diff --git a/phpseclib/Crypt/PublicKeyLoader.php b/phpseclib/Crypt/PublicKeyLoader.php
index db4abf7c..c7c7e0af 100644
--- a/phpseclib/Crypt/PublicKeyLoader.php
+++ b/phpseclib/Crypt/PublicKeyLoader.php
@@ -15,8 +15,8 @@
 
 namespace phpseclib3\Crypt;
 
+use phpseclib3\Crypt\Common\AsymmetricKey;
 use phpseclib3\Exception\NoKeyLoadedException;
-use phpseclib3\Crypt\Common\PrivateKey;
 use phpseclib3\File\X509;
 
 /**
diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 9d468ec1..cdc5b697 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -826,7 +826,7 @@ abstract class ASN1
      *
      * "Special" mappings can be applied via $special.
      *
-     * @param string $source
+     * @param Element|string|array $source
      * @param array $mapping
      * @param array $special
      * @return string
@@ -841,7 +841,7 @@ abstract class ASN1
     /**
      * ASN.1 Encode (Helper function)
      *
-     * @param string $source
+     * @param Element|string|array $source
      * @param array $mapping
      * @param int $idx
      * @param array $special
diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index 874bcb11..ba6a0481 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -3061,7 +3061,7 @@ class X509
 
           -- http://tools.ietf.org/html/rfc5280#section-4.1.2.5
         */
-        if (strtolower($date) == 'lifetime') {
+        if (is_string($date) && strtolower($date) === 'lifetime') {
             $temp = '99991231235959Z';
             $temp = chr(ASN1::TYPE_GENERALIZED_TIME) . ASN1::encodeLength(strlen($temp)) . $temp;
             $this->endDate = new Element($temp);
diff --git a/tests/Unit/Crypt/DHTest.php b/tests/Unit/Crypt/DHTest.php
index e6e15ba3..cf911b61 100644
--- a/tests/Unit/Crypt/DHTest.php
+++ b/tests/Unit/Crypt/DHTest.php
@@ -19,11 +19,11 @@ class Unit_Crypt_DHTest extends PhpseclibTestCase
     {
         $a = DH::createParameters('diffie-hellman-group1-sha1');
         $a = str_replace("\r\n", "\n", trim($a));
-        $b = '-----BEGIN DH PARAMETERS-----
+        $b = str_replace("\r\n", "\n", '-----BEGIN DH PARAMETERS-----
 MIGHAoGBAP//////////yQ/aoiFowjTExmKLgNwc0SkCTgiKZ8x0Agu+pjsTmyJR
 Sgh5jjQE3e+VGbPNOkMbMCsKbfJfFDdP4TVtbVHCReSFtXZiXn7G9ExC6aY37WsL
 /1y29Aa37e44a/taiZ+lrp8kEXxLH+ZJKGZR7OZTgf//////////AgEC
------END DH PARAMETERS-----';
+-----END DH PARAMETERS-----');
         $this->assertSame($b, "$a");
     }
 
@@ -43,11 +43,11 @@ Sgh5jjQE3e+VGbPNOkMbMCsKbfJfFDdP4TVtbVHCReSFtXZiXn7G9ExC6aY37WsL
         $base = new BigInteger(2);
         $a = DH::createParameters($prime, $base);
         $a = str_replace("\r\n", "\n", trim($a));
-        $b = '-----BEGIN DH PARAMETERS-----
+        $b = str_replace("\r\n", "\n", '-----BEGIN DH PARAMETERS-----
 MIGHAoGBAP//////////yQ/aoiFowjTExmKLgNwc0SkCTgiKZ8x0Agu+pjsTmyJR
 Sgh5jjQE3e+VGbPNOkMbMCsKbfJfFDdP4TVtbVHCReSFtXZiXn7G9ExC6aY37WsL
 /1y29Aa37e44a/taiZ+lrp8kEXxLH+ZJKGZR7OZTgf//////////AgEC
------END DH PARAMETERS-----';
+-----END DH PARAMETERS-----');
         $this->assertSame($b, "$a");
     }