/// <summary>
/// Verify an OTP value
/// </summary>
/// <param name="initialStep">The initial step to try</param>
/// <param name="valueToVerify">The value to verify</param>
/// <param name="matchedStep">Output parameter that provides the step where the match was found. If no match was found it will be 0</param>
/// <param name="window">The window to verify</param>
/// <returns>True if a match is found</returns>
protected bool Verify(long initialStep, string valueToVerify, out long matchedStep, VerificationWindow window)
{
if (window == null)
{
window = new VerificationWindow();
}
foreach (var frame in window.ValidationCandidates(initialStep))
{
if (Compute(frame, HashMode) != valueToVerify)
{
continue;
}
matchedStep = frame;
return(true);
}
matchedStep = 0;
return(false);
}
private bool VerifyTotpForSpecificTime(DateTime timestamp, string totp, VerificationWindow window, out long timeStepMatched) => Verify(CalculateTimeStepFromTimestamp(timestamp), totp, out timeStepMatched, window);
/// <summary> /// Verify a value that has been provided with the calculated value /// </summary> /// <param name="timestamp">The timestamp to use</param> /// <param name="totp">the trial TOTP value</param> /// <param name="timeStepMatched"> /// This is an output parameter that gives that time step that was used to find a match. /// This is usefule in cases where a TOTP value should only be used once. This value is a unique identifier of the /// time step (not the value) that can be used to prevent the same step from being used multiple times /// </param> /// <param name="window">The window of steps to verify</param> /// <returns>True if there is a match.</returns> public bool VerifyTotp(DateTime timestamp, string totp, out long timeStepMatched, VerificationWindow window = null) => VerifyTotpForSpecificTime(_correctedTime.GetCorrectedTime(timestamp), totp, window, out timeStepMatched);
/// <summary> /// Verify a value that has been provided with the calculated value. /// </summary> /// <remarks> /// It will be corrected against a corrected UTC time using the provided time correction. If none was provided then simply the current UTC will be used. /// </remarks> /// <param name="totp">the trial TOTP value</param> /// <param name="timeStepMatched"> /// This is an output parameter that gives that time step that was used to find a match. /// This is useful in cases where a TOTP value should only be used once. This value is a unique identifier of the /// time step (not the value) that can be used to prevent the same step from being used multiple times /// </param> /// <param name="window">The window of steps to verify</param> /// <returns>True if there is a match.</returns> public bool VerifyTotp(string totp, out long timeStepMatched, VerificationWindow window = null) => VerifyTotpForSpecificTime(_correctedTime.CorrectedUtcNow, totp, window, out timeStepMatched);