Codec.Encryption.Modes

Crypto-4.2.5.1: Collects together existing Haskell cryptographic functions into a package

Copyright | (c) Dominic Steinitz 2001-2003
License | BSD-style (see the file ReadMe.tex)
Maintainer | dominic.steinitz@blueyonder.co.uk
Stability | experimental
Portability | portable
Safe Haskell | Safe
Language | Haskell98

Codec.Encryption.Modes

Contents

- Function types

Description

This module currently supports Cipher Block Chaining (CBC) mode. See http://www.itl.nist.gov/fipspubs/fip81.htm for further details.

Synopsis

- cbc :: Bits block => (key -> block -> block) -> block -> key -> [block] -> [block]
- unCbc :: Bits block => (key -> block -> block) -> block -> key -> [block] -> [block]

# Function types

cbc :: Bits block => (key -> block -> block) -> block -> key -> [block] -> [block]

In CBC or Cipher Block Chaining mode each block is XORed with the previous enciphered block before encryption. For the first block, start with an initialization vector. Take an encryption function, an initialisation vector, a key and a list of blocks and return the encrypted blocks using CBC.

unCbc :: Bits block => (key -> block -> block) -> block -> key -> [block] -> [block]

To decipher in CBC or Cipher Block Chaining mode, decipher each block, then XOR the result with the previous block of plaintext result. Note that the initialization vector is treated as the zeroth block of plaintext. Take a decryption function, an initialisation vector, a key and a list of encrypted blocks using CBC and return plaintext blocks.