Crypto.Cipher.XSalsa

crypton-1.0.1: Cryptography Primitives sink

License | BSD-style
Maintainer | Brandon Hamilton <brandon.hamilton@gmail.com>
Stability | stable
Portability | good
Safe Haskell | None
Language | Haskell2010

Crypto.Cipher.XSalsa

Description

Implementation of XSalsa20 algorithm https://cr.yp.to/snuffle/xsalsa-20081128.pdf Based on the Salsa20 algorithm with 256 bit key extended with 192 bit nonce

Synopsis

- initialize :: (ByteArrayAccess key, ByteArrayAccess nonce) => Int -> key -> nonce -> State
- derive :: ByteArrayAccess nonce => State -> nonce -> State
- combine :: ByteArray ba => State -> ba -> (ba, State)
- generate :: ByteArray ba => State -> Int -> (ba, State)
- data State

# Documentation

initialize #

Arguments

:: (ByteArrayAccess key, ByteArrayAccess nonce) |
=> Int | number of rounds (8,12,20)
-> key | the key (256 bits)
-> nonce | the nonce (192 bits)
-> State | the initial XSalsa state

Initialize a new XSalsa context with the number of rounds, the key and the nonce associated.

derive #

Arguments

:: ByteArrayAccess nonce |
=> State | base XSalsa state
-> nonce | the remainder nonce (128 bits)
-> State | the new XSalsa state

Use an already initialized context and new nonce material to derive another XSalsa context.

This allows a multi-level cascade where a first key `k1` and nonce `n1` is used to get `HState(k1,n1)`, and this value is then used as key `k2` to build `XSalsa(k2,n2)`. Function `initialize` is to be called with the first 192 bits of `n1|n2`, and the call to `derive` should add the remaining 128 bits.

The output context always uses the same number of rounds as the input context.

combine #

Arguments

:: ByteArray ba |
=> State | the current Salsa state
-> ba | the source to xor with the generator
-> (ba, State) |

Combine the salsa output and an arbitrary message with a xor, and return the combined output and the new state.

generate #

Arguments

:: ByteArray ba |
=> State | the current Salsa state
-> Int | the length of data to generate
-> (ba, State) |

Generate a number of bytes from the Salsa output directly

data State #

Salsa context

#### Instances

Instances details

NFData State # |
Instance details Defined in Crypto.Cipher.Salsa Methods rnf :: State -> () #