public EncryptedMessage(NodeDssMessage msg, byte[] Key, byte[] IV)
{
var jsonMessage = JsonUtility.ToJson(msg);
Cipher = System.Convert.ToBase64String(AES.EncryptStringToBytes_Aes(jsonMessage, Key, IV));
Hmac = System.Convert.ToBase64String(HMAC.Sign(Key, jsonMessage));
}
/// <summary>
/// Internal helper for sending HTTP data to the node-dss server using POST
/// </summary>
/// <param name="msg">the message to send</param>
private IEnumerator PostToServer(NodeDssMessage msg)
{
if (RemotePeerId.Length == 0)
{
throw new InvalidOperationException("Cannot send SDP message to remote peer; invalid empty remote peer ID.");
}
byte[] data;
if (Encrypt)
{
data = System.Text.Encoding.UTF8.GetBytes(JsonUtility.ToJson(new EncryptedMessage(msg, this.Key, this.IV)));
}
else
{
data = System.Text.Encoding.UTF8.GetBytes(JsonUtility.ToJson(msg));
}
var www = new UnityWebRequest($"{HttpServerAddress}data/{RemotePeerId}", UnityWebRequest.kHttpVerbPOST);
www.uploadHandler = new UploadHandlerRaw(data);
yield return(www.SendWebRequest());
if (AutoLogErrors && (www.isNetworkError || www.isHttpError))
{
Debug.Log($"Failed to send message to remote peer {RemotePeerId}: {www.error}");
}
}
/// <summary>
/// Internal helper to wrap a coroutine into a synchronous call for use inside
/// a <see cref="Task"/> object.
/// </summary>
/// <param name="msg">the message to send</param>
private IEnumerator PostToServerAndWait(NodeDssMessage message, TaskCompletionSource <bool> tcs)
{
yield return(StartCoroutine(PostToServer(message)));
const bool dummy = true; // unused
tcs.SetResult(dummy);
}
private Task SendMessageImplAsync(NodeDssMessage message)
{
// This method needs to return a Task object which gets completed once the signaler message
// has been sent. Because the implementation uses a Unity coroutine, use a reset event to
// signal the task to complete from the coroutine after the message is sent.
// Note that the coroutine is a Unity object so needs to be started from the main Unity app thread.
// Also note that TaskCompletionSource<bool> is used as a no-result variant; there is no meaning
// to the bool value.
// https://stackoverflow.com/questions/11969208/non-generic-taskcompletionsource-or-alternative
var tcs = new TaskCompletionSource <bool>();
_mainThreadWorkQueue.Enqueue(() => StartCoroutine(PostToServerAndWait(message, tcs)));
return(tcs.Task);
}
public static NodeDssMessage DecryptMessage(string cipherText, string hmac, byte[] Key, byte[] IV)
{
byte[] cipherBytes = System.Convert.FromBase64String(cipherText);
byte[] hmacBytes = System.Convert.FromBase64String(hmac);
var jsonPlainText = AES.DecryptStringFromBytes_Aes(cipherBytes, Key, IV);
if (HMAC.Verify(Key, jsonPlainText, hmacBytes))
{
NodeDssMessage nodeMessage = JsonUtility.FromJson <NodeDssMessage>(jsonPlainText);
return(nodeMessage);
}
else
{
throw new InvalidOperationException("Cannot verify the sender of the SDP message; invalid HMAC");
}
}
