public bool ValidateCVV(string number, string cvv)
{
var validationExpression = new CreditCardValidationExpression();
// American Express requires 4 digit cvv
if (Regex.IsMatch(number, validationExpression.GetExpression(CardType.Amex)) &&
Regex.IsMatch(cvv, "^[0-9]{4}$"))
{
return(true);
}
// while the rest require 3 digit cvv
return((Regex.IsMatch(number, validationExpression.GetExpression(CardType.Visa)) ||
Regex.IsMatch(number, validationExpression.GetExpression(CardType.Discover)) ||
Regex.IsMatch(number, validationExpression.GetExpression(CardType.MasterCard))) &&
Regex.IsMatch(cvv, "^[0-9]{3}$"));
}
public static CardType ParseFromNumber(string number)
{
var validationExpression = new CreditCardValidationExpression();
return(new[]
{
Amex,
Visa,
MasterCard,
Discover
}
.Where(card => Regex.IsMatch(number, validationExpression.GetExpression(card)))
.FirstOrDefault());
}