diff --git a/composer.json b/composer.json
index 5c4975a83..77438a31a 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
         "ext-zlib": "*",
 
         "psr/log": "^2.0 || ^3.0",
-        "robrichards/xmlseclibs": "^3.1.5",
+        "robrichards/xmlseclibs": "^4.0.0",
         "simplesamlphp/xml-common": "^2.7",
         "webmozart/assert": "^2.0"
     },
diff --git a/src/SAML2/Utils.php b/src/SAML2/Utils.php
index 7958b9301..8c9e0ad25 100644
--- a/src/SAML2/Utils.php
+++ b/src/SAML2/Utils.php
@@ -176,7 +176,7 @@ public static function castKey(XMLSecurityKey $key, string $algorithm, ?string $
             throw new Exception('Unsupported signing algorithm.');
         }
 
-        $keyInfo = openssl_pkey_get_details($key->key);
+        $keyInfo = openssl_pkey_get_details(openssl_pkey_get_public($key->key));
         if ($keyInfo === false) {
             throw new Exception('Unable to get key details from XMLSecurityKey.');
         }
@@ -420,6 +420,9 @@ private static function doDecryptElement(
             throw new Exception('Could not locate key algorithm in encrypted data.');
         }
 
+        // Enable support for RSA 1.5 in the library. If it's blacklisted, we will throw an exception below.0
+        $enc->allowRSA15KeyTransport = true;
+
         $symmetricKeyInfo = $enc->locateKeyInfo($symmetricKey);
         if (!$symmetricKeyInfo) {
             throw new Exception('Could not locate <dsig:KeyInfo> for the encrypted key.');
diff --git a/tests/SAML2/Response/XmlSignatureWrappingTest.php b/tests/SAML2/Response/XmlSignatureWrappingTest.php
index 64fd66743..e1809a0d2 100644
--- a/tests/SAML2/Response/XmlSignatureWrappingTest.php
+++ b/tests/SAML2/Response/XmlSignatureWrappingTest.php
@@ -62,7 +62,7 @@ public function testThatASignatureReferencingAnEmbeddedAssertionIsNotValid(): vo
     public function testThatASignatureReferencingAnotherAssertionIsNotValid(): void
     {
         $this->expectException(Exception::class);
-        $this->expectExceptionMessage('Reference validation failed');
+        $this->expectExceptionMessage('Reference URI does not identify a node');
 
         $assertion = $this->getSignedAssertionWithSignatureThatReferencesAnotherAssertion();
         $this->signatureValidator->hasValidSignature($assertion, $this->identityProviderConfiguration);