正常時 modeを art_res –> direct_checkid_accepted にする。異常時はdirect_checkid_errorですが、これは別途。
9.1.1 Direct Authentication Request Response
When Authentication Request is sent over direct communication successfully, the OP returns the response in the HTTP response body.
If the request does not require user interaction, it may return the positive or negative assertion.
If the request requires user interaction, following parameters and any relevant extension parameters are returned in the HTTP response body.
As specified in Section 4.1.2.
art_res“direct_checkid_accepted” when the direct authentication request message was valid and “openid.artifact” is returned.
Value: A unique short string less than 30 characters. This value is constructed from a cryptographically strong random or pseudorandom number sequence [RFC1750] generated by the OP. The Artifact may be used over an indirect request, the Artifact Authentication Request, subsequently.
Value: Comma-separated list of signed fields.
Note: Since there is only one parameter, openid.artifact, it will be "artifact".
Value: Base 64 encoded signature calculated as specified in Section 6.
Value: A handle for an association between the Relying Party and the OP that SHOULD be used to sign the response.
In addition to the above, any extension parameters can be returned in the Artifact Response.