Mess with tokens

.github/workflows/bad_code.yml

@@ -0,0 +1,20 @@
+name: Bad code
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby 3.1
+      uses: actions/setup-ruby@v1
+      with:
+        ruby-version: 3.1.x
+    - name: Check code
+      run: ./scripts/bad_code.sh

lib/map.rb

@@ -40,7 +40,7 @@ class Map
 
       @sha256_arr = @sha256
       @sha256 = @sha256.pack('C*')
-      @sha256_str = @sha256.map { |b| b.to_s(16) }.join
+      @sha256_str = @sha256.map { |b| b.to_s(16).rjust(2, '0') }.join
     end
   end
 end

lib/net_base.rb

@@ -14,7 +14,7 @@ class NetBase
     @port = nil
     @s = nil
     @ack = 0
-    @peer_token = [0xFF, 0xFF, 0xFF, 0xFF].map { |b| b.to_s(16) }.join
+    @peer_token = [0xFF, 0xFF, 0xFF, 0xFF].map { |b| b.to_s(16).rjust(2, '0') }.join
   end
 
   def bind(socket)

lib/teeworlds_client.rb

@@ -104,7 +104,7 @@ class TeeworldsClient
     @game_client = GameClient.new(self)
     # me trying to write cool code
     @client_token = (1..4).to_a.map { |_| rand(0..255) }
-    @client_token = @client_token.map { |b| b.to_s(16) }.join
+    @client_token = @client_token.map { |b| b.to_s(16).rjust(2, '0') }.join
     puts "client token #{@client_token}"
     @netbase = NetBase.new(verbose: @verbose)
     NetChunk.reset

lib/teeworlds_server.rb

@@ -34,7 +34,7 @@ class TeeworldsServer
 
   def run(ip, port)
     @server_token = (1..4).to_a.map { |_| rand(0..255) }
-    @server_token = @server_token.map { |b| b.to_s(16) }.join
+    @server_token = @server_token.map { |b| b.to_s(16).rjust(2, '0') }.join
     puts "server token #{@server_token}"
     @netbase = NetBase.new(verbose: @verbose)
     NetChunk.reset
@@ -107,8 +107,10 @@ class TeeworldsServer
   end
 
   def send_ctrl_with_token(addr, token)
-    msg = [NET_CTRLMSG_TOKEN] + token
+    msg = [NET_CTRLMSG_TOKEN] + str_bytes(@server_token)
+    @netbase.peer_token = token.pack('C*')
     @netbase.send_packet(msg, 0, control: true, addr:)
+    # @netbase.peer_token = @server_token
   end
 
   def send_map(addr)
@@ -154,7 +156,7 @@ class TeeworldsServer
   def on_ctrl_token(packet)
     u = Unpacker.new(packet.payload[1..])
     token = u.get_raw(4)
-    # puts "got token #{token.map { |b| b.to_s(16) }.join('')}"
+    # puts "got token #{token.map { |b| b.to_s(16).rjust(2, '0') }.join('')}"
     send_ctrl_with_token(packet.addr, token)
   end
 

scripts/bad_code.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+arg_fix=0
+
+if [ "$1" == "--fix" ]
+then
+	arg_fix=1
+fi
+
+if [ "$arg_fix" == "1" ]
+then
+	while read -r bad_file
+	do
+		echo "[*] fixing '$bad_file' ..."
+		for del in ';' '$' ' '
+		do
+			del_end="$del"
+			[[ "$del" == '$' ]] && del_end=''
+			sed "s/.to_s(16)$del/.to_s(16).rjust(2, '0')$del_end/g" "$bad_file" > "$bad_file".tmp
+		done
+		mv "$bad_file".tmp "$bad_file"
+	done < <(grep -nri "to_s(16)" --exclude=bad_code.sh |
+		grep -v "to_s(16).rjust(2, '0')" |
+		cut -d':' -f1)
+fi
+
+if grep -nri "to_s(16)" --exclude=bad_code.sh | grep -v "to_s(16).rjust(2, '0')"
+then
+	if [ "$arg_fix" == "1" ]
+	then
+		echo "[-] Error: could not fix those ^"
+		exit 1
+	fi
+	echo "[-] Error: found usage of 'to_s(16)' without 'rjust(2, '0')'"
+	echo "[-]        all hexadecimal string bytes have to be zero padded!"
+	echo "[-]"
+	echo "[-]        bad:  FAF"
+	echo "[-]        good: 0FAF"
+	echo "[-]"
+	echo "[-]	 run ./scripts/bad_code.sh --fix to fix"
+	echo "[-]"
+	exit 1
+fi