/// <summary>
/// Gets the encrypted answer from form.
/// </summary>
/// <returns></returns>
/// <exception type="CaptchaExpiredException">Thrown when the user takes too long to submit a captcha answer.</exception>
protected virtual AnswerAndDate GetEncryptedAnswerFromForm()
{
string formValue = Page.Request.Form[HiddenEncryptedAnswerFieldName];
AnswerAndDate answerAndDate = AnswerAndDate.ParseAnswerAndDate(formValue, CaptchaTimeout);
if (answerAndDate.Expired)
{
throw new CaptchaExpiredException(Resources.CaptchaExpired_WaitedTooLong);
}
return(answerAndDate);
}
private bool ValidateCaptcha()
{
string answer = GetClientSpecifiedAnswer();
AnswerAndDate answerAndDate = GetEncryptedAnswerFromForm();
string expectedAnswer = answerAndDate.Answer;
bool isValid = !String.IsNullOrEmpty(answer) &&
String.Equals(answer, expectedAnswer, StringComparison.OrdinalIgnoreCase);
return(isValid);
}