first draft of ActivityPub webfinger

modules/fediverse.py

@@ -14,10 +14,17 @@ def _parse_username(s):
     if username.startswith("@"):
         username = username[1:]
     if username and instance:
+        return username, instance
+    return None, None
+def _format_username(username, instance):
     return "@%s@%s" % (username, instance)
+def _setting_parse(s):
+    username, instance = _parse_username(s)
+    if username and instance:
+        return _format_username(username, instance)
     return None
 
-@utils.export("set", utils.FunctionSetting(_parse_username, "fediverse",
+@utils.export("set", utils.FunctionSetting(_setting_parse, "fediverse",
     help="Set your fediverse account", example="@gargron@mastodon.social"))
 class Module(ModuleManager.BaseModule):
     _name = "Fedi"
@@ -41,8 +48,7 @@ class Module(ModuleManager.BaseModule):
         username = None
         instance = None
         if account:
-            account = account.lstrip("@")
-            username, _, instance = account.partition("@")
+            username, instance = _parse_username(account)
 
         if not username or not instance:
             raise utils.EventError("Please provide @<user>@<instance>")
@@ -129,3 +135,31 @@ class Module(ModuleManager.BaseModule):
 
             event["stdout"].write("%s: %s - %s" % (preferred_username,
                 content, shorturl))
+
+    @utils.hook("api.get.ap-webfinger")
+    @utils.kwarg("authenticated", False)
+    def webfinger(self, event):
+        our_username = self.bot.get_setting("fediverse", None)
+        our_username, our_instance = _parse_username(our_username)
+
+        resource = event["params"].get("resource", None)
+        if resource and resource.startswith("acct:"):
+            request = resource.split(":", 1)[1]
+            requested_username, requested_instance = _parse_username(request)
+
+            if (requested_username == our_username and
+                    requested_instance == our_instance):
+                event["response"].content_type = "application/jrd+json"
+
+                location = "https://%s" % event["url_for"]("api", "ap-user",
+                    {"u": our_username})
+
+                event["response"].write_json({
+                    "aliases": [location],
+                    "links": [{
+                        "href": location,
+                        "rel": "self",
+                        "type": ACTIVITY_TYPE
+                    }],
+                    "subject": resouce
+                })

modules/rest_api.py

@@ -75,6 +75,19 @@ class Handler(http.server.BaseHTTPRequestHandler):
     def _minify_setting(self):
         return _bot.get_setting("rest-api-minify", False)
 
+    def url_for(self, headers, route, endpoint, get_params={}):
+        hostname = headers.get("Host", None)
+        if not hostname:
+            return None
+        else:
+            get_params_str = ""
+            if get_params:
+                get_params = "?%s" % urllib.parse.urlencode(get_params)
+            return "%s/%s/%s%s" % (hostname, route, endpoint, get_params_str)
+    def _url_for(self, headers):
+        return lambda route, endpoint, get_params={}: self.url_for(
+            headers, route, endpoint, get_params)
+
     def _handle(self, method, path, endpoint, args):
         headers = utils.CaseInsensitiveDict(dict(self.headers.items()))
         params = self._url_params()
@@ -103,7 +116,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
                         event_response = _events.on("api").on(method).on(
                             endpoint).call_for_result_unsafe(params=params,
                             path=args, data=data, headers=headers,
-                            response=response)
+                            response=response, url_for=self._url_for(headers))
                     except Exception as e:
                         _log.error("failed to call API endpoint \"%s\"",
                             [path], exc_info=True)