I am not familiar with SiteMinder. But you may have some misunderstanding between WS-Federation and SAML. WS-Federation is a protocol (similar to OAuth). SAML is a kind of token (similar to SWT). A protocol is used to send the token. Ideally, you use
WS-Federation to send SAML tokens, and ACS supports WS-Federation as custom identity providers. You mentioned SiteMinder already supports SAML. So the next thing to check is if it uses WS-Federation or another protocol to send the SAML token. If it uses WS-Federation,
it will be fine. Otherwise it’s not supported by ACS.
Thank you for your comment. I do understand the difference between a protocol and a token. SAML however is used both as a token (as in SAML Assertion) and a protocol. I see that ACS supports SAML as input cliams token as well as output claims token, but
not as a protocol. Which makes it very hard for me to integrate with with SiteMider.
Does anyone know if SAML (Protocol) support for IDP is forthcoming in ACS?
That is correct, the document refers to SiteMinder + ADFS integration, which is supported. SiteMinder federation services support SAML and WS-Federaion, so it can integrate with ADFS. The issue of integration with ACS is that it only supports Metadata exchange
for WS-Fed and does not support SAML (Protocol) whereas SiteMinder supports SAML metadata exchage, and while it does support WS-Fed partnerships, it does not provide a mechnism for Metadata Exchange for it (so it has to be manually configured). Since you cannot
manually configure a WS-Fed partnership in ACS, there is an incompatability between the two systems.