Sample code for 30+ languages & platforms
Unicode C

Generate TOTP using Base32 Secret (6 Digits, Time-based, 30-second period)

See more Encryption Examples

Generates a 6-digit time-based TOTP code using a base32 secret with a 30-second time period.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkCrypt2W.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCrypt2W crypt;
    const wchar_t *secretKey;
    HCkStringBuilderW sbKey;
    int numRemoved;
    int numDigits;
    int timePeriod;

    success = FALSE;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.
    // 
    crypt = CkCrypt2W_Create();

    // Base32 secret key:
    secretKey = L"oebf ytfl qmzb p4xd 2ztf zyz4 hjrw 3uyo";

    sbKey = CkStringBuilderW_Create();
    success = CkStringBuilderW_Append(sbKey,secretKey);

    // Remove SPACE chars.
    numRemoved = CkStringBuilderW_Replace(sbKey,L" ",L"");

    // Note: A new token is generated every 30 seconds.  You must generate within the same 30 second interval to get the same result.

    // Generate 6 digits.
    numDigits = 6;
    // 30 second time period.
    timePeriod = 30;
    wprintf(L"Your token is: %s\n",CkCrypt2W_totp(crypt,CkStringBuilderW_getAsString(sbKey),L"base32",L"0",L"",timePeriod,numDigits,-1,L"sha1"));


    CkCrypt2W_Dispose(crypt);
    CkStringBuilderW_Dispose(sbKey);

    }