More information

index.html

@@ -16,6 +16,7 @@
             <td><a href=".">Contents</a></td>
             <td><a href="./transport.html">Transport layer</a></td>
             <td><a href="./packet.html">Packet format</a></td>
+            <td><a href="./protocol.html">Application Protocol</a></td>
         </tr>
     </table>
 
@@ -36,7 +37,7 @@
     <p>If you're here because you work on one of those aforementioned closed source projects, hello! Feel free to share
         knowledge with the rest of the world, or point out corrections. Or don't; you do you.</p>
 
-    <h1>Contents</h1>
+    <h2>Contents</h2>
     <ol>
         <li><a href="./transport.html">Transport layer</a></li>
         <ol>
@@ -52,7 +53,29 @@
         </ol>
     </ol>
 
-    <p><small>This site intentionally looks not-great. I don't feel like changing that, and honestly quite like the aesthetic.</small></p>
+    <h2>Getting started</h2>
+    <p>My aim with these pages is to cover as much as possible, so you don't need to try and figure them out yourself.
+        That said, being able to follow along yourself will almost certainly help get more out of this. For following
+        along with source code, you're really going to want to grab yourself a dumped copy of a game (it's going to be a
+        lot easier, and cheeper, than dumping one yourself). I trust you can figure out where to find that.</p>
+    <p>For network related things, your options are a little broader. The ideal would be physical ownership of a
+        cabinet, and a subscription to genuine e-amusement. Odds are you don't have both of those :P. A connection to an
+        alternative network works just as well. In the more likely case that you don't have a physical cabinet, it's
+        time to crack out that dumped copy of a game and just run it on your own PC (or a VM, if you're not on Windows)
+        (odds are whatever you downloaded came with the program you'll need to start it pre-packaged. If not, it rhymes
+        with rice.).</p>
+    <p>You will also need a local e-amusement-emulating server. By the time I'm done with these pages, there will
+        hopefully be everything you need to be able to write your own. Unfortunately I'm not finished writing them;
+        depending on where you acquired your game, it may have shipped with one of said servers. If it didn't, Asphyxia
+        CORE will do the trick (yes, it's closed source).</p>
+    <p>If this all sounds like way too much work, and/or you're just here because of curiosity, I plan to prepare some
+        pcaps of network traffic to play around with without needing a running copy of a game or a network tap on a cab.
+    </p>
+
+    <a href="./transport.html">Next page</a>
+
+    <p><small>This site intentionally looks not-great. I don't feel like changing that, and honestly quite like the
+            aesthetic.</small></p>
 </body>
 
 </html>

packet.html

@@ -17,6 +17,7 @@
             <td><a href=".">Contents</a></td>
             <td><a href="./transport.html">Transport layer</a></td>
             <td><a href="./packet.html">Packet format</a></td>
+            <td><a href="./protocol.html">Application Protocol</a></td>
         </tr>
     </table>
 
@@ -888,6 +889,8 @@
             self.request_allocation(4)</code></pre></p>
     </details>
 
+    <a href="./transport.html">Prev page</a> | <a href="./protocol.html">Next page</a>
+
 </body>
 
 </html>

styles.css

@@ -1,9 +1,10 @@
 body {
     /* font-family: sans-serif; */
     line-height: 1.25;
-    max-width: 720px;
+    max-width: 1000px;
     margin: 16px auto;
     color: #222;
+    padding: 0 16px;
 }
 
 table {
@@ -37,7 +38,6 @@ p {
 }
 
 code {
-    display: inline-block;
     letter-spacing: .02em;
     padding: 2px 4px;
     font-size: 90%;
@@ -46,7 +46,11 @@ code {
     border-radius: 4px;
     word-break: break-word;
 }
+code > a {
+    color: inherit;
+}
 pre > code {
+    display: block;
     word-break: normal;
     border-radius: 4px;
     background: #f8f8f8;
@@ -55,10 +59,12 @@ pre > code {
     color: #333;
     padding: 9.5px;
     line-height: 1.4;
+    width: min-content;
+}
+pre {
     max-width: 100%;
     overflow-x: auto;
     display: block;
-    width: min-content;
 }
 
 summary {

transport.html

@@ -14,6 +14,7 @@
             <td><a href=".">Contents</a></td>
             <td><a href="./transport.html">Transport layer</a></td>
             <td><a href="./packet.html">Packet format</a></td>
+            <td><a href="./protocol.html">Application Protocol</a></td>
         </tr>
     </table>
 
@@ -25,13 +26,21 @@
         <li><code>none</code></li>
         <li><code>lz77</code></li>
     </ul>
+    <details>
+        <summary>Source code details</summary>
+        <figure>
+            <img src="./images/lz77.png">
+            <figcaption><code>libavs-win32-ea3.dll:0x1000fa29</code></figcaption>
+        </figure>
+    </details>
     <p>Encryption is performed <b>after</b> compression, and uses RC4. RC4 is symmetric, so decryption is performed the same as encryption. That is, <code>packet = encrypt(compress(data))</code> and <code>data = decompress(decrypt(data))</code>.</p>
 
     <h2 id="keys">Encryption keys</h2>
     <p>Encryption is not performed using a single static key. Instead, each request and response has its own key that is generated.</p>
     <p>These keys are generated baesd on the <code>X-Eamuse-Info</code> header.</p>
     <p>This header loosely follows the format <code>1-[0-9a-f]{8}-[0-9a-f]{4}</code>. This corresponds to <code>[version]-[serial]-[salt]</code>. <b>TODO: Confirm this</b></p>
-    <p>Our per-packet key is then generated using <code>md5(serial | salt | KEY)</code>. Identifying <code>KEY</code> is left as an exercise for the reader, however should not be especially challenging.</p>
+    <p>Our per-packet key is then generated using <code>md5(serial | salt | KEY)</code>. Identifying <code>KEY</code> is left as an exercise for the reader, however should not be especially challenging. <span style="color: #fff">Check the page source if you're stuck.</span></p>
+    <!-- It's 69d74627d985ee2187161570d08d93b12455035b6df0d8205df5, if you were wondering. libavs-win32-ea3.dll:0x10054160 -->
 
     <h2 id="lz77">LZ77</h2>
     <p>Packets are compressed using lzss. The compressed data structure is a repeating cycle of an 8 bit flags byte, followed by 8 values. Each value is either a single literal byte, if the corresponding bit in the preceeding flag is high, or is a two byte lookup into the window.</p>
@@ -39,5 +48,7 @@
 
     <p>The exact algorithm used for compression is not especially important, as long as it follows this format. One can feasibly perform no compression at all, and instead insert <code>0xFF</code> every 8 bytes (starting at index 0), to indicate that all values are literals. While obviously poor for compression, this is an easy way to test without first implementing a compressor.</p>
 
+    <a href="./index.html">Prev page</a> | <a href="./packet.html">Next page</a>
+
 </body>
 </html>