This happens only with OMEMO enabled.

I managed to fix it by modifying the arrayBuffer <-> string methods:

  u.arrayBufferToString2 = function (ab) { 
    return new TextDecoder("utf-8").decode(ab);
  };
  u.stringToArrayBuffer2 = function (string) {
    const bytes = new TextEncoder("utf-8").encode(string)
    return bytes.buffer;
  };

Now it seems to work for me. I guess you need to implement it with a API which is supported by more/older browsers as well.

When I look at the libsignal docs: Does the api even need conversion?

Type:  ByteBuffer | ArrayBuffer | Uint8Array | String

Thanks, unfortunately TextDecoder/TextEncoder is not implemented in Edge.

https://caniuse.com/#search=textdecoder

This might be a solution: https://github.com/dcodeIO/bytebuffer.js

Does the api even need conversion?

We don't just encrypt with libsignal, the browser's builtin crypto is used to encrypt the actual message and then they keys that were generated to do that are encrypted by libsignal.

Fixed in master, will be included in the next release.

With rev 45643d5 I am not able to write encrypted messages. Receiving client running "Conversations" just does not show any new message. Receiving Client running Pidgin with Lurch is showing: "There was an error decrypting an OMEMO message addressed to this device. See the debug log for details." Lurch debug log shows "failed to decrypt payload (-10020)"

Reverted to 4.0.0 to make basic sending work again

Edit: Did not do any bisecting. Any change between Tag 4.0.0 and HEAD can be the culprit, not necessarily the change to fix this bug

@sleeksorrow thanks for reporting, I'll look into it

I did a git bisect and found that the offending commit is this one: e05b7e9