72 lines
2.1 KiB
Nim
72 lines
2.1 KiB
Nim
when defined(server):
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import mummy
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when defined(client):
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import whisky
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import times, json, zippy
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import ./[types, utils, serialize, crypto]
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proc sendEvent*(ws: WebSocket, event: Event, key: Key = default(Key)) =
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var packer = Packer.init()
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let iv = generateBytes(Iv)
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var data = string.toBytes($event.data)
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packer.add(cast[uint8](event.eventType))
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packer.add(cast[uint32](event.timestamp))
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if event.eventType != CLIENT_KEY_EXCHANGE and event.eventType != CLIENT_HEARTBEAT:
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# Compress data
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let compressed = compress(data, BestCompression, dfGzip)
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# Encrypt data
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let (encData, gmac) = encrypt(key, iv, compressed)
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packer.addData(iv) # 12 bytes IV
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packer.addData(gmac) # 16 bytes Authentication Tag
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packer.addDataWithLengthPrefix(encData)
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else:
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packer.addDataWithLengthPrefix(data)
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let body = packer.pack()
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ws.send(Bytes.toString(body), BinaryMessage)
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proc recvEvent*(message: Message, key: Key = default(Key)): Event =
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var unpacker = Unpacker.init(message.data)
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let
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eventType = cast[EventType](unpacker.getUint8())
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timestamp = cast[int64](unpacker.getUint32())
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var data: string
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if eventType != CLIENT_KEY_EXCHANGE and eventType != CLIENT_HEARTBEAT:
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let
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iv = unpacker.getByteArray(Iv)
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gmac = unpacker.getByteArray(AuthenticationTag)
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encData = string.toBytes(unpacker.getDataWithLengthPrefix())
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# Decrypt data
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let (decData, tag) = decrypt(key, iv, encData)
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if tag != gmac:
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raise newException(CatchableError, "Invalid authentication tag.")
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# Decompress data
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data = Bytes.toString(uncompress(decData, dfGzip))
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else:
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data = unpacker.getDataWithLengthPrefix()
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return Event(
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eventType: eventType,
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timestamp: timestamp,
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data: parseJson(data)
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)
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proc sendHeartbeat*(ws: WebSocket) =
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let event = Event(
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eventType: CLIENT_HEARTBEAT,
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timestamp: now().toTime().toUnix(),
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data: %*{}
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)
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ws.sendEvent(event) |