Returns null when value is a usable canonical issuer, otherwise the
reason it is not.
Accepts an absolute https: URL, with a path prefix if the deployment needs
one, and an http: URL only for a loopback host. Rejects query strings and
fragments (OIDC Discovery derives the metadata URL from the issuer, so either
would produce a different document URL than the one served) and embedded
credentials.
Returns
nullwhenvalueis a usable canonical issuer, otherwise the reason it is not.Accepts an absolute
https:URL, with a path prefix if the deployment needs one, and anhttp:URL only for a loopback host. Rejects query strings and fragments (OIDC Discovery derives the metadata URL from the issuer, so either would produce a different document URL than the one served) and embedded credentials.