Credit Card Identification and Validation Class - The credit_card class provides methods for cleaning, validating and identifying the type of credit card numbers.

<?php
/*
+----------------------------------------------------------------------+
| Copyright (c) 2000 J.A.Greant |
| (See end of file for usage notes and licensing information.) |
+----------------------------------------------------------------------+
*/

class credit_card
{
function clean_no ($cc_no)
{
// Remove non-numeric characters from $cc_no
return ereg_replace ('[^0-9]+', '', $cc_no);
}

function identify ($cc_no)
{
$cc_no = credit_card::clean_no ($cc_no);

// Get card type based on prefix and length of card number
if (ereg ('^4(.{12}|.{15})$', $cc_no))
return 'Visa';
if (ereg ('^5[1-5].{14}$', $cc_no))
return 'Mastercard';
if (ereg ('^3[47].{13}$', $cc_no))
return 'American Express';
if (ereg ('^3(0[0-5].{11}|[68].{12})$', $cc_no))
return 'Diners Club/Carte Blanche';
if (ereg ('^6011.{12}$', $cc_no))
return 'Discover Card';
if (ereg ('^(3.{15}|(2131|1800).{11})$', $cc_no))
return 'JCB';
if (ereg ('^2(014|149).{11})$', $cc_no))
return 'enRoute';

return 'unknown';
}

function validate ($cc_no)
{
// Reverse and clean the number
$cc_no = strrev (credit_card::clean_no ($cc_no));

// VALIDATION ALGORITHM
// Loop through the number one digit at a time
// Double the value of every second digit (starting from the right)
// Concatenate the new values with the unaffected digits
for ($ndx = 0; $ndx < strlen ($cc_no); ++$ndx)
$digits .= ($ndx % 2) ? $cc_no[$ndx] * 2 : $cc_no[$ndx];

// Add all of the single digits together
for ($ndx = 0; $ndx < strlen ($digits); ++$ndx)
$sum += $digits[$ndx];

// Valid card numbers will be transformed into a multiple of 10
return ($sum % 10) ? FALSE : TRUE;
}

function check ($cc_no)
{
$valid = credit_card::validate ($cc_no);
$type = credit_card::identify ($cc_no);
return array ($valid, $type, 'valid' => $valid, 'type' => $type);
}
}
/*
+----------------------------------------------------------------------+
| FILE NAME: credit_card.pkg |
+----------------------------------------------------------------------+
| Author: J.A.Greant |
| Email : zak@nucleus.com |
| Date : 2000/11/23 |
+----------------------------------------------------------------------+
| The credit_card class provides methods for cleaning, validating and |
| identifying the type of credit card number. The validation algorithm |
| and identification procedures are based on information found at: |
| http://www.beachnet.com/~hstiles/cardtype.html |
| |
| credit_card::clean_no() method |
| ------------------------------ |
| Strips all non-numeric characters from the passed value and returns |
| an integer. This method is called by the other methods in the |
| credit_card class. |
| |
| USAGE EXAMPLE: |
| $cc_no ="5454 5454 5454 5454"; // Has spaces for readability |
| $cleaned_cc_no = credit_card::clean_no ($cc_no); |
| print $cleaned_cc_no; // Displays 5454545454545454 |
| |
| credit_card::identify() method |
| ------------------------------ |
| Finds the type of credit card (Mastercard, Visa, etc...) based on |
| the length and format of the credit card number. The method can |
| identify American Express, Diners Club/Carte Blanche, Discover, |
| enRoute, JCB, Mastercard and Visa cards. |
| |
| USAGE EXAMPLE: |
| $cc_no ="5454 5454 5454 5454"; |
| print credit_card::identify ($cc_no); // Returns "Mastercard" |
| |
| credit_card::validate() method |
| ------------------------------ |
| Validate a credit card number using the LUHN formula (mod 10). |
| Note that many other kinds of card and account numbers are based on |
| the LUHN algorith - including Canadian Social Insurance Numbers. |
| |
| USAGE EXAMPLE: |
| $cc_no ="5454 5454 5454 5454"; |
| print credit_card::validate ($cc_no); // Returns TRUE |
| |
| credit_card::check() method |
| --------------------------- |
| The check() method validates and identifies a credit card, returning |
| an array. Indexes 0 and 'valid' will contain TRUE if the card number |
| is valid (FALSE if it isn't), while indexes 1 and 'type' will |
| the type of card (if known). The presence of the numeric keys allows |
| the method to be used with the list() function. |
| |
| USAGE EXAMPLE: |
| $cc_no ="4111 1111 1111 1111"; |
| list ($valid, $type) = credit_card::check ($cc_no); |
| print $valid; // Displays 1 (TRUE) |
| print $type; // Displays "Visa" |
+----------------------------------------------------------------------+

+----------------------------------------------------------------------+
| CVS LOG INFO |
+----------------------------------------------------------------------+
$Log: credit_card_validator.pkg,v $
Revision 1.2 2000/11/24 07:02:15 zak
Added top copyright notice

Revision 1.1 2000/11/24 06:58:42 zak
Initial commit of credit card class to repository.
Cleaned and modified code.
Also rewrote significant parts of code so that I could change to the
more friendly BSD-style license.


+----------------------------------------------------------------------+
| Copyright (c) 2000 J.A.Greant (zak@nucleus.com) |
| All rights reserved. |
+----------------------------------------------------------------------+
| Redistribution and use in source and binary forms, with or without |
| modification, is permitted provided that the following conditions |
| are met: |
+----------------------------------------------------------------------+
| Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| |
| Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| |
| Neither the name of the author nor the names of any contributors to |
| this software may be used to endorse or promote products derived |
| from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. |
+----------------------------------------------------------------------+
*/
?>