ARDUINO-OATH-TOKEN | Basic TOTP implementation in C for Arduino

ARDUINO-OATH-TOKEN is a C++ library typically used in Internet of Things (IoT), Arduino applications. ARDUINO-OATH-TOKEN has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

This is a basic Open-Source implementation of a TOTP (compliant with OATH*) code in Arduino. Basicaly it generates 6 digits OTP based in a EPOCH time stored in a variable called birthTime There is no time drift. The OTP is updated each 30 seconds. For HMAC-SHA1 hash this implementation uses the code from Cathedrow / Cryptosuite (However a small change was added to sha1.h and sha1.c: The method size_t Sha1Class::writebytes(const uint8_t* data, int length). For debug purposes the main important functions are printed to serial output. A picture of a working prototype can be found at: