exth_crypto v0.1.6 ExthCrypto.KDF.NistSp80056

Implements NIST SP 800-56 Key Deriviation Function, as defined in http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-56Ar2.pdf.

See Section 5.8.1 “The Single-step Key-Derivation Function”

Link to this section Summary

Functions

single_step_kdf(shared_secret, key_data_len, arg, extra_data \\ <<>>)

Simples the The Single-step Key-Derivation Function as defined in NISP-SP-800-56

Link to this section Functions

single_step_kdf(shared_secret, key_data_len, arg, extra_data \\ <<>>)

single_step_kdf(binary(), integer(), ExthCrypto.Hash.hash_type(), binary()) ::
  {:ok, binary()} | {:error, String.t()}

Simples the The Single-step Key-Derivation Function as defined in NISP-SP-800-56.

Note: we do not currently support HMAC.

TODO: Test canonical tests

Examples

iex> ExthCrypto.KDF.NistSp80056.single_step_kdf("secret", 20, ExthCrypto.Hash.sha1(), "extra")
{:ok, ExthCrypto.Hash.SHA.sha1(<<0, 0, 0, 1>> <> "secret" <> "extra")}

iex> <<bytes::binary-size(32), _rest::binary()>> = ExthCrypto.Hash.SHA.sha1(<<0, 0, 0, 1>> <> "secret" <> "extra") <> ExthCrypto.Hash.SHA.sha1(<<0, 0, 0, 2>> <> "secret" <> "extra")
iex> {:ok, bytes} == ExthCrypto.KDF.NistSp80056.single_step_kdf("secret", 32, ExthCrypto.Hash.sha1(), "extra")
true

iex> ExthCrypto.KDF.NistSp80056.single_step_kdf("secret", 32, ExthCrypto.Hash.sha1(), "extra")
{:ok, <<35, 233, 145, 168, 1, 248, 54, 133, 234, 105, 153, 226, 62, 181,
        40, 209, 153, 239, 241, 41, 16, 157, 216, 219, 15, 132, 68, 116,
        206, 152, 20, 98>>}

iex> {:ok, key} = ExthCrypto.KDF.NistSp80056.single_step_kdf("secret", 200, ExthCrypto.Hash.sha1(), "extra")
iex> ExthCrypto.Math.bin_to_hex(key)
"23e991a801f83685ea6999e23eb528d199eff129109dd8db0f844474ce981462fca2dc108bde378d83d9e714a9964d9cd9b1364a167d98fbfe1f94bc6f606879f9150be2979fe27812b7de86546e1994672038b9493abfb4b959676b5927c75dd9f33489f865a71905100633412d9ae93677ca6b4b3646310550252cf1c30da0f9014c72728a66ce20489ec89c718231f163a359a282ff8f73b65e129a1980e130d58cb88d3b041eb29ea69561f0b24b80cb7f421042edf07374bfa553be44ee6b5bf4459de8ef2a"