mirror of https://github.com/vacp2p/nim-libp2p.git
84 lines
2.3 KiB
Nim
84 lines
2.3 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.
|
|
|
|
## This module integrates BearSSL Cyrve25519 mul and mulgen
|
|
##
|
|
## This module uses unmodified parts of code from
|
|
## BearSSL library <https://bearssl.org/>
|
|
## Copyright(C) 2018 Thomas Pornin <pornin@bolet.org>.
|
|
|
|
# RFC @ https://tools.ietf.org/html/rfc7748
|
|
|
|
{.push raises: [].}
|
|
|
|
import bearssl/[ec, rand]
|
|
import stew/results
|
|
from stew/assign2 import assign
|
|
export results
|
|
|
|
const Curve25519KeySize* = 32
|
|
|
|
type
|
|
Curve25519* = object
|
|
Curve25519Key* = array[Curve25519KeySize, byte]
|
|
Curve25519Error* = enum
|
|
Curver25519GenError
|
|
|
|
proc intoCurve25519Key*(s: openArray[byte]): Curve25519Key =
|
|
assert s.len == Curve25519KeySize
|
|
assign(result, s)
|
|
|
|
proc getBytes*(key: Curve25519Key): seq[byte] =
|
|
@key
|
|
|
|
proc byteswap(buf: var Curve25519Key) {.inline.} =
|
|
for i in 0 ..< 16:
|
|
let x = buf[i]
|
|
buf[i] = buf[31 - i]
|
|
buf[31 - i] = x
|
|
|
|
proc mul*(_: type[Curve25519], point: var Curve25519Key, multiplier: Curve25519Key) =
|
|
let defaultBrEc = ecGetDefault()
|
|
|
|
# multiplier needs to be big-endian
|
|
var multiplierBs = multiplier
|
|
multiplierBs.byteswap()
|
|
let res = defaultBrEc.mul(
|
|
addr point[0],
|
|
Curve25519KeySize,
|
|
addr multiplierBs[0],
|
|
Curve25519KeySize,
|
|
EC_curve25519,
|
|
)
|
|
assert res == 1
|
|
|
|
proc mulgen(_: type[Curve25519], dst: var Curve25519Key, point: Curve25519Key) =
|
|
let defaultBrEc = ecGetDefault()
|
|
|
|
var rpoint = point
|
|
rpoint.byteswap()
|
|
|
|
let size =
|
|
defaultBrEc.mulgen(addr dst[0], addr rpoint[0], Curve25519KeySize, EC_curve25519)
|
|
|
|
assert size == Curve25519KeySize
|
|
|
|
proc public*(private: Curve25519Key): Curve25519Key =
|
|
Curve25519.mulgen(result, private)
|
|
|
|
proc random*(_: type[Curve25519Key], rng: var HmacDrbgContext): Curve25519Key =
|
|
var res: Curve25519Key
|
|
let defaultBrEc = ecGetDefault()
|
|
let len = ecKeygen(addr rng.vtable, defaultBrEc, nil, addr res[0], EC_curve25519)
|
|
# Per bearssl documentation, the keygen only fails if the curve is
|
|
# unrecognised -
|
|
doAssert len == Curve25519KeySize, "Could not generate curve"
|
|
|
|
res
|