Agreed. Although I would say that for scope issue, how an AS handles and errors based on scope is fully at its own discretion. ignore invalid scopes could be allowed. I would recommend against it in case future scopes are added, but as long as the scope mirrored back in the response matches the scopes presented to the user for validation, that's all that really matters from my perspective.
On Thu, Aug 6, 2026 at 7:23 PM Emelia S. <emelia= [email protected]> wrote: > Hi Donald, > > Looking at the table of results and test cases, for 1, 3 and 4, these are > the correct responses per the results table, as otherwise the authorization > server would be an open redirector. For test case 0, the response_type is > required, so yes, redirecting back with the error of either > invalid_request, or unsupported_response_type if it's present but > unsupported, would be correct. For test case 5, redirecting back with > invalid_scope would be correct, provided the client and redirect URI > match. > > Do be careful not to mixup response_type (OAuth, OIDC) and response_mode > (from OIDC), response_mode can often be inferred from response_type (e.g., > code response_type often defaults to query as a response_mode). > > Hope that helps. > > Yours, > Emelia > > On 6 Aug 2026, at 18:30, [email protected] wrote: > > I am the Technical Manager of the Green Button Alliance. I am responsible > for certifying that electric, natural gas, and water utilities comply with > the North American Energy Standards (NAESB) Energy Service Provider > Interface (ESPI) standard and need a ruling from the IETF OAuth WG > regarding an issue that has arisen for Hydro One Networks, Inc. > > Hydro One Networks, Inc., the largest electric utility in Ontario, Canada, > implemented the NAESB ESPI (a.k.a. Green Button) standard in 2023, which > uses the OAuth 2.0 standard for customers to authorize client applications > to access their energy data. At the time, they were using an IBM Tivoli > Authorization Server, which fully complied with the Green Button Alliance > legislatively mandated certification test for Section 4.1.2.1. > Authorization Error Response. They recently upgraded to the IBM Verify > Authorization Server, which no longer passes the same Section 4.1.2.1. > Authorization Error Response tests. IBM has agreed to comply with the IETF > OAuth Working Group’s response to my questions. > > The GBA Certification test platform currently submits the following > invalid Authorization Endpoint requests and expects the Authorization > Server to comply with Section 4.1.2.1. Authorization Error Response error > messages: > > *iTestID* > *Label* > *Test Name* > *Query string* > *Status Code* > *Expected Error Message* > 0 > Case 0: no response_type > Malformed Authorization Code Request (No response_type field-value) > > ?client_id=(client_id)&redirect_uri=(redirect_uri)&scope=(scope)&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=invalid_request parameter and no or empty location header > 1 > Case 1: no client_id > Malformed Authorization Code Request (No client_id field-value) > > ?response_type=code&redirect_uri=(redirect_uri)&scope=(scope)&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=invalid_request parameter and no or empty location header > 2 > Case 2: invalid response_type > Malformed Authorization Code Request (Invalid response_type field-value: > ?response_type=badresponsetype& > client_id=(client_id)&redirect_uri=(redirect_uri)&scope=(scope)&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=unsupported_response_type parameter and no or empty location header > 3 > Case 3: invalid client_id > Malformed Authorization Code Request (Invalid client_id field-value) > ?response_type=code& > client_id=invalid_third_party&redirect_uri=(redirect_uri)&scope=(scope)&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=unauthorized_client parameter and no or empty location header > 4 > Case 4: invalid redirect_uri > Malformed Authorization Code Request (Invalid redirect_uri field-value) > ?response_type=code& client_id=(client_id)&redirect_uri= > https://services.greenbuttondata.org&scope=(scope)&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=invalid_request parameter and no or empty location header > 5 > Case 5: invalid scope > Malformed Authorization Code Request (Invalid scope field-value) > ?response_type=code& > client_id=(client_id)&redirect_uri=(redirect_uri)&scope=FB=????&state=ee148ec2-9898-466e-a013-4dedf1eb3018 > 302/303 > ?error=invalid_scope parameter and no or empty location header > > > All scope string values are application variable contents shown as () > entries if present. Malformed values are shown as strings. I do not test > for missing state= elements, although the NAESB ESPI standard requires them. > > The following table contains the current response by the IBM Verify > Authorization Server for each of the above test cases: > > *iTestID* > *Status Code* > *Response* > 0 > 303 > > https://cmdcert.greenbuttonalliance.org:8445/ThirdParty/espi/1_1/OAuthCallBack > ?error=unsupported_response_type&error_description=... > 1 > 401 > The response included a full-screen HTML showing the error “CSIAQ0154E The > requested OAuth 2.0 Client does not exist” > 2 > 303 > > https://cmdcert.greenbuttonalliance.org:8445/ThirdParty/espi/1_1/OAuthCallBack > ?error=unsupported_response_type&error_description... > 3 > 401 > The response included a full-screen HTML showing the error “CSIAQ0154E The > requested OAuth 2.0 Client does not exist” > 4 > 400 > The response included a full-screen HTML showing the error “CSIAQ0167E The > redirection URI provided in the request is either invalid or does not match > any of the OAuth 2.0 Client’s pre-registered redirect URLs” > 5 > 302 > https://...verify.ibm.com/idaas/mtfim/sps/idaas/login... > > > Note: > https://cmdcert.greenbuttonalliance.org:8445/ThirdParty/espi/1_1/OAuthCallback > is the value of the redirect_uri for all but the negative redirect_uri > tests > > The IBM team indicated that case 5 (invalid scope): The OpenID Connect > spec allows ignoring unknown scopes vs. returning an invalid_scope error ( > https://openid.net/specs/openid-connect-core-1_0.html#AuthRequest). The > referenced section of the OpenID Connect standard is the Authentication > section, which is NOT what case 5 is testing. However, Section 3.1.2.2. > Authentication Request Validation of the OpenID Connect specification > indicates the Authorization Server MUST validate all the OAuth 2.0 > parameters according to the OAuth 2.0 specification. That includes (2) > verifying that a scope parameter is present and contains the openid scope > value (If no openid scope value is present, the request may still be a > valid OAuth 2.0 request but is not an OpenID Connect request). > > The IBM team indicated that case 4 (invalid redirect): An OpenID Connect > certification has precedence over the IETF OAuth 2.0 RFC 6749 and > referenced their official OpenID Foundation cert test for invalid redirect > URI, which expects an error page, not a redirect ( > https://www.certification.openid.net/log-detail.html?log=Lbzq5uCWSM1Sij3&public=true > ). > > The NAESB ESPI standard does not support the OpenID Connect standard, so > we contend that the IBM Verify team’s position that their OpenID Connect > server does not need to comply with the IETF RFC 6749 and 6750 standards is > a “red herring”. For cases 0 and 2, they have demonstrated the ability to > support Section 4.1.2.4 Authorization Error Response properly. > > The business issue and why I am submitting this email is that Hydro One > Networks, Inc. is required by Ontario legislation to be certified by the > Green Button Alliance as being in compliance with the NAESB ESPI standard. > Without that certification, Hydro One Networks, Inc. will face continuing > financial penalties from the Ontario Energy Board. > > > Best regards, > Don > Donald F. Coffin > Founder/CTO > > REMI Networks > 2335 Dunwoody Crossing Suite E > Dunwoody, GA 30338-8221 > > _______________________________________________ > OAuth mailing list -- [email protected] > To unsubscribe send an email to [email protected] > > > _______________________________________________ > OAuth mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
_______________________________________________ OAuth mailing list -- [email protected] To unsubscribe send an email to [email protected]
