[ADD] Add basic privilege checking for RouteRoomAliases

For now, this checking is incomplete, and it probably will stay
that way until rooms are properly implemented.

docs/user/admin/privileges.md

@@ -16,10 +16,10 @@ registration tokens.
 configuration.
 - **GRANT_PRIVILEGES:** Allows a user to modify his or her own
 privileges or the privileges of other local users.
-- **ALIAS:** Allows a user to modify room aliases created by other
-users. By default, users can only manage their own room aliases, but
-an administrator may wish to take over an alias or remove an offensive
-alias.
+- **ALIAS:** Allows a user to modify and see room aliases created by 
+other users. By default, users can only manage their own room aliases, 
+but an administrator may wish to take over an alias or remove an 
+offensive alias.
 - **PROC_CONTROL:** Allows a user to get statistics on the running
 process, as well as shutdown and resetart the Telodendria daemon
 itself. Typically this will pair well with **CONFIG**, because there

src/Routes/RouteRoomAliases.c

@@ -50,14 +50,29 @@ ROUTE_IMPL(RouteRoomAliases, path, argp)
 
     User *user = NULL;
 
-    /* TODO: Also check permissions. */
     response = MatrixGetAccessToken(args->context, &token);
     if (response)
     {
         goto finish;
     }
     user = UserAuthenticate(db, token);
-    /* TODO: Check if user is authorised. */
+    if (!user)
+    {
+        HttpResponseStatus(args->context, HTTP_UNAUTHORIZED);
+        response = MatrixErrorCreate(M_UNKNOWN_TOKEN, NULL);
+        goto finish;
+    }
+
+    /* TODO: Check whenever the user is in the room or if its world readable 
+     * once this is implemented instead of just checking for the ALIAS 
+     * privilege. */
+    if (!(UserGetPrivileges(user) & USER_ALIAS))
+    {
+        msg = "User is not allowed to get this room's aliases.";
+        HttpResponseStatus(args->context, HTTP_FORBIDDEN);
+        response = MatrixErrorCreate(M_FORBIDDEN, msg);
+        goto finish;
+    }
 
     ref = DbLock(db, 1, "aliases");
     aliases = DbJson(ref);