SAMLParser: Only extract signing certificate.

When faced with two certificates, one marked as use="signing", while
the other was use="encryption", we chose the first one (even though
it may not have supported signature verification.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2474 44740490-163a-0410-bde0-09ae8108e29a

lib/SimpleSAML/Metadata/SAMLParser.php

@@ -472,6 +472,10 @@ class SimpleSAML_Metadata_SAMLParser {
 				continue;
 			}
 
+			if ($key['signing'] !== TRUE) {
+				continue;
+			}
+
 			$certData = base64_decode($key['X509Certificate']);
 			if($certData === FALSE) {
 				/* Empty/invalid certificate. */
@@ -535,6 +539,10 @@ class SimpleSAML_Metadata_SAMLParser {
 				continue;
 			}
 
+			if ($key['signing'] !== TRUE) {
+				continue;
+			}
+
 			$certData = base64_decode($key['X509Certificate']);
 			if($certData === FALSE) {
 				/* Empty/invalid certificate. */
@@ -624,6 +632,10 @@ class SimpleSAML_Metadata_SAMLParser {
 				continue;
 			}
 
+			if ($key['signing'] !== TRUE) {
+				continue;
+			}
+
 			$certData = base64_decode($key['X509Certificate']);
 			if($certData === FALSE) {
 				/* Empty/invalid certificate. */
@@ -701,6 +713,10 @@ class SimpleSAML_Metadata_SAMLParser {
 				continue;
 			}
 
+			if ($key['signing'] !== TRUE) {
+				continue;
+			}
+
 			$certData = base64_decode($key['X509Certificate']);
 			if($certData === FALSE) {
 				/* Empty/invalid certificate. */