Have you ever wondered how Apple can put out statistics such as “The average iPhone is unlocked 80 times a day”? How the heck do they know?
Now I do not know for sure that they use this database, however I'd consider putting some cash down on this bet. The Aggregate Dictionary database aggregates (hence the name) certain features of the iOS operation system.
This database is located on the physical device in the path below, and it is not backed up in iTunes/iCloud backups.
- /private/var/mobile/Library/AggregateDictionary/ADDataStore.sqlitedb
It is worth mentioning here, the ‘dbbuffer’ plaintext file) in this same directory – is exactly what the filename suggests, a buffer for the database. Worth looking at for entries not yet written into the main database.
The ADDataStore.sqlitedb aggregates data on a 7-day per-day basis (first day in, first day out). You will generally see the last weeks worth of data. The day is stored in the column ‘daysSince1970’ which can be converted to human-readable time by using the SQL date function as shown below. It is worth noting this data is being stored in UTC.
I’ve known about this database for a while but have not had the chance to really dig into it. Recently, a reader emailed me about a case they were working on and wanted to know if the passcode was turned on or off on a specific day. Luckily this investigator had a physical acquisition to analyze and the specific day was in the last week of when the acquisition was created. The physical acquisition has many more of these logging databases are available for analysis too! - Want to see more about these awesome databases, check out my iOS of Sauron presentation.
The ADDataStore.sqlite database stores all sorts of seemingly odd settings in the ‘key’ column of the ‘Scalers’ table. The key that I was interested for this readers inquiry was the ‘com.apple.passcode.PasscodeType’ key which stores the passcode type. The ‘value’ column stores a numerical representation of the passcode type last used during each day (UTC time). If the user changes their passcode type throughout the day, it will store the last one configured.
I have enumerated the following passcode types. The example device show above used the 6-Digit passcode, then recently switched to a Custom Numeric passcode.
- -1 = 6-Digit
- 0 = No Passcode
- 1 = 4-Digit
- 2 = Custom Alphanumeric
- 3 = Custom Numeric
We can take a look at how many times the device was unlocked successfully or unsuccessfully by using the keys ‘com.apple.passcode.NumPasscodeEntered’ and ‘com.apple.passcode.NumPasscodeFailed’, respectively. The user was mostly successful inputting their passcode, but put the wrong passcode in once (highlighted in pink).
Hrm. Those values look small – the user is probably using TouchID instead of manually entering their passcode. TouchID allows users to enroll up to five fingers to unlock their devices. Note: They still need a passcode to do this, but it allows the user to have a more complex passcode because they can use their enrolled fingerprints to unlock the device for convenience and general usability
Looking at the ‘com.apple.fingerprintMain.templateCount’ key we can determine how many finger “templates” have been enrolled. The example tells us that four fingerprints were enrolled.
By default the enrolled fingers are named ‘Finger 1’, ‘Finger 2’, and so on as shown below. (Nerd Note: When you are in this screen as a user of the device you can check if a finger is enrolled because it will be highlighted in gray as shown - well, I thought it was neat.).
*** WARNING - RESEARCH BELOW IS ONGOING - READ AT YOUR OWN RISK ***
...just kidding...its actually kinda interesting.
I did want to show the complexity of this database therefore I decided to post this as some readers might find it interesting, however don't take my word on this - I can be wrong. In encourage everyone to do their own testing!
This is where it becomes less clear and more research will need to be done. In the Scaler table at any given moment there are many entries that contain the keyword “fingerprint” for all sorts data. I've listed some of the more interesting keys below.
- com.apple.fingerprintMain.enabled – Binary value – 1 = Enabled, 0 = Not enabled
- com.apple.fingerprint.countimagesForProcessing – This appears to be the number of times that TouchID was used (whether or not it was used to unlock the device).
- com.apple.fingerprint.match.autonomousAttempts & com.apple.fingerprint.match.attempts - Match attempts (Not entirely sure the difference as of yet – I think one may be for unlocks (autonomous) and others for other TouchID functions.)
- com.apple.fingerprint.unlock.touchesTouchIDNotAllowed – How many times a TouchID was attempted but not allowed for some reason, perhaps fingers were the wrong ones or greasy from a hamburger! (c’mon, we’ve all been there)
- com.apple.fingerprint.unlock.bioLockouts – I found this key to be incremented when I attempted to unlock the device with the wrong finger too many times.
- com.apple.fingerprint.unlock.passcodeUnlocksNonMandatory – The user put in the passcode, however they were not required to do so.
Enrolling Fingerprints
- com.apple.fingerprint.enroll.attempts – Fingerprints “enrolled”
- com.apple.fingerprint.enroll.popup.tooLittleMoves – Apparently I didn’t move my finger enough when enrolling.
TouchID Passes – Various keys that I’ve seen that show the specifics of how a TouchID match was passed. Many of these are hard to test to explain.
- com.apple.fingerprint.match.autonomousPassesAfterHomeButton – Incremented when a match was made after the home button was pressed.
- com.apple.fingerprint.match.autonomousPassesAfterPowerButton – Incremented after boot when TouchID was used (after passcode of course).
- com.apple.fingerprint.match.autonomousPassesButtonDown – Incremented after the home button was pressed or “pressed” if you have an solid state button.
- com.apple.fingerprint.match.autonomousPassesButtonLifting
- com.apple.fingerprint.match.autonomousPassesButtonUp
- com.apple.fingerprint.match.autonomousPassesButtonUpWithPressureMitigation
- com.apple.fingerprint.match.autonomousPassesHumid – I assume this one has to do if you are a live body or not.
- com.apple.fingerprint.match.passesButtonDown
- com.apple.fingerprint.match.passesButtonUp
TouchID Fails – On the flip side, if a fingerprint fails – we have many keys with many reasons, many with the same characteristics as above but failed.
- com.apple.fingerprint.match.autonomousFailsBadImageBadBlocks
- com.apple.fingerprint.match.autonomousFailsCancels
- com.apple.fingerprint.match.autonomousFailsFingerOffAfterHomeButton
- com.apple.fingerprint.match.autonomousFailsNoMatchAfterHomeButton
- com.apple.fingerprint.match.autonomousFailsNoMatchAfterPowerButton
- com.apple.fingerprint.match.autonomousFailsNoMatchButtonDown
- com.apple.fingerprint.match.autonomousFailsNoMatchButtonLifting
- com.apple.fingerprint.match.autonomousFailsNoMatchButtonUp
- com.apple.fingerprint.match.autonomousFailsNoMatchButtonUpWithPressureMitigation
- com.apple.fingerprint.match.autonomousFailsNoMatchHumid – I guess I might have been a bit under the weather? ;)
- com.apple.fingerprint.match.failsNoMatchButtonUp
- com.apple.fingerprint.match.failsNoMatchHumid
Getting specific, TouchID unlocks appear to be recorded in the ‘com.apple.fingerprintMain.unlock.unlocksByFinger*’ keys.
As far as as I can tell the keys containing “unlocksByFinger” (colored below in yellow) contain the actual number of unlocks, however in the example below the total unlocks were 11, not 22. I am not sure why there are two entries – I’m sure they record different items, however I cannot find documentation to sort out each one. I would rely on the ‘com.apple.fingerprintMain.unlock.unlocksByFinger#Fail’ entries. (As an aside, it’s worth noting that if you get ‘Finger2’ entries, they have an ‘s’ appended ie: com.apple.fingerprintMain.unlock.unlocksByFinger2Fails, maybe a strange type in the code?)
The ‘fail’ in the key would seem to suggest it records “failed” attempts however my testing shows these are in the green highlighted ‘unlocksCanceled’ entries instead.
What’s the ‘QT’ stand for? I have no idea. I tried looking through Apple documentation to find out, but I’ve got nothin’. Suggestions are welcome!
You might think, “Hey, I see Finger 0, Finger 1 in there – that must be the unlocks for each enrolled fingerprint right?”. That’s what I thought, however that was not the case in my testing. In my tests no matter which finger I unlocked the phone with it would be added to the ‘Finger0’ count.
Another key that looks interesting and related are the ‘com.apple.fingerprint.sortedTemplateMatchCount#’ keys. I would have thought these would be equal to the number of times the fingerprint template was used, however it appears that is not the case. I can try two different fingers (each enrolled) and sometimes they show up under the expected number (ie: finger 1 = com.apple.fingerprint.sortedTemplateMatchCount1) and sometimes it won’t – however one of them will increment. Not sure what is going on here.
In conclusion - I’ve only barely touched one of the tables in this database. There is so much data in this database! There is also the ‘DistributionKeys’ and ‘DistributionValues’ tables which store more numerical-based stats versus the incremental/binary stats of the 'Scaler' table. Try the following SQL query on your own and see what you find!
select DistributionKeys.key, date(DistributionKeys.daysSince1970*86400,'unixepoch','localtime') as daysSince1970, DistributionValues.secondsInDayOffset, DistributionValues.value from DistributionKeys left join DistributionValues on DistributionKeys.rowid = DistributionValues.distributionID whereDistributionKeys.key like '%unlock%'
I will hopefully be putting out a few more blog entries on other data found in this database (and other databases!). I will of course post updates to this research if and when I get the chance to do it! Stay tuned!