2.2.4 wsignin1.0 Response Message
The wsignin1.0 response message is sent to the relying party that requested the security token to be issued. For normative descriptions and specifications on this response message, see [WSFederation1.2] section 13.2.3. This message consists of an HTTP POST with the following parameters encoded in the POST body, as specified in [WSFederation1.2] section 13.2.3:
wa: This value MUST be the literal string "wsignin1.0".
wresult: This value MUST be the issued security token encoded as a wst:RequestSecurityTokenResponse. The restrictions on the format of this element are specified further in section 184.108.40.206.
wctx (optional): This value is an opaque context that MUST be returned with the response if it was included in the request by the relying party.<22>