diff --git a/phpseclib/Crypt/Blowfish.php b/phpseclib/Crypt/Blowfish.php
index 9c91a0e1..5cf8b7a2 100644
--- a/phpseclib/Crypt/Blowfish.php
+++ b/phpseclib/Crypt/Blowfish.php
@@ -327,10 +327,10 @@ class Blowfish extends BlockCipher
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::isValidEngine()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         if ($engine == self::ENGINE_OPENSSL) {
             if (version_compare(PHP_VERSION, '5.3.7') < 0 && $this->key_length != 16) {
@@ -343,7 +343,7 @@ class Blowfish extends BlockCipher
             $this->cipher_name_openssl = 'bf-' . $this->openssl_translate_mode();
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/Crypt/Common/AsymmetricKey.php b/phpseclib/Crypt/Common/AsymmetricKey.php
index 08124730..6cc92471 100644
--- a/phpseclib/Crypt/Common/AsymmetricKey.php
+++ b/phpseclib/Crypt/Common/AsymmetricKey.php
@@ -299,7 +299,7 @@ abstract class AsymmetricKey
      * @access private
      * @param string $key
      * @param string $type
-     * @return array
+     * @return array|bool
      */
     protected function load($key, $type)
     {
@@ -339,7 +339,7 @@ abstract class AsymmetricKey
      * @access private
      * @param string $key
      * @param string $type
-     * @return array
+     * @return array|bool
      */
     protected function setPublicKey($key, $type)
     {
diff --git a/phpseclib/Crypt/Common/Keys/OpenSSH.php b/phpseclib/Crypt/Common/Keys/OpenSSH.php
index eb1ba7a3..fc7fc822 100644
--- a/phpseclib/Crypt/Common/Keys/OpenSSH.php
+++ b/phpseclib/Crypt/Common/Keys/OpenSSH.php
@@ -64,7 +64,7 @@ abstract class OpenSSH
      * @access public
      * @param string $key
      * @param string $type
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $type)
     {
diff --git a/phpseclib/Crypt/Common/Keys/PKCS1.php b/phpseclib/Crypt/Common/Keys/PKCS1.php
index afa9ad15..6ae8588d 100644
--- a/phpseclib/Crypt/Common/Keys/PKCS1.php
+++ b/phpseclib/Crypt/Common/Keys/PKCS1.php
@@ -122,7 +122,7 @@ abstract class PKCS1 extends PKCS
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     protected static function load($key, $password)
     {
diff --git a/phpseclib/Crypt/Common/Keys/PKCS8.php b/phpseclib/Crypt/Common/Keys/PKCS8.php
index 74222ab5..e4002fe7 100644
--- a/phpseclib/Crypt/Common/Keys/PKCS8.php
+++ b/phpseclib/Crypt/Common/Keys/PKCS8.php
@@ -320,7 +320,7 @@ abstract class PKCS8 extends PKCS
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     protected static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/Common/Keys/PuTTY.php b/phpseclib/Crypt/Common/Keys/PuTTY.php
index 12e4377a..44224510 100644
--- a/phpseclib/Crypt/Common/Keys/PuTTY.php
+++ b/phpseclib/Crypt/Common/Keys/PuTTY.php
@@ -77,7 +77,7 @@ abstract class PuTTY
      * @param string $publicHandler
      * @param string $type
      * @param string $password
-     * @return array
+     * @return array|bool
      */
     protected static function load($key, $password)
     {
diff --git a/phpseclib/Crypt/Common/Signature/Raw.php b/phpseclib/Crypt/Common/Signature/Raw.php
index 73aeee8a..7977417c 100644
--- a/phpseclib/Crypt/Common/Signature/Raw.php
+++ b/phpseclib/Crypt/Common/Signature/Raw.php
@@ -33,7 +33,7 @@ abstract class Raw
      *
      * @access public
      * @param array $sig
-     * @return array
+     * @return array|bool
      */
     public static function load($sig)
     {
diff --git a/phpseclib/Crypt/Common/SymmetricKey.php b/phpseclib/Crypt/Common/SymmetricKey.php
index 14f73fc9..6f198cd3 100644
--- a/phpseclib/Crypt/Common/SymmetricKey.php
+++ b/phpseclib/Crypt/Common/SymmetricKey.php
@@ -1712,10 +1712,10 @@ abstract class SymmetricKey
      *
      * @see self::__construct()
      * @param int $engine
-     * @access public
+     * @access private
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         switch ($engine) {
             case self::ENGINE_OPENSSL:
@@ -1756,6 +1756,29 @@ abstract class SymmetricKey
         return false;
     }
 
+    /**
+     * Test for engine validity
+     *
+     * @see self::__construct()
+     * @param string $engine
+     * @access public
+     * @return bool
+     */
+    public function isValidEngine($engine)
+    {
+        static $reverseMap;
+        if (!isset($reverseMap)) {
+            $reverseMap = array_map('strtolower', self::ENGINE_MAP);
+            $reverseMap = array_flip($reverseMap);
+        }
+        $engine = strtolower($engine);
+        if (!isset($reverseMap[$engine])) {
+            return false;
+        }
+
+        return $this->isValidEngineHelper($reverseMap[$engine]);
+    }
+
     /**
      * Sets the preferred crypt engine
      *
@@ -1816,7 +1839,7 @@ abstract class SymmetricKey
             self::ENGINE_EVAL
         ];
         foreach ($candidateEngines as $engine) {
-            if ($this->isValidEngine($engine)) {
+            if ($this->isValidEngineHelper($engine)) {
                 $this->engine = $engine;
                 break;
             }
diff --git a/phpseclib/Crypt/DES.php b/phpseclib/Crypt/DES.php
index 6981cd96..b7c45ee4 100644
--- a/phpseclib/Crypt/DES.php
+++ b/phpseclib/Crypt/DES.php
@@ -603,10 +603,10 @@ class DES extends BlockCipher
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::isValidEngine()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         if ($this->key_length_max == 8) {
             if ($engine == self::ENGINE_OPENSSL) {
@@ -615,7 +615,7 @@ class DES extends BlockCipher
             }
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/Crypt/DSA.php b/phpseclib/Crypt/DSA.php
index 9cbee43e..19b0bae2 100644
--- a/phpseclib/Crypt/DSA.php
+++ b/phpseclib/Crypt/DSA.php
@@ -109,7 +109,7 @@ class DSA extends AsymmetricKey
      * @access public
      * @param int $L
      * @param int $N
-     * @return \phpseclib\Crypt\DSA
+     * @return \phpseclib\Crypt\DSA|bool
      */
     static function createParameters($L = 2048, $N = 224)
     {
@@ -183,7 +183,7 @@ class DSA extends AsymmetricKey
      *  - 'publickey':  The public key.
      *
      * @access public
-     * @return \phpseclib\Crypt\DSA
+     * @return array|DSA
      */
     static function createKey()
     {
diff --git a/phpseclib/Crypt/DSA/Keys/OpenSSH.php b/phpseclib/Crypt/DSA/Keys/OpenSSH.php
index 6458ba35..0b5d47b4 100644
--- a/phpseclib/Crypt/DSA/Keys/OpenSSH.php
+++ b/phpseclib/Crypt/DSA/Keys/OpenSSH.php
@@ -37,7 +37,7 @@ abstract class OpenSSH extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Keys/PKCS1.php b/phpseclib/Crypt/DSA/Keys/PKCS1.php
index 7a3920ba..fefe3117 100644
--- a/phpseclib/Crypt/DSA/Keys/PKCS1.php
+++ b/phpseclib/Crypt/DSA/Keys/PKCS1.php
@@ -46,7 +46,7 @@ abstract class PKCS1 extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Keys/PKCS8.php b/phpseclib/Crypt/DSA/Keys/PKCS8.php
index 1415175a..4a94a861 100644
--- a/phpseclib/Crypt/DSA/Keys/PKCS8.php
+++ b/phpseclib/Crypt/DSA/Keys/PKCS8.php
@@ -69,7 +69,7 @@ abstract class PKCS8 extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Keys/PuTTY.php b/phpseclib/Crypt/DSA/Keys/PuTTY.php
index 7b297631..af7a7ea4 100644
--- a/phpseclib/Crypt/DSA/Keys/PuTTY.php
+++ b/phpseclib/Crypt/DSA/Keys/PuTTY.php
@@ -55,7 +55,7 @@ abstract class PuTTY extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Keys/Raw.php b/phpseclib/Crypt/DSA/Keys/Raw.php
index 18d0b03a..ab6085fa 100644
--- a/phpseclib/Crypt/DSA/Keys/Raw.php
+++ b/phpseclib/Crypt/DSA/Keys/Raw.php
@@ -34,7 +34,7 @@ abstract class Raw
      * @access public
      * @param array $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Keys/XML.php b/phpseclib/Crypt/DSA/Keys/XML.php
index 02644b7d..0741ae5f 100644
--- a/phpseclib/Crypt/DSA/Keys/XML.php
+++ b/phpseclib/Crypt/DSA/Keys/XML.php
@@ -39,7 +39,7 @@ abstract class XML
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/DSA/Signature/PKCS.php b/phpseclib/Crypt/DSA/Signature/PKCS.php
index fa09e54a..eeb97755 100644
--- a/phpseclib/Crypt/DSA/Signature/PKCS.php
+++ b/phpseclib/Crypt/DSA/Signature/PKCS.php
@@ -36,7 +36,7 @@ abstract class PKCS
      *
      * @access public
      * @param array $key
-     * @return array
+     * @return array|bool
      */
     public static function load($sig)
     {
diff --git a/phpseclib/Crypt/Hash.php b/phpseclib/Crypt/Hash.php
index e5af7b48..2b4f7b83 100644
--- a/phpseclib/Crypt/Hash.php
+++ b/phpseclib/Crypt/Hash.php
@@ -134,7 +134,7 @@ class Hash
      * Keys can be of any length.
      *
      * @access public
-     * @param string $key
+     * @param string|bool $key
      */
     public function setKey($key = false)
     {
diff --git a/phpseclib/Crypt/RC2.php b/phpseclib/Crypt/RC2.php
index 8854be51..013b32ec 100644
--- a/phpseclib/Crypt/RC2.php
+++ b/phpseclib/Crypt/RC2.php
@@ -284,10 +284,10 @@ class RC2 extends BlockCipher
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::__construct()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         switch ($engine) {
             case self::ENGINE_OPENSSL:
@@ -298,7 +298,7 @@ class RC2 extends BlockCipher
                 $this->cipher_name_openssl = 'rc2-' . $this->openssl_translate_mode();
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/Crypt/RC4.php b/phpseclib/Crypt/RC4.php
index 865776ff..e2d8b24e 100644
--- a/phpseclib/Crypt/RC4.php
+++ b/phpseclib/Crypt/RC4.php
@@ -139,10 +139,10 @@ class RC4 extends StreamCipher
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::__construct()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         if ($engine == self::ENGINE_OPENSSL) {
             if (version_compare(PHP_VERSION, '5.3.7') >= 0) {
@@ -164,7 +164,7 @@ class RC4 extends StreamCipher
             }
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/Crypt/RSA/Keys/MSBLOB.php b/phpseclib/Crypt/RSA/Keys/MSBLOB.php
index 8ac478e0..33500fe7 100644
--- a/phpseclib/Crypt/RSA/Keys/MSBLOB.php
+++ b/phpseclib/Crypt/RSA/Keys/MSBLOB.php
@@ -71,7 +71,7 @@ abstract class MSBLOB
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/RSA/Keys/OpenSSH.php b/phpseclib/Crypt/RSA/Keys/OpenSSH.php
index 40f20330..b8ba1bb5 100644
--- a/phpseclib/Crypt/RSA/Keys/OpenSSH.php
+++ b/phpseclib/Crypt/RSA/Keys/OpenSSH.php
@@ -37,7 +37,7 @@ abstract class OpenSSH extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/RSA/Keys/PKCS1.php b/phpseclib/Crypt/RSA/Keys/PKCS1.php
index 125927ce..6c73d65d 100644
--- a/phpseclib/Crypt/RSA/Keys/PKCS1.php
+++ b/phpseclib/Crypt/RSA/Keys/PKCS1.php
@@ -44,7 +44,7 @@ abstract class PKCS1 extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/RSA/Keys/PKCS8.php b/phpseclib/Crypt/RSA/Keys/PKCS8.php
index 382fb2b7..40888020 100644
--- a/phpseclib/Crypt/RSA/Keys/PKCS8.php
+++ b/phpseclib/Crypt/RSA/Keys/PKCS8.php
@@ -70,7 +70,7 @@ abstract class PKCS8 extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/RSA/Keys/PuTTY.php b/phpseclib/Crypt/RSA/Keys/PuTTY.php
index 4353fd02..ca9195d0 100644
--- a/phpseclib/Crypt/RSA/Keys/PuTTY.php
+++ b/phpseclib/Crypt/RSA/Keys/PuTTY.php
@@ -50,7 +50,7 @@ abstract class PuTTY extends Progenitor
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/RSA/Keys/Raw.php b/phpseclib/Crypt/RSA/Keys/Raw.php
index e2bd636c..fe3c4c62 100644
--- a/phpseclib/Crypt/RSA/Keys/Raw.php
+++ b/phpseclib/Crypt/RSA/Keys/Raw.php
@@ -42,7 +42,7 @@ abstract class Raw
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
@@ -95,7 +95,7 @@ abstract class Raw
      * @access public
      * @param \phpseclib\Math\BigInteger $n
      * @param \phpseclib\Math\BigInteger $e
-     * @return string
+     * @return array
      */
     public static function savePublicKey(BigInteger $n, BigInteger $e)
     {
diff --git a/phpseclib/Crypt/RSA/Keys/XML.php b/phpseclib/Crypt/RSA/Keys/XML.php
index a31a4be0..07549026 100644
--- a/phpseclib/Crypt/RSA/Keys/XML.php
+++ b/phpseclib/Crypt/RSA/Keys/XML.php
@@ -40,7 +40,7 @@ abstract class XML
      * @access public
      * @param string $key
      * @param string $password optional
-     * @return array
+     * @return array|bool
      */
     public static function load($key, $password = '')
     {
diff --git a/phpseclib/Crypt/Rijndael.php b/phpseclib/Crypt/Rijndael.php
index e78d578c..1553bb09 100644
--- a/phpseclib/Crypt/Rijndael.php
+++ b/phpseclib/Crypt/Rijndael.php
@@ -273,10 +273,10 @@ class Rijndael extends BlockCipher
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::__construct()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         switch ($engine) {
             case self::ENGINE_OPENSSL:
@@ -294,7 +294,7 @@ class Rijndael extends BlockCipher
                 }
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/Crypt/TripleDES.php b/phpseclib/Crypt/TripleDES.php
index 9dede481..3c665f29 100644
--- a/phpseclib/Crypt/TripleDES.php
+++ b/phpseclib/Crypt/TripleDES.php
@@ -178,10 +178,10 @@ class TripleDES extends DES
      *
      * @see \phpseclib\Crypt\Common\SymmetricKey::__construct()
      * @param int $engine
-     * @access public
+     * @access protected
      * @return bool
      */
-    public function isValidEngine($engine)
+    protected function isValidEngineHelper($engine)
     {
         if ($engine == self::ENGINE_OPENSSL) {
             $this->cipher_name_openssl_ecb = 'des-ede3';
@@ -189,7 +189,7 @@ class TripleDES extends DES
             $this->cipher_name_openssl = $mode == 'ecb' ? 'des-ede3' : 'des-ede3-' . $mode;
         }
 
-        return parent::isValidEngine($engine);
+        return parent::isValidEngineHelper($engine);
     }
 
     /**
diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 295a2b72..53ac6ff2 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -26,6 +26,7 @@ namespace phpseclib\File;
 use ParagonIE\ConstantTime\Base64;
 use phpseclib\File\ASN1\Element;
 use phpseclib\Math\BigInteger;
+use phpseclib\Common\Functions\Strings;
 
 /**
  * Pure-PHP ASN.1 Parser
@@ -248,7 +249,7 @@ abstract class ASN1
      * @param string $encoded
      * @param int $start
      * @param int $encoded_pos
-     * @return array
+     * @return array|bool
      * @access private
      */
     private static function decode_ber($encoded, $start = 0, $encoded_pos = 0)
@@ -513,7 +514,7 @@ abstract class ASN1
      * @param array $decoded
      * @param array $mapping
      * @param array $special
-     * @return array
+     * @return array|bool|Element
      * @access public
      */
     public static function asn1map($decoded, $mapping, $special = [])
@@ -826,7 +827,7 @@ abstract class ASN1
      * ASN.1 Encode (Helper function)
      *
      * @param string $source
-     * @param string $mapping
+     * @param array $mapping
      * @param int $idx
      * @return string
      * @throws \RuntimeException if the input has an error in it
@@ -1348,27 +1349,6 @@ abstract class ASN1
         return $temp != false ? $temp : $str;
     }
 
-    /**
-     * DER-decode the length
-     *
-     * DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4.  See
-     * {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 paragraph 8.1.3} for more information.
-     *
-     * @access public
-     * @param string $string
-     * @return int
-     */
-    public static function decodeLength(&$string)
-    {
-        $length = ord(Strings::shift($string));
-        if ($length & 0x80) { // definite length, long form
-            $length&= 0x7F;
-            $temp = Strings::shift($string, $length);
-            list(, $length) = unpack('N', substr(str_pad($temp, 4, chr(0), STR_PAD_LEFT), -4));
-        }
-        return $length;
-    }
-
     /**
      * DER-encode the length
      *
diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index a95784b5..51161b21 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -36,6 +36,7 @@ use phpseclib\File\ASN1\Element;
 use phpseclib\Math\BigInteger;
 use phpseclib\File\ASN1\Maps;
 
+
 /**
  * Pure-PHP X.509 Parser
  *
@@ -1564,7 +1565,7 @@ class X509
      * @param mixed $format optional
      * @param array $dn optional
      * @access public
-     * @return bool
+     * @return array|bool
      */
     public function getDN($format = self::DN_ARRAY, $dn = null)
     {
@@ -2796,7 +2797,7 @@ class X509
         */
         if (strtolower($date) == 'lifetime') {
             $temp = '99991231235959Z';
-            $temp = chr(ASN1::TYPE_GENERALIZED_TIME) . Functions::encodeLength(strlen($temp)) . $temp;
+            $temp = chr(ASN1::TYPE_GENERALIZED_TIME) . ASN1::encodeLength(strlen($temp)) . $temp;
             $this->endDate = new Element($temp);
         } else {
             $this->endDate = @date('D, d M Y H:i:s O', @strtotime($date));
@@ -3117,24 +3118,26 @@ class X509
      *
      * @param string $id
      * @param array $cert optional
+     * @param string $path
      * @access public
      * @return mixed
      */
-    public function getExtension($id, $cert = null)
+    public function getExtension($id, $cert = null, $path=null)
     {
-        return $this->getExtensionHelper($id, $cert);
+        return $this->getExtensionHelper($id, $cert, $path);
     }
 
     /**
      * Returns a list of all extensions in use in certificate, CSR or CRL
      *
      * @param array $cert optional
+     * @param string $path optional
      * @access public
      * @return array
      */
-    public function getExtensions($cert = null)
+    public function getExtensions($cert = null, $path = null)
     {
-        return $this->getExtensionsHelper($cert);
+        return $this->getExtensionsHelper($cert, $path);
     }
 
     /**
@@ -3430,7 +3433,7 @@ class X509
      * Format a public key as appropriate
      *
      * @access private
-     * @return array
+     * @return array|bool
      */
     private function formatSubjectPublicKey()
     {
@@ -3602,7 +3605,7 @@ class X509
      *
      * @param array $crl optional
      * @access public
-     * @return array
+     * @return array|bool
      */
     public function listRevoked($crl = null)
     {
@@ -3676,7 +3679,7 @@ class X509
      * @param string $serial
      * @param array $crl optional
      * @access public
-     * @return array
+     * @return array|bool
      */
     public function getRevokedCertificateExtensions($serial, $crl = null)
     {
@@ -3686,7 +3689,7 @@ class X509
 
         if (is_array($rclist = $this->subArray($crl, 'tbsCertList/revokedCertificates'))) {
             if (($i = $this->revokedCertificate($rclist, $serial)) !== false) {
-                return $this->getExtensionsHelper($crl, "tbsCertList/revokedCertificates/$i/crlEntryExtensions");
+                return $this->getExtensions($crl, "tbsCertList/revokedCertificates/$i/crlEntryExtensions");
             }
         }
 
diff --git a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
index 7237c5ac..f858ce17 100644
--- a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
+++ b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
@@ -61,7 +61,7 @@ abstract class Barrett extends Base
      *
      * @param string $n
      * @param string $m
-     * @return array
+     * @return array|string
      */
     protected static function reduce($n, $m)
     {
diff --git a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
index 2ab676e6..58374b3d 100644
--- a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
+++ b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
@@ -55,7 +55,7 @@ abstract class EvalBarrett extends Base
      *
      * @param array $m
      * @param string $class
-     * @return callable
+     * @return callable|void
      */
     protected static function generateCustomReduction(BCMath $m, $class)
     {
diff --git a/phpseclib/Math/BigInteger/Engines/Engine.php b/phpseclib/Math/BigInteger/Engines/Engine.php
index 89787416..9f3dc497 100644
--- a/phpseclib/Math/BigInteger/Engines/Engine.php
+++ b/phpseclib/Math/BigInteger/Engines/Engine.php
@@ -396,7 +396,7 @@ abstract class Engine implements \Serializable
     /**
      * Logical Not
      *
-     * @return \phpseclib\Math\BigInteger\Engines\Engine
+     * @return Engine|string
      */
     public function bitwise_not()
     {
@@ -465,7 +465,7 @@ abstract class Engine implements \Serializable
      * Instead of the top x bits being dropped they're appended to the shifted bit string.
      *
      * @param int $shift
-     * @return \phpseclib\Math\BigInteger\Engine\Engines
+     * @return \phpseclib\Math\BigInteger\Engines\Engine
      */
     public function bitwise_leftRotate($shift)
     {
@@ -563,7 +563,7 @@ abstract class Engine implements \Serializable
     /**
      * Performs some pre-processing for powMod
      *
-     * @return \phpseclib\Math\BigInteger\Engines\Engine
+     * @return bool|Engine
      */
     protected function powModOuter(Engine $e, Engine $n)
     {
@@ -591,11 +591,11 @@ abstract class Engine implements \Serializable
      * however, this function performs a modular reduction after every multiplication and squaring operation.
      * As such, this function has the same preconditions that the reductions being used do.
      *
-     * @param \phpseclib\Math\BigInteger\Engine $x
-     * @param \phpseclib\Math\BigInteger\Engine $e
-     * @param \phpseclib\Math\BigInteger\Engine $n
+     * @param \phpseclib\Math\BigInteger\Engines\Engine $x
+     * @param \phpseclib\Math\BigInteger\Engines\Engine $e
+     * @param \phpseclib\Math\BigInteger\Engines\Engine $n
      * @param string $class
-     * @return \phpseclib\Math\BigInteger\Engine
+     * @return \phpseclib\Math\BigInteger\Engines\Engine
      */
     protected static function slidingWindow(Engine $x, Engine $e, Engine $n, $class)
     {
@@ -691,7 +691,7 @@ abstract class Engine implements \Serializable
     /**
      * Performs some pre-processing for randomRangePrime
      *
-     * @return \phpseclib\Math\BigInteger\Engines\Engine
+     * @return bool|Engine
      */
     protected static function randomRangePrimeOuter(Engine $min, Engine $max)
     {
@@ -781,7 +781,7 @@ abstract class Engine implements \Serializable
     /**
      * Performs some post-processing for randomRangePrime
      *
-     * @return \phpseclib\Math\BigInteger\Engine
+     * @return bool|Engine
      */
     protected static function randomRangePrimeInner(Engine $x, Engine $min, Engine $max)
     {
diff --git a/phpseclib/Math/BigInteger/Engines/GMP.php b/phpseclib/Math/BigInteger/Engines/GMP.php
index 5e5a0197..9a406a27 100644
--- a/phpseclib/Math/BigInteger/Engines/GMP.php
+++ b/phpseclib/Math/BigInteger/Engines/GMP.php
@@ -546,7 +546,7 @@ class GMP extends Engine
      *
      * Returns the nth root of a positive biginteger, where n defaults to 2
      *
-     * @return \phpseclib\Math\BigInteger\Engines\Engine\GMP
+     * @return \phpseclib\Math\BigInteger\Engines\GMP
      */
     protected function rootInner($n)
     {
diff --git a/phpseclib/Math/BigInteger/Engines/PHP.php b/phpseclib/Math/BigInteger/Engines/PHP.php
index 8e448cc0..bee28778 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP.php
@@ -1314,7 +1314,7 @@ abstract class PHP extends Engine
     protected function powHelper(PHP $n)
     {
         if ($n->compare(static::$zero) == 0) {
-            return new self(1);
+            return new static(1);
         } // n^0 = 1
 
 
diff --git a/phpseclib/Math/BigInteger/Engines/PHP/Montgomery.php b/phpseclib/Math/BigInteger/Engines/PHP/Montgomery.php
index 8bffb1ca..cdbf23a1 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP/Montgomery.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP/Montgomery.php
@@ -46,7 +46,7 @@ abstract class Montgomery extends Base
      * @param \phpseclib\Math\BigInteger\Engine $e
      * @param \phpseclib\Math\BigInteger\Engine $n
      * @param string $class
-     * @return \phpseclib\Math\BigInteger\Engine
+     * @return \phpseclib\Math\BigInteger\Engine|Engine
      */
     protected static function slidingWindow(Engine $x, Engine $e, Engine $n, $class)
     {
diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index 4397586e..63496e69 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -3024,7 +3024,7 @@ class SFTP extends SSH2
      * Returns a string if NET_SFTP_LOGGING == self::LOG_COMPLEX, an array if NET_SFTP_LOGGING == self::LOG_SIMPLE and false if !defined('NET_SFTP_LOGGING')
      *
      * @access public
-     * @return string or Array
+     * @return array|string
      */
     public function getSFTPLog()
     {
@@ -3086,7 +3086,7 @@ class SFTP extends SSH2
      * @return bool
      * @access private
      */
-    private function disconnect_helper($reason)
+    protected function disconnect_helper($reason)
     {
         $this->pwd = false;
         parent::disconnect_helper($reason);
diff --git a/phpseclib/Net/SSH1.php b/phpseclib/Net/SSH1.php
index 973b13f6..8cb3c625 100644
--- a/phpseclib/Net/SSH1.php
+++ b/phpseclib/Net/SSH1.php
@@ -1079,7 +1079,7 @@ class SSH1
      * http://www.securiteam.com/securitynews/5LP042K3FY.html
      *
      * @see self::_send_binary_packet()
-     * @return array
+     * @return array|bool
      * @access private
      */
     private function get_binary_packet()
diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 49653416..5fc9dc6d 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -652,7 +652,7 @@ class SSH2
      * @see self::_get_channel_packet()
      * @access private
      */
-    private $curTimeout;
+    protected $curTimeout;
 
     /**
      * Real-time log file pointer
@@ -881,6 +881,22 @@ class SSH2
      */
     private static $connections;
 
+    /**
+     * Send the identification string first?
+     *
+     * @var bool
+     * @access private
+     */
+    private $send_id_string_first = true;
+
+    /**
+     * Send the key exchange initiation packet first?
+     *
+     * @var bool
+     * @access private
+     */
+    private $send_kex_first = true;
+
     /**
      * Default Constructor.
      *
@@ -890,7 +906,7 @@ class SSH2
      * @param int $port
      * @param int $timeout
      * @see self::login()
-     * @return \phpseclib\Net\SSH2
+     * @return SSH2|void
      * @access public
      */
     public function __construct($host, $port = 22, $timeout = 10)
@@ -995,13 +1011,69 @@ class SSH2
      * OpenSSL, mcrypt, Eval, PHP
      *
      * @param int $engine
-     * @access private
+     * @access public
      */
     public function setCryptoEngine($engine)
     {
         $this->crypto_engine = $engine;
     }
 
+    /**
+     * Send Identification String First
+     *
+     * https://tools.ietf.org/html/rfc4253#section-4.2 says "when the connection has been established,
+     * both sides MUST send an identification string". It does not say which side sends it first. In
+     * theory it shouldn't matter but it is a fact of life that some SSH servers are simply buggy
+     *
+     * @access public
+     */
+    function sendIdentificationStringFirst()
+    {
+        $this->send_id_string_first = true;
+    }
+
+    /**
+     * Send Identification String Last
+     *
+     * https://tools.ietf.org/html/rfc4253#section-4.2 says "when the connection has been established,
+     * both sides MUST send an identification string". It does not say which side sends it first. In
+     * theory it shouldn't matter but it is a fact of life that some SSH servers are simply buggy
+     *
+     * @access public
+     */
+    function sendIdentificationStringLast()
+    {
+        $this->send_id_string_first = false;
+    }
+
+    /**
+     * Send SSH_MSG_KEXINIT First
+     *
+     * https://tools.ietf.org/html/rfc4253#section-7.1 says "key exchange begins by each sending
+     * sending the [SSH_MSG_KEXINIT] packet". It does not say which side sends it first. In theory
+     * it shouldn't matter but it is a fact of life that some SSH servers are simply buggy
+     *
+     * @access public
+     */
+    function sendKEXINITFirst()
+    {
+        $this->send_kex_first = true;
+    }
+
+    /**
+     * Send SSH_MSG_KEXINIT Last
+     *
+     * https://tools.ietf.org/html/rfc4253#section-7.1 says "key exchange begins by each sending
+     * sending the [SSH_MSG_KEXINIT] packet". It does not say which side sends it first. In theory
+     * it shouldn't matter but it is a fact of life that some SSH servers are simply buggy
+     *
+     * @access public
+     */
+    function sendKEXINITLast()
+    {
+        $this->send_kex_first = false;
+    }
+
     /**
      * Connect to an SSHv2 server
      *
@@ -1044,7 +1116,9 @@ class SSH2
 
         $this->identifier = $this->generate_identifier();
 
-        fputs($this->fsock, $this->identifier . "\r\n");
+        if ($this->send_id_string_first) {
+            fputs($this->fsock, $this->identifier . "\r\n");
+        }
 
         /* According to the SSH2 specs,
 
@@ -1120,16 +1194,26 @@ class SSH2
             throw new \RuntimeException("Cannot connect to SSH $matches[1] servers");
         }
 
-        $response = $this->get_binary_packet();
-        if ($response === false) {
-            throw new \RuntimeException('Connection closed by server');
+        if (!$this->send_id_string_first) {
+            fputs($this->fsock, $this->identifier . "\r\n");
         }
 
-        if (!strlen($response) || ord($response[0]) != NET_SSH2_MSG_KEXINIT) {
-            throw new \UnexpectedValueException('Expected SSH_MSG_KEXINIT');
+        if (!$this->send_kex_first) {
+            $response = $this->get_binary_packet();
+            if ($response === false) {
+                throw new \RuntimeException('Connection closed by server');
+            }
+
+            if (!strlen($response) || ord($response[0]) != NET_SSH2_MSG_KEXINIT) {
+                throw new \UnexpectedValueException('Expected SSH_MSG_KEXINIT');
+            }
+
+            if (!$this->key_exchange($response)) {
+                return false;
+            }
         }
 
-        if (!$this->key_exchange($response)) {
+        if ($this->send_kex_first && !$this->key_exchange()) {
             return false;
         }
 
@@ -1177,13 +1261,13 @@ class SSH2
     /**
      * Key Exchange
      *
-     * @param string $kexinit_payload_server
+     * @param string $kexinit_payload_server optional
      * @throws \UnexpectedValueException on receipt of unexpected packets
      * @throws \RuntimeException on other errors
      * @throws \phpseclib\Exception\NoSupportedAlgorithmsException when none of the algorithms phpseclib has loaded are compatible
      * @access private
      */
-    private function key_exchange($kexinit_payload_server)
+    private function key_exchange($kexinit_payload_server = false)
     {
         $kex_algorithms = [
             // Elliptic Curve Diffie-Hellman Key Agreement (ECDH) using
@@ -1321,6 +1405,49 @@ class SSH2
 
         $client_cookie = Random::string(16);
 
+        $kexinit_payload_client = pack(
+            'Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN',
+            NET_SSH2_MSG_KEXINIT,
+            $client_cookie,
+            strlen($str_kex_algorithms),
+            $str_kex_algorithms,
+            strlen($str_server_host_key_algorithms),
+            $str_server_host_key_algorithms,
+            strlen($encryption_algorithms_client_to_server),
+            $encryption_algorithms_client_to_server,
+            strlen($encryption_algorithms_server_to_client),
+            $encryption_algorithms_server_to_client,
+            strlen($mac_algorithms_client_to_server),
+            $mac_algorithms_client_to_server,
+            strlen($mac_algorithms_server_to_client),
+            $mac_algorithms_server_to_client,
+            strlen($compression_algorithms_client_to_server),
+            $compression_algorithms_client_to_server,
+            strlen($compression_algorithms_server_to_client),
+            $compression_algorithms_server_to_client,
+            0,
+            '',
+            0,
+            '',
+            0,
+            0
+        );
+
+        if ($this->send_kex_first) {
+            if (!$this->send_binary_packet($kexinit_payload_client)) {
+                return false;
+            }
+
+            $kexinit_payload_server = $this->get_binary_packet();
+            if ($kexinit_payload_server === false) {
+                throw new \RuntimeException('Connection closed by server');
+            }
+
+            if (!strlen($kexinit_payload_server) || ord($kexinit_payload_server[0]) != NET_SSH2_MSG_KEXINIT) {
+                throw new \UnexpectedValueException('Expected SSH_MSG_KEXINIT');
+            }
+        }
+
         $response = $kexinit_payload_server;
         Strings::shift($response, 1); // skip past the message number (it should be SSH_MSG_KEXINIT)
         $server_cookie = Strings::shift($response, 16);
@@ -1392,39 +1519,9 @@ class SSH2
 
         $first_kex_packet_follows = $first_kex_packet_follows != 0;
 
-        // the sending of SSH2_MSG_KEXINIT could go in one of two places.  this is the second place.
-        $kexinit_payload_client = pack(
-            'Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN',
-            NET_SSH2_MSG_KEXINIT,
-            $client_cookie,
-            strlen($str_kex_algorithms),
-            $str_kex_algorithms,
-            strlen($str_server_host_key_algorithms),
-            $str_server_host_key_algorithms,
-            strlen($encryption_algorithms_client_to_server),
-            $encryption_algorithms_client_to_server,
-            strlen($encryption_algorithms_server_to_client),
-            $encryption_algorithms_server_to_client,
-            strlen($mac_algorithms_client_to_server),
-            $mac_algorithms_client_to_server,
-            strlen($mac_algorithms_server_to_client),
-            $mac_algorithms_server_to_client,
-            strlen($compression_algorithms_client_to_server),
-            $compression_algorithms_client_to_server,
-            strlen($compression_algorithms_server_to_client),
-            $compression_algorithms_server_to_client,
-            0,
-            '',
-            0,
-            '',
-            0,
-            0
-        );
-
-        if (!$this->send_binary_packet($kexinit_payload_client)) {
+        if (!$this->send_kex_first && !$this->send_binary_packet($kexinit_payload_client)) {
             return false;
         }
-        // here ends the second place.
 
         // we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
 
@@ -3829,7 +3926,7 @@ class SSH2
      * @return bool
      * @access private
      */
-    private function disconnect_helper($reason)
+    protected function disconnect_helper($reason)
     {
         if ($this->bitmap & self::MASK_CONNECTED) {
             $data = pack('CNNa*Na*', NET_SSH2_MSG_DISCONNECT, $reason, 0, '', 0, '');
@@ -4236,7 +4333,7 @@ class SSH2
                     case $r->compare($q) >= 0:
                     case $s->equals($zero):
                     case $s->compare($q) >= 0:
-                        $this->disconnectHepler(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+                        $this->disconnect_helper(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
                         throw new \RuntimeException('Invalid signature');
                 }
 
diff --git a/tests/Unit/Crypt/RC4Test.php b/tests/Unit/Crypt/RC4Test.php
index e7aa6e3b..872b6a48 100644
--- a/tests/Unit/Crypt/RC4Test.php
+++ b/tests/Unit/Crypt/RC4Test.php
@@ -215,20 +215,20 @@ class Unit_Crypt_RC4Test extends PhpseclibTestCase
     {
         $objects = $engines = array();
         $temp = new RC4(RC4::MODE_CTR);
-        $temp->setPreferredEngine(RC4::ENGINE_INTERNAL);
+        $temp->setPreferredEngine('internal');
         $objects[] = $temp;
         $engines[] = 'internal';
 
-        if ($temp->isValidEngine(RC4::ENGINE_MCRYPT)) {
+        if ($temp->isValidEngine('mcrypt')) {
             $temp = new RC4(RC4::MODE_CTR);
-            $temp->setPreferredEngine(RC4::ENGINE_MCRYPT);
+            $temp->setPreferredEngine('mcrypt');
             $objects[] = $temp;
             $engines[] = 'mcrypt';
         }
 
-        if ($temp->isValidEngine(RC4::ENGINE_OPENSSL)) {
+        if ($temp->isValidEngine('openssl')) {
             $temp = new RC4(RC4::MODE_CTR);
-            $temp->setPreferredEngine(RC4::ENGINE_OPENSSL);
+            $temp->setPreferredEngine('openssl');
             $objects[] = $temp;
             $engines[] = 'OpenSSL';
         }
diff --git a/tests/Unit/Crypt/TripleDESTest.php b/tests/Unit/Crypt/TripleDESTest.php
index cd8a7ccf..64350663 100644
--- a/tests/Unit/Crypt/TripleDESTest.php
+++ b/tests/Unit/Crypt/TripleDESTest.php
@@ -167,7 +167,7 @@ class Unit_Crypt_TripleDESTest extends PhpseclibTestCase
         $des->disablePadding();
         $result = $des->encrypt($plaintext);
         $plaintext = bin2hex($plaintext);
-        $this->assertEquals($result, $expected, "Failed asserting that $plaintext yielded expected output in $engin engine");
+        $this->assertEquals($result, $expected, "Failed asserting that $plaintext yielded expected output in $engine engine");
     }
 
     public function testInnerChaining()
diff --git a/tests/Unit/File/X509/CRLTest.php b/tests/Unit/File/X509/CRLTest.php
new file mode 100644
index 00000000..78ad5d7d
--- /dev/null
+++ b/tests/Unit/File/X509/CRLTest.php
@@ -0,0 +1,24 @@
+<?php
+/**
+ * @author    Jim Wigginton <terrafrost@php.net>
+ * @copyright 2017 Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ */
+
+use phpseclib\File\X509;
+
+class Unit_File_X509_CRLTest extends PhpseclibTestCase
+{
+    public function testLoadCRL()
+    {
+        $test = file_get_contents(__DIR__ . '/crl.bin');
+
+        $x509 = new X509();
+
+        $x509->loadCRL($test);
+
+        $reason = $x509->getRevokedCertificateExtension('9048354325167497831898969642461237543', 'id-ce-cRLReasons');
+
+        $this->assertSame('unspecified', $reason);
+    }
+}
diff --git a/tests/Unit/File/X509/X509Test.php b/tests/Unit/File/X509/X509Test.php
index 41258b21..773e2c41 100644
--- a/tests/Unit/File/X509/X509Test.php
+++ b/tests/Unit/File/X509/X509Test.php
@@ -181,6 +181,7 @@ aBtsWpliLSex/HHhtRW9AkBGcq67zKmEpJ9kXcYLEjJii3flFS+Ct/rNm+Hhm1l7
         $issuer->setDN($subject->getDN());
 
         $x509 = new X509();
+        $x509->setEndDate('lifetime');
 
         $result = $x509->sign($issuer, $subject);
         $cert = $x509->saveX509($result);
diff --git a/tests/Unit/File/X509/crl.bin b/tests/Unit/File/X509/crl.bin
new file mode 100644
index 00000000..ef6d3ee1
Binary files /dev/null and b/tests/Unit/File/X509/crl.bin differ