public string GetIINIssuer(string cardNumber, out IINResult result)
{
// Get the list of range elements and sort them into "from" value descending
// order. This ensures we pick up values that start with 5020 before those that
// start with 500 and before those that start with 50.
var ranges = from e in iinDoc.Descendants("range")
orderby e.Attribute("from").Value descending
select e;
// Scan through each range looking for a "from" value that matches the initial
// digits of card number. If we find a match, it's a possible IIN candidate.
foreach (XElement range in ranges)
{
// Read the validation data from the range element.
string from = range.Attribute("from").Value;
string to = range.Attribute("to").Value;
bool isActive = bool.Parse(range.Attribute("active").Value);
bool useLuhnValidation = bool.Parse(range.Attribute("luhn").Value);
string validCardLength = range.Attribute("length").Value;
string issuer = range.Attribute("issuer").Value;
// There can be several valid lengths of card number so parse the
// comma seperator list into an array so we can check against it.
// Note - the valid lengths may not be a contiguous set of values so we
// can't just check the card length to see if it's within min and max limits.
string[] validLengths = validCardLength.Split(new char[] { ',' });
int[] validNoOfDigits = new int[validLengths.Length];
for (int i = 0; i < validLengths.Length; i++)
{
validNoOfDigits[i] = int.Parse(validLengths[i]);
}
// Do we have a "to" value?
if (to.Trim().Length == 0)
{
// No, so check against just the "from" value.
int lengthOfFrom = from.Length;
if (cardNumber.Substring(0, lengthOfFrom) == from)
{
// This range is potentially valid for the card number.
// Check that the card number length matches the list of valid lengths.
bool isValidLength = IsCardNumberlengthValid(cardNumber, validNoOfDigits);
if (isValidLength)
{
if (isActive)
{
if (useLuhnValidation)
{
result = IINResult.ValidIIN;
}
else
{
result = IINResult.ValidIINButNoLuhnValidation;
}
return(issuer);
}
else
{
result = IINResult.ValidIINButInactive;
return(string.Empty);
}
}
else
{
result = IINResult.ValidIINButIncorrectCardNumberLength;
return(string.Empty);
}
}
}
else
{
// Yes we have a "to" value, so We have a range of IINs to test against.
int lengthOfFrom = from.Length;
int fromNumber = int.Parse(from);
int toNumber = int.Parse(to);
int cardNumberIIN = int.Parse(cardNumber.Substring(0, lengthOfFrom));
if (cardNumberIIN >= fromNumber && cardNumberIIN <= toNumber)
{
// This range is potentially value for the card number.
bool isValidLength = IsCardNumberlengthValid(cardNumber, validNoOfDigits);
if (isValidLength)
{
if (isActive)
{
if (useLuhnValidation)
{
result = IINResult.ValidIIN;
}
else
{
result = IINResult.ValidIINButNoLuhnValidation;
}
return(issuer);
}
else
{
result = IINResult.ValidIINButInactive;
return(string.Empty);
}
}
else
{
result = IINResult.ValidIINButIncorrectCardNumberLength;
return(string.Empty);
}
}
}
}
// The card number doesn't start with a valid value so return no issuer.
result = IINResult.InvalidIIN;
return(string.Empty);
}
public string GetIINIssuer(string cardNumber, out IINResult result)
{
// Get the list of range elements and sort them into "from" value descending
// order. This ensures we pick up values that start with 5020 before those that
// start with 500 and before those that start with 50.
var ranges = from e in iinDoc.Descendants("range")
orderby e.Attribute("from").Value descending
select e;
// Scan through each range looking for a "from" value that matches the initial
// digits of card number. If we find a match, it's a possible IIN candidate.
foreach (XElement range in ranges)
{
// Read the validation data from the range element.
string from = range.Attribute("from").Value;
string to = range.Attribute("to").Value;
bool isActive = bool.Parse(range.Attribute("active").Value);
bool useLuhnValidation = bool.Parse(range.Attribute("luhn").Value);
string validCardLength = range.Attribute("length").Value;
string issuer = range.Attribute("issuer").Value;
// There can be several valid lengths of card number so parse the
// comma seperator list into an array so we can check against it.
// Note - the valid lengths may not be a contiguous set of values so we
// can't just check the card length to see if it's within min and max limits.
string[] validLengths = validCardLength.Split(new char[] { ',' });
int[] validNoOfDigits = new int[validLengths.Length];
for (int i = 0; i < validLengths.Length; i++)
{
validNoOfDigits[i] = int.Parse(validLengths[i]);
}
// Do we have a "to" value?
if (to.Trim().Length == 0)
{
// No, so check against just the "from" value.
int lengthOfFrom = from.Length;
if (cardNumber.Substring(0, lengthOfFrom) == from)
{
// This range is potentially valid for the card number.
// Check that the card number length matches the list of valid lengths.
bool isValidLength = IsCardNumberlengthValid(cardNumber, validNoOfDigits);
if (isValidLength)
{
if (isActive)
{
if (useLuhnValidation)
result = IINResult.ValidIIN;
else
result = IINResult.ValidIINButNoLuhnValidation;
return issuer;
}
else
{
result = IINResult.ValidIINButInactive;
return string.Empty;
}
}
else
{
result = IINResult.ValidIINButIncorrectCardNumberLength;
return string.Empty;
}
}
}
else
{
// Yes we have a "to" value, so We have a range of IINs to test against.
int lengthOfFrom = from.Length;
int fromNumber = int.Parse(from);
int toNumber = int.Parse(to);
int cardNumberIIN = int.Parse(cardNumber.Substring(0, lengthOfFrom));
if (cardNumberIIN >= fromNumber && cardNumberIIN <= toNumber)
{
// This range is potentially value for the card number.
bool isValidLength = IsCardNumberlengthValid(cardNumber, validNoOfDigits);
if (isValidLength)
{
if (isActive)
{
if (useLuhnValidation)
result = IINResult.ValidIIN;
else
result = IINResult.ValidIINButNoLuhnValidation;
return issuer;
}
else
{
result = IINResult.ValidIINButInactive;
return string.Empty;
}
}
else
{
result = IINResult.ValidIINButIncorrectCardNumberLength;
return string.Empty;
}
}
}
}
// The card number doesn't start with a valid value so return no issuer.
result = IINResult.InvalidIIN;
return string.Empty;
}
