v0.8.1

CHANGES:

• Add Chacha20 implementation (based on abeaumont/ocaml-chacha), supporting
  both DJB's original specification (nonce 64 bit, counter 64 bit) and IETF
  (RFC 8439: nonce 96 bit, counter 32 bit)
  (#72 @hannesm)
• Add Poly1305 implementation based on floodyberry/poly1305-donna (#72 @hannesm)
• Unified AEAD module type, implemented by CCM, GCM, and Chacha20/Poly1305
  The functions "authenticate_encrypt" and "authenticate_decrypt" are defined,
  which append (encrypt) and check equality (decrypt, using Eqaf for
  constant-time comparison) the authentication tag directly.
  Breaking changes:
  • GCM "~iv" is now "~nonce"
  • GCM encrypt returns the encrypted data and authentication tag appended
  • GCM decrypt returns the plaintext as option (None on authentication failure)
    (#73 @hannesm)