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ASP FAQ Tutorials :: Classic ASP 1.0 :: Forms :: How do I validate a credit card number in ASP?
How do I validate a credit card number in ASP?
While with ASP alone you can't verify that a credit card belongs to this person, that it isn't stolen, that the credit is good or that the purchase price doesn't exceed the card's limit -- you can verify that it is a possible number (using a rough translation of Luhn / checksum) before bothering to waste transaction time with a true verification authority.
Most hosts will have credit card acceptance already set up for you. However, if you're doing it yourself, you're going to need a little bit more than a Luhn validation function. You will need an SSL certificate from Thawte or Verisign. For various reasons, I recommend Thawte. You will also need a secure place to store customer information. Keep in mind that you should try to avoid storing credit credit information if possible; the potential liability here is enormous. If you're going to store this information, you better have a well-guarded fort, and consider encrypting the number (see Article #2249 and Article #2397).
You can look at these other vendors for credit card processing, either in component form or as a real-time service:
alphabetware
Authorize.net
Charge.com
Comersus
CyberStrong eShop
Ebanyan
effengüd PayMate
E-Z Shop
IISCart
IP*Works
PDshopPro
PSiGate
Ustore Paypal
xAuthorize
You can also see some of the shopping cart products listed in Article #2225. (Depending on capabilities, some vendors might be listed in both articles.)
| <% function isCreditCard(cardNo) isCreditCard = false lCard = len(cardNo) lC = right(cardNo, 1) cStat = 0 for i = (lCard - 1) to 1 step -1 tempChar = mid(cardNo, i, 1) d = cint(tempChar) if lcard mod 2 = 1 then temp = d * (1 + ((i+1) mod 2)) else temp = d * (1 + (i mod 2)) end if if temp < 10 then cStat = cStat + temp else cStat = cStat + temp - 9 end if next cStat = (10 - (cStat mod 10)) mod 10 if cint(lC) = cStat then isCreditCard = true end function ' test: ' 4111111111111111 should pass (test number) response.write("1:" & isCreditCard("4111111111111111") & "<br>") ' 4111111111111112 should fail response.write("2:" & isCreditCard("4111111111111112") & "<br>") %> |
Most hosts will have credit card acceptance already set up for you. However, if you're doing it yourself, you're going to need a little bit more than a Luhn validation function. You will need an SSL certificate from Thawte or Verisign. For various reasons, I recommend Thawte. You will also need a secure place to store customer information. Keep in mind that you should try to avoid storing credit credit information if possible; the potential liability here is enormous. If you're going to store this information, you better have a well-guarded fort, and consider encrypting the number (see Article #2249 and Article #2397).
You can look at these other vendors for credit card processing, either in component form or as a real-time service:
alphabetware
Authorize.net
Charge.com
Comersus
CyberStrong eShop
Ebanyan
effeng&amp;amp;#252;d PayMate
E-Z Shop
IISCart
IP*Works
PDshopPro
PSiGate
Ustore Paypal
xAuthorize
You can also see some of the shopping cart products listed in Article #2225. (Depending on capabilities, some vendors might be listed in both articles.)
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