Quassel IRC

My Debian Buster installation of the Quassel client (version 0.12.5) fails to connect with the message "Error while setting the maximum protocol version". I verified with Wireshark that my Linux client is actually communicating to the server on port 4242.

This seems to relate to code in
qt5/qtbase/src/network/ssl/qsslcontext_openssl11.cpp.html.

I have no problem to connect to my server with the Android client.

The error did not occur before version 5.11.1+dfsg-7 of qtbase was released to Debian testing on Sept. 10, 2018.

The relevant code in qtbase was changed with
e3cea2a7b9f8 ("QSslSocket (OpenSSL 1.1) - respect requested protocol version").

This is the protocol information provided by openssl:

$ openssl s_client connect myserver.domain:4242 -prexit
CONNECTED
write:errno=0
--
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 176 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1.2
Cipher : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1536645791
Timeout : 7200 (sec)
Verify return code: 0 (ok)
Extended master secret: no
---
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 176 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1.2
Cipher : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1536645791
Timeout : 7200 (sec)
Verify return code: 0 (ok)
Extended master secret: no
---