Add support idp_cert_multi with string keys

Author: Alexandre Chakroun

lib/onelogin/ruby-saml/settings.rb

@@ -195,17 +195,13 @@ def get_idp_cert_multi
 
         certs = {:signing => [], :encryption => [] }
 
-        if idp_cert_multi.key?(:signing) and not idp_cert_multi[:signing].empty?
-          idp_cert_multi[:signing].each do |idp_cert|
-            formatted_cert = OneLogin::RubySaml::Utils.format_cert(idp_cert)
-            certs[:signing].push(OpenSSL::X509::Certificate.new(formatted_cert))
-          end
-        end
+        [:signing, :encryption].each do |type|
+          certs_for_type = idp_cert_multi[type] || idp_cert_multi[type.to_s]
+          next if !certs_for_type || certs_for_type.empty?
 
-        if idp_cert_multi.key?(:encryption) and not idp_cert_multi[:encryption].empty?
-          idp_cert_multi[:encryption].each do |idp_cert|
+          certs_for_type.each do |idp_cert|
             formatted_cert = OneLogin::RubySaml::Utils.format_cert(idp_cert)
-            certs[:encryption].push(OpenSSL::X509::Certificate.new(formatted_cert))
+            certs[type].push(OpenSSL::X509::Certificate.new(formatted_cert))
           end
         end