Implement same-device flow redirection including Error Response

[nanderstabel]

Description

The error response must be made in the same manner as defined in Section 3.1.2.6 of [OpenID.Core].In addition to the error codes defined in Section 4.1.2.1 of OAuth 2.0 and Section 3.1.2.6 of [OpenID.Core], this specification also defines the following error codes:

• user_cancelled: End-User cancelled the Authorization Request from the RP.

• registration_value_not_supported: the Self-Issued OP does not support some Relying Party parameter values received in the request.

• subject_syntax_types_not_supported: the Self-Issued OP does not support any of the Subject Syntax Types supported by the RP, which were communicated in the request in the subject_syntax_types_supported parameter.

• invalid_registration_uri: the client_metadata_uri in the Self-Issued OpenID Provider request returns an error or contains invalid data.

• invalid_registration_object: the client_metadata parameter contains an invalid RP parameter Object.
  Other error codes MAY be used.Note that HTTP error codes do not work in the cross-device Self-Issued OP protocol flows.

Motivation

Essential part of the same-device flow.

Resources

https://openid.net/specs/openid-connect-self-issued-v2-1_0.html#section-10.3
OpenID.Core]

To-do List

• Implement proper redirection for same-device flow
• Add the Error Responses