poor man's fingering

website/routes/routes_openid.py

@@ -1,3 +1,6 @@
+import re
+from urllib.parse import urlparse
+
 from flask import jsonify, request
 from ..routes import bp
 from ..oauth2 import require_oauth
@@ -37,3 +40,19 @@ def oidc_configuration():
         "subject_types_supported": ["pairwise"],
         "id_token_signing_alg_values_supported": ["RS256", "none"],
     })
+
+
+@bp.route("/.well-known/webfinger")
+def webfinger():
+    ne = urlparse(ISSUER_URL).netloc
+    acct = re.search(r'([a-z]+)@{}'.format(ne), request.args['resource'])
+    return jsonify({
+        "subject": f"acct:{acct}",
+        "links":
+        [
+            {
+                "rel": "http://openid.net/specs/connect/1.0/issuer",
+                "href": ISSUER_URL
+            }
+        ]
+    })