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Johan_Lång's avatar
Johan_Lång
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Mar 16, 2020

SAML SLO Error

BIGIP is acting SP to an IDP. This IDP is one of our authentication methods to the Webtop.   For instance, if you are logging out with the Logout-button from the webtop a samlrequest is sent to ...
application delivery
BIG-IP
BIG-IP Access Policy Manager (APM)
  • Johan_Lång's avatar
    Johan_Lång
    Mar 16, 2020

    Seems like the IDP didnt understood "ResponseLocation". The Reponse was sent to Location rather than ResponseLocation, this is something BIGIP does default:

     

    <SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://<bigip>/saml/sp/profile/post/sls" ResponseLocation="https://<bigip>/saml/sp/profile/post/slr">

     

    Temporarily i made an irule that makes an 307 response from /saml/sp/profile/post/sls to /saml/sp/profile/post/slr instead.

     

    Waiting for the IDP to update bigips metadata with only:

    <SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://<bigip>/saml/sp/profile/post/slr">

     

    Could this cause any trouble?

     

legan's avatar
legan
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I did already set the Logout Url in the Azure AD app registration to : https:/vpnbox/saml/sp/profile/post/slr, but that also redirected me to vdesk/my.acl.php3?errorcode=8001.

I have now done as you said: modified the XML and uploaded and I only see the Logout URL change, so I expect it's the same as what I did when manually changing the Logout URL in Azure AD.

 

APM log says:/Common/cpp_cra_aad_mfa:Common:22da7c68:SAML SSO: Invalid SLO request path. Expected (/saml/sp/profile/redirect/slr), received (/saml/sp/profile/post/slr?SAMLResponse=...).

Johan_Lång's avatar
Johan_Lång
Icon for Cirrus rankCirrus
Oct 15, 2020

​Have you kept HTTP-redirect binding in the metadata? try to remove that and only keep HTTP-Post.

Because as the APM log indicates, Azure sends it as a GET/Redirect (look at the traffic with chrome + f12 and preferly with a saml-trace tool) and not a POST. You can also try to change that manually from Azure, using POST as a reponse instead of Redirect (if that is possible).

If the only solution is to use redirect, then only provide http-redirect as a binding in your metadata from big-ip, and change the location to /saml/sp/profile/redirect/slr