How to configure service provider with spring-security-saml2 to consume EncryptedAssertions?

Question

I am using this excellent repo vdenotaris/spring-boot-security-saml-sample as a guide and I am trying to set it up to verify and decrypt incoming SAML messages that contain EncryptedAssertion.

The idP's metadata defines the signing and encrypting key in the XML. That is setup in the service provider.

@Bean
public ExtendedMetadata extendedMetadata() {
    ExtendedMetadata extendedMetadata = new ExtendedMetadata();
    extendedMetadata.setIdpDiscoveryEnabled(false);
    extendedMetadata.setSignMetadata(false);
    extendedMetadata.setEcpEnabled(true);
    return extendedMetadata;
}

@Bean
@Qualifier("metadata")
public CachingMetadataManager metadata() throws MetadataProviderException {
    List<MetadataProvider> providers = new ArrayList<MetadataProvider>();
    
    try {
        ClasspathResource metadata = new ClasspathResource("/metadata/the-idp-metadata.xml");
        Timer timer = new Timer(true);
        ResourceBackedMetadataProvider provider = new ResourceBackedMetadataProvider(timer, metadata);
        provider.setParserPool(ParserPoolHolder.getPool());
        provider.initialize();
    
        ExtendedMetadataDelegate exMetadataDelegate = new ExtendedMetadataDelegate(provider, extendedMetadata());
        exMetadataDelegate.setMetadataTrustCheck(true);
        exMetadataDelegate.setMetadataRequireSignature(false);
        providers.add(exMetadataDelegate);
    }
    catch(ResourceException ex) {
        throw new MetadataProviderException(ex.getMessage(), ex);
    }
    
    CachingMetadataManager cmm = new CachingMetadataManager(providers);
    cmm.setRefreshCheckInterval(0);
    
    return cmm;
}

When I manually send it a sample of a SAML message that has an encrypted assertion it fails with the following message.

org.springframework.security.authentication.AuthenticationServiceException: Incoming SAML message is invalid
    at org.springframework.security.saml.SAMLProcessingFilter.attemptAuthentication(SAMLProcessingFilter.java:91)
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:212)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:186)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:74)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.saml.metadata.MetadataGeneratorFilter.doFilter(MetadataGeneratorFilter.java:87)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.opensaml.common.SAMLException: Unsupported request
    at org.springframework.security.saml.processor.SAMLProcessorImpl.getBinding(SAMLProcessorImpl.java:265)
    at org.springframework.security.saml.processor.SAMLProcessorImpl.retrieveMessage(SAMLProcessorImpl.java:172)
    at org.springframework.security.saml.SAMLProcessingFilter.attemptAuthentication(SAMLProcessingFilter.java:80)
    ... 53 common frames omitted

I've read here Metadata Configuration that you can configure the signing and encryption key that the idp uses in order for the assertion to be decrypted (at least that is what I am assuming).

Is that the correct way to go about having the service consume EncryptedAssertions? I keep hitting this invalid message wall and not finding a good solid tutorial or documentation that explicitly describe how to handle this. Also unsure if the solution lies in the WebSSOProfileConsumerImpl class that I have to modify?

Any help or examples would be greatly appreciated.

Answer 1

We generally use SAML Tools (https://www.samltool.com/generic_sso_res.php), which contains a few examples with encrypted assertions.

For automated tests, we tend to generate SAML requests and responses on the fly, signing XML ourselves, and feed it to the application in an integration test.