issuer URIs with a path part don't work

[zenomt]

i originally opened this as nodeSolidServer/oidc-auth-manager#44 but perhaps i should have started here to target the right audience.

oidc-auth-mananger seems to make an invalid assumption that all OIDC Issuers are URIs with an empty path part. if a webid has an OIDC Issuer URI with a path part (like my webid https://zenomt.zenomt.com/card.ttl#me with issuer https://zenomt.com/oidc/), it can never be matched against the id_token iss claim because the discovered issuer URI is reduced to its origin before being compared. see these lines in preferred-provider.js.

OIDC Issuers are allowed to have path parts.

[jaxoncreed]

Good point. This should be fixed, though until we encounter a solid-compatible openid-provider this will be a low priority.

[zenomt]

@jaxoncreed my own OpenID provider and my own webid would be "Solid-compatible" if this issue was fixed.