saltine-0.2.1.0: Cryptography that's easy to digest (NaCl/libsodium bindings).
Copyright(c) Thomas DuBuisson 2017
(c) Max Amanshauser 2021
LicenseMIT
Maintainermax@lambdalifting.org
Stabilityexperimental
Portabilitynon-portable
Safe HaskellSafe-Inferred
LanguageHaskell2010

Crypto.Saltine.Core.AEAD

Description

Secret-key authenticated encryption with additional data (AEAD): Crypto.Saltine.Core.AEAD

The aead function encrypts and authenticates a message ByteString and additional authenticated data ByteString using a secret key and a nonce. The aeadOpen function verifies and decrypts a ciphertext ByteString using a secret key and a nonce. If the ciphertext fails validation, aeadOpen returns Nothing.

The Crypto.Saltine.Core.AEAD 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. With XChaCha20Poly1305 nonces are long enough that you can also generate nonces randomly as they have negligible risk of collision.

The keysize is identical for all the *ChaCha20Poly1305* variants, but the nonce length differs. Since libsodium keeps separate definitions, we do the same.

This module reexports the XChaCha20Poly1305 variant, which is the recommended one.

Documentation