diff -r 6843c4551cde -r 06672690d71b rust/hedgewars-server/src/server/handlers/loggingin.rs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/hedgewars-server/src/server/handlers/loggingin.rs	Mon Dec 10 22:44:46 2018 +0100
@@ -0,0 +1,99 @@
+use mio;
+
+use crate::{
+    server::{
+        client::HWClient,
+        core::HWServer,
+        coretypes::ClientId,
+        actions::{Action, Action::*}
+    },
+    protocol::messages::{
+        HWProtocolMessage, HWServerMessage::*
+    },
+    utils::is_name_illegal
+};
+#[cfg(feature = "official-server")]
+use openssl::sha::sha1;
+use std::fmt::{Formatter, LowerHex};
+use log::*;
+
+#[derive(PartialEq)]
+struct Sha1Digest([u8; 20]);
+
+impl LowerHex for Sha1Digest {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
+        for byte in &self.0 {
+            write!(f, "{:02x}", byte)?;
+        }
+        Ok(())
+    }
+}
+
+#[cfg(feature = "official-server")]
+fn get_hash(client: &HWClient, salt1: &str, salt2: &str) -> Sha1Digest {
+    let s = format!("{}{}{}{}{}", salt1, salt2,
+                    client.web_password, client.protocol_number, "!hedgewars");
+    Sha1Digest(sha1(s.as_bytes()))
+}
+
+pub fn handle(server: & mut HWServer, client_id: ClientId, message: HWProtocolMessage) {
+    match message {
+        HWProtocolMessage::Nick(nick) => {
+            let client = &mut server.clients[client_id];
+            debug!("{} {}", nick, is_name_illegal(&nick));
+            let actions = if client.room_id != None {
+                unreachable!()
+            }
+            else if !client.nick.is_empty() {
+                vec![ProtocolError("Nickname already provided.".to_string())]
+            }
+            else if is_name_illegal(&nick) {
+                vec![ByeClient("Illegal nickname! Nicknames must be between 1-40 characters long, must not have a trailing or leading space and must not have any of these characters: $()*+?[]^{|}".to_string())]
+            }
+            else {
+                client.nick = nick.clone();
+                vec![Nick(nick).send_self().action(),
+                     CheckRegistered]
+            };
+
+            server.react(client_id, actions);
+        }
+        HWProtocolMessage::Proto(proto) => {
+            let client = &mut server.clients[client_id];
+            let actions = if client.protocol_number != 0 {
+                vec![ProtocolError("Protocol already known.".to_string())]
+            }
+            else if proto == 0 {
+                vec![ProtocolError("Bad number.".to_string())]
+            }
+            else {
+                client.protocol_number = proto;
+                vec![Proto(proto).send_self().action(),
+                     CheckRegistered]
+            };
+            server.react(client_id, actions);
+        }
+        #[cfg(feature = "official-server")]
+        HWProtocolMessage::Password(hash, salt) => {
+            let c = &server.clients[client_id];
+
+            let client_hash = get_hash(c, &salt, &c.server_salt);
+            let server_hash = get_hash(c, &c.server_salt, &salt);
+            let actions = if client_hash == server_hash {
+                vec![ServerAuth(format!("{:x}", server_hash)).send_self().action(),
+                     JoinLobby]
+            } else {
+                vec![ByeClient("Authentication failed".to_string())]
+            };
+            server.react(client_id, actions);
+        }
+        #[cfg(feature = "official-server")]
+        HWProtocolMessage::Checker(protocol, nick, password) => {
+            let c = &mut server.clients[client_id];
+            c.nick = nick;
+            c.web_password = password;
+            c.set_is_checker(true);
+        }
+        _ => warn!("Incorrect command in logging-in state"),
+    }
+}