How to read and parse SAMLResponse in custom Odata read call

[dtag_nps_basis_team90]

Hello All,

Can you please suggest if SAML Response can be read in a custom Odata Read call in below scenario.

1. When user logs in to the portal, SSO authentication is done. During this authentication process, the logged in user is changed based on the configuration in USREXTID table. For example, if user A is maintained as substitute of user B, then user A will access all applications as user B. This is as per SAML configurations.

2. After authentication, while loading the landing page in Fiori there is a Odata call to backend to fetch user attributes. In this call, we are able to fetch attributes of only UserB (as per above configuration). But in this call, we also want to read the actual user ID who is accessing the application. Is it possible to read SAML response or NameID attribute in odata read call.

3. We do not want to read the data from table USREXTID, because same user can have multiple substitute users. Hence, we want to know if its possible to read and parse SAMLresponse.

Best Regards!