FileZilla Forums

First of all, thanks for this great tool and the development effort. I'm here to help, not criticize.

This morning, after updating the FZ client to the last version 3.45.1, I discovered that I can't retrieve directory listings against my own FTP server using explicit FTP over TLS anymore:
I also tried two older versions (that I had at hand):
FZ 3.42.1 --> doesn't work either
FZ 3.35.1 --> works great!

I found this entry in the tls.log in the server: I also tried ftptest.net with the same results.

If I include the "NoSessionReuseRequired" TLSOption in the server, everything works... with the unwanted (un)security side effect...

I can provide detailed logs/access if required.

Configurations:
FTP Server
--------------
ProFTPD Version 1.3.5e (fully updated)

FileZilla Client
----------------
Version: 3.42.1
Build information:
Compiled for: x86_64-apple-darwin18.5.0
Compiled on: x86_64-apple-darwin18.5.0
Build date: 2019-05-08
Compiled with: Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Compiler flags: -Werror=partial-availability -Wall -g -std=c++14
Linked against:
wxWidgets: 3.0.5
SQLite: 3.26.0
GnuTLS: 3.6.7
Operating system:
Name: Mac OS X (Darwin 18.7.0 x86_64)
Version: 10.14
CPU features: sse sse2 sse3 ssse3 sse4.1 sse4.2 avx avx2 aes pclmulqdq rdrnd bmi2 bmi2 lm
Settings dir: /Users/xxx/.config/filezilla/

FileZilla Client
----------------
Version: 3.45.1
Build information:
Compiled for: x86_64-apple-darwin18.7.0
Compiled on: x86_64-apple-darwin18.7.0
Build date: 2019-09-25
Compiled with: Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Compiler flags: -Werror=partial-availability -Wall -g
Linked against:
wxWidgets: 3.0.5
SQLite: 3.26.0
GnuTLS: 3.6.7
Operating system:
Name: Mac OS X (Darwin 18.7.0 x86_64)
Version: 10.14
CPU features: sse sse2 sse3 ssse3 sse4.1 sse4.2 avx avx2 aes pclmulqdq rdrnd bmi2 bmi2 lm
Settings dir: /Users/xxx/.config/filezilla/

This is a bug in your FTP server. Please try again with the most recent version of your FTP server.

botg wrote: ↑

2019-10-08 21:57

This is a bug in your FTP server. Please try again with the most recent version of your FTP server.

The last available version of the ProFTPd daemon for my Linux server distribution is 1.3.5e, so I just donwloaded and compiled the lastest versions myself:

• ProFTPd 1.3.6a
• and even the ProFTPd 1.3.7rc1

and both of them fail exactly the same way. They only work if I enable the following line in my proftpd.conf file:
mentioned here: http://www.proftpd.org/docs/howto/TLS.html

What it is strange to me, is that and older version like FileZilla 3.35.1 works fine: what have changed since then?

Best regards

To my knowledge, the error occurs only with FTP over TLS v1.3. Older FileZilla clients only worked with up to TLS 1.2.

The FTP server offers TLS 1.3 because the used OpenSSL dependency enabled it. However, it is neither aware nor does it know how to handle TLS 1.3. Limit the TLS version the server offers to 1.2 and it will probably work, short-term. Long-term, proper support for TLS 1.3 has to be added.