PYOTP - The Python One Time Password Library
This is compatible with Google Authenticator apps available for Android and iPhone, and now in use on GMail
Quick overview of using One Time Passwords on your phone
- OTP's involve a shared secret, stored both on the phone and the server
- OTP's can be generated on a phone without internet connectivity(AT&T mode)
- OTP's should always be used as a second factor of authentication(if your phone is lost, you account is still secured with a password)
- Google Authenticator allows you to store multiple OTP secrets and provision those using a QR Code(no more typing in the secret)
pip install pyotp
Time based OTP's
totp = pyotp.TOTP('base32secret3232') totp.now() # => 492039 # OTP verified for current time totp.verify(492039) # => True time.sleep(30) totp.verify(492039) # => False
Counter based OTP's
hotp = pyotp.HOTP('base32secret3232') hotp.at(0) # => 260182 hotp.at(1) # => 55283 hotp.at(1401) # => 316439 # OTP verified with a counter hotp.verify(316439, 1401) # => True hotp.verify(316439, 1402) # => False
Generating a Base32 Secret key
pyotp.random_base32() # returns a 16 character base32 secret. Compatible with Google Authenticator
Google Authenticator Compatible
The library works with the Google Authenticator iPhone and Android app, and also includes the ability to generate provisioning URI's for use with the QR Code scanner built into the app.
totp.provisioning_uri("email@example.com") # => 'otpauth://firstname.lastname@example.org?secret=JBSWY3DPEHPK3PXP' hotp.provisioning_uri("email@example.com", 0) # => 'otpauth://firstname.lastname@example.org?secret=JBSWY3DPEHPK3PXP&counter=0'
This can then be rendered as a QR Code which can then be scanned and added to the users list of OTP credentials.
Scan the following barcode with your phone, using Google Authenticator
Now run the following and compare the output
import pyotp totp = pyotp.TOTP("JBSWY3DPEHPK3PXP") print "Current OTP: %s" % totp.now()
- Ported to Python