This module is part of a chain of OTP libraries all written in different languages. See https://github.com/OTPLibraries
A simple One Time Password (OTP) library in C/C++
Fully compatible with Authy and Google Authenticator. Full support for QR Code URI is provided. Does not support generating QR Code images.
We use OpenSSL with -lcrypto for cryptographic functions.
For linux users, you will want to install libcrypto via sudo apt install libssl-dev
This library works with C++, but is targeted at C. I made a .hpp header that wraps the C functions, which I find gross. Feel free to clean it up and do a pull request. I do, however, have to recommend you use the .hpp header due to namespace flooding.
See the build.bat or build.sh file for self-building guidance. If you don't want to use the .hpp C++ wrapper, you can extern "C" #include "cotp.h" which will flood your global space with the header file contents. We have a Makefile for use: make libs for just the library or make all to also build the test examples.
This library allows you to create a function in a specified format to communicate with the OTP generation. You will have to manually do the cryptographic functions and time returning function for TOTP, which is easy in OpenSSL; I suggest it just for that. See the test files for pre-made functions that will hook you up.
- Create OTPData with the required information using *otp_new().
- Create a COTP_ALGO function which SHA1/256/512's then HMAC's its input and returns 0 for error or the result length
- Create a COTP_TIME function which returns a uint64_t that is the current time in seconds.
- Invoke the functions you need and pass your OTPData structure pointer.
This library is licensed under MIT.
This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit. (http://www.openssl.org/)
- SHA256 needs to be verified if it's working fully
- SHA512 needs to be verified if it's working fully