Each time you sync an iOS based device, a backup is made (unless you disable the option). These are stored in ~/Library/Application Support/MobileSync/Backup. Here you will find a number of folders, each beginning with the UDID of the iPhone, iPad or iPod Touch that has been backed up. The contents of these folders can be used to restore a device in the event that the device falls outside your control. Within the folders are a bunch of files with alphanumeric names that look garbled, even though some can be viewed using a standard text or property list editor (while others are binary). But there are also a bunch of other files in here. These can be parsed using a script, such as this one (which parses the database files), or you can use a GUI tool to put Humpty Dumpty back together again, such as iPhone Backup Extractor.
When you open iPhone Backup Extractor, click on the Read Backups button and you will be shown a list that should correspond (albeit using prettier names) to the entries in the Backup directory. Select the one that you would like to extract and then click on Choose. From here, click on iOS Files and then click on Extract. You will then be asked where to extract the file to. Choose a location.
Once extracted you can find out a lot of information about the apps you use and how they interact with your data. Most useful applications are going to cache your data (that’s what makes most of them useful) so don’t be surprised to see data such as conversations, contacts and even passwords in raw text or sqlite databases that you might not have thought so easily accessed (even without your phone). Keep in mind, the iTunes backup is considered secure to your iOS based device and if a user profile shouldn’t be considered secure then there is an Encrypt iPhone backup option available in iTunes that makes this whole process a moot point…
Anyway, back to finding that pincode… Next, browse into the extracted iOS Files and then into the Library/Preferences directory. Here you will find a file called com.apple.springboard.plist with a SBParentalControlsPin key. I extracted my files on my test device to my desktop, so I can see this with a quick defaults command:
defaults read /Users/seldon/Desktop/iOS Files/Library/Preferences/com.apple.springboard SBParentalControlsPIN
If a iPhone backup has been encrypted then it can be decrypted only if you know the correct password to decrypt. Once you have the passcode, you can safely manage the device again. There are also a lot of other things that you can enjoy playing around with if you’re interested to see what kind of data is stored where, either in the operating system or for each application (eg – com.apple.mobilephone.speeddial.plist is why I can never seem to remember my wifes phone number).
While much of the data for an iOS based device is stored in property lists, some is also stored in a sqlite database (typically in .sqlitedb files). You can interact with these via the sqlite3 command, built into Mac OS X or using a tool such as http://sourceforge.net/projects/sqlitebrowser if you’re not into SELECT commands in sqlite3. Overall, there is a lot of information that can be learned playing around with this stuff. If you haven’t given it a shot yet, I’d recommend it. However, again, don’t be alarmed about any of the security impacts of this stuff, just encrypt the backups and it’s not an issue.