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Credit Card Number

Credit Card Number is a Java library that can provide details of a bank issued credit card number.

(Also see Magnetic Track Parser.)

The goal of this project is to use publicly and freely available documentation to create a reliable Java library to provide information about credit card numbers.

Resources

Some resources consulted are:

• Payment card number
• How do you detect Credit card type based on number?
• Finding or Verifying Credit Card Numbers
• Major Industry Identifier
• Luhn Algorithm
• Where can I find test credit card numbers?

Design Principles

• All classes are immutable and thread-safe
• Secure data follows standards in the Java Cryptography Architecture (JCA) Reference Guide
• The standard toString() function formats data in a readable form
• Internationalization of card numbers is supported
• Validity is enforced by JUnit 5 tests
• Java 8 or newer is required
• Android friendly

Download and Use in Projects

You can download the jar on the Maven Central Repository. The download page has instructions on how to use the library in your Maven or Gradle build.

Examples

How to Get Bank Card Information

To get bank card information, use code like:

AccountNumber pan = AccountNumbers.completeAccountNumber("5266-0922-0141-6174");
ExpirationDate expiration = new ExpirationDate(2015, 4);
Name name = new Name("Sualeh", "Fatehi");
ServiceCode serviceCode = new ServiceCode("225");
BankCard card = new BankCard(pan, expiration, name, serviceCode);
System.out.println(card);

and you will get this output:

Bank Card Information:
  Raw Account Number: 5266-0922-0141-6174
  Primary Account Number: 5266092201416174
    Major Industry Identifier: 5 - Banking and financial
    Issuer Identification Number: 52660922
    Card Brand: MasterCard
    Last Four Digits: 6174
    Passes Luhn Check? Yes
    Is Primary Account Number Valid? Yes
  Name: Sualeh Fatehi
  Expiration Date: 2015-04
    Is Expired? Yes
  Service Code:
    2 - Interchange: International interchange. Technology: Integrated circuit card.
    2 - Authorization Processing: By issuer.
    5 - Allowed Services: Goods and services only. PIN Requirements: PIN required.

How to Secure the Credit Card Number

If you need the account number information, but want to be secure by not storing the actual primary account number in memory, you can use code like:

AccountNumber pan = AccountNumbers.completeAccountNumber("5266-0922-0141-6174");
pan.dispose();
System.out.println(pan.getAccountNumber());

and you will get this output:

null

The account number is no longer retained in memory. Even though the memory has been cleared of the account number, you may want to allow the original reference to be garbage collected by doing this:

// (Call dispose() first)
AccountNumber securePan = pan.toSecureAccountNumber();

How to Encrypt the Credit Card Number

If you need the account number information, but want to encrypt it using a cryptographic algorithm such as AES, you can use code like:

AccountNumber sealedPan = AccountNumbers.sealedAccountNumber("5266-0922-0141-6174", cipher);
System.out.println(sealedPan.getAccountNumber());

and you will get this output:

null

The account number can be decrypted by doing this:

AccountNumber pan = AccountNumbers.completeAccountNumber(sealedPan, key);
System.out.println(pan.getAccountNumber());

The cipher and key are from javax.crypto and java.security.

Internationalization is Supported

You can use code like:

AccountNumber pan = AccountNumbers.completeAccountNumber("५२६६ ०९२२ ०१४१ ६१७४");
System.out.println(pan.getAccountNumber());

and you will get this output:

5266092201416174

Look-ahead Typing

The Credit Card Number library allows look-ahead typing and identifies the card brand by at least the first four digits of the card number.

You can use code like:

CardBrand cardBrand = CardBrand.from("5366");
System.out.println(cardBrand);

and you will get this output:

MasterCard