Perform optional schema validation (default: true)

Author: tvdijen

src/Binding.php

@@ -25,6 +25,20 @@
  */
 abstract class Binding
 {
+    /**
+     * The schema to be used for schema validation
+     *
+     * @var string
+     */
+    protected static string $schemaFile = 'resources/schemas/saml-schema-protocol-2.0.xsd';
+
+    /**
+     * Whether or not to perform schema validation
+     *
+     * @var bool
+     */
+    protected bool $schemaValidation = true;
+
     /**
      * The RelayState associated with the message.
      *
@@ -157,7 +171,20 @@ public function getDestination(): ?string
 
 
     /**
-     * Set the RelayState associated with he message.
+     * Override the destination of a message.
+     *
+     * Set to null to use the destination set in the message.
+     *
+     * @param string|null $destination The destination the message should be delivered to.
+     */
+    public function setDestination(?string $destination = null): void
+    {
+        $this->destination = $destination;
+    }
+
+
+    /**
+     * Set the RelayState associated with the message.
      *
      * @param string|null $relayState The RelayState.
      */
@@ -179,15 +206,24 @@ public function getRelayState(): ?string
 
 
     /**
-     * Override the destination of a message.
+     * Set the schema validation for the message.
      *
-     * Set to null to use the destination set in the message.
+     * @param bool $schemaValidation
+     */
+    public function setSchemaValidation(bool $schemaValidation): void
+    {
+        $this->schemaValidation = $schemaValidation;
+    }
+
+
+    /**
+     * Get the schema validation setting.
      *
-     * @param string|null $destination The destination the message should be delivered to.
+     * @return bool
      */
-    public function setDestination(?string $destination = null): void
+    public function getSchemaValidation(): bool
     {
-        $this->destination = $destination;
+        return $this->schemaValidation;
     }
 
 

src/Binding/HTTPPost.php

@@ -91,9 +91,11 @@ public function receive(ServerRequestInterface $request): AbstractMessage
         }
 
         $msgStr = base64_decode($msgStr, true);
-        $msgStr = DOMDocumentFactory::fromString($msgStr)->saveXML();
 
-        $document = DOMDocumentFactory::fromString($msgStr);
+        $document = DOMDocumentFactory::fromString(
+            xml: $msgStr,
+            schemaFile: $this->getSchemaValidation() ? self::$schemaFile : null,
+        );
         Utils::getContainer()->debugMessage($document->documentElement, 'in');
 
         $msg = MessageFactory::fromXML($document->documentElement);

src/Binding/HTTPRedirect.php

@@ -148,7 +148,10 @@ public function receive(ServerRequestInterface $request): AbstractMessage
             throw new Exception('Error while inflating SAML message.');
         }
 
-        $document = DOMDocumentFactory::fromString($message);
+        $document = DOMDocumentFactory::fromString(
+            xml: $message,
+            schemaFile: $this->getSchemaValidation() ? self::$schemaFile : null,
+        );
         Utils::getContainer()->debugMessage($document->documentElement, 'in');
         $message = MessageFactory::fromXML($document->documentElement);
 

src/Binding/SOAP.php

@@ -101,8 +101,12 @@ public function receive(/** @scrutinizer ignore-unused */ServerRequestInterface
         $xpCache = XPath::getXPath($document->documentElement);
         /** @var \DOMElement[] $results */
         $results = XPath::xpQuery($xml, '/SOAP-ENV:Envelope/SOAP-ENV:Body/*[1]', $xpCache);
+        $document = DOMDocumentFactory::fromString(
+            xml: $results[0]->ownerDocument->saveXML($results[0]),
+            schemaFile: $this->getSchemaValidation() ? self::$schemaFile : null,
+        );
 
-        return MessageFactory::fromXML($results[0]);
+        return MessageFactory::fromXML($document->documentElement);
     }
 
 

src/SAML2/Entity/ServiceProvider.php

@@ -57,6 +57,7 @@ final class ServiceProvider
     protected bool $responseWasSigned;
 
     /**
+     * @param bool $performSchemaValidation  Whether messages must be validated against the schema
      * @param bool $encryptedAssertions  Whether assertions must be encrypted
      * @param bool $disableScoping  Whether to send the samlp:Scoping element in requests
      * @param bool $enableUnsolicited  Whether to process unsolicited responses
@@ -68,6 +69,7 @@ final class ServiceProvider
     public function __construct(
         protected MetadataProviderInterface $metadataProvider,
         protected Metadata\ServiceProvider $spMetadata,
+        protected readonly bool $performSchemaValidation = true,
         protected readonly bool $encryptedAssertions = false,
         protected readonly bool $disableScoping = false,
         protected readonly bool $enableUnsolicited = false,
@@ -139,6 +141,7 @@ public function receiveResponse(ServerRequestInterface $request): Response
             $binding->setSPMetadata($this->spMetadata);
         }
 
+        $binding->setSchemaValidation($this->performSchemaValidation);
         $rawResponse = $binding->receive($request);
         Assert::isInstanceOf($rawResponse, Response::class, ResourceNotRecognizedException::class); // Wrong type of msg
 

src/SOAPClient.php

@@ -172,6 +172,17 @@ public function send(
             );
         }
 
+        $xpCache = XPath::getXPath($document->documentElement);
+        /** @var \DOMElement[] $results */
+        $results = XPath::xpQuery($xml, '/SOAP-ENV:Envelope/SOAP-ENV:Body/*[1]', $xpCache);
+
+        // This is already too late to perform schema validation.
+        // TODO:  refactor the SOAPClient and artifact binding. The SOAPClient should be a generic tool from xml-soap
+        $document = DOMDocumentFactory::fromString(
+            xml: $results[0]->ownerDocument->saveXML(),
+            schemaFile: $this->getSchemaValidation() ? self::$schemaFile : null,
+        );
+
         // Extract the message from the response
         /** @var \SimpleSAML\XML\SerializableElementInterface[] $messages */
         $messages = $env->getBody()->getElements();