TLS session resumption on data connection failed. Closing control connection to start over.

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Guenther80
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TLS session resumption on data connection failed. Closing control connection to start over.

#1 Post by Guenther80 » 2021-06-18 16:14

Hi,

today i got prompted to update to 3.54.1 – and i did.

I clicked on changelog and it opened

https://filezilla-project.org/versions. ... 2&product=

...therefore i guess before the update i was using 3.52.2.

Since I updated i get lots of

TLS session resumption on data connection failed. Closing control connection to start over.

Looking at the changelog i assume this is related to
3.53.0-rc1 (2021-03-05)
New features:
Require explicit confirmation on FTP servers not supporting TLS session esumption on the data connection
Any ideas what i can do to fix this problem? right now i have to babysit the uploads to reconnect, then requeue all failed uploads which is quite cumbersome.

it seems to happen once i transmit a large file which takes long enough for the connection to end, then once the large transmition finishes the next one fails and all others fail too :(

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boco
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#2 Post by boco » 2021-06-19 00:41

The mentioned change does not have anything to do with it. It only concerns connections to servers not supporting TLS session resumption at all and require confirmation from the user. It would trigger a confirmation dialog in that case, not an error.

That being said, I'm getting that error, too, the last few versions. I'm experiencing it with one server I use, but not with FileZilla Server. My suspicion is that it could have something to do with TLS 1.3, as FileZilla Server uses only TLS 1.2 so far.

Could you please check if you are using TLS 1.3 with your server? Click the lock icon in the status bar and check the Protocol entry at the bottom.
### BEGIN SIGNATURE BLOCK ###
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Guenther80
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#3 Post by Guenther80 » 2021-06-21 07:21

boco wrote:
2021-06-19 00:41
The mentioned change does not have anything to do with it. It only concerns connections to servers not supporting TLS session resumption at all and require confirmation from the user. It would trigger a confirmation dialog in that case, not an error.
Ah, OK, did not know that.
Well, it still could be, that this feature introduced a bug as a side effect. After all, thematic, it seems pretty close to me, and it never happened for me in 3.52.2 but happens almost every time with 3.54.1 (basically every time I transmit more than a few files)
boco wrote:
2021-06-19 00:41
Could you please check if you are using TLS 1.3 with your server? Click the lock icon in the status bar and check the Protocol entry at the bottom.
TLS 1.0

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botg
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#4 Post by botg » 2021-06-21 11:39

Closing the control connection as result of a failed resume on a server supporting resume is part of the explicit confirmation feature.

If you experience this issue it means that your server isn't properly caching sessions, discarding the prematurely and probably even sharing them between unrelated control connections.

Guenther80
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#5 Post by Guenther80 » 2021-06-21 11:46

botg wrote:
2021-06-21 11:39
Closing the control connection as result of a failed resume on a server supporting resume is part of the explicit confirmation feature.

If you experience this issue it means that your server isn't properly caching sessions, discarding the prematurely and probably even sharing them between unrelated control connections.
I am a bit confused, sorry. If I understand you correct, you are trying to tell me, that its the servers fault that filezilla became unusable after upgrading filezilla?

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botg
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#6 Post by botg » 2021-06-22 07:41

I fail to see how it became unusable. It even detects the faulty server behavior and reconnects automatically.

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boco
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Re: TLS session resumption on data connection failed. Closing control connection to start over.

#7 Post by boco » 2021-06-22 17:09

In my case, all transfer after that fail as well. The recovery by closing and reconnecting is unsuccessful.

(Unfortunately, FileZilla Server is only TLS 1.2 and I don't have any other TLS 1.3 server for testing if it is TLS 1.3 or not. Hopefully, the new FileZilla Server will arrive soon.)
### BEGIN SIGNATURE BLOCK ###
No support requests per PM! You will NOT get any reply!!!
FTP connection problems? Do yourself a favor and read Network Configuration.
FileZilla connection test: https://filezilla-project.org/conntest.php
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