Cannot connect using Explicit SSL/TLS :: Support Forum

matej sk
Joined:: 2014-01-21
Posts:: 3

Cannot connect using Explicit SSL/TLS

2014-01-21 18:41

Hello,

I am having trouble connecting to a FTPS server using WinSCP 5.5.1 (Build 3970), with Explicit TLS/SSL. I have tried all options of the min+max SSL/TLS version setting. The connection goes like this:

220-FileZilla Server version 0.9.41 beta
220-written by Tim Kosse (Tim.Kosse@gmx.de)
220 Please visit http://sourceforge.net/projects/filezilla/
AUTH TLS
234 Using authentication type TLS
(now client sends packet with content X to server)
(client waits for 15 seconds default)
(client sends packet with content Y to server, immediately closes TCP by FIN+ACK)

According to my wireshark debugging:

0A

I *think* the trouble here is that WinSCP incorrectly sends only part of the SSL/TLS Client Hello when it sees the supposedly-end-of-line character.

Do you need any more info?

Thank you for your help.

Edit: Running on Windows 7 Enterprise SP1, 32-bit.
Attached sample packet dump, IP addresses have been anonymized.
Reproducible always.

winscp-tlstimeout.anonymized.cap.gz (1.8 KB)

Description: TLS client timeout packet dump (gzipped due to forum restrictions)

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martin◆ Site Admin
Joined:: 2002-12-10
Posts:: 41,469
Location:: Prague, Czechia

Re: Cannot connect using Explicit SSL/TLS

2014-01-22

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

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matej sk
Joined:: 2014-01-21
Posts:: 3

Re: Cannot connect using Explicit SSL/TLS

2014-01-24 14:08

matej sk wrote:

I *think* the trouble here is that WinSCP incorrectly sends only part of the SSL/TLS Client Hello when it sees the supposedly-end-of-line character.

Sorry for the report and thank you for your time helping on e-mail.
The packet splitting at the 0x0A character seems to have been caused by my VMware Player with NAT mode networking.
The bug is not in the WinSCP client.

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Cannot connect using Explicit SSL/TLS