def get_oauth2_metadata_from_conformance(strict=true)
      options = {
        authorize_url: nil,
        token_url: nil
      }
      begin
        capability_statement.rest.each do |rest|
          if strict
            rest.security.service.each do |service|
              service.coding.each do |coding|
                next unless coding.code == 'SMART-on-FHIR'
                 options.merge! get_oauth2_metadata_from_service_definition(rest)
              end
            end
          else
            options.merge! get_oauth2_metadata_from_service_definition(rest)
          end
        end
      rescue => e
        FHIR.logger.error "Failed to locate SMART-on-FHIR OAuth2 Security Extensions: #{e.message}"
      end
      options.delete_if { |_k, v| v.nil? }
      options.clear if options.keys.size != 2
      options
    end
def get_oauth2_metadata_from_conformance(strict=true)
      options = {
        authorize_url: nil,
        token_url: nil
      }
      begin
        capability_statement.rest.each do |rest|
          if strict
            rest.security.service.each do |service|
              service.coding.each do |coding|
                next unless coding.code == 'SMART-on-FHIR'
                 options.merge! get_oauth2_metadata_from_service_definition(rest)
              end
            end
          else
            options.merge! get_oauth2_metadata_from_service_definition(rest)
          end
        end
      rescue => e
        FHIR.logger.error "Failed to locate SMART-on-FHIR OAuth2 Security Extensions: #{e.message}"
      end
      options.delete_if { |_k, v| v.nil? }
      options.clear if options.keys.size != 2
      options
    end
Get the OAuth2 server and endpoints from the capability statement
 (the server should not require OAuth2 or other special security to access
 the capability statement).
 <rest>
   <mode value="server"/>
   <documentation value="All the functionality defined in FHIR"/>
   <security>
   <extension url="http://fhir-registry.smarthealthit.org/StructureDefinition/oauth-uris">
     <extension url="register">
       <valueUri value="https://authorize-dstu2.smarthealthit.org/register"/>
     </extension>
     <extension url="authorize">
       <valueUri value="https://authorize-dstu2.smarthealthit.org/authorize"/>
     </extension>
     <extension url="token">
       <valueUri value="https://authorize-dstu2.smarthealthit.org/token"/>
     </extension>
   </extension>
   <service>
     <coding>
       <system value="http://hl7.org/fhir/vs/restful-security-service"/>
       <code value="OAuth2"/>
     </coding>
     <text value="OAuth version 2 (see oauth.net)."/>
   </service>
   <description value="SMART on FHIR uses OAuth2 for authorization"/>
 </security>