The responses recommending usage of Google Charts are absolutely terrible from information security point of view. That’s essentially sharing the TOTP secret as well as your username (alice@google.com) and issuer (Example) with a third-party company with no legal obligation to keep them secret, and doing that over a GET request! Doing so you violate not … Read more
While playing around with Google Authenticator, I came across this question and in particular the code contributed by Espo. I personally wasn’t satisfied with the conversion from Java to C# and so I thought I would share my version. Aside from heavily refactoring the code: Introduced check for little-endian byte ordering and convert to big-endian … Read more
I wanted to set a bounty on my question, but I have succeeded in creating solution. My problem seemed to be connected with incorrect value of secret key (it must be correct parameter for base64.b32decode() function). Below I post full working solution with explanation on how to use it. Code The following code is enough. … Read more