We are acting as service provider (supporting SAML2.0) and we are working on a proposal to federate with a new federation whose IDP is ADFS2.0. We are currently supporting several other Federations that are currently using OKTA as their IDP.
We expect the IDP to post SAML assertion either through (SP initiated or IDP initiated). If ADFS2.0 is acting as IDP, will the SAML assertion will be similar to OKTA or will it be different? (I heard that the SAML assertion from ADFS2.0 will be compressed in addition to Base64 encoding while from OKTA it is only base64 encoded.)
You can expect both OKTA and ADFS to support the SAML2 standard.
If you are using the HTTP Redirect binding the xml is deflated+Base64-encoded. If you are using the HTTP POST binding the xml is only Base64-encoded. For receiving SAML2 assertions you shouldn't use the HTTP Redirect binding due to data length restrictions. So if you have a working implementation for OKTA it should work for ADFS too.