426 lines
16 KiB
Nim
426 lines
16 KiB
Nim
## Nim-LibP2P
|
|
## Copyright (c) 2019 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.
|
|
import chronos, chronicles
|
|
import nimcrypto/[sysrand, hmac, sha2, sha, hash, rijndael, twofish, bcmode]
|
|
import secure,
|
|
../../connection,
|
|
../../peerinfo,
|
|
../../stream/lpstream,
|
|
../../crypto/crypto,
|
|
../../crypto/ecnist,
|
|
../../protobuf/minprotobuf,
|
|
../../peer,
|
|
../../utility
|
|
export hmac, sha2, sha, hash, rijndael, bcmode
|
|
|
|
logScope:
|
|
topic = "secio"
|
|
|
|
const
|
|
SecioCodec* = "/secio/1.0.0"
|
|
SecioMaxMessageSize = 8 * 1024 * 1024 ## 8mb
|
|
SecioMaxMacSize = sha512.sizeDigest
|
|
SecioNonceSize = 16
|
|
SecioExchanges = "P-256,P-384,P-521"
|
|
SecioCiphers = "TwofishCTR,AES-256,AES-128"
|
|
SecioHashes = "SHA256,SHA512"
|
|
|
|
type
|
|
Secio = ref object of Secure
|
|
localPrivateKey: PrivateKey
|
|
localPublicKey: PublicKey
|
|
remotePublicKey: PublicKey
|
|
|
|
SecureCipherType {.pure.} = enum
|
|
Aes128, Aes256, Twofish
|
|
|
|
SecureMacType {.pure.} = enum
|
|
Sha1, Sha256, Sha512
|
|
|
|
SecureCipher = object
|
|
case kind: SecureCipherType
|
|
of SecureCipherType.Aes128:
|
|
ctxaes128: CTR[aes128]
|
|
of SecureCipherType.Aes256:
|
|
ctxaes256: CTR[aes256]
|
|
of SecureCipherType.Twofish:
|
|
ctxtwofish256: CTR[twofish256]
|
|
|
|
SecureMac = object
|
|
case kind: SecureMacType
|
|
of SecureMacType.Sha256:
|
|
ctxsha256: HMAC[sha256]
|
|
of SecureMacType.Sha512:
|
|
ctxsha512: HMAC[sha512]
|
|
of SecureMacType.Sha1:
|
|
ctxsha1: HMAC[sha1]
|
|
|
|
SecioConn = ref object of SecureConn
|
|
writerMac: SecureMac
|
|
readerMac: SecureMac
|
|
writerCoder: SecureCipher
|
|
readerCoder: SecureCipher
|
|
|
|
SecioError* = object of CatchableError
|
|
|
|
proc init(mac: var SecureMac, hash: string, key: openarray[byte]) =
|
|
if hash == "SHA256":
|
|
mac = SecureMac(kind: SecureMacType.Sha256)
|
|
mac.ctxsha256.init(key)
|
|
elif hash == "SHA512":
|
|
mac = SecureMac(kind: SecureMacType.Sha512)
|
|
mac.ctxsha512.init(key)
|
|
elif hash == "SHA1":
|
|
mac = SecureMac(kind: SecureMacType.Sha1)
|
|
mac.ctxsha1.init(key)
|
|
|
|
proc update(mac: var SecureMac, data: openarray[byte]) =
|
|
case mac.kind
|
|
of SecureMacType.Sha256:
|
|
update(mac.ctxsha256, data)
|
|
of SecureMacType.Sha512:
|
|
update(mac.ctxsha512, data)
|
|
of SecureMacType.Sha1:
|
|
update(mac.ctxsha1, data)
|
|
|
|
proc sizeDigest(mac: SecureMac): int {.inline.} =
|
|
case mac.kind
|
|
of SecureMacType.Sha256:
|
|
result = int(mac.ctxsha256.sizeDigest())
|
|
of SecureMacType.Sha512:
|
|
result = int(mac.ctxsha512.sizeDigest())
|
|
of SecureMacType.Sha1:
|
|
result = int(mac.ctxsha1.sizeDigest())
|
|
|
|
proc finish(mac: var SecureMac, data: var openarray[byte]) =
|
|
case mac.kind
|
|
of SecureMacType.Sha256:
|
|
discard finish(mac.ctxsha256, data)
|
|
of SecureMacType.Sha512:
|
|
discard finish(mac.ctxsha512, data)
|
|
of SecureMacType.Sha1:
|
|
discard finish(mac.ctxsha1, data)
|
|
|
|
proc reset(mac: var SecureMac) =
|
|
case mac.kind
|
|
of SecureMacType.Sha256:
|
|
reset(mac.ctxsha256)
|
|
of SecureMacType.Sha512:
|
|
reset(mac.ctxsha512)
|
|
of SecureMacType.Sha1:
|
|
reset(mac.ctxsha1)
|
|
|
|
proc init(sc: var SecureCipher, cipher: string, key: openarray[byte],
|
|
iv: openarray[byte]) {.inline.} =
|
|
if cipher == "AES-128":
|
|
sc = SecureCipher(kind: SecureCipherType.Aes128)
|
|
sc.ctxaes128.init(key, iv)
|
|
elif cipher == "AES-256":
|
|
sc = SecureCipher(kind: SecureCipherType.Aes256)
|
|
sc.ctxaes256.init(key, iv)
|
|
elif cipher == "TwofishCTR":
|
|
sc = SecureCipher(kind: SecureCipherType.Twofish)
|
|
sc.ctxtwofish256.init(key, iv)
|
|
|
|
proc encrypt(cipher: var SecureCipher, input: openarray[byte],
|
|
output: var openarray[byte]) {.inline.} =
|
|
case cipher.kind
|
|
of SecureCipherType.Aes128:
|
|
cipher.ctxaes128.encrypt(input, output)
|
|
of SecureCipherType.Aes256:
|
|
cipher.ctxaes256.encrypt(input, output)
|
|
of SecureCipherType.Twofish:
|
|
cipher.ctxtwofish256.encrypt(input, output)
|
|
|
|
proc decrypt(cipher: var SecureCipher, input: openarray[byte],
|
|
output: var openarray[byte]) {.inline.} =
|
|
case cipher.kind
|
|
of SecureCipherType.Aes128:
|
|
cipher.ctxaes128.decrypt(input, output)
|
|
of SecureCipherType.Aes256:
|
|
cipher.ctxaes256.decrypt(input, output)
|
|
of SecureCipherType.Twofish:
|
|
cipher.ctxtwofish256.decrypt(input, output)
|
|
|
|
proc macCheckAndDecode(sconn: SecioConn, data: var seq[byte]): bool =
|
|
## This procedure checks MAC of recieved message ``data`` and if message is
|
|
## authenticated, then decrypt message.
|
|
##
|
|
## Procedure returns ``false`` if message is too short or MAC verification
|
|
## failed.
|
|
var macData: array[SecioMaxMacSize, byte]
|
|
let macsize = sconn.readerMac.sizeDigest()
|
|
if len(data) < macsize:
|
|
trace "Message is shorter then MAC size", message_length = len(data),
|
|
mac_size = macsize
|
|
return false
|
|
let mark = len(data) - macsize
|
|
sconn.readerMac.update(data.toOpenArray(0, mark - 1))
|
|
sconn.readerMac.finish(macData)
|
|
sconn.readerMac.reset()
|
|
if not equalMem(addr data[mark], addr macData[0], macsize):
|
|
trace "Invalid MAC",
|
|
calculated = toHex(macData.toOpenArray(0, macsize - 1)),
|
|
stored = toHex(data.toOpenArray(mark, len(data) - 1))
|
|
return false
|
|
|
|
sconn.readerCoder.decrypt(data.toOpenArray(0, mark - 1),
|
|
data.toOpenArray(0, mark - 1))
|
|
data.setLen(mark)
|
|
result = true
|
|
|
|
method readMessage(sconn: SecioConn): Future[seq[byte]] {.async.} =
|
|
## Read message from channel secure connection ``sconn``.
|
|
try:
|
|
var buf = newSeq[byte](4)
|
|
await sconn.readExactly(addr buf[0], 4)
|
|
let length = (int(buf[0]) shl 24) or (int(buf[1]) shl 16) or
|
|
(int(buf[2]) shl 8) or (int(buf[3]))
|
|
trace "Recieved message header", header = buf.shortLog, length = length
|
|
if length <= SecioMaxMessageSize:
|
|
buf.setLen(length)
|
|
await sconn.readExactly(addr buf[0], length)
|
|
trace "Received message body", length = length,
|
|
buffer = buf.shortLog
|
|
if sconn.macCheckAndDecode(buf):
|
|
result = buf
|
|
else:
|
|
trace "Message MAC verification failed", buf = buf.shortLog
|
|
else:
|
|
trace "Received message header size is more then allowed",
|
|
length = length, allowed_length = SecioMaxMessageSize
|
|
except AsyncStreamIncompleteError:
|
|
trace "Connection dropped while reading"
|
|
except AsyncStreamReadError:
|
|
trace "Error reading from connection"
|
|
|
|
method writeMessage(sconn: SecioConn, message: seq[byte]) {.async.} =
|
|
## Write message ``message`` to secure connection ``sconn``.
|
|
let macsize = sconn.writerMac.sizeDigest()
|
|
var msg = newSeq[byte](len(message) + 4 + macsize)
|
|
sconn.writerCoder.encrypt(message, msg.toOpenArray(4, 4 + len(message) - 1))
|
|
let mo = 4 + len(message)
|
|
sconn.writerMac.update(msg.toOpenArray(4, 4 + len(message) - 1))
|
|
sconn.writerMac.finish(msg.toOpenArray(mo, mo + macsize - 1))
|
|
sconn.writerMac.reset()
|
|
let length = len(message) + macsize
|
|
msg[0] = byte((length shr 24) and 0xFF)
|
|
msg[1] = byte((length shr 16) and 0xFF)
|
|
msg[2] = byte((length shr 8) and 0xFF)
|
|
msg[3] = byte(length and 0xFF)
|
|
trace "Writing message", message = msg.shortLog
|
|
try:
|
|
await sconn.write(msg)
|
|
except AsyncStreamWriteError:
|
|
trace "Could not write to connection"
|
|
|
|
proc newSecioConn(conn: Connection,
|
|
hash: string,
|
|
cipher: string,
|
|
secrets: Secret,
|
|
order: int,
|
|
remotePubKey: PublicKey): SecioConn =
|
|
## Create new secure connection, using specified hash algorithm ``hash``,
|
|
## cipher algorithm ``cipher``, stretched keys ``secrets`` and order
|
|
## ``order``.
|
|
new result
|
|
|
|
result.stream = conn
|
|
result.closeEvent = newAsyncEvent()
|
|
|
|
let i0 = if order < 0: 1 else: 0
|
|
let i1 = if order < 0: 0 else: 1
|
|
|
|
trace "Writer credentials", mackey = secrets.macOpenArray(i0).shortLog,
|
|
enckey = secrets.keyOpenArray(i0).shortLog,
|
|
iv = secrets.ivOpenArray(i0).shortLog
|
|
trace "Reader credentials", mackey = secrets.macOpenArray(i1).shortLog,
|
|
enckey = secrets.keyOpenArray(i1).shortLog,
|
|
iv = secrets.ivOpenArray(i1).shortLog
|
|
result.writerMac.init(hash, secrets.macOpenArray(i0))
|
|
result.readerMac.init(hash, secrets.macOpenArray(i1))
|
|
result.writerCoder.init(cipher, secrets.keyOpenArray(i0),
|
|
secrets.ivOpenArray(i0))
|
|
result.readerCoder.init(cipher, secrets.keyOpenArray(i1),
|
|
secrets.ivOpenArray(i1))
|
|
|
|
result.peerInfo = PeerInfo.init(remotePubKey)
|
|
|
|
proc transactMessage(conn: Connection,
|
|
msg: seq[byte]): Future[seq[byte]] {.async.} =
|
|
var buf = newSeq[byte](4)
|
|
try:
|
|
trace "Sending message", message = msg.shortLog, length = len(msg)
|
|
await conn.write(msg)
|
|
await conn.readExactly(addr buf[0], 4)
|
|
let length = (int(buf[0]) shl 24) or (int(buf[1]) shl 16) or
|
|
(int(buf[2]) shl 8) or (int(buf[3]))
|
|
trace "Recieved message header", header = buf.shortLog, length = length
|
|
if length <= SecioMaxMessageSize:
|
|
buf.setLen(length)
|
|
await conn.readExactly(addr buf[0], length)
|
|
trace "Received message body", conn = $conn,
|
|
length = length,
|
|
buff = buf.shortLog
|
|
result = buf
|
|
else:
|
|
trace "Received size of message exceed limits", conn = $conn,
|
|
length = length
|
|
except AsyncStreamIncompleteError:
|
|
trace "Connection dropped while reading", conn = $conn
|
|
except AsyncStreamReadError:
|
|
trace "Error reading from connection", conn = $conn
|
|
except AsyncStreamWriteError:
|
|
trace "Could not write to connection", conn = $conn
|
|
|
|
method handshake*(s: Secio, conn: Connection, initiator: bool = false): Future[SecureConn] {.async.} =
|
|
var
|
|
localNonce: array[SecioNonceSize, byte]
|
|
remoteNonce: seq[byte]
|
|
remoteBytesPubkey: seq[byte]
|
|
remoteEBytesPubkey: seq[byte]
|
|
remoteEBytesSig: seq[byte]
|
|
remotePubkey: PublicKey
|
|
remoteEPubkey: PublicKey = PublicKey(scheme: ECDSA)
|
|
remoteESignature: Signature
|
|
remoteExchanges: string
|
|
remoteCiphers: string
|
|
remoteHashes: string
|
|
remotePeerId: PeerID
|
|
localPeerId: PeerID
|
|
localBytesPubkey = s.localPublicKey.getBytes()
|
|
|
|
if randomBytes(localNonce) != SecioNonceSize:
|
|
raise newException(CatchableError, "Could not generate random data")
|
|
|
|
var request = createProposal(localNonce,
|
|
localBytesPubkey,
|
|
SecioExchanges,
|
|
SecioCiphers,
|
|
SecioHashes)
|
|
|
|
localPeerId = PeerID.init(s.localPublicKey)
|
|
|
|
trace "Local proposal", schemes = SecioExchanges,
|
|
ciphers = SecioCiphers,
|
|
hashes = SecioHashes,
|
|
pubkey = localBytesPubkey.shortLog,
|
|
peer = localPeerId
|
|
|
|
var answer = await transactMessage(conn, request)
|
|
|
|
if len(answer) == 0:
|
|
trace "Proposal exchange failed", conn = $conn
|
|
raise newException(SecioError, "Proposal exchange failed")
|
|
|
|
if not decodeProposal(answer, remoteNonce, remoteBytesPubkey, remoteExchanges,
|
|
remoteCiphers, remoteHashes):
|
|
trace "Remote proposal decoding failed", conn = $conn
|
|
raise newException(SecioError, "Remote proposal decoding failed")
|
|
|
|
if not remotePubkey.init(remoteBytesPubkey):
|
|
trace "Remote public key incorrect or corrupted", pubkey = remoteBytesPubkey.shortLog
|
|
raise newException(SecioError, "Remote public key incorrect or corrupted")
|
|
|
|
remotePeerId = PeerID.init(remotePubkey)
|
|
|
|
# TODO: PeerID check against supplied PeerID
|
|
let order = getOrder(remoteBytesPubkey, localNonce, localBytesPubkey,
|
|
remoteNonce)
|
|
trace "Remote proposal", schemes = remoteExchanges, ciphers = remoteCiphers,
|
|
hashes = remoteHashes,
|
|
pubkey = remoteBytesPubkey.shortLog, order = order,
|
|
peer = remotePeerId
|
|
|
|
let scheme = selectBest(order, SecioExchanges, remoteExchanges)
|
|
let cipher = selectBest(order, SecioCiphers, remoteCiphers)
|
|
let hash = selectBest(order, SecioHashes, remoteHashes)
|
|
if len(scheme) == 0 or len(cipher) == 0 or len(hash) == 0:
|
|
trace "No algorithms in common", peer = remotePeerId
|
|
raise newException(SecioError, "No algorithms in common")
|
|
|
|
trace "Encryption scheme selected", scheme = scheme, cipher = cipher,
|
|
hash = hash
|
|
|
|
var ekeypair = ephemeral(scheme)
|
|
# We need EC public key in raw binary form
|
|
var epubkey = ekeypair.pubkey.eckey.getRawBytes()
|
|
var localCorpus = request[4..^1] & answer & epubkey
|
|
var signature = s.localPrivateKey.sign(localCorpus)
|
|
|
|
var localExchange = createExchange(epubkey, signature.getBytes())
|
|
var remoteExchange = await transactMessage(conn, localExchange)
|
|
if len(remoteExchange) == 0:
|
|
trace "Corpus exchange failed", conn = $conn
|
|
raise newException(SecioError, "Corpus exchange failed")
|
|
|
|
if not decodeExchange(remoteExchange, remoteEBytesPubkey, remoteEBytesSig):
|
|
trace "Remote exchange decoding failed", conn = $conn
|
|
raise newException(SecioError, "Remote exchange decoding failed")
|
|
|
|
if not remoteESignature.init(remoteEBytesSig):
|
|
trace "Remote signature incorrect or corrupted", signature = remoteEBytesSig.shortLog
|
|
raise newException(SecioError, "Remote signature incorrect or corrupted")
|
|
|
|
var remoteCorpus = answer & request[4..^1] & remoteEBytesPubkey
|
|
if not remoteESignature.verify(remoteCorpus, remotePubkey):
|
|
trace "Signature verification failed", scheme = $remotePubkey.scheme,
|
|
signature = $remoteESignature,
|
|
pubkey = $remotePubkey,
|
|
corpus = $remoteCorpus
|
|
raise newException(SecioError, "Signature verification failed")
|
|
|
|
trace "Signature verified", scheme = remotePubkey.scheme
|
|
|
|
if not remoteEPubkey.eckey.initRaw(remoteEBytesPubkey):
|
|
trace "Remote ephemeral public key incorrect or corrupted",
|
|
pubkey = toHex(remoteEBytesPubkey)
|
|
raise newException(SecioError, "Remote ephemeral public key incorrect or corrupted")
|
|
|
|
var secret = getSecret(remoteEPubkey, ekeypair.seckey)
|
|
if len(secret) == 0:
|
|
trace "Shared secret could not be created",
|
|
pubkeyScheme = remoteEPubkey.scheme,
|
|
seckeyScheme = ekeypair.seckey.scheme
|
|
raise newException(SecioError, "Shared secret could not be created")
|
|
|
|
trace "Shared secret calculated", secret = secret.shortLog
|
|
|
|
var keys = stretchKeys(cipher, hash, secret)
|
|
|
|
trace "Authenticated encryption parameters",
|
|
iv0 = toHex(keys.ivOpenArray(0)), key0 = keys.keyOpenArray(0).shortLog,
|
|
mac0 = keys.macOpenArray(0).shortLog,
|
|
iv1 = keys.ivOpenArray(1).shortLog, key1 = keys.keyOpenArray(1).shortLog,
|
|
mac1 = keys.macOpenArray(1).shortLog
|
|
|
|
# Perform Nonce exchange over encrypted channel.
|
|
|
|
var secioConn = newSecioConn(conn, hash, cipher, keys, order, remotePubkey)
|
|
result = secioConn
|
|
await secioConn.writeMessage(remoteNonce)
|
|
var res = await secioConn.readMessage()
|
|
|
|
if res != @localNonce:
|
|
trace "Nonce verification failed", receivedNonce = res.shortLog,
|
|
localNonce = localNonce.shortLog
|
|
raise newException(CatchableError, "Nonce verification failed")
|
|
else:
|
|
trace "Secure handshake succeeded"
|
|
|
|
method init(s: Secio) {.gcsafe.} =
|
|
procCall Secure(s).init()
|
|
s.codec = SecioCodec
|
|
|
|
proc newSecio*(localPrivateKey: PrivateKey): Secio =
|
|
new result
|
|
result.localPrivateKey = localPrivateKey
|
|
result.localPublicKey = localPrivateKey.getKey()
|
|
result.init()
|