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j256 / two-factor-auth

Two Factor Authentication Java code implementing the Time-based One-time Password Algorithm
ISC License
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Added support for OTPs with more than 6 digits (the standard allows 8… #14

Closed vigorouscoding closed 3 years ago

vigorouscoding commented 6 years ago

… digits) but kept 6 as the default (as per the standard)

As the Google Authenticator allows the use of 8 digits for the OTPs (see https://github.com/google/google-authenticator/wiki/Key-Uri-Format), I thought it might make a nice addition to your code. I tried to keep the source code style in line with yours and also added a few tests.

Basically I just added a default setting DEFAULT_OTP_LENGTH = 6 which is used if no length is given in order to ensure that functionality does not change if it your library is used somewhere. Alternatively users would now be able to use the new parameter length in all the functions to request a OTP with a different length. I did not add checks that only 6 or 8 digits are allowed, however.

I hope this meets your standards and you will accept the PR :)

j256 commented 3 years ago

This is superceded by https://github.com/j256/two-factor-auth/pull/23. I made some changes to your code but took the functionality. Changed the length argument to be int not Integer. Also fixed a problem with the zero prefix which would have caused issues if the generated number was less than 8 digits. Thanks again @vigorouscoding !