[Share Code] Touch ID Authentication in Pythonista

Phuket2

I don't understand the code. Beyond me at the moment. But seems to be working 100% now. I can do 2 bad tries and the third try, use the right finger and its authenticated. Look, it could have been me. I am sitting in a bar drinking, so my fingers getting wet. I thought I was drying them. Maybe not enough. Also, the glass is cold, which makes my fingers cold. It could have an effect on the sensor, not sure. But seems to be working well now.
Surprised you are having problems on your iPad Air 2.

omz

I don't think I can submit a pull request, but here's my fork with some improvements:

https://gist.github.com/omz/66a763a9db15dc847690

I've refactored the code a little to make it usable as a module. The authenticate() function basically encapsulates all the callback logic, so you can simply call it, and it'll either return True or raise an AuthFailedException (there are subclasses for more specific errors).

It also supports a timeout, and you can specify whether the device passcode should be allowed as an alternative if TouchID fails.

filippocld

@Phuket2 Glad it works, for my ipad i'll have to take it to the apple store.

@omz thanks, i was planning to do it but you anticipated me :-)

filippocld

I'd do 2 things:
-Implement it in the keychain module( i wanted to do it but i cant find the keychain module)
-add the ability to set a password instead of a passcode

omz

@hyshai I don't get notifications for Gist comments, so let's move this here... You said that my fork crashes on iPhone 6 / iOS 8.4.1. Could you provide a few more details? Does it crash immediately or after the TouchID dialog is shown. Does @filippocld's version crash as well? Which beta build do you have installed?

userista

@omz sorry about that. I figured out what causes the crash - a policy with the value of 2 causes it. If I change policy = 2 if allow_passcode else 1 to policy = 1 it works fine.

(I'm running 160032 on 8.4.1 iPhone 6)

ProfSpaceCadet

I made a module based on your code: https://gist.github.com/d44b83d80f2f77e4f832

To run it you just call authenticate() with an optional string if you want to supply a reason. It will return True if the user authenticated (with either TouchID or passcode) and False if it was cancelled.

gregr

@ProfSpaceCadet nice. Although rather than doing

	while result == None:
		pass

while you're waiting for a result (which will likely burn CPU), would probably be better to add a threading.Event, and wait on that event instead of looping.

Phuket2

@gregr , @ProfSpaceCadet , maybe a time out param , maybe default 30 secs

Phuket2

@omz said:

I don't think I can submit a pull request, but here's my fork with some improvements:

https://gist.github.com/omz/66a763a9db15dc847690

I've refactored the code a little to make it usable as a module. The authenticate() function basically encapsulates all the callback logic, so you can simply call it, and it'll either return True or raise an AuthFailedException (there are subclasses for more specific errors).

It also supports a timeout, and you can specify whether the device passcode should be allowed as an alternative if TouchID fails.

@omz is the code still up to date? I noticed if it times out my Pythonista_startup script runs. Is it intentional as part of security or has something broken. Testing in Pythonista v2 beta

Edit: for is_available I returned False. If Touch ID is not available, should it not ask for a passcode rather than just returning a message to the console

Phuket2

@Phuket2 said:

@omz said:

I don't think I can submit a pull request, but here's my fork with some improvements:

https://gist.github.com/omz/66a763a9db15dc847690

I've refactored the code a little to make it usable as a module. The authenticate() function basically encapsulates all the callback logic, so you can simply call it, and it'll either return True or raise an AuthFailedException (there are subclasses for more specific errors).

It also supports a timeout, and you can specify whether the device passcode should be allowed as an alternative if TouchID fails.

@omz is the code still up to date? I noticed if it times out my Pythonista_startup script runs. Is it intentional as part of security or has something broken. Testing in Pythonista v2 beta

Edit: for is_available I returned False. If Touch ID is not available, should it not ask for a passcode rather than just returning a message to the console

@omz , if you call the authenticate method without Params, cashes straight away. I am guessing it has to do with you reason param default ''. It does not like that. If I change the default in the call, it's fine. Also, timeout works differently if I pass a named param timeout = 20 for example. The exception is raised rather than rerunning my Pythonista_startup (a reboot I guess)

lachlantula

@omz Your fork crashes my Pythonista 3 unfortunately, however I've tried HyShai's fix with no change. Here's my implementation.

from func import TouchID
cfg['touchIDEnabled'] = True
...

if cfg['touchIDEnabled'] == True:
    fp = TouchID.authenticate('To continue to x, please use fingerprint.', allow_passcode=False)

My TouchID file is the exact same as the original, besides the change HyShai suggested. Probably worth mentioning that my actual script is 1100+ lines long (main reason being I have a very complex UI that I did manually rather than using the builder), which I imagine doesn't help. Any ideas?

Pythonista 3, iOS 10.1.1.

Edit: looks like there's nothing wrong with the module, I tried a similar implementation in another file (obviously massively shorter) and it worked fine. I might have to work on some optimisation, see what happens. I'm on an air2.

Edit2: Simply commenting stuff out, running, uncommenting seems to fix the crashes. Strange but it's happened before to me. ¯\_(ツ)_/¯

cvp

@omz
Same problem for me, crash in a big script of 250 lines, no problem with a little test script.
Error is "Fatal Python error: Segmentation fault"

Crash just after the touchid window, either if correct finger, cancel or timeout!