nim-libp2p/libp2p/crypto/hkdf.nim

34 lines
1.0 KiB
Nim

# Nim-LibP2P
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
# at your option.
# This file may not be copied, modified, or distributed except according to
# those terms.
# https://tools.ietf.org/html/rfc5869
{.push raises: [Defect].}
import nimcrypto
import bearssl/[kdf, rand, hash]
type HkdfResult*[len: static int] = array[len, byte]
proc hkdf*[T: sha256; len: static int](_: type[T]; salt, ikm, info: openArray[byte]; outputs: var openArray[HkdfResult[len]]) =
var
ctx: HkdfContext
hkdfInit(
ctx, addr sha256Vtable,
if salt.len > 0: unsafeAddr salt[0] else: nil, csize_t(salt.len))
hkdfInject(
ctx, if ikm.len > 0: unsafeAddr ikm[0] else: nil, csize_t(ikm.len))
hkdfFlip(ctx)
for i in 0..outputs.high:
discard hkdfProduce(
ctx,
if info.len > 0: unsafeAddr info[0]
else: nil, csize_t(info.len),
addr outputs[i][0], csize_t(outputs[i].len))