nim-libp2p/libp2p/crypto/hkdf.nim

57 lines
1.1 KiB
Nim

# Nim-LibP2P
# Copyright (c) 2023 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: [].}
import nimcrypto
import bearssl/[kdf, 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),
)