How to test reply path for onion messages

[valentinewallace]

Hi! I'm trying to test that LDK properly constructs reply_paths when sending onion messages.

I'm wondering if there's a way to send an onion message to an eclair node such that it will trigger the node to respond using the message's reply_path? :)

[t-bast]

There's nothing automatic built-in, because there's no response that really makes sense to send, it will depend on the actual scenario using onion messages.

However, it is straight-forward to add, so I went ahead and created a branch for you that automatically responds to incoming onion messages that contain a reply_path: https://github.com/ACINQ/eclair/tree/respond-to-onion-message

Thanks for the cross-impl tests!

[valentinewallace]

Oh awesome, thank you! I'll give that a shot

[valentinewallace]

@t-bast I'm running 7797292 and testing an onion message:
Eclair A -> LDK -> Eclair B --(reply)--> LDK -> Eclair A

but LDK isn't getting the reply onion message. Also don't see "sending dummy response to onion message" in eclair.log.

Running eclair command:

./bin/eclair-cli -p polarpass sendonionmessage --recipientNode=026006be22a0f7dfbed1ade19710e07580dbd2b09c8d05fce36795b4941f408ec2 --intermediateNodes=03c51ecba86e2345688512e1a8a8462c59d32b917d3af51497a72e6dee8b470358 --replyPath=03c51ecba86e2345688512e1a8a8462c59d32b917d3af51497a72e6dee8b470358 --content=2b03ffffff
{
  "sent": true,
  "failureMessage": "No response"
}

Also tried with an reply path containing both the intermediate LDK node ID and Eclair A's node id.

Here are my logs for the receiving/replying node: https://pastebin.com/gg7Wj60e

Any ideas? :)

[t-bast]

Your node is not running 7797292 @valentinewallace :)
The first log line says it all:

2022-04-08 16:11:33,233 INFO  fr.acinq.eclair.Setup - version=0.7.0 commit=a804905

This commit is eclair v0.7.0 without the custom changes to respond to onion messages.

[valentinewallace]

Ah, sorry about that @t-bast 😅

Sooo I'm now running the right commit (logs here for proof ;) https://pastebin.com/mpmMRSsy) but as you can see it's getting java.lang.IllegalStateException: No native library found: at /fr/acinq/secp256k1/jni/native/darwin-aarch64/libsecp256k1-jni.dylib.

I haven't seen this error come up in eclair's issue tracking. Doesn't seem to occur when built on the prior 0.7.0 commit. Let me know if you have any tips, otherwise I can try to cherry-pick the changes onto the 0.7.0 commit maybe..

Running on the M1 Mac btw.

[t-bast]

Hum that one is probably for @sstone, it's related to the move from bouncycastle to secp256k1 bindings...
An easy solution is indeed to just rebase the commit I gave you on top of 0.7.0, this should be trivial and should unblock you!

[sstone]

Yes sorry about that we removed fallback to bouncycastle when secp256k1 is not available but do not yet provide bindings for macos M1 (darwin-aarch64). For now unfortunately you'll have to either use an older version of eclair as Bastien suggested, or an Intel mac.