Gamespy in Republic Commando

Gamespy protocol analysis in Star Wars Republic Commando

Note: This documentation may be incomplete and some information/aspects may be interpreted/understood wrong!

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    Gamespy Gamename: swrcommando
    Gamespy Gamekey: y2s8Fh
    Gamespy Version: 0~3 (Hybrid) Plaintext and partial encrypted communication

The communication between Master Server and Game Server is completly in plaintext, however communication between Master Server and Game Client is partially encrypted.

Master Server <-> Game Server

The communication between Master Server and Game Server is in plaintext and only uses UDP protocol. Master Server listens on port 27900:

When a Game Server boots up for first time, it sends out 2 UDP packets to let Master Server know a new remote host is coming up. Master Server doesn't have to respond:

0x09     <packet ID>
0x00     <no use>
0x00     <no use>
0x00     <no use>
0x00     <no use>
0x73     s    <gamespy gamename>
0x77     w
0x72     r
0x63     c
0x6f     o
0x6d     m
0x6d     m
0x61     a
0x6e     n
0x64     d
0x6f     o
0x00     <null terminator>

Once Game Server is booted up and ready to accept connections, it sends all relevant game info to Master Server, essentially a \\status\\ packet every 30 seconds or so:

0x03    <packet ID>
0xd6    -- <Next 4 bytes are random ID generated by game server>
0x0c    --
0x82    --
0xe0    --
0x6c    l    <localip0>
0x6f    o
0x63    c
0x61    a
0x6c    l
0x69    i
0x70    p
0x30    0
0x00    <null seperator>
0x31    1    <First local IP>
0x39    9
0x32    2
0x2e    .
0x31    1
0x36    6
0x38    8
0x2e    .
0x31    1
0x38    8
0x38    8
0x2e    .
0x33    3
0x00    <null seperator>
0x6c    l    <localip1>
0x6f    o
0x63    c
0x61    a
0x6c    l
0x69    i
0x70    p
0x31    1
0x00    <null seperator>
0x31    1    <Second local IP>
0x39    9
0x32    2
0x2e    .
0x31    1
0x36    6
0x38    8
0x2e    .
0x32    2
0x30    0
0x33    3
0x2e    .
0x31    1
0x00    <null seperator>
0x6c    l    <localip2>
0x6f    o
0x63    c
0x61    a
0x6c    l
0x69    i
0x70    p
0x32    2
0x00    <null seperator>
0x31    1    <Third local IP>
0x39    9
0x32    2
0x2e    .
0x31    1
0x36    6
0x38    8
0x2e    .
0x31    1
0x37    7
0x34    4
0x2e    .
0x31    1
0x00    <null seperator>
0x6c    l    <localport>
0x6f    o
0x63    c
0x61    a
0x6c    l
0x70    p
0x6f    o
0x72    r
0x74    t
0x00    <null seperator>
0x31    1    <query port of the game server, default 11138, every server instance increases number by 1 up to 11187 (x49)>
0x31    1
0x31    1
0x33    3
0x38    8
0x00    <null seperator>
0x6e    n    <NAT Negotiation>
0x61    a
0x74    t
0x6e    n
0x65    e
0x67    g
0x00    <null seperator>
0x30    0    <0 = disabled>
0x00    <null seperator>
0x73    s    <statechanged indicates when game server performs mapchange or shuts down, etc>
0x74    t
0x61    a
0x74    t
0x65    e
0x63    c
0x68    h
0x61    a
0x6e    n
0x67    g
0x65    e
0x64    d
0x00    <null seperator>
0x33    3    <3 = ready to accept connections>
0x00    <null seperator>
0x67    g    <gamespy gamename>
0x61    a
0x6d    m
0x65    e
0x6e    n
0x61    a
0x6d    m
0x65    e
0x00    <null seperator>
0x73    s    <swrcommando>
0x77    r
0x72    r
0x63    c
0x6f    o
0x6d    m
0x6d    m
0x61    a
0x6e    n
0x64    d
0x6f    o
0x00    <null seperator>
0x68    h    <server name displayed in browser>
0x6f    o
0x73    s
0x74    t
0x6e    n
0x61    a
0x6d    m
0x65    e
0x00    <null seperator>
0x74    t    <server name: test test>
0x65    e
0x73    s
0x74    t
0x20    (space)
0x74    t
0x65    e
0x73    s
0x74    t
0x00    <null seperator>
0x67    g    <game version, republic commando only uses 2226>
0x61    a
0x6d    m
0x65    e
0x76    v
0x65    e
0x72    r
0x00    <null seperator>
0x32    2
0x32    2
0x32    2
0x36    6
0x00    <null seperator>
0x68    h    <hostport (connect port) of the game server, default: 7777>
0x6f    o
0x73    s
0x74    t
0x70    p
0x6f    o
0x72    r
0x74    t
0x00    <null seperator>
0x37    7    <default: 7777>
0x37    7
0x37    7
0x37    7
0x00    <null seperator>
0x6d    m    <mapname of server>
0x61    a
0x70    p
0x6e    n
0x61    a
0x6d    m
0x65    e
0x00    <null seperator>
0x4b    K    <english name: canyon>
0x41    A
0x4d    M
0x50    P
0x46    F
0x53    S
0x43    C
0x48    H
0x49    I
0x46    F
0x46    F
0x00    <null seperator>
0x67    g    <gametype of server>
0x61    a
0x6d    m
0x65    e
0x74    t
0x79    y
0x70    p
0x65    e
0x00    <null seperator>
0x44    D    <DM - deathmatch>
0x4d    M
0x00    <null seperator>
0x6e    n    <amount of players on the server currently>
0x75    u
0x6d    m
0x70    p
0x6c    l
0x61    a
0x79    y
0x65    e
0x72    r
0x73    s
0x00    <null seperator>
0x30    0    <player ammount>
0x00    <null seperator>
0x6d    m    <max players capacity>
0x61    a
0x78    x
0x70    p
0x6c    l
0x61    a
0x79    y
0x65    e
0x72    r
0x73    s
0x00    <null seperator>
0x38    8    <set to 8 maxplayers>
0x00    <null seperator>
0x67    g    <state of current gamemode>
0x61    a
0x6d    m
0x65    e
0x6d    m
0x6f    o
0x64    d
0x65    e
0x00    <null seperator>
0x6f    o    <set to openplaying, unknown if game actually uses this>
0x70    p
0x65    e
0x6e    n
0x70    p
0x6c    l
0x61    a
0x79    y
0x69    i
0x6e    n
0x67    g
0x00    <null seperator>
0x6e    n    <number of teams>
0x75    u
0x6d    m
0x74    t
0x65    e
0x61    a
0x6d    m
0x73    s
0x00    <null seperator>
0x30    0    <set to 0 for deathmatch, may be set to 2 for teamdeathmatch/ctf/assault>
0x00    <null seperator>
0x66    f    <goalscore>
0x72    r
0x61    a
0x67    g
0x6c    l
0x69    i
0x6d    m
0x69    i
0x74    t
0x00    <null seperator>
0x31    1    <set to 10>
0x30    0
0x00    <null seperator>
0x74    t    <timelimit in minutes>
0x69    i
0x6d    m
0x65    e
0x6c    l
0x69    i
0x6d    m
0x69    i
0x74    t
0x00    <null seperator>
0x36    6    <60 minutes>
0x30    0
0x00    <null seperator>
0x64    d    <set whether server is in dedicated mode or not>
0x65    e
0x64    d
0x69    i
0x63    c
0x61    a
0x74    t
0x65    e
0x64    d
0x73    s
0x65    e
0x72    r
0x76    v
0x65    e
0x72    r
0x00    <null seperator>
0x31    1    <0 = off | 1 = on>
0x00    <null seperator>
0x66    f    <friendlyfire %>
0x72    r
0x69    i
0x65    e
0x6e    n
0x64    d
0x6c    l
0x79    y
0x66    f
0x69    i
0x72    r
0x65    e
0x00    <null seperator>
0x30    0    <value between 0 and 100>
0x00    <null seperator>
0x00    <null seperator>
0x00    <null seperator>
0x00    <null seperator>
0x70    p    <player_ : array for player names/ids>
0x6c    l
0x61    a
0x79    y
0x65    e
0x72    r
0x5f    _
0x00    <null seperator>
0x73    s    <score_ : array for player scores>
0x63    c
0x6f    o
0x72    r
0x65    e
0x5f    _
0x00    <null seperator>
0x64    d    <deaths_ : array for player deaths>
0x65    e
0x61    a
0x74    t
0x68    h
0x73    s
0x5f    _
0x00    <null seperator>
0x70    p    <ping_ : array for player pings>
0x69    i
0x6e    n
0x67    g
0x5f    _
0x00    <null seperator>
0x74    t    <team_ : array for player pings>
0x65    e
0x61    a
0x6d    m
0x5f    _
0x00    <null seperator>
0x00    <null seperator>
0x00    <null seperator>
0x00    <null seperator>
0x74    t    <team_t : array for player team (trandoshan team), unknown if it gets used>
0x65    e
0x61    a
0x6d    m
0x5f    _
0x74    t
0x00    <null seperator>
0x73    s    <score_t : array for player score (trandoshan team), unknown if it gets used>
0x63    c
0x6f    o
0x72    r
0x65    e
0x5f    _
0x74    t
0x00    <null seperator>
0x00    <end of packet indicator>