Padding not supported: OAEPPadding

Question

I'm attempting to create a functionality that reads certificates from the Windows store. My setup involves an SSO-SAML enabled environment with ADFS as the identity provider (IdP). I've enabled encryption for the assertion. However, I'm encountering a problem during the assertion decryption process. To decrypt the assertion, I've extracted the private key from the MMC. But on attempting to decrypt the assertion using this key, I get the

javax.crypto.NoSuchPaddingException: Padding not supported: OAEPPadding exception.

I am using OpenSaml-2 with xmlsec-2.1.7.

Could anyone please guide to resolve this issue.

Please find the code below.

public static Assertion getDecryptedAssertion(EncryptedAssertion encryptedAssertion, 
        KeyStoreWrapper ksWrapper) throws Exception {

    ChainingEncryptedKeyResolver keyResolver = new ChainingEncryptedKeyResolver();
    keyResolver.getResolverChain().add(new InlineEncryptedKeyResolver());
    keyResolver.getResolverChain().add(new EncryptedElementTypeEncryptedKeyResolver());
    keyResolver.getResolverChain().add(new SimpleRetrievalMethodEncryptedKeyResolver());
        
    // Create the credentials.
    BasicX509Credential decryptionCredential = new BasicX509Credential();
    decryptionCredential.setPrivateKey(ksWrapper.getPrivateKeyNew());

    StaticKeyInfoCredentialResolver resolver = new StaticKeyInfoCredentialResolver(decryptionCredential);

    // Create a decrypter.
    Decrypter decrypter = new Decrypter(null, resolver, keyResolver);
    decrypter.setRootInNewDocument(true);
    decrypter.setJCAProviderName("SunMSCAPI");

    // Decrypt the assertion.
    Assertion decryptedAssertion = null;
        
    try {
        decryptedAssertion = decrypter.decrypt(encryptedAssertion);
    } catch (Exception e) {
        throw new Exception("Error while decrypting the saml response ASSERTION.", e);
    }
    return decryptedAssertion;
}