Sample Node Signatures dont seem to work on websites now

[TheBlueMatt]

They seemed to use to work great any time I tried them, but now when I try them it either fails or seems to recover a different pubkey than mine (which is indistinguishable from an invalid signature). I don't see anything that changed in our code so maybe something changed elsewhere or we're buggy for some messages?

[dunxen]

BOLT 11 signature recovery? Not sure I follow.

[TheBlueMatt]

No, like the zbase32 signmessage stuff - I'm not sure why, but I used to login to amboss/etc/etc all totally fine on ldk-sample with the signing command there but now its reliably failing, so needs investigation. Also cc @tnull cause I know he recently added that to ldk-node not sure if he tested it.

[dunxen]

No, like the zbase32 signmessage stuff

Didn't know the sample had that. Probably just missed it. I'm playing with it at the moment for V2 establishment stuff. Might take a peek.

[TheBlueMatt]

Still need to look at this, but it hasn't happened yet and we haven't touched the code so I'm still dubious its our fault.

[tnull]

Mh, just tested with LDK Node and could log on to Amboss without issue:

let message = "amboss-XXXXXXXX";
let sig = node.sign_message(message.as_bytes()).unwrap();
println!("SIG: {}", sig);

where sign_message calls lightning::message_signing::sign(msg, &keys_manager.get_node_secret_key()) internally.

[tnull]

One potential error source might be that the sample's signmessage command includes a LF in the message for me:

> signmessage asdf
LINE: [115, 105, 103, 110, 109, 101, 115, 115, 97, 103, 101, 32, 97, 115, 100, 102, 10]
MSG_START_POS: 12
LINE_FROM_POS: [97, 115, 100, 102, 10]

Unfortunately I don't have a sample node running on mainnet so can't verify if removing the last character indeed let's me log into Amboss, but I assume dropping the last char would help.

@TheBlueMatt could you verify this is the case?

[TheBlueMatt]

Yep, that works!