nim-libp2p/libp2p/crypto/curve25519.nim
Giovanni Petrantoni c02fca25f8
Noise (#90)
* Start ChaCha20Poly1305 integration (BearSSL)

* Add Curve25519 (BearSSL) required operations for noise

* Fix curve mulgen iterate/derive

* Fix misleading header

* Add chachapoly proper test

* Curve25519 integration tests (failing, something is wrong)

* Add few converters, finish c25519 integration tests

* Remove implicit converters

* removed internal globals

* Start noise implementation

* Fix public() using proper bear mulgen

* Noise protocol WIP

* Noise progress

* Add a quick nim version of HKDF

* Converted hkdf to iterator, useful for noise

* Noise protocol implementation progress

* Noise progress

* XX handshake almost there

* noise progress

* Noise, testing handshake with test vectors

* Noise handshake progress, still wrong somewhere!

* Noise handshake success!

* Full verified noise XX handshake completed

* Fix and rewrite test to be similar to switch one

* Start with connection upgrade

* Switch chachapoly to CT implementations

* Improve HKDF implementation

* Use a type insted of tuple for HandshakeResult

* Remove unnecessary Let

* More cosmetic fixes

* Properly check randomBytes result

* Fix chachapoly signature

* Noise full circle (altho dispatcher is nil cursed)

* Allow nil aads in chachapoly routines

* Noise implementation up to running full test

* Use bearssl HKDF as well

* Directly use bearssl rng for curve25519 keys

* Add a (disabled/no CI) noise interop test server

* WIP on fixing interop issues

* More fixes in noise implementation for interop

* bump chronos requirement (nimble)

* Add a chachapoly test for very small size payloads

* Noise, more tracing

* Add 2 properly working noise tests

* Fix payload packing, following the spec properly (and not go version but
rather rust)

* Sanity, replace discard with asyncCheck

* Small fixes and optimization

* Use stew endian2 rather then system endian module

* Update nimble deps (chronos)

* Minor cosmetic/code sanity fixes

* Noise, handle Nonce max

* Noise tests, make sure to close secured conns

* More polish, improve code readability too

* More polish and testing again which test fails

* Further polishing

* Restore noise tests

* Remove useless Future[void]

* Remove useless CipherState initializer

* add a proper read wait future in second noise test

* Remove noise generic secure implementation for now

* Few fixes to run eth2 sim

* Add more debug info in noise traces

* Merge size + payload write in sendEncryptedMessage

* Revert secure interface, add outgoing property directly in newNoise

* remove sendEncrypted and receiveEncrypted

* Use openarray in chachapoly and curve25519 helpers
2020-03-17 13:30:01 +01:00

113 lines
4.8 KiB
Nim

## Nim-Libp2p
## Copyright (c) 2020 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
import bearssl
import nimcrypto/sysrand
const
Curve25519KeySize* = 32
type
Curve25519* = object
Curve25519Key* = array[Curve25519KeySize, byte]
pcuchar = ptr cuchar
Curver25519RngError* = object of CatchableError
proc intoCurve25519Key*(s: openarray[byte]): Curve25519Key =
assert s.len == Curve25519KeySize
copyMem(addr result[0], unsafeaddr s[0], Curve25519KeySize)
proc getBytes*(key: Curve25519Key): seq[byte] = @key
const
ForbiddenCurveValues: array[12, Curve25519Key] = [
[0.byte, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[1.byte, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[224.byte, 235, 122, 124, 59, 65, 184, 174, 22, 86, 227, 250, 241, 159, 196, 106, 218, 9, 141, 235, 156, 50, 177, 253, 134, 98, 5, 22, 95, 73, 184, 0],
[95.byte, 156, 149, 188, 163, 80, 140, 36, 177, 208, 177, 85, 156, 131, 239, 91, 4, 68, 92, 196, 88, 28, 142, 134, 216, 34, 78, 221, 208, 159, 17, 87],
[236.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 127],
[237.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 127],
[238.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 127],
[205.byte, 235, 122, 124, 59, 65, 184, 174, 22, 86, 227, 250, 241, 159, 196, 106, 218, 9, 141, 235, 156, 50, 177, 253, 134, 98, 5, 22, 95, 73, 184, 128],
[76.byte, 156, 149, 188, 163, 80, 140, 36, 177, 208, 177, 85, 156, 131, 239, 91, 4, 68, 92, 196, 88, 28, 142, 134, 216, 34, 78, 221, 208, 159, 17, 215],
[217.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255],
[218.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255],
[219.byte, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 25],
]
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], dst: var Curve25519Key, scalar: Curve25519Key, point: Curve25519Key) =
let defaultBrEc = brEcGetDefault()
# The source point is provided in array G (of size Glen bytes);
# the multiplication result is written over it.
dst = scalar
# point needs to be big-endian
var
rpoint = point
rpoint.byteswap()
let
res = defaultBrEc.mul(
cast[pcuchar](addr dst[0]),
Curve25519KeySize,
cast[pcuchar](addr rpoint[0]),
Curve25519KeySize,
EC_curve25519)
assert res == 1
proc mulgen*(_: type[Curve25519], dst: var Curve25519Key, point: Curve25519Key) =
let defaultBrEc = brEcGetDefault()
var
rpoint = point
rpoint.byteswap()
block iterate:
while true:
block derive:
let
size = defaultBrEc.mulgen(
cast[pcuchar](addr dst[0]),
cast[pcuchar](addr rpoint[0]),
Curve25519KeySize,
EC_curve25519)
assert size == Curve25519KeySize
for forbid in ForbiddenCurveValues:
if dst == forbid:
break derive
break iterate
proc public*(private: Curve25519Key): Curve25519Key =
Curve25519.mulgen(result, private)
proc random*(_: type[Curve25519Key]): Curve25519Key =
var rng: BrHmacDrbgContext
let seeder = brPrngSeederSystem(nil)
brHmacDrbgInit(addr rng, addr sha256Vtable, nil, 0)
if seeder(addr rng.vtable) == 0:
raise newException(ValueError, "Could not seed RNG")
let defaultBrEc = brEcGetDefault()
if brEcKeygen(addr rng.vtable, defaultBrEc, nil, addr result[0], EC_curve25519) != Curve25519KeySize:
raise newException(Curver25519RngError, "Could not generate random data")