From bdea06d4d42ce37ebe19d947f88a87c015aa5042 Mon Sep 17 00:00:00 2001
From: Bob Mottram <bob@freedombone.net>
Date: Mon, 24 May 2021 12:38:12 +0100
Subject: [PATCH] Remove imposters during identify

---
 README.md |  6 ++++++
 miniircd  | 29 +++++++++++++++++++++++------
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 91f6544..dc52498 100644
--- a/README.md
+++ b/README.md
@@ -133,6 +133,10 @@ To identify yourself connect with your previous nick, then:
 	
 The first account to be registered gets oper status. Note that this applies for all channels.
 
+If there is an imposter occupying your usual nickname then you can identify yourself with your full credentials, and the imposter will be removed.
+
+    /identify [nickname] [password]
+
 A passwords file in the state directory contains password hashes. The word "oper" is appended to any accounts with oper status.
 
 To subsequently change password:
@@ -176,6 +180,8 @@ To set the allowed number of new registrations:
 
     /newreg [number]
 
+So if you encounter a spam flood then you can allow only registered users on channels and set the new registrations temporarily to zero.
+
 
 License
 -------
diff --git a/miniircd b/miniircd
index 0e76bd3..4bf4a72 100755
--- a/miniircd
+++ b/miniircd
@@ -511,16 +511,15 @@ class Client:
         self.server.new_registrations -= 1
         return True
 
-    def __msg_nickserv_identify(self, password: str) -> bool:
-        identify_nick = self.nickname.decode('utf-8')
-        salt = self.__get_salt(identify_nick)
+    def __msg_nickserv_identify(self, nickname: str, password: str) -> bool:
+        salt = self.__get_salt(nickname)
         if not salt:
             self.reply(b"406 %s :Not registered" % self.nickname)
             self.is_operator = False
             self.is_registered = False
             return False
         hashed_password = self.__hash_password(salt, password)
-        retval = self.__identify(identify_nick, salt, hashed_password)
+        retval = self.__identify(nickname, salt, hashed_password)
         if retval > 0:
             self.is_registered = True
         if retval > 1:
@@ -530,6 +529,8 @@ class Client:
             self.is_registered = False
             self.reply(b"401 %s :No such nick" % self.nickname)
             return False
+        else:
+            self.server.remove_imposters(self.nickname, nickname)
         return True
 
     def __command_handler(
@@ -979,8 +980,13 @@ class Client:
                 self.is_operator = False
                 self.is_registered = False
                 return
-            password = arguments[0].decode('utf-8')
-            if self.__msg_nickserv_identify(password):
+            if len(arguments) == 2:
+                nickname = arguments[0].decode('utf-8')
+                password = arguments[1].decode('utf-8')
+            else:
+                nickname = self.nickname.decode('utf-8')
+                password = arguments[-1].decode('utf-8')
+            if self.__msg_nickserv_identify(nickname, password):
                 self.message((f"Identify success").encode())
             else:
                 self.message((f"Identify failed").encode())
@@ -1451,6 +1457,17 @@ class Server:
             except BaseException:
                 pass
 
+    def remove_imposters(curr_nickname: str, true_nickname: str) -> None:
+        if curr_nickname == true_nickname:
+            return
+        imposter = self.get_client(true_nickname)
+        if imposter:
+            genuine = self.get_client(curr_nickname)
+            if genuine:
+                self.remove_client(imposter, b'imposter')
+                genuine.nickname = true_nickname
+                self.client_changed_nickname(genuine, curr_nickname)
+
     def update_bouncer(self, line: bytes) -> None:
         self.bouncer.append(line)
         while len(self.bouncer) >= self.bouncer_size: