Hey just started poking around at

Question

Hey just started poking around at <https github com russhwolf multiplatform settings> Very neat but I can t figure out if there s a way to get ObservableSettings that are also encrypted on iOS

russhwolf · Answer

There currently isn t Keychain updates aren t natively observable on iOS Here s a ticket that probably won t move ever unless iOS changes <https github com russhwolf multiplatform settings issues 71|https github com russhwolf multiplatform settings issues 71>

StavFX · Answer

That s the answer I was afraid of Thanks slightly smiling face

mbonnin · Answer

Out of curiosity is there a real benefit of using encrypted settings I would expect the OS to sandbox apps already so that the preferences are not readable by other processes than the app itself And in the event that an attacker can run as the app process encrypting the preferences will not help mucH

streetsofboston · Answer

Encrypted settings are tamper proof and IIRC stored on the Secure Enclave iOS and Titan Mx Android chips

streetsofboston · Answer

Your app can require additional bio metrics or password interaction to unlock the settings data stored on those chips Eg you can store a Auth Token in the encrypted settings

streetsofboston · Answer

or the key to decrypt that token

mbonnin · Answer

That makes sense I think but I still fail to understand how secure enclaves make it any harder for an attacker compared to rooting the phone and running a modified APK

mbonnin · Answer

Is there some kind of verification chain that can make sure only code signed with my signing key can access the secure enclave That sounds quite complicated to achieve

mbonnin · Answer

Put it otherwise is there any evidence of an exploit that would have been prevented by using encrypted settings

streetsofboston · Answer

There must be slightly smiling face Apple and Google advocate to store sensitive data and auth access tokens or at least keys that can de encrypt those tokens on their secure chips These chips are an extra layer of security even on rooted phones that even physical tampering eg opening the phone and prying out on that chip won t work for the attacker the chip will basically self destruct when that is attempted

mbonnin · Answer

I take Google advice on security hence my interrogations here For physical tampering I would expect the full disk to be encrypted these days the famous case so encrypting preferences on an already encrypted disk doesn t protect more against someone spying on the bus or unsoldering the flash memory I think

mbonnin · Answer

If anyone has links I m happy to write a blog post about this this is a long time questionning of mine slightly smiling face

streetsofboston · Answer

Those chips are pretty expensive and both Apple and Google thought it was a good idea to include them for the secure keystores I know a few things about encryption and security but i m not an expert slightly smiling face In this way I do trust Apple and Google to have a good reason to include them so that apps can use them I think encrypting these types of things using these security chip is yet another layer of security even if others fails eg disk has been hacked rooted and even the disk decrypted