saml: Add EncryptedElementType key resolver to SAML plugin (#7268)

There are multiple ways in which a SAML response can be formatted, especially when encryption is enabled. This PR removes the hardcoding of EncryptedKeyResolver= InlineEncryptedKeyResolver in favor of using a ChainingEncryptedKeyResolver which will try multiple resolvers. It preserves the InlineEncryptedKeyResolver as the first option but adds EncryptedElementTypeEncryptedKeyResolver to the chain of resolvers to try.

ChainingEncryptedKeyResolver is a bit finicky in that you can't provide it a list of resolvers, you can only fetch its internal list and add to it.

Theoretically we could add all of the resolver types to the chain, but for now just preserving the ones known to be in use.

Co-authored-by: Marcus Sorensen <mls@apple.com>

Author: Marcus Sorensen

plugins/user-authenticators/saml2/src/main/java/org/apache/cloudstack/api/command/SAML2LoginAPIAuthenticatorCmd.java

@@ -55,9 +55,10 @@
 import org.opensaml.saml2.core.Response;
 import org.opensaml.saml2.core.StatusCode;
 import org.opensaml.saml2.encryption.Decrypter;
+import org.opensaml.saml2.encryption.EncryptedElementTypeEncryptedKeyResolver;
 import org.opensaml.xml.ConfigurationException;
+import org.opensaml.xml.encryption.ChainingEncryptedKeyResolver;
 import org.opensaml.xml.encryption.DecryptionException;
-import org.opensaml.xml.encryption.EncryptedKeyResolver;
 import org.opensaml.xml.encryption.InlineEncryptedKeyResolver;
 import org.opensaml.xml.io.UnmarshallingException;
 import org.opensaml.xml.security.SecurityHelper;
@@ -253,7 +254,9 @@ public String authenticate(final String command, final Map<String, Object[]> par
                     Credential credential = SecurityHelper.getSimpleCredential(idpMetadata.getEncryptionCertificate().getPublicKey(),
                             spMetadata.getKeyPair().getPrivate());
                     StaticKeyInfoCredentialResolver keyInfoResolver = new StaticKeyInfoCredentialResolver(credential);
-                    EncryptedKeyResolver keyResolver = new InlineEncryptedKeyResolver();
+                    ChainingEncryptedKeyResolver keyResolver = new ChainingEncryptedKeyResolver();
+                    keyResolver.getResolverChain().add(new InlineEncryptedKeyResolver());
+                    keyResolver.getResolverChain().add(new EncryptedElementTypeEncryptedKeyResolver());
                     Decrypter decrypter = new Decrypter(null, keyInfoResolver, keyResolver);
                     decrypter.setRootInNewDocument(true);
                     List<EncryptedAssertion> encryptedAssertions = processedSAMLResponse.getEncryptedAssertions();