How do I configure my SAML Service Provider to send metadata to the Identity Provider?

Question

I am using the ITfoxTec SAML library in my .Net Web API project.

I have it working with a SAML Identity Provider testing service called Okta and it's working great.

But now I need to use a corporate SAML Identity Provider that is more complicated.

I am required to send metadata, so I used one of those online SAML metadata generators and got this:

<?xml version="1.0"?>
<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
                     validUntil="2023-02-03T18:10:14Z"
                     cacheDuration="PT604800S"
                     entityID="54ab9813-9546-4630-90eb-f31f69fbe535">
    <md:SPSSODescriptor AuthnRequestsSigned="true" WantAssertionsSigned="true" protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
        <md:NameIDFormat>urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified</md:NameIDFormat>
        <md:AssertionConsumerService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"
                                     Location="https://portal.xyz.com/claims"
                                     index="1" />
        
    </md:SPSSODescriptor>
</md:EntityDescriptor>

I made the metadata XML file available on my site:

https://portal.xyz.com/public/5001_Saml2.xml

However when I try to connect to the SAML IdP, I get this error in the console:

System.InvalidOperationException occurred HResult=0x80131509 Message=Incorrect Content-Type

The controller my app uses to connect to the IdP is here:

[Route("Login")]
public IActionResult Login(string? returnUrl = null)
{
    var binding = new Saml2RedirectBinding();
    binding.SetRelayStateQuery(new Dictionary<string, string> { { relayStateReturnUrl, returnUrl ?? Url.Content("~/") } });

    return binding.Bind(new Saml2AuthnRequest(config)).ToActionResult();
}

I'm not sure what I'm doing wrong, does anyone know how to setup Metadata like this for ITfoxTec SAML 2.0?

Thanks!

Answer 1

You should let the ITfoxtec Identity SAML library create the online metadata, then it should work.

You can e.g., find a metadata generation example in the TestWebAppCore sample.