'] === $subjectKeyID:
+                            if ($currentCert === $ca) {
+                                break 3;
+                            }
+                            $chain[] = $ca;
+                            break 2;
+                    }
+                }
+            }
+            if ($i == count($this->CAs)) {
+                break;
+            }
+        }
+        foreach ($chain as $key=>$value) {
+            $chain[$key] = new File_X509();
+            $chain[$key]->loadX509($value);
+        }
+        return $chain;
     }
 
     /**
@@ -2633,12 +2762,29 @@ class File_X509 {
      */
     function loadCSR($csr)
     {
+        if (is_array($csr) && isset($csr['certificationRequestInfo'])) {
+            unset($this->currentCert);
+            unset($this->currentKeyIdentifier);
+            $this->dn = $csr['certificationRequestInfo']['subject'];
+            if (!isset($this->dn)) {
+                return false;
+            }
+
+            $this->currentCert = $csr;
+            unset($this->signatureSubject);
+            return $csr;
+        }
+
         // see http://tools.ietf.org/html/rfc2986
 
         $asn1 = new File_ASN1();
 
-        $csr = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]| #', '', $csr);
-        $orig = $csr = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $csr) ? base64_decode($csr) : false;
+        $temp = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]| #', '', $csr);
+        $temp = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $temp) ? base64_decode($temp) : false;
+        if ($temp != false) {
+            $csr = $temp;
+        }
+        $orig = $csr;
 
         if ($csr === false) {
             $this->currentCert = false;
@@ -2691,19 +2837,26 @@ class File_X509 {
      * Save CSR request
      *
      * @param Array $csr
+     * @param Integer $format optional
      * @access public
      * @return String
      */
-    function saveCSR($csr)
+    function saveCSR($csr, $format = FILE_X509_FORMAT_PEM)
     {
         if (!is_array($csr) || !isset($csr['certificationRequestInfo'])) {
             return false;
         }
 
-        switch ($csr['certificationRequestInfo']['subjectPKInfo']['algorithm']['algorithm']) {
-            case 'rsaEncryption':
-                $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey'] = 
-                    base64_encode("\0" . base64_decode(preg_replace('#-.+-|[\r\n]#', '', $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey'])));
+        switch (true) {
+            case !($algorithm = $this->_subArray($csr, 'certificationRequestInfo/subjectPKInfo/algorithm/algorithm')):
+            case is_object($csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey']);
+                break;
+            default:
+                switch ($algorithm) {
+                    case 'rsaEncryption':
+                        $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey'] = 
+                            base64_encode("\0" . base64_decode(preg_replace('#-.+-|[\r\n]#', '', $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey'])));
+                }
         }
 
         $asn1 = new File_ASN1();
@@ -2719,7 +2872,13 @@ class File_X509 {
         $this->_mapOutAttributes($csr, 'certificationRequestInfo/attributes', $asn1);
         $csr = $asn1->encodeDER($csr, $this->CertificationRequest);
 
-        return "-----BEGIN CERTIFICATE REQUEST-----\r\n" . chunk_split(base64_encode($csr)) . '-----END CERTIFICATE REQUEST-----';
+        switch ($format) {
+            case FILE_X509_FORMAT_DER:
+                return $csr;
+            // case FILE_X509_FORMAT_PEM:
+            default:
+                return "-----BEGIN CERTIFICATE REQUEST-----\r\n" . chunk_split(base64_encode($csr)) . '-----END CERTIFICATE REQUEST-----';
+        }
     }
 
     /**
@@ -2731,10 +2890,20 @@ class File_X509 {
      */
     function loadCRL($crl)
     {
+        if (is_array($crl) && isset($crl['tbsCertList'])) {
+            $this->currentCert = $crl;
+            unset($this->signatureSubject);
+            return $crl;
+        }
+
         $asn1 = new File_ASN1();
 
-        $crl = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]#', '', $crl);
-        $orig = $crl = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $crl) ? base64_decode($crl) : false;
+        $temp = preg_replace('#^(?:[^-].+[\r\n]+)+|-.+-|[\r\n]| #', '', $crl);
+        $temp = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $temp) ? base64_decode($temp) : false;
+        if ($temp != false) {
+            $crl = $temp;
+        }
+        $orig = $crl;
 
         if ($crl === false) {
             $this->currentCert = false;
@@ -2775,10 +2944,11 @@ class File_X509 {
      * Save Certificate Revocation List.
      *
      * @param Array $crl
+     * @param Integer $format optional
      * @access public
      * @return String
      */
-    function saveCRL($crl)
+    function saveCRL($crl, $format = FILE_X509_FORMAT_PEM)
     {
         if (!is_array($crl) || !isset($crl['tbsCertList'])) {
             return false;
@@ -2816,7 +2986,13 @@ class File_X509 {
 
         $crl = $asn1->encodeDER($crl, $this->CertificateList);
 
-        return "-----BEGIN X509 CRL-----\r\n" . chunk_split(base64_encode($crl)) . '-----END X509 CRL-----';
+        switch ($format) {
+            case FILE_X509_FORMAT_DER:
+                return $crl;
+            // case FILE_X509_FORMAT_PEM:
+            default:
+                return "-----BEGIN X509 CRL-----\r\n" . chunk_split(base64_encode($crl)) . '-----END X509 CRL-----';
+        }
     }
 
     /**
@@ -3077,8 +3253,7 @@ class File_X509 {
 
         if (!empty($this->endDate)) {
             $tbsCertList['nextUpdate'] = array('generalTime' => $this->endDate); // $this->setEndDate()
-        }
-        else {
+        } else {
             unset($tbsCertList['nextUpdate']);
         }
 
@@ -3088,7 +3263,7 @@ class File_X509 {
         else {
             $crlNumber = $this->getExtension('id-ce-cRLNumber');
             $crlNumber = $crlNumber !== false ? $crlNumber->add(new Math_BigInteger(1)) : NULL;
-            }
+        }
 
         $this->removeExtension('id-ce-authorityKeyIdentifier');
         $this->removeExtension('id-ce-issuerAltName');
@@ -3705,10 +3880,10 @@ class File_X509 {
     /**
      * Compute a public key identifier.
      *
-     *  Although key identifiers may be set to any unique value, this function
+     * Although key identifiers may be set to any unique value, this function
      * computes key identifiers from public key according to the two
      * recommended methods (4.2.1.2 RFC 3280).
-     *  Highly polymorphic: try to accept all possible forms of key:
+     * Highly polymorphic: try to accept all possible forms of key:
      * - Key object
      * - File_X509 object with public or private key defined
      * - Certificate or CSR array
@@ -3776,7 +3951,7 @@ class File_X509 {
             $hash[0] = chr((ord($hash[0]) & 0x0F) | 0x40);
         }
 
-    return $hash;
+        return $hash;
     }
 
     /**
@@ -3839,7 +4014,6 @@ class File_X509 {
      * @access private
      * @return Integer or false
      */
-
     function _revokedCertificate(&$rclist, $serial, $create = false)
     {
         $serial = new Math_BigInteger($serial);
@@ -3945,7 +4119,7 @@ class File_X509 {
 
         $result = array();
 
-        if (!is_array($rclist = $this->_subArray($crl, 'tbsCertList/revokedCertificates'))) {
+        if (is_array($rclist = $this->_subArray($crl, 'tbsCertList/revokedCertificates'))) {
             foreach ($rclist as $rc) {
                 $result[] = $rc['userCertificate']->toString();
             }
@@ -4045,4 +4219,22 @@ class File_X509 {
 
         return false;
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index fc2bf2e9..3fb149df 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -399,7 +399,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_VERSION) {
-            user_error('Expected SSH_FXP_VERSION', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_VERSION');
             return false;
         }
 
@@ -588,7 +588,7 @@ class Net_SFTP extends Net_SSH2 {
                 $this->_logError($response);
                 return false;
             default:
-                user_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS');
                 return false;
         }
 
@@ -645,7 +645,7 @@ class Net_SFTP extends Net_SSH2 {
                 $this->_logError($response);
                 return false;
             default:
-                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
                 return false;
         }
 
@@ -655,7 +655,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -731,7 +731,7 @@ class Net_SFTP extends Net_SSH2 {
                 $this->_logError($response);
                 return false;
             default:
-                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
                 return false;
         }
 
@@ -780,7 +780,7 @@ class Net_SFTP extends Net_SSH2 {
                     }
                     break 2;
                 default:
-                    user_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS', E_USER_NOTICE);
+                    $this->_handle_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS');
                     return false;
             }
         }
@@ -793,7 +793,7 @@ class Net_SFTP extends Net_SSH2 {
         //  -- http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.1.3
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -996,7 +996,7 @@ class Net_SFTP extends Net_SSH2 {
                 return false;
         }
 
-        user_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS', E_USER_NOTICE);
+        $this->_handle_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS');
         return false;
     }
 
@@ -1089,7 +1089,7 @@ class Net_SFTP extends Net_SSH2 {
         */
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1116,7 +1116,7 @@ class Net_SFTP extends Net_SSH2 {
                 return false;
         }
 
-        user_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS', E_USER_NOTICE);
+        $this->_handle_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS');
         return false;
     }
 
@@ -1249,7 +1249,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1288,7 +1288,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1365,7 +1365,7 @@ class Net_SFTP extends Net_SSH2 {
                 $this->_logError($response);
                 return false;
             default:
-                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
                 return false;
         }
 
@@ -1374,7 +1374,7 @@ class Net_SFTP extends Net_SSH2 {
         // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.2.3
         if ($mode & NET_SFTP_LOCAL_FILE) {
             if (!is_file($data)) {
-                user_error("$data is not a valid file", E_USER_NOTICE);
+                $this->_handle_error("$data is not a valid file");
                 return false;
             }
             $fp = @fopen($data, 'rb');
@@ -1425,7 +1425,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1453,7 +1453,7 @@ class Net_SFTP extends Net_SSH2 {
         while ($i--) {
             $response = $this->_get_sftp_packet();
             if ($this->packet_type != NET_SFTP_STATUS) {
-                user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_STATUS');
                 return false;
             }
 
@@ -1504,7 +1504,7 @@ class Net_SFTP extends Net_SSH2 {
                 $this->_logError($response);
                 return false;
             default:
-                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                $this->_handle_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
                 return false;
         }
 
@@ -1542,7 +1542,7 @@ class Net_SFTP extends Net_SSH2 {
                     $this->_logError($response);
                     break 2;
                 default:
-                    user_error('Expected SSH_FXP_DATA or SSH_FXP_STATUS', E_USER_NOTICE);
+                    $this->_handle_error('Expected SSH_FXP_DATA or SSH_FXP_STATUS');
                     if ($local_file !== false) {
                         fclose($fp);
                     }
@@ -1560,7 +1560,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1604,7 +1604,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
@@ -1723,7 +1723,7 @@ class Net_SFTP extends Net_SSH2 {
 
         $response = $this->_get_sftp_packet();
         if ($this->packet_type != NET_SFTP_STATUS) {
-            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_FXP_STATUS');
             return false;
         }
 
diff --git a/phpseclib/Net/SSH1.php b/phpseclib/Net/SSH1.php
index 69669aa7..6b1f504e 100644
--- a/phpseclib/Net/SSH1.php
+++ b/phpseclib/Net/SSH1.php
@@ -428,7 +428,7 @@ class Net_SSH1 {
      * @var Array
      * @access private
      */
-    var $interactive_buffer = '';
+    var $interactiveBuffer = '';
 
     /**
      * Default Constructor.
@@ -467,7 +467,7 @@ class Net_SSH1 {
 
         $this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
         if (!$this->fsock) {
-            user_error(rtrim("Cannot connect to $host. Error $errno. $errstr"), E_USER_NOTICE);
+            $this->_handle_error(rtrim("Cannot connect to $host. Error $errno. $errstr"));
             return;
         }
 
@@ -484,11 +484,11 @@ class Net_SSH1 {
         }
 
         if (!preg_match('#SSH-([0-9\.]+)-(.+)#', $init_line, $parts)) {
-            user_error('Can only connect to SSH servers', E_USER_NOTICE);
+            $this->_handle_error('Can only connect to SSH servers');
             return;
         }
         if ($parts[1][0] != 1) {
-            user_error("Cannot connect to SSH $parts[1] servers", E_USER_NOTICE);
+            $this->_handle_error("Cannot connect to SSH $parts[1] servers");
             return;
         }
 
@@ -496,7 +496,7 @@ class Net_SSH1 {
 
         $response = $this->_get_binary_packet();
         if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
-            user_error('Expected SSH_SMSG_PUBLIC_KEY', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_SMSG_PUBLIC_KEY');
             return;
         }
 
@@ -584,7 +584,7 @@ class Net_SSH1 {
         $data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_SESSION_KEY', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_SESSION_KEY');
             return;
         }
 
@@ -614,7 +614,7 @@ class Net_SSH1 {
         $response = $this->_get_binary_packet();
 
         if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
-            user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_SMSG_SUCCESS');
             return;
         }
 
@@ -638,7 +638,7 @@ class Net_SSH1 {
         $data = pack('CNa*', NET_SSH1_CMSG_USER, strlen($username), $username);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_USER', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_USER');
             return false;
         }
 
@@ -648,14 +648,14 @@ class Net_SSH1 {
             $this->bitmap |= NET_SSH1_MASK_LOGIN;
             return true;
         } else if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_FAILURE) {
-            user_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE');
             return false;
         }
 
         $data = pack('CNa*', NET_SSH1_CMSG_AUTH_PASSWORD, strlen($password), $password);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_AUTH_PASSWORD', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_AUTH_PASSWORD');
             return false;
         }
 
@@ -673,7 +673,7 @@ class Net_SSH1 {
         } else if ($response[NET_SSH1_RESPONSE_TYPE] == NET_SSH1_SMSG_FAILURE) {
             return false;
         } else {
-            user_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE');
             return false;
         }
     }
@@ -701,14 +701,14 @@ class Net_SSH1 {
     function exec($cmd, $block = true)
     {
         if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         $data = pack('CNa*', NET_SSH1_CMSG_EXEC_CMD, strlen($cmd), $cmd);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_EXEC_CMD', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_EXEC_CMD');
             return false;
         }
 
@@ -753,21 +753,21 @@ class Net_SSH1 {
         $data = pack('CNa*N4C', NET_SSH1_CMSG_REQUEST_PTY, strlen('vt100'), 'vt100', 24, 80, 0, 0, NET_SSH1_TTY_OP_END);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_REQUEST_PTY', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_REQUEST_PTY');
             return false;
         }
 
         $response = $this->_get_binary_packet();
 
         if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
-            user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_SMSG_SUCCESS');
             return false;
         }
 
         $data = pack('C', NET_SSH1_CMSG_EXEC_SHELL);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_EXEC_SHELL', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_EXEC_SHELL');
             return false;
         }
 
@@ -806,12 +806,12 @@ class Net_SSH1 {
     function read($expect, $mode = NET_SSH1_READ_SIMPLE)
     {
         if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         if (!($this->bitmap & NET_SSH1_MASK_SHELL) && !$this->_initShell()) {
-            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            $this->_handle_error('Unable to initiate an interactive shell session');
             return false;
         }
 
@@ -841,19 +841,19 @@ class Net_SSH1 {
     function interactiveWrite($cmd)
     {
         if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         if (!($this->bitmap & NET_SSH1_MASK_SHELL) && !$this->_initShell()) {
-            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            $this->_handle_error('Unable to initiate an interactive shell session');
             return false;
         }
 
         $data = pack('CNa*', NET_SSH1_CMSG_STDIN_DATA, strlen($cmd), $cmd);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Error sending SSH_CMSG_STDIN', E_USER_NOTICE);
+            $this->_handle_error('Error sending SSH_CMSG_STDIN');
             return false;
         }
 
@@ -876,12 +876,12 @@ class Net_SSH1 {
     function interactiveRead()
     {
         if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         if (!($this->bitmap & NET_SSH1_MASK_SHELL) && !$this->_initShell()) {
-            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            $this->_handle_error('Unable to initiate an interactive shell session');
             return false;
         }
 
@@ -960,7 +960,7 @@ class Net_SSH1 {
     function _get_binary_packet()
     {
         if (feof($this->fsock)) {
-            //user_error('connection closed prematurely', E_USER_NOTICE);
+            //$this->_handle_error('connection closed prematurely');
             return false;
         }
 
@@ -984,7 +984,7 @@ class Net_SSH1 {
         $temp = unpack('Ncrc', substr($raw, -4));
 
         //if ( $temp['crc'] != $this->_crc($padding . $type . $data) ) {
-        //    user_error('Bad CRC in packet from server', E_USER_NOTICE);
+        //    $this->_handle_error('Bad CRC in packet from server');
         //    return false;
         //}
 
@@ -1017,7 +1017,7 @@ class Net_SSH1 {
      */
     function _send_binary_packet($data) {
         if (feof($this->fsock)) {
-            //user_error('connection closed prematurely', E_USER_NOTICE);
+            //$this->_handle_error('connection closed prematurely');
             return false;
         }
 
@@ -1418,4 +1418,22 @@ class Net_SSH1 {
     {
         return rtrim($this->server_identification);
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 144eba40..bdee4222 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -699,6 +699,13 @@ class Net_SSH2 {
      */
     var $quiet_mode = false;
 
+    /**
+     * Time of first network activity
+     *
+     * @access private
+     */
+    var $last_packet;
+
     /**
      * Default Constructor.
      *
@@ -712,6 +719,7 @@ class Net_SSH2 {
      */
     function Net_SSH2($host, $port = 22, $timeout = 10)
     {
+        $this->last_packet = strtok(microtime(), ' ') + strtok(''); // == microtime(true) in PHP5
         $this->message_numbers = array(
             1 => 'NET_SSH2_MSG_DISCONNECT',
             2 => 'NET_SSH2_MSG_IGNORE',
@@ -785,7 +793,7 @@ class Net_SSH2 {
         $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
         $this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
         if (!$this->fsock) {
-            user_error(rtrim("Cannot connect to $host. Error $errno. $errstr"), E_USER_NOTICE);
+            $this->_handle_error(rtrim("Cannot connect to $host. Error $errno. $errstr"));
             return;
         }
         $elapsed = strtok(microtime(), ' ') + strtok('') - $start;
@@ -793,7 +801,7 @@ class Net_SSH2 {
         $timeout-= $elapsed;
 
         if ($timeout <= 0) {
-            user_error(rtrim("Cannot connect to $host. Timeout error"), E_USER_NOTICE);
+            $this->_handle_error(rtrim("Cannot connect to $host. Timeout error"));
             return;
         }
 
@@ -806,7 +814,7 @@ class Net_SSH2 {
         // on windows this returns a "Warning: Invalid CRT parameters detected" error
         // the !count() is done as a workaround for <https://bugs.php.net/42682>
         if (!@stream_select($read, $write, $except, $sec, $usec) && !count($read)) {
-            user_error(rtrim("Cannot connect to $host. Banner timeout"), E_USER_NOTICE);
+            $this->_handle_error(rtrim("Cannot connect to $host. Banner timeout"));
             return;
         }
 
@@ -828,7 +836,7 @@ class Net_SSH2 {
         }
 
         if (feof($this->fsock)) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -862,7 +870,7 @@ class Net_SSH2 {
         }
 
         if ($matches[1] != '1.99' && $matches[1] != '2.0') {
-            user_error("Cannot connect to SSH $matches[1] servers", E_USER_NOTICE);
+            $this->_handle_error("Cannot connect to SSH $matches[1] servers");
             return;
         }
 
@@ -870,12 +878,12 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return;
         }
 
         if (ord($response[0]) != NET_SSH2_MSG_KEXINIT) {
-            user_error('Expected SSH_MSG_KEXINIT', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_MSG_KEXINIT');
             return;
         }
 
@@ -1020,7 +1028,7 @@ class Net_SSH2 {
         // we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
         for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_server_to_client); $i++);
         if ($i == count($encryption_algorithms)) {
-            user_error('No compatible server to client encryption algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible server to client encryption algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1057,7 +1065,7 @@ class Net_SSH2 {
 
         for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_client_to_server); $i++);
         if ($i == count($encryption_algorithms)) {
-            user_error('No compatible client to server encryption algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible client to server encryption algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1095,7 +1103,7 @@ class Net_SSH2 {
         // through diffie-hellman key exchange a symmetric key is obtained
         for ($i = 0; $i < count($kex_algorithms) && !in_array($kex_algorithms[$i], $this->kex_algorithms); $i++);
         if ($i == count($kex_algorithms)) {
-            user_error('No compatible key exchange algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible key exchange algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1148,19 +1156,19 @@ class Net_SSH2 {
         $data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
 
         if (!$this->_send_binary_packet($data)) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
         extract(unpack('Ctype', $this->_string_shift($response, 1)));
 
         if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
-            user_error('Expected SSH_MSG_KEXDH_REPLY', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_MSG_KEXDH_REPLY');
             return false;
         }
 
@@ -1198,12 +1206,12 @@ class Net_SSH2 {
 
         for ($i = 0; $i < count($server_host_key_algorithms) && !in_array($server_host_key_algorithms[$i], $this->server_host_key_algorithms); $i++);
         if ($i == count($server_host_key_algorithms)) {
-            user_error('No compatible server host key algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible server host key algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
         if ($public_key_format != $server_host_key_algorithms[$i] || $this->signature_format != $server_host_key_algorithms[$i]) {
-            user_error('Sever Host Key Algorithm Mismatch', E_USER_NOTICE);
+            $this->_handle_error('Sever Host Key Algorithm Mismatch');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1218,14 +1226,14 @@ class Net_SSH2 {
         $response = $this->_get_binary_packet();
 
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
         extract(unpack('Ctype', $this->_string_shift($response, 1)));
 
         if ($type != NET_SSH2_MSG_NEWKEYS) {
-            user_error('Expected SSH_MSG_NEWKEYS', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_MSG_NEWKEYS');
             return false;
         }
 
@@ -1339,7 +1347,7 @@ class Net_SSH2 {
 
         for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_client_to_server); $i++);
         if ($i == count($mac_algorithms)) {
-            user_error('No compatible client to server message authentication algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible client to server message authentication algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1364,7 +1372,7 @@ class Net_SSH2 {
 
         for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_server_to_client); $i++);
         if ($i == count($mac_algorithms)) {
-            user_error('No compatible server to client message authentication algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible server to client message authentication algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
 
@@ -1406,14 +1414,14 @@ class Net_SSH2 {
 
         for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_server_to_client); $i++);
         if ($i == count($compression_algorithms)) {
-            user_error('No compatible server to client compression algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible server to client compression algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
         $this->decompress = $compression_algorithms[$i] == 'zlib';
 
         for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_client_to_server); $i++);
         if ($i == count($compression_algorithms)) {
-            user_error('No compatible client to server compression algorithms found', E_USER_NOTICE);
+            $this->_handle_error('No compatible client to server compression algorithms found');
             return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
         }
         $this->compress = $compression_algorithms[$i] == 'zlib';
@@ -1433,7 +1441,7 @@ class Net_SSH2 {
      * @internal It might be worthwhile, at some point, to protect against {@link http://tools.ietf.org/html/rfc4251#section-9.3.9 traffic analysis}
      *           by sending dummy SSH_MSG_IGNORE messages.
      */
-    function login($username, $password = '')
+    function login($username, $password = null)
     {
         if (!($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR)) {
             return false;
@@ -1449,14 +1457,14 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
         extract(unpack('Ctype', $this->_string_shift($response, 1)));
 
         if ($type != NET_SSH2_MSG_SERVICE_ACCEPT) {
-            user_error('Expected SSH_MSG_SERVICE_ACCEPT', E_USER_NOTICE);
+            $this->_handle_error('Expected SSH_MSG_SERVICE_ACCEPT');
             return false;
         }
 
@@ -1465,6 +1473,34 @@ class Net_SSH2 {
             return $this->_privatekey_login($username, $password);
         }
 
+        if (!isset($password)) {
+            $packet = pack('CNa*Na*Na*',
+                NET_SSH2_MSG_USERAUTH_REQUEST, strlen($username), $username, strlen('ssh-connection'), 'ssh-connection',
+                strlen('none'), 'none'
+            );
+
+            if (!$this->_send_binary_packet($packet)) {
+                return false;
+            }
+
+            $response = $this->_get_binary_packet();
+            if ($response === false) {
+                $this->_handle_error('Connection closed by server');
+                return false;
+            }
+
+            extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+            switch ($type) {
+                case NET_SSH2_MSG_USERAUTH_SUCCESS:
+                    $this->bitmap |= NET_SSH2_MASK_LOGIN;
+                    return true;
+                //case NET_SSH2_MSG_USERAUTH_FAILURE:
+                default:
+                    return false;
+            }
+        }
+
         $packet = pack('CNa*Na*Na*CNa*',
             NET_SSH2_MSG_USERAUTH_REQUEST, strlen($username), $username, strlen('ssh-connection'), 'ssh-connection',
             strlen('password'), 'password', 0, strlen($password), $password
@@ -1485,7 +1521,7 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -1557,7 +1593,7 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -1670,7 +1706,7 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -1705,7 +1741,7 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -1858,7 +1894,7 @@ class Net_SSH2 {
 
         $response = $this->_get_binary_packet();
         if ($response === false) {
-            user_error('Connection closed by server', E_USER_NOTICE);
+            $this->_handle_error('Connection closed by server');
             return false;
         }
 
@@ -1869,7 +1905,7 @@ class Net_SSH2 {
                 break;
             case NET_SSH2_MSG_CHANNEL_FAILURE:
             default:
-                user_error('Unable to request pseudo-terminal', E_USER_NOTICE);
+                $this->_handle_error('Unable to request pseudo-terminal');
                 return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
         }
 
@@ -1910,12 +1946,12 @@ class Net_SSH2 {
         $this->curTimeout = $this->timeout;
 
         if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         if (!($this->bitmap & NET_SSH2_MASK_SHELL) && !$this->_initShell()) {
-            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            $this->_handle_error('Unable to initiate an interactive shell session');
             return false;
         }
 
@@ -1923,7 +1959,7 @@ class Net_SSH2 {
         while (true) {
             if ($mode == NET_SSH2_READ_REGEX) {
                 preg_match($expect, $this->interactiveBuffer, $matches);
-                $match = $matches[0];
+                $match = isset($matches[0]) ? $matches[0] : array();
             }
             $pos = !empty($match) ? strpos($this->interactiveBuffer, $match) : false;
             if ($pos !== false) {
@@ -1949,12 +1985,12 @@ class Net_SSH2 {
     function write($cmd)
     {
         if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
-            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            $this->_handle_error('Operation disallowed prior to login()');
             return false;
         }
 
         if (!($this->bitmap & NET_SSH2_MASK_SHELL) && !$this->_initShell()) {
-            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            $this->_handle_error('Unable to initiate an interactive shell session');
             return false;
         }
 
@@ -1999,7 +2035,8 @@ class Net_SSH2 {
     function _get_binary_packet()
     {
         if (!is_resource($this->fsock) || feof($this->fsock)) {
-            user_error('Connection closed prematurely', E_USER_NOTICE);
+            $this->_handle_error('Connection closed prematurely');
+            $this->bitmask = 0;
             return false;
         }
 
@@ -2015,7 +2052,7 @@ class Net_SSH2 {
             $raw = $this->decrypt->decrypt($raw);
         }
         if ($raw === false) {
-            user_error('Unable to decrypt content', E_USER_NOTICE);
+            $this->_handle_error('Unable to decrypt content');
             return false;
         }
 
@@ -2039,7 +2076,7 @@ class Net_SSH2 {
         if ($this->hmac_check !== false) {
             $hmac = fread($this->fsock, $this->hmac_size);
             if ($hmac != $this->hmac_check->hash(pack('NNCa*', $this->get_seq_no, $packet_length, $padding_length, $payload . $padding))) {
-                user_error('Invalid HMAC', E_USER_NOTICE);
+                $this->_handle_error('Invalid HMAC');
                 return false;
             }
         }
@@ -2051,10 +2088,12 @@ class Net_SSH2 {
         $this->get_seq_no++;
 
         if (defined('NET_SSH2_LOGGING')) {
+            $current = strtok(microtime(), ' ') + strtok('');
             $message_number = isset($this->message_numbers[ord($payload[0])]) ? $this->message_numbers[ord($payload[0])] : 'UNKNOWN (' . ord($payload[0]) . ')';
             $message_number = '<- ' . $message_number .
-                              ' (' . round($stop - $start, 4) . 's)';
+                              ' (since last: ' . round($current - $this->last_packet, 4) . ', network: ' . round($stop - $start, 4) . 's)';
             $this->_append_log($message_number, $payload);
+            $this->last_packet = $current;
         }
 
         return $this->_filter($payload);
@@ -2204,7 +2243,7 @@ class Net_SSH2 {
 
             $response = $this->_get_binary_packet();
             if ($response === false) {
-                user_error('Connection closed by server', E_USER_NOTICE);
+                $this->_handle_error('Connection closed by server');
                 return false;
             }
 
@@ -2226,7 +2265,7 @@ class Net_SSH2 {
                             return $client_channel == $channel ? true : $this->_get_channel_packet($client_channel, $skip_extended);
                         //case NET_SSH2_MSG_CHANNEL_OPEN_FAILURE:
                         default:
-                            user_error('Unable to open channel', E_USER_NOTICE);
+                            $this->_handle_error('Unable to open channel');
                             return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
                     }
                     break;
@@ -2236,7 +2275,7 @@ class Net_SSH2 {
                             return true;
                         //case NET_SSH2_MSG_CHANNEL_FAILURE:
                         default:
-                            user_error('Unable to request pseudo-terminal', E_USER_NOTICE);
+                            $this->_handle_error('Unable to request pseudo-terminal');
                             return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
                     }
                 case NET_SSH2_MSG_CHANNEL_CLOSE:
@@ -2325,7 +2364,7 @@ class Net_SSH2 {
                 case NET_SSH2_MSG_CHANNEL_EOF:
                     break;
                 default:
-                    user_error('Error reading channel data', E_USER_NOTICE);
+                    $this->_handle_error('Error reading channel data');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
             }
         }
@@ -2344,7 +2383,8 @@ class Net_SSH2 {
     function _send_binary_packet($data)
     {
         if (!is_resource($this->fsock) || feof($this->fsock)) {
-            user_error('Connection closed prematurely', E_USER_NOTICE);
+            $this->_handle_error('Connection closed prematurely');
+            $this->bitmask = 0;
             return false;
         }
 
@@ -2383,10 +2423,12 @@ class Net_SSH2 {
         $stop = strtok(microtime(), ' ') + strtok('');
 
         if (defined('NET_SSH2_LOGGING')) {
+            $current = strtok(microtime(), ' ') + strtok('');
             $message_number = isset($this->message_numbers[ord($data[0])]) ? $this->message_numbers[ord($data[0])] : 'UNKNOWN (' . ord($data[0]) . ')';
             $message_number = '-> ' . $message_number .
-                              ' (' . round($stop - $start, 4) . 's)';
+                              ' (since last: ' . round($current - $this->last_packet, 4) . ', network: ' . round($stop - $start, 4) . 's)';
             $this->_append_log($message_number, $data);
+            $this->last_packet = $current;
         }
 
         return $result;
@@ -2423,8 +2465,8 @@ class Net_SSH2 {
                 // identified
                 case NET_SSH2_LOG_REALTIME:
                     echo "<pre>\r\n" . $this->_format_log(array($message), array($message_number)) . "\r\n</pre>\r\n";
-                    flush();
-                    ob_flush();
+                    @flush();
+                    @ob_flush();
                     break;
                 // basically the same thing as NET_SSH2_LOG_REALTIME with the caveat that NET_SSH2_LOG_REALTIME_FILE
                 // needs to be defined and that the resultant log file will be capped out at NET_SSH2_LOG_MAX_SIZE. 
@@ -2852,7 +2894,7 @@ class Net_SSH2 {
                    padding, unsigned, and in network byte order). */
                 $temp = unpack('Nlength', $this->_string_shift($signature, 4));
                 if ($temp['length'] != 40) {
-                    user_error('Invalid signature', E_USER_NOTICE);
+                    $this->_handle_error('Invalid signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
                 }
 
@@ -2860,7 +2902,7 @@ class Net_SSH2 {
                 $s = new Math_BigInteger($this->_string_shift($signature, 20), 256);
 
                 if ($r->compare($q) >= 0 || $s->compare($q) >= 0) {
-                    user_error('Invalid signature', E_USER_NOTICE);
+                    $this->_handle_error('Invalid signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
                 }
 
@@ -2880,7 +2922,7 @@ class Net_SSH2 {
                 list(, $v) = $v->divide($q);
 
                 if (!$v->equals($r)) {
-                    user_error('Bad server signature', E_USER_NOTICE);
+                    $this->_handle_error('Bad server signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
                 }
 
@@ -2905,7 +2947,7 @@ class Net_SSH2 {
                 $rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
                 $rsa->loadKey(array('e' => $e, 'n' => $n), CRYPT_RSA_PUBLIC_FORMAT_RAW);
                 if (!$rsa->verify($this->exchange_hash, $signature)) {
-                    user_error('Bad server signature', E_USER_NOTICE);
+                    $this->_handle_error('Bad server signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
                 }
                 */
@@ -2920,7 +2962,7 @@ class Net_SSH2 {
                 // also, see SSHRSA.c (rsa2_verifysig) in PuTTy's source.
 
                 if ($s->compare(new Math_BigInteger()) < 0 || $s->compare($n->subtract(new Math_BigInteger(1))) > 0) {
-                    user_error('Invalid signature', E_USER_NOTICE);
+                    $this->_handle_error('Invalid signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
                 }
 
@@ -2931,15 +2973,33 @@ class Net_SSH2 {
                 $h = chr(0x01) . str_repeat(chr(0xFF), $nLength - 3 - strlen($h)) . $h;
 
                 if ($s != $h) {
-                    user_error('Bad server signature', E_USER_NOTICE);
+                    $this->_handle_error('Bad server signature');
                     return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
                 }
                 break;
             default:
-                user_error('Unsupported signature format', E_USER_NOTICE);
+                $this->_handle_error('Unsupported signature format');
                 return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
         }
 
         return $this->signature_format . ' ' . base64_encode($this->server_public_host_key);
     }
+
+    /**
+     * Error Handler
+     *
+     * Throws exceptions if PHPSECLIB_USE_EXCEPTIONS is defined.
+     * Unless PHPSECLIB_EXCEPTION_CLASS is set it'll throw generic Exceptions.
+     *
+     * @param String $string
+     * @access private
+     */
+    function _handle_error($err_msg) {
+        if (defined('PHPSECLIB_USE_EXCEPTIONS') && version_compare(PHP_VERSION, '5.1.0', '>=')) {
+            $class = defined('PHPSECLIB_EXCEPTION_CLASS') && class_exists(PHPSECLIB_EXCEPTION_CLASS) ? PHPSECLIB_EXCEPTION_CLASS : 'Exception';
+            throw(new $class($err_msg));
+        } else {
+            user_error($err_msg);
+        }
+    }
 }
\ No newline at end of file