Co-authored by Hoi Kit Goodwin Lam.
A complete JavaSE 7 implementation of the Data Encryption Standard as documented in FIPS 46-3.
(see http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf)
###DES Class
Main DES class, handling the overall logic of the standard. Allows standard DES encryption and
decryption options while also supporting cipher-block chaining mode encryption and decryption.
(see https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher-block_chaining_.28CBC.29
and http://www.itl.nist.gov/fipspubs/fip81.htm)
###FeistelFunction Class Handles the main logic involving the F-Function, including expansion, key mixing, substitutions and permutation. Not intended for use by outside classes.
###RoundKeyGenerator Class Handles all logic relating to generating all the round-keys out of the 56 bit input key. Not intended for use by outside classes.
###DESInterface
Not required for use with this DES implementation.
Basic UI for testing functionality with an input file.