Does Delta Chat support TLS 1.3


I run a dovecot IMAP server configured to allow TLS 1.3 only. Delta Chat fails to login unless I allow TLS 1.2 as well (log snippet attached). Since my dovecot config works well with other mail clients I wanted to ask whether Delta Chat does support TLS 1.3 at all (especially on iOS).

However, the dovecot log indicates that TLS 1.3 is not supported.

Pardon me if this question has been answered somewhere else. I cloudn’t find anything on Github or here.

Delta Chat version
v.1.32.0 (iOS)

Expected behavior
Delta Chat successfully perfoms the TLS handshake

Actual behavior
IMAP login fails

Steps to reproduce the problem

  1. Configure dovecot with ssl_min_protocol = TLSv1.3
  2. Try to log in with Delta Chat

Debug logs

dovecot: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:0A000102:SSL routines::unsupported protocol (no auth attempts in 0 secs):

Delta Chat: Error: error code -9806

We created an issue for this