{

public static class RandomCreditCardNumberGenerator

{

/*

Copy Kev Hunter's changes August 16, 2009 from from https://kevhunter.wordpress.com/2009/08/16/creating-fake-credit-card-numbers/

Include comments from Zoltan siaynoq(http://en.gravatar.com/siaynoq) April 20, 2011

Included in GitHub by MNF 31 May 2016.

MNF 31 May 2016 Added PrefixAndLength struct and methods to generate random numbers of different types in the same call to GetCreditCardNumbers

This is a port of the port of of the Javascript credit card number generator now in C#

* by Kev Hunter https://kevhunter.wordpress.com

* See the license below. Obviously, this is not a Javascript credit card number

generator. However, The following class is a port of a Javascript credit card

number generator.

@author robweber

Javascript credit card number generator Copyright (C) 2006 Graham King

graham@darkcoding.net

This program is free software; you can redistribute it and/or modify it

under the terms of the GNU General Public License as published by the

Free Software Foundation; either version 2 of the License, or (at your

option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

Public License for more details.

You should have received a copy of the GNU General Public License along

with this program; if not, write to the Free Software Foundation, Inc.,

51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

www.darkcoding.net

*/

/*

Example of use:

var random = new Random();

var cardsList = random.GetCreditCardNumbers(RandomCreditCardNumberGenerator.BuildPrefixAndLengthArrayForVisaMasterCardAmex(), 10);

*/

public static string[] AMEX_PREFIX_LIST = new[] {"34", "37"};

public static string[] DINERS_PREFIX_LIST = new[]

{

"300",

"301", "302", "303", "36", "38"

};

public static string[] DISCOVER_PREFIX_LIST = new[] {"6011"};

public static string[] ENROUTE_PREFIX_LIST = new[]

{

"2014",

"2149"

};

public static String[] JCB_PREFIX_LIST = new[]

{

"35"

};

public static string[] MASTERCARD_PREFIX_LIST = new[]

{

"51",

"52", "53", "54", "55",

"2221",

"2222",

"2223",

"2224",

"2225",

"2226",

"2227",

"2228",

"2229",

"223",

"224",

"225",

"226",

"227",

"228",

"229",

"23",

"24",

"25",

"26",

"270",

"271",

"2720"

};

public static string[] VISA_PREFIX_LIST = new[]

{

"4539",

"4556", "4916", "4532", "4929", "40240071", "4485", "4716", "4"

};

public static string[] VOYAGER_PREFIX_LIST = new[] {"8699"};

public struct PrefixAndLength

{

public PrefixAndLength(string prefix, int length)

{

Prefix = prefix;

Length = length;

}

public string Prefix { get; set; }

public int Length { get; set; }

}

public static IEnumerable<PrefixAndLength> BuildPrefixAndLengthList(string[] prefixList, int length)

{

var list=from p in prefixList select new PrefixAndLength(p, length);

return list;

}

/// <summary>

/// This is an example how BuildPrefixAndLengthList can be used

/// </summary>

/// <returns></returns>

public static PrefixAndLength[] BuildPrefixAndLengthArrayForVisaMasterCardAmex()

{

var list=BuildPrefixAndLengthList(VISA_PREFIX_LIST, 16)

.Union(BuildPrefixAndLengthList(MASTERCARD_PREFIX_LIST, 16))

.Union(BuildPrefixAndLengthList(AMEX_PREFIX_LIST, 15))

;

return list.ToArray();

}

/// <summary>

/// Better to use extension overload with [this Random random] paramenter. See http://stackoverflow.com/questions/2706500/how-do-i-generate-a-random-int-number-in-c

/// </summary>

/// <param name="prefixAndLengthList"></param>

/// <param name="howMany"></param>

/// <returns></returns>

public static IEnumerable<string> GetCreditCardNumbers(PrefixAndLength[] prefixAndLengthList,

int howMany)

{

Random rndGen = new Random();

return GetCreditCardNumbers(rndGen, prefixAndLengthList, howMany);

}

public static IEnumerable<string> GetCreditCardNumbers(this Random random, PrefixAndLength[] prefixAndLengthList, int howMany)

{

var result = new Stack<string>();

for (int i = 0; i < howMany; i++)

{

int randomPrefix = random.Next(0, prefixAndLengthList.Length - 1);

var prefixAndLength = prefixAndLengthList[randomPrefix];

result.Push(CreateFakeCreditCardNumber(random, prefixAndLength.Prefix, prefixAndLength.Length));

}

return result;

}

/*

'prefix' is the start of the CC number as a string, any number

private of digits 'length' is the length of the CC number to generate.

* Typically 13 or 16

*/

private static string CreateFakeCreditCardNumber(this Random random, string prefix, int length)

{

string ccnumber = prefix;

while (ccnumber.Length < (length - 1))

{

double rnd = (random.NextDouble()*1.0f - 0f);

ccnumber += Math.Floor(rnd*10);

}

// reverse number and convert to int

var reversedCCnumberstring = ccnumber.ToCharArray().Reverse();

var reversedCCnumberList = reversedCCnumberstring.Select(c => Convert.ToInt32(c.ToString()));

// calculate sum //Luhn Algorithm http://en.wikipedia.org/wiki/Luhn_algorithm

int sum = 0;

int pos = 0;

int[] reversedCCnumber = reversedCCnumberList.ToArray();

while (pos < length - 1)

{

int odd = reversedCCnumber[pos]*2;

if (odd > 9)

odd -= 9;

sum += odd;

if (pos != (length - 2))

sum += reversedCCnumber[pos + 1];

pos += 2;

}

// calculate check digit

int checkdigit =

Convert.ToInt32((Math.Floor((decimal) sum/10) + 1)*10 - sum)%10;

ccnumber += checkdigit;

return ccnumber;

}

public static IEnumerable<string> GetCreditCardNumbers(string[] prefixList, int length,

int howMany)

{

var result = new Stack<string>();

var random = new Random();

for (int i = 0; i < howMany; i++)

{

int randomPrefix = random.Next(0, prefixList.Length - 1);

if(randomPrefix>1) //Why??, is it a bug ? it never will select last element

{

randomPrefix--;

}

string ccnumber = prefixList[randomPrefix];

result.Push(CreateFakeCreditCardNumber(random, ccnumber, length));

}

return result;

}

public static IEnumerable<string> GenerateMasterCardNumbers(int howMany)

{

return GetCreditCardNumbers(MASTERCARD_PREFIX_LIST, 16, howMany);

}

public static string GenerateMasterCardNumber()

{

return GetCreditCardNumbers(MASTERCARD_PREFIX_LIST, 16, 1).First();

}

public static bool IsValidCreditCardNumber(string creditCardNumber)

{

try

{

var reversedNumber = creditCardNumber.ToCharArray().Reverse();

int mod10Count = 0;

for (int i = 0; i < reversedNumber.Count(); i++)

{

int augend = Convert.ToInt32(reversedNumber.ElementAt(i).ToString());

if (((i + 1)%2) == 0)

{

string productstring = (augend*2).ToString();

augend = 0;

for (int j = 0; j < productstring.Length; j++)

{

augend += Convert.ToInt32(productstring.ElementAt(j).ToString());

}

}

mod10Count += augend;

}

if ((mod10Count%10) == 0)

{

return true;

}

}

catch

{

return false;

}

return false;

}

}