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diff --git a/doc-src/tutorials/gamecenter.html b/doc-src/tutorials/gamecenter.html deleted file mode 100644 index af11b5bb..00000000 --- a/doc-src/tutorials/gamecenter.html +++ /dev/null @@ -1,119 +0,0 @@ - -## The setup - -In this tutorial, I'm going to show you how simple it is to creatively -interfere with Apple Game Center traffic using mitmproxy. To set things up, -install the [mitmproxy root certificate](@!urlTo("certinstall.html")!@). Then -start mitmproxy on your desktop, and confige the iPhone to use it as a proxy. - - -## Taking a look at the Game Center traffic - -Lets take a first look at the Game Center traffic. The game I'll use in this -tutorial is [Super Mega -Worm](http://itunes.apple.com/us/app/super-mega-worm/id388541990?mt=8) - a -great little retro-apocalyptic sidescroller for the iPhone: - -<center> - <img class="img-responsive" src="@!urlTo('tutorials/supermega.png')!@"/> -</center> - -After finishing a game (take your time), watch the traffic flowing through -mitmproxy: - -<center> - <img class="img-responsive" src="@!urlTo('tutorials/one.png')!@"/> -</center> - -We see a bunch of things we might expect - initialisation, the retrieval of -leaderboards and so forth. Then, right at the end, there's a POST to this -tantalising URL: - -<pre> -https://service.gc.apple.com/WebObjects/GKGameStatsService.woa/wa/submitScore -</pre> - -The contents of the submission are particularly interesting: - -<!--(block|syntax("xml"))--> -<plist version="1.0"> - <dict> - <key>scores</key> - <array> - <dict> - <key>category</key> - <string>SMW_Adv_USA1</string> - <key>context</key> - <integer>0</integer> - <key>score-value</key> - <integer>0</integer> - <key>timestamp</key> - <integer>1363515361321</integer> - </dict> - </array> - </dict> -</plist> -<!--(end)--> - -This is a [property list](http://en.wikipedia.org/wiki/Property_list), -containing an identifier for the game, a score (55, in this case), and a -timestamp. Looks pretty simple to mess with. - - -## Modifying and replaying the score submission - -Lets edit the score submission. First, select it in mitmproxy, then press -__enter__ to view it. Make sure you're viewing the request, not the response - -you can use __tab__ to flick between the two. Now press __e__ for edit. You'll -be prompted for the part of the request you want to change - press __r__ for -raw body. Your preferred editor (taken from the EDITOR environment variable) will -now fire up. Lets bump the score up to something a bit more ambitious: - -<!--(block|syntax("xml"))--> -<plist version="1.0"> - <dict> - <key>scores</key> - <array> - <dict> - <key>category</key> - <string>SMW_Adv_USA1</string> - <key>context</key> - <integer>0</integer> - <key>score-value</key> - <integer>2200272667</integer> - <key>timestamp</key> - <integer>1363515361321</integer> - </dict> - </array> - </dict> -</plist> -<!--(end)--> - -Save the file and exit your editor. - -The final step is to replay this modified request. Simply press __r__ for -replay. - -## The glorious result and some intrigue - -<center> - <img class="img-responsive" src="@!urlTo('tutorials/leaderboard.png')!@"/> -</center> - -And that's it - according to the records, I am the greatest Super Mega Worm -player of all time. - -There's a curious addendum to this tale. When I first wrote this tutorial, all -the top competitors' scores were the same: 2,147,483,647 (this is no longer the -case, beacause there are now so many fellow cheaters using this tutorial). If -you think that number seems familiar, you're right: it's 2^31-1, the maximum -value you can fit into a signed 32-bit int. Now let me tell you another -peculiar thing about Super Mega Worm - at the end of every game, it submits -your highest previous score to the Game Center, not your current score. This -means that it stores your highscore somewhere, and I'm guessing that it reads -that stored score back into a signed integer. So, if you _were_ to cheat by the -relatively pedestrian means of modifying the saved score on your jailbroken -phone, then 2^31-1 might well be the maximum score you could get. Then again, -if the game itself stores its score in a signed 32-bit int, you could get the -same score through perfect play, effectively beating the game. So, which is it -in this case? I'll leave that for you to decide. |