Compute security fields for IFSF Host-to-Host Interface financial transaction messages under ANSI X9.24 version 2004 and ANSI X9.24 2009 encryption schemes.

IFSF Host-to-Host standard in an adaption of ISO 8583 mainly devised for fuel payment transactions, but also used in several other financial applications.

<dependency>
  <groupId>com.github.alessandrozamberletti</groupId>
  <artifactId>ansix9242004</artifactId>
  <version>1.8</version>
  <scope>test</scope>
</dependency>

The following fields can be calculated and parsed:

• Personal Identification Number (PIN) DE-52;
• Encrypted sensitive data DE-127;
• Message authentication code (MAC) DE-64, DE-128.

To ease handling of field DE-52, utility methods to build and parse ISO 9564-1 Format 0 PIN blocks are also provided.

Formatting sensitive data in TLV format, hashing of the message for which ISO-9797-1 MAC has to be computed, and padding (using ether method 1 or method 2) are not in the scope of this library.

The library should only be used for testing purposes as it does not provide any sort of security.

• Java Triple DES DUKPT Library by Software Verde (Andrew Groot and Josh Green).
  https://github.com/SoftwareVerde/java-dukpt
• Message Authentication Code (MAC) algorithm (Mohammad).
  https://medium.com/@mohammad2603/message-authentication-code-mac-algorithm-ea9edaf66b3c
• Retail MAC Calculation in Java (Bharathi Subramanian).
  https://bharathisubramanian.wordpress.com/2013/03/23/retail-mac-calculation-in-java/
• DUKPT Within a Point of Sale Environment: How Does It Work? (Futurex).
  https://www.futurex.com/blog/dukpt-in-point-of-sale-how-does-it-work
• DUKPT Explained with examples (Arthur Van Der Merwe).
  https://arthurvandermerwe.com/2015/05/30/dukpt-explained-with-examples/
• How to decrypt card data.
  https://idtechproducts.com/technical-post/how-to-decrypt-credit-card-data-part-ii/
• "Key" to Secure Data - P2PE - Derived Unique Key Per Transaction (Andrew McKenna).
  https://www.foregenix.com/blog/p2pe-derived-unique-key-per-transaction-dukpt
• IFSF Recommended Security Standards v2.00.

• Java Triple DES DUKPT Library by Software Verde (authors: Andrew Groot and Josh Green).
  https://github.com/SoftwareVerde/java-dukpt
• Retail MAC Calculation in Java (Bharathi Subramanian).
  https://bharathisubramanian.wordpress.com/2013/03/23/retail-mac-calculation-in-java/