Copyright	(c) Joseph Abrahamson 2013
License	MIT
Maintainer	me@jspha.com
Stability	experimental
Portability	non-portable
Safe Haskell	None
Language	Haskell2010

Crypto.Saltine.Core.SecretBox

Description

Secret-key authenticated encryption: Crypto.Saltine.Core.SecretBox

The secretbox function encrypts and authenticates a message ByteString using a secret key and a nonce. The secretboxOpen function verifies and decrypts a ciphertext ByteString using a secret key and a nonce. If the ciphertext fails validation, secretboxOpen returns Nothing.

The Crypto.Saltine.Core.SecretBox module is designed to meet the standard notions of privacy and authenticity for a secret-key authenticated-encryption scheme using nonces. For formal definitions see, e.g., Bellare and Namprempre, "Authenticated encryption: relations among notions and analysis of the generic composition paradigm," Lecture Notes in Computer Science 1976 (2000), 531–545, http://www-cse.ucsd.edu/~mihir/papers/oem.html.

Note that the length is not hidden. Note also that it is the caller's responsibility to ensure the uniqueness of nonces—for example, by using nonce 1 for the first message, nonce 2 for the second message, etc. Nonces are long enough that randomly generated nonces have negligible risk of collision.

Crypto.Saltine.Core.SecretBox is crypto_secretbox_xsalsa20poly1305, a particular combination of Salsa20 and Poly1305 specified in "Cryptography in NaCl" (http://nacl.cr.yp.to/valid.html). This function is conjectured to meet the standard notions of privacy and authenticity.

This is version 2010.08.30 of the secretbox.html web page.

Synopsis

Documentation

data Key Source

An opaque secretbox cryptographic key.

Instances

Eq Key Source
Ord Key Source
IsEncoding Key Source

data Nonce Source

An opaque secretbox nonce.

Instances

Eq Nonce Source
Ord Nonce Source
IsNonce Nonce Source
IsEncoding Nonce Source

secretbox Source

Arguments

:: Key
-> Nonce
-> ByteString	Message
-> ByteString	Ciphertext

Encrypts a message. It is infeasible for an attacker to decrypt the message so long as the Nonce is never repeated.

secretboxOpen Source

Arguments

:: Key
-> Nonce
-> ByteString	Ciphertext
-> Maybe ByteString	Message

Decrypts a message. Returns Nothing if the keys and message do not match.

newKey :: IO Key Source

Creates a random key of the correct size for secretbox.

newNonce :: IO Nonce Source

Creates a random nonce of the correct size for secretbox.