鉴于信用卡号并没有其他信息，PHP确定其是否为有效号码的最佳方式是什么？
现在我需要能够使用American Express，Discover，MasterCard和Visa的东西，但如果它也可以与其他类型一起使用可能会有所帮助。
答案 0 :(得分：144)
验证卡号有三个部分：
大多数卡使用Luhn算法进行校验和：
Luhn Algorithm described on Wikipedia
维基百科链接上有许多实现的链接，包括PHP：
<?
/* Luhn algorithm number checker - (c) 2005-2008 shaman - www.planzero.org *
* This code has been released into the public domain, however please *
* give credit to the original author where possible. */
function luhn_check($number) {
// Strip any non-digits (useful for credit card numbers with spaces and hyphens)
$number=preg_replace('/\D/', '', $number);
// Set the string length and parity
$number_length=strlen($number);
$parity=$number_length % 2;
// Loop through each digit and do the maths
$total=0;
for ($i=0; $i<$number_length; $i++) {
$digit=$number[$i];
// Multiply alternate digits by two
if ($i % 2 == $parity) {
$digit*=2;
// If the sum is two digits, add them together (in effect)
if ($digit > 9) {
$digit-=9;
}
}
// Total up the digits
$total+=$digit;
}
// If the total mod 10 equals 0, the number is valid
return ($total % 10 == 0) ? TRUE : FALSE;
}
?>
答案 1 :(得分：26)
来自10 regular expressions you can't live without in PHP：
function check_cc($cc, $extra_check = false){
$cards = array(
"visa" => "(4\d{12}(?:\d{3})?)",
"amex" => "(3[47]\d{13})",
"jcb" => "(35[2-8][89]\d\d\d{10})",
"maestro" => "((?:5020|5038|6304|6579|6761)\d{12}(?:\d\d)?)",
"solo" => "((?:6334|6767)\d{12}(?:\d\d)?\d?)",
"mastercard" => "(5[1-5]\d{14})",
"switch" => "(?:(?:(?:4903|4905|4911|4936|6333|6759)\d{12})|(?:(?:564182|633110)\d{10})(\d\d)?\d?)",
);
$names = array("Visa", "American Express", "JCB", "Maestro", "Solo", "Mastercard", "Switch");
$matches = array();
$pattern = "#^(?:".implode("|", $cards).")$#";
$result = preg_match($pattern, str_replace(" ", "", $cc), $matches);
if($extra_check && $result > 0){
$result = (validatecard($cc))?1:0;
}
return ($result>0)?$names[sizeof($matches)-2]:false;
}
示例输入：
$cards = array(
"4111 1111 1111 1111",
);
foreach($cards as $c){
$check = check_cc($c, true);
if($check!==false)
echo $c." - ".$check;
else
echo "$c - Not a match";
echo "<br/>";
}
这给了我们
4111 1111 1111 1111 - Visa
答案 2 :(得分：12)
最好不要在最后验证代码。将卡信息直接发送到您的支付网关，然后处理他们的回复。如果你不先做Luhn检查，那么它可以帮助他们检测欺诈行为 - 让他们看到失败的尝试。
答案 3 :(得分：6)
PHP代码
function validateCC($cc_num, $type) {
if($type == "American") {
$denum = "American Express";
} elseif($type == "Dinners") {
$denum = "Diner's Club";
} elseif($type == "Discover") {
$denum = "Discover";
} elseif($type == "Master") {
$denum = "Master Card";
} elseif($type == "Visa") {
$denum = "Visa";
}
if($type == "American") {
$pattern = "/^([34|37]{2})([0-9]{13})$/";//American Express
if (preg_match($pattern,$cc_num)) {
$verified = true;
} else {
$verified = false;
}
} elseif($type == "Dinners") {
$pattern = "/^([30|36|38]{2})([0-9]{12})$/";//Diner's Club
if (preg_match($pattern,$cc_num)) {
$verified = true;
} else {
$verified = false;
}
} elseif($type == "Discover") {
$pattern = "/^([6011]{4})([0-9]{12})$/";//Discover Card
if (preg_match($pattern,$cc_num)) {
$verified = true;
} else {
$verified = false;
}
} elseif($type == "Master") {
$pattern = "/^([51|52|53|54|55]{2})([0-9]{14})$/";//Mastercard
if (preg_match($pattern,$cc_num)) {
$verified = true;
} else {
$verified = false;
}
} elseif($type == "Visa") {
$pattern = "/^([4]{1})([0-9]{12,15})$/";//Visa
if (preg_match($pattern,$cc_num)) {
$verified = true;
} else {
$verified = false;
}
}
if($verified == false) {
//Do something here in case the validation fails
echo "Credit card invalid. Please make sure that you entered a valid <em>" . $denum . "</em> credit card ";
} else { //if it will pass...do something
echo "Your <em>" . $denum . "</em> credit card is valid";
}
}
用法
echo validateCC("1738292928284637", "Dinners");
更多理论信息可在此处找到：
答案 4 :(得分：5)
我们可以使用以下方法验证信用卡。它对我来说很完美。
protected function luhn($number)
{
// Force the value to be a string as this method uses string functions.
// Converting to an integer may pass PHP_INT_MAX and result in an error!
$number = (string)$number;
if (!ctype_digit($number)) {
// Luhn can only be used on numbers!
return FALSE;
}
// Check number length
$length = strlen($number);
// Checksum of the card number
$checksum = 0;
for ($i = $length - 1; $i >= 0; $i -= 2) {
// Add up every 2nd digit, starting from the right
$checksum += substr($number, $i, 1);
}
for ($i = $length - 2; $i >= 0; $i -= 2) {
// Add up every 2nd digit doubled, starting from the right
$double = substr($number, $i, 1) * 2;
// Subtract 9 from the double where value is greater than 10
$checksum += ($double >= 10) ? ($double - 9) : $double;
}
// If the checksum is a multiple of 10, the number is valid
return ($checksum % 10 === 0);
}
protected function ValidCreditcard($number)
{
$card_array = array(
'default' => array(
'length' => '13,14,15,16,17,18,19',
'prefix' => '',
'luhn' => TRUE,
),
'american express' => array(
'length' => '15',
'prefix' => '3[47]',
'luhn' => TRUE,
),
'diners club' => array(
'length' => '14,16',
'prefix' => '36|55|30[0-5]',
'luhn' => TRUE,
),
'discover' => array(
'length' => '16',
'prefix' => '6(?:5|011)',
'luhn' => TRUE,
),
'jcb' => array(
'length' => '15,16',
'prefix' => '3|1800|2131',
'luhn' => TRUE,
),
'maestro' => array(
'length' => '16,18',
'prefix' => '50(?:20|38)|6(?:304|759)',
'luhn' => TRUE,
),
'mastercard' => array(
'length' => '16',
'prefix' => '5[1-5]',
'luhn' => TRUE,
),
'visa' => array(
'length' => '13,16',
'prefix' => '4',
'luhn' => TRUE,
),
);
// Remove all non-digit characters from the number
if (($number = preg_replace('/\D+/', '', $number)) === '')
return FALSE;
// Use the default type
$type = 'default';
$cards = $card_array;
// Check card type
$type = strtolower($type);
if (!isset($cards[$type]))
return FALSE;
// Check card number length
$length = strlen($number);
// Validate the card length by the card type
if (!in_array($length, preg_split('/\D+/', $cards[$type]['length'])))
return FALSE;
// Check card number prefix
if (!preg_match('/^' . $cards[$type]['prefix'] . '/', $number))
return FALSE;
// No Luhn check required
if ($cards[$type]['luhn'] == FALSE)
return TRUE;
return $this->luhn($number);
}
答案 5 :(得分：3)
luhn algorithm是一个校验和，可用于验证大量信用卡格式的格式（以及加拿大社会保险号码......）
维基百科文章还链接到许多不同的实现;这是一个PHP：
http://planzero.org/code/bits/viewcode.php?src=luhn_check.phps
答案 6 :(得分：2)
有一个PEAR包可以处理许多财务数字的验证，还有信用卡验证：http://pear.php.net/package/Validate_Finance_CreditCard
顺便说一下，PayPal有一些Test Credit Card Account Numbers。
答案 7 :(得分：0)
只是抛出一些其他人可能觉得有用的代码片段（不是PHP代码）。
PYTHON （单行代码;可能效率不高）
验证：
>>> not(sum(map(int, ''.join(str(n*(i%2+1)) for i, n in enumerate(map(int, reversed('1234567890123452'))))))%10)
True
>>> not(sum(map(int, ''.join(str(n*(i%2+1)) for i, n in enumerate(map(int, reversed('1234567890123451'))))))%10)
False
要返回所需的校验位：
>>> (10-sum(map(int, ''.join(str(n*(i%2+1)) for i, n in enumerate(map(int, reversed('123456789012345')), start=1)))))%10
2
>>> (10-sum(map(int, ''.join(str(n*(i%2+1)) for i, n in enumerate(map(int, reversed('234567890123451')), start=1)))))%10
1
MySQL功能
功能＆＃34; ccc＆＃34;和＆＃34; ccd＆＃34; （信用卡支票和信用卡号码）
请注意＆＃34; ccc＆＃34;函数有一个额外的检查，如果计算的和为0，则返回的结果将始终为FALSE，因此全零的CC编号永远不会验证为正确（在正常行为下，它将正确验证）。可以根据需要添加/删除此功能;可能有用，具体取决于具体要求。
DROP FUNCTION IF EXISTS ccc;
DROP FUNCTION IF EXISTS ccd;
DELIMITER //
CREATE FUNCTION ccc (n TINYTEXT) RETURNS BOOL
BEGIN
DECLARE x TINYINT UNSIGNED;
DECLARE l TINYINT UNSIGNED DEFAULT length(n);
DECLARE i TINYINT UNSIGNED DEFAULT l;
DECLARE s SMALLINT UNSIGNED DEFAULT 0;
WHILE i > 0 DO
SET x = mid(n,i,1);
IF (l-i) mod 2 = 1 THEN
SET x = x * 2;
END IF;
SET s = s + x div 10 + x mod 10;
SET i = i - 1;
END WHILE;
RETURN s != 0 && s mod 10 = 0;
END;
CREATE FUNCTION ccd (n TINYTEXT) RETURNS TINYINT
BEGIN
DECLARE x TINYINT UNSIGNED;
DECLARE l TINYINT UNSIGNED DEFAULT length(n);
DECLARE i TINYINT UNSIGNED DEFAULT l;
DECLARE s SMALLINT UNSIGNED DEFAULT 0;
WHILE i > 0 DO
SET x = mid(n,i,1);
IF (l-i) mod 2 = 0 THEN
SET x = x * 2;
END IF;
SET s = s + x div 10 + x mod 10;
SET i = i - 1;
END WHILE;
RETURN ceil(s/10)*10-s;
END;
然后可以在SQL查询中直接使用函数：
mysql> SELECT ccc(1234567890123452);
+-----------------------+
| ccc(1234567890123452) |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.00 sec)
mysql> SELECT ccc(1234567890123451);
+-----------------------+
| ccc(1234567890123451) |
+-----------------------+
| 0 |
+-----------------------+
1 row in set (0.00 sec)
mysql> SELECT ccd(123456789012345);
+----------------------+
| ccd(123456789012345) |
+----------------------+
| 2 |
+----------------------+
1 row in set (0.00 sec)
mysql> SELECT ccd(234567890123451);
+----------------------+
| ccd(234567890123451) |
+----------------------+
| 1 |
+----------------------+
1 row in set (0.00 sec)
答案 8 :(得分：-1)
这只是为了确保使用一些基本的RegEX模式确保数字有效。
请注意，这并不会检查某些人是否正在使用这些号码。
http://www.roscripts.com/How_to_validate_credit_card_numbers-106.html