pbkdf

A password-based key derivation function (PBKDF2) per RFC2898.

Usage

A sample GHCi session:

  > :set -XOverloadedStrings
  > -- import qualified
  > import qualified Crypto.KDF.PBKDF as KDF
  >
  > -- supply your own HMAC function
  > import qualified Crypto.Hash.SHA256 as SHA256
  >
  > -- derive a 32-byte key from a secret
  > KDF.derive SHA256.hmac "my password" "my salt" 100 32
  Just "\"\NAKqxp\165S\t\212i\139\SUB(\132\176\204\224<\164\177\144\&1D\209\175\145\139[K\159h\205"

Documentation

Haddocks (API documentation, etc.) are hosted at docs.ppad.tech/pbkdf.

Performance

The aim is best-in-class performance for pure, highly-auditable Haskell code.

Current benchmark figures on an M4 Silicon MacBook Air look like (use cabal bench to run the benchmark suite):

  benchmarking ppad-pbkdf/PBKDF-SHA256/derive (outlen 32)
  time                 13.72 μs   (13.70 μs .. 13.73 μs)
                       1.000 R²   (1.000 R² .. 1.000 R²)
  mean                 13.71 μs   (13.70 μs .. 13.72 μs)
  std dev              38.24 ns   (30.32 ns .. 50.00 ns)

  benchmarking ppad-pbkdf/PBKDF-SHA512/derive (outlen 32)
  time                 15.88 μs   (15.86 μs .. 15.89 μs)
                       1.000 R²   (1.000 R² .. 1.000 R²)
  mean                 15.81 μs   (15.75 μs .. 15.84 μs)
  std dev              153.4 ns   (107.5 ns .. 249.9 ns)

Security

This library aims at the maximum security achievable in a garbage-collected language under an optimizing compiler such as GHC, in which strict constant-timeness can be challenging to achieve.

The PBKDF implementation within has been tested against the Project Wycheproof vectors available for SHA-256 and SHA-512, using the HMAC functions from ppad-sha256 and ppad-sha512 respectively.

If you discover any vulnerabilities, please disclose them via security@ppad.tech.

Development

You'll require Nix with flake support enabled. Enter a development shell with:

$ nix develop

Then do e.g.:

$ cabal repl ppad-pbkdf

to get a REPL for the main library.