`UserInfo` endpoint lookup never returns

As part of the OIDC login flow, during the backchannel exchange to get the access and id token (assuming you are in the auth code flow, but that's not relevant to the issue), one can perform a check against the UserInfo endpoint of the OIDC provider to check that the sub claim of the obtained ID token matches the one of the userinfo associated to the access token.

However, in the case of NSS, a lookup at https://inrupt.net/.well-known/openid-configuration shows that the userinfo endpoint exists, but a GET to https://inrupt.net/userinfo just hangs, and never get either a success or an error response. This prevents proper functioning of some OIDC libraries, and requires to be worked around. Should this be fixed in the NSS repo, or rather at the oidc-op level ?

重現 https://inrupt.net/userinfo 上掛起的 GET 請求，並將其與 https://inrupt.net/.well-known/openid-configuration 中公布的端點進行比較。追蹤確認 UserInfo 行為是由 NSS 還是 oidc-op 負責；完成的條件是該端點返回成功回應或錯誤回應，讓 OIDC 程式庫能夠完成驗證。