saml: SAML 1.1: Prepare for IdP initiated authentication.

With IdP initiated authentication, we will not have the IdP entityID
available when receiving the response. This patch prepares the code for
that.

Unfortunately, the IdP entityID is required for the Artifact receiver,
so give an error when receiving an unsolicited response there.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2567 44740490-163a-0410-bde0-09ae8108e29a

modules/saml/www/sp/saml1-acs.php

@@ -28,18 +28,18 @@ if ($state['saml:sp:AuthId'] !== $sourceId) {
 	throw new SimpleSAML_Error_Exception('The authentication source id in the URL does not match the authentication source which sent the request.');
 }
 
-if (!isset($state['saml:idp'])) {
-	/* We seem to have received a response without sending a request. */
-	throw new SimpleSAML_Error_Exception('SAML 1 response received before SAML 1 request.');
-}
+assert('isset($state["saml:idp"])');
 
 
 $spMetadata = $source->getMetadata();
 
-$idpEntityId = $state['saml:idp'];
-$idpMetadata = $source->getIdPMetadata($idpEntityId);
-
 if (array_key_exists('SAMLart', $_REQUEST)) {
+	if (!isset($state['saml:idp'])) {
+		/* Unsolicited response. */
+		throw new SimpleSAML_Error_Exception('IdP initiated authentication not supported with the SAML 1.1 SAMLart protocol.');
+	}
+	$idpMetadata = $source->getIdPMetadata($state['saml:idp']);
+
 	$responseXML = SimpleSAML_Bindings_Shib13_Artifact::receive($spMetadata, $idpMetadata);
 	$isValidated = TRUE; /* Artifact binding validated with ssl certificate. */
 } elseif (array_key_exists('SAMLResponse', $_REQUEST)) {
@@ -59,7 +59,7 @@ $response->validate();
 $responseIssuer = $response->getIssuer();
 $attributes = $response->getAttributes();
 
-if ($responseIssuer !== $idpEntityId) {
+if (isset($state['saml:idp']) && $responseIssuer !== $state['saml:idp']) {
 	throw new SimpleSAML_Error_Exception('The issuer of the response wasn\'t the destination of the request.');
 }
 
@@ -68,7 +68,7 @@ $logoutState = array(
 	);
 $state['LogoutState'] = $logoutState;
 
-$source->handleResponse($state, $idpEntityId, $attributes);
+$source->handleResponse($state, $responseIssuer, $attributes);
 assert('FALSE');
 
 ?>
\ No newline at end of file