Sesame-Server/Sources/App/API/ServerMessage.swift
2023-08-09 16:26:07 +02:00

48 lines
1.3 KiB
Swift

import Foundation
import NIOCore
#if canImport(CryptoKit)
import CryptoKit
#else
import Crypto
#endif
struct ServerMessage {
static let authTokenSize = SHA256.byteCount
static let maxLength = authTokenSize + 200
let authToken: Data
let message: Data
/**
Decode a message from a byte buffer.
The buffer must contain at least `ServerMessage.length` bytes, or it will return `nil`.
- Parameter buffer: The buffer containing the bytes.
*/
init?(decodeFrom buffer: ByteBuffer) {
guard buffer.readableBytes < ServerMessage.maxLength else {
log("Received invalid message with \(buffer.readableBytes) bytes")
return nil
}
guard let data = buffer.getBytes(at: 0, length: buffer.readableBytes) else {
log("Failed to read bytes of received message")
return nil
}
self.authToken = Data(data.prefix(ServerMessage.authTokenSize))
self.message = Data(data.dropFirst(ServerMessage.authTokenSize))
}
static func token(from buffer: ByteBuffer) -> Data? {
guard buffer.readableBytes == authTokenSize else {
return nil
}
guard let bytes = buffer.getBytes(at: 0, length: authTokenSize) else {
return nil
}
return Data(bytes)
}
}