C++

Google Authenticator Algorithm

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Example code implementing the Google Authenticator algorithm. C++

#include <CkCrypt2.h>

void ChilkatSample(void)
    {
    //  This example assumes the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Generating TOTP Base32 Secret: 
    //  When you enable 2FA with a TOTP-based authenticator app, Google will provide you with a QR code
    //  that you can scan using the app. This QR code contains a TOTP base32 secret.
    //  You can also choose to view and copy the secret manually.

    const char *secretBase32 = "JBSWY3DPEHPK3PXP";

    //  Do the following to calculate the 6-digit decimal Google authenticator token for a base32 secret,
    //  given the current system date/time.
    CkCrypt2 crypt;
    const char *otp = crypt.totp(secretBase32,"base32","0","",30,6,-1,"sha1");

    std::cout << "6-digit decimal token = " << otp << "\r\n";
    }