C# - How to decrypt a SAML response that contains X509 & cipher value

Question

We have a tool that is not in .net and it decrypts a SAML xml request, I 'm trying to replicate the behavior in .net, however, I'm not sure the correct way to do it, I see the X509 and cipher in the xml body, using that I need to decrypt it??

SAML XML Body

<samlp:Response xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Destination="https://uat.com/" ID="_fee80033-e30f-4104-a149-a0387a751b50" IssueInstant="2022-11-04T06:12:39.266Z" Version="2.0">
    <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient">TEST:SAML2.0:DEV</saml:Issuer>
    <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
        <ds:SignedInfo>
            <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"></ds:CanonicalizationMethod>
            <ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"></ds:SignatureMethod>
            <ds:Reference URI="#_fee80033-e30f-4104-a149-a0387a751b50">
                <ds:Transforms>
                    <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"></ds:Transform>
                    <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"></ds:Transform>
                </ds:Transforms>
                <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"></ds:DigestMethod>
                <ds:DigestValue>JQfbd3hmIoYA0GiKQnS/iWLOZMk=</ds:DigestValue>
            </ds:Reference>
        </ds:SignedInfo>
        <ds:SignatureValue>ZVlFqS+BHn5jPvyLgf3k0G6/p9l52jLTivNpJsfn9IaTqyVxo8R+PeH59yxeR58XoYybtjn2FXlv
tB66sJUIdwJRAAFQQxBVsG8eLmDF23rVAr1VXVVeisKhs/A4NlJ+1hirilxhXIeV8ig16hjiTylC
vnVAyGGWMAcBCUFlrL9X9I2dkRgiZTQvjtFBJ4QBM+5lSoy8nho8hOvwNL2Oj4LemQWIoAuc65rI
pZbaA0IXRT8x5iedFca7N/xJVCiaIZh5SobGRB8iIXh0kDdKNUNyyaxxvQCEFt+JDnGwSCKvgHDb
HImEqNmMgcMuSgE9P3zffFDr4Rw+6VKN5KuIYw==</ds:SignatureValue>
        <ds:KeyInfo>
            <ds:X509Data>
                <ds:X509Certificate>certificatekey</ds:X509Certificate>
            </ds:X509Data>
        </ds:KeyInfo>
    </ds:Signature>
    <samlp:Status>
        <samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"></samlp:StatusCode>
    </samlp:Status>
    <saml:EncryptedAssertion xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">
        <xenc:EncryptedData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#" Type="http://www.w3.org/2001/04/xmlenc#Element">
            <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"></xenc:EncryptionMethod>
            <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
                <xenc:EncryptedKey>
                    <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"></xenc:EncryptionMethod>
                    <KeyInfo xmlns="http://www.w3.org/2000/09/xmldsig#">
                        <X509Data>
                            <X509Certificate>certificatekey</X509Certificate>
                        </X509Data>
                    </KeyInfo>
                    <xenc:CipherData>
                        <xenc:CipherValue>cipherValue</xenc:CipherValue>
                    </xenc:CipherData>
                </xenc:EncryptedKey>
            </ds:KeyInfo>
            <xenc:CipherData>
                <xenc:CipherValue>cipherValue</xenc:CipherValue>
            </xenc:CipherData>
        </xenc:EncryptedData>
    </saml:EncryptedAssertion>
</samlp:Response>

I'm not sure whether the below code is correct for me.

using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Security.Cryptography.Xml;

XmlDocument doc = new XmlDocument();
doc.Load("/Data/SAML.xml");
Decrypt(doc);

public static void Decrypt(XmlDocument Doc)
        {
            // Check the arguments.
            if (Doc == null)
                throw new ArgumentNullException("Doc");

            // Create a new EncryptedXml object.
            EncryptedXml exml = new EncryptedXml(Doc);
            var cspParams = new CspParameters();
            cspParams.KeyContainerName = "XML_ENC_RSA_KEY";
            var rsaKey = new RSACryptoServiceProvider(cspParams);
            // Decrypt the XML document.
            exml.AddKeyNameMapping("rsaKey", rsaKey);
            exml.DecryptDocument();
        }