X509: set another parameters field to null

phpseclib/File/X509.php

@@ -1512,6 +1512,8 @@ class File_X509
                            it seems like perhaps the ASN.1 description ought not say the parameters field is OPTIONAL, but whatever.
                          */
                         $cert['tbsCertificate']['subjectPublicKeyInfo']['algorithm']['parameters'] = null;
+                        // https://tools.ietf.org/html/rfc3279#section-2.2.1
+                        $cert['signatureAlgorithm']['parameters'] = null;
                 }
         }
 

tests/Unit/File/X509/X509Test.php

@@ -137,6 +137,7 @@ aBtsWpliLSex/HHhtRW9AkBGcq67zKmEpJ9kXcYLEjJii3flFS+Ct/rNm+Hhm1l7
         $cert = $x509->loadX509($cert);
 
         $this->assertArrayHasKey('parameters', $cert['tbsCertificate']['subjectPublicKeyInfo']['algorithm']);
+        $this->assertArrayHasKey('parameters', $cert['signatureAlgorithm']);
     }
 
     private function _encodeOID($oid)