[GAIN-POC] prompt and acr_values in the authz request should be optional - default applied
Opened this issue · 6 comments
May we say that the RP is not forced having acr_values in the request, and the OP SHOULD adopt its most secure or its default?
In other words, I'd say that the OP adopts its default if the RP doesn't request for some specific acr_values
do you agree?
In the current specs it is not clear which parameters are mandatory and which are optional
At the same way the parameter "prompt"
it should be optional and the IDP should act with its defaults if the RP omits that
In SPID acr_values and prompt are mandatory, see LL.GG. OIDC SPID
That's why I am suggesting to not have them mandatory and the idp should define their default
^ @AntonioFlorio @agcolella @nunzionapoli
I think it's better for SPID to keep the claims as mandatory, as defined in the guidelines
These claims are very important for interoperability with different systems/federation outside the italy.
I tag this issue with gain-poc
that's the stage where I'm facing all the interoperability issues with third parties
FYI 1
OpenID Connect Dynamic Client Registration 1.0 defines the default_acr_values
client metadata as follows.
OPTIONAL. Default requested Authentication Context Class Reference values. Array of strings that specifies the default
acr
values that the OP is being requested to use for processing requests from this Client, with the values appearing in order of preference. The Authentication Context Class satisfied by the authentication performed is returned as theacr
Claim Value in the issued ID Token. Theacr
Claim is requested as a Voluntary Claim by this parameter. Theacr_values_supported
discovery element contains a list of the supportedacr
values supported by this server. Values specified in theacr_values
request parameter or an individualacr
Claim request override these default values.
FYI 2
OAuth 2.0 Step-up Authentication Challenge Protocol recommends that an ACR request by the acr_values
request parameter (which requests the acr
claim as a voluntary claim) be “treated as required” and the authorization server return the unmet_authentication_requirements
error in case none of specified ACRs can be satisfied.
See "Unmet Authentication Requirements for Step-up Authentication" for details.