How to implement single logout using okta as IDP? - logout

Question

In Okta developer account I have enabled the SAML Single Logout and get Identity Provider Single Logout URL. I have created following logout request using NameID and SessionIndex obtained from SAML response that we get during single sign-on process.
Logout Request :
<?xml version="1.0" encoding="UTF-8"?>
<samlp:LogoutRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Destination="https://dev-6#####.oktapreview.com/app/nepasoftdev660864_spdemo_1/exk606bnr5BZOBF7z0h7/slo/saml" ID="_b2be5dbd-928a-4554-a879-25a179e36ee2" IssueInstant="2016-03-25T10:20:47Z" Version="2.0">
<saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">http://192.###.###.##/spdemo</saml:Issuer>
<saml:NameID xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient">ramesh.shrestha#nepasoft.com</saml:NameID>
<samlp:SessionIndex>id1458901238038.94596883</samlp:SessionIndex>
</samlp:LogoutRequest>
I am getting the following Logout Response with status code RequestDenied
<?xml version="1.0" encoding="UTF-8"?>
<saml2p:LogoutResponse xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" Destination="http://localhost:10262/Logout.aspx" ID="id1846510753301801884197562" InResponseTo="_b2be5dbd-928a-4554-a879-25a179e36ee2" IssueInstant="2016-03-25T10:22:40.389Z" Version="2.0">
<saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">http://192.###.###.##/spdemo</saml2: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:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
<ds:Reference URI="#id1846510753301801884197562">
<ds:Transforms>
<ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
<ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
<ds:DigestValue>LQwvto+ERXvrQRUB7LOUUznSXII=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>P+T1K.....ZYvCw==</ds:SignatureValue>
<ds:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>MIID.....7zK0rH</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</ds:Signature>
<saml2p:Status>
<saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:RequestDenied" />
</saml2p:Status>
</saml2p:LogoutResponse>
Why might be the reason for getting RequestDenied status? Did i missed something on logout request or misconfigured during enabling single logout in Okta?
Thanks in advanced.

Answer 1

You also need to sign the LogoutRequest so you would need to include a Signature element (similar to what you are getting back in the LogoutResponse).
That said, I'm running into the same issue you are. I have signed my LogoutRequest but am still getting a LogoutResponse with status RequestDenied.
I did find this thread (https://support.okta.com/help/answers?id=906F0000000I07YIAS) on Okta's support page which indicates that the HTTP-Redirect binding is not supported for logout so you may need to you HTTP-Post. I've not tried that yet.