[PROBLEM] 425 Unable to build data connection: Operation not permitted

[diez.david]

Hello,

I have an issue that forbids me to download a whole list at once.
FlashFXP downloads and retrieves 1 file and when it's complete FlashFXP can't connect anymore to the server, giving "425 Unable to build data connection: Operation not permitted" error, failing the transfer.

Here's an example log:

[18:30:12] [R] Connecting to Server -> IP=[server's IP] PORT=21 (attempt # 1)
[18:30:12] [R] Connected to Server
[18:30:12] [R] 220 ProFTPD 1.3.3a Server ([unknown IP]) [[server's IP]]
[18:30:12] [R] AUTH TLS
[18:30:12] [R] 234 AUTH TLS successful
[18:30:12] [R] Connected. Negotiating TLSv1 session
[18:30:12] [R] TLSv1 negotiation successful...
[18:30:12] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[18:30:12] [R] PBSZ 0
[18:30:12] [R] 200 PBSZ 0 successful
[18:30:12] [R] USER admin
[18:30:13] [R] 331 Password required for admin
[18:30:13] [R] PASS (hidden)
[18:30:14] [R] 230 Welcome, admin.
[18:30:14] [R] SYST
[18:30:14] [R] 215 UNIX Type: L8
[18:30:14] [R] FEAT
[18:30:14] [R] 211-Features:
[18:30:14] [R] MDTM
[18:30:14] [R] MFMT
[18:30:14] [R] TVFS
[18:30:14] [R] AUTH TLS
[18:30:14] [R] MFF modify;UNIX.group;UNIX.mode;
[18:30:14] [R] MLST modify*;perm*;size*;type*;unique*;UNIX.group*;UNIX .mode*;UNIX.owner*;
[18:30:14] [R] PBSZ
[18:30:14] [R] PROT
[18:30:14] [R] REST STREAM
[18:30:14] [R] SIZE
[18:30:14] [R] 211 End
[18:30:14] [R] PWD
[18:30:14] [R] 257 "/" is the current directory
[18:30:14] [R] CWD /complete
[18:30:14] [R] 250 CWD command successful
[18:30:14] [R] PWD
[18:30:14] [R] 257 "/complete" is the current directory
[18:30:14] [R] PROT P
[18:30:14] [R] 200 Protection set to Private
[18:30:14] [R] PASV
[18:30:14] [R] 227 Entering Passive Mode (46,166,134,61,149,87).
[18:30:14] [R] Opening data connection IP: [server's IP] PORT: 38231
[18:30:14] [R] MLSD
[18:30:14] [R] Connected. Negotiating TLSv1 session
[18:30:14] [R] TLSv1 negotiation successful...
[18:30:14] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[18:30:14] [R] 150 Opening ASCII mode data connection for MLSD
[18:30:15] [R] 226 Transfer complete
[18:30:15] [R] List Complete: 1 KB in 0,48 seconds (1,1 KB/s)
[18:30:15] [R] TYPE I
[18:30:15] [R] 200 Type set to I
[18:30:15] [R] PASV
[18:30:15] [R] 227 Entering Passive Mode (46,166,134,61,137,23).
[18:30:15] [R] Opening data connection IP: [server's IP] PORT: 35095
[18:30:15] [R] REST 7316826112
[18:30:15] [R] 350 Restarting at 7316826112. Send STORE or RETRIEVE to initiate transfer
[18:30:15] [R] RETR [previous file in list]
[18:30:15] [R] Connected. Negotiating TLSv1 session
[18:30:15] [R] TLSv1 negotiation successful...
[18:30:15] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[18:30:15] [R] 150 Opening BINARY mode data connection for [previous file in list] (963412518 bytes)
[18:52:03] [R] 226 Transfer complete
[18:52:03] Resumed: [previous file in list] 918,78 MB in 21 minutes 48 seconds (719,4 KB/s)
[18:52:03] [R] MLST [next file in list]
[18:52:03] [R] 250-Start of list for [next file in list]
[18:52:03] [R] 250-modify=20111209181331;perm=adfrw;size=13967293923; type=file;unique=26UADC002;UNIX.group=1000;UNIX.mo de=0644;UNIX.owner=1000; [next file in list]
[18:52:03] [R] 250 End of list
[18:52:03] [R] PASV
[18:52:04] [R] 227 Entering Passive Mode (46,166,134,61,196,5).
[18:52:04] [R] Opening data connection IP: [server's IP] PORT: 50181
[18:52:04] [R] RETR [next file in list]
[18:52:04] [R] Connected. Negotiating TLSv1 session
[18:52:04] [R] 150 Opening BINARY mode data connection for [next file in list] (13967293923 bytes)
[18:52:04] [R] TLSv1 negotiation successful...
[18:52:04] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[18:52:04] [R] 425 Unable to build data connection: Operation not permitted
[18:52:04] [R] Transfer Failed!
[18:52:04] [R] MLST [next file in list]
[18:52:04] [R] 250-Start of list for [next file in list]
[18:52:04] [R] 250-modify=20111209181331;perm=adfrw;size=13967293923; type=file;unique=26UADC002;UNIX.group=1000;UNIX.mo de=0644;UNIX.owner=1000; [next file in list]
[18:52:04] [R] 250 End of list
[18:52:04] [R] PASV
[18:52:04] [R] 227 Entering Passive Mode (46,166,134,61,186,79).
[18:52:04] [R] Opening data connection IP: [server's IP] PORT: 47695
[18:52:04] [R] RETR [next file in list]
[18:52:04] [R] Connected. Negotiating TLSv1 session
[18:52:04] [R] 150 Opening BINARY mode data connection for [next file in list] (13967293923 bytes)
[18:52:04] [R] TLSv1 negotiation successful...
[18:52:04] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[18:52:04] [R] 425 Unable to build data connection: Operation not permitted
[18:52:04] [R] Transfer Failed!

I've tried every settings combinations I can, issue is still there.
The fact is that I've already downloaded whole lists of files on this server, but I had to reinstall my computer (Win7 Ultimate x64) while I did not backed up FlashFXP settings, forcing me to reinstall it without those working settings.
Or maybe it comes from the last version of FlashFXP, really don't know.

If you have a clue, I'm in.

Thanks,
David.

[bigstar]

Are you using the latest 4.1 stable or 4.1 beta?

Has the ProFTPD server software or config been updated or changed recently?

The only thing I can think of off the top of my head is an old issue with SSL session reuse on proftpd but I thought this was a thing of the past.

You might try adjusting the SSL/TLS settings in the site manager, I will look into this and try to reproduce the issue on a local test machine.

[diez.david]

Hi and thanks for your quick reply.

I'm using 4.1.6 build 1673.
Concerning ProFTPd I can't access its config as I'm not its administrator. Then I don't know if it has changed or been updated.
I'll test with different settings of SSL and TLS.

Thanks,
David.

[diez.david]

Here's some news.
First I forgot to mention that my transfers drops every 20/25 minutes.
Second I just had a new context to this error:
[19:10:43] [R] List Complete: 673 bytes in 0,98 seconds (0,7 KB/s)
[19:14:58] [R] CWD /complete
[19:14:58] [R] 250 CWD command successful
[19:14:58] [R] PWD
[19:14:58] [R] 257 "/complete" is the current directory
[19:14:58] [R] PASV
[19:14:58] [R] 227 Entering Passive Mode (46,166,134,61,161,74).
[19:14:58] [R] Opening data connection IP: [server's IP] PORT: 41290
[19:14:58] [R] MLSD
[19:14:58] [R] Connected. Negotiating TLSv1 session
[19:14:59] [R] 150 Opening ASCII mode data connection for MLSD
[19:14:59] [R] TLSv1 negotiation successful...
[19:14:59] [R] TLSv1 encrypted session using cipher DHE-RSA-AES256-SHA (256 bits)
[19:14:59] [R] 425 Unable to build data connection: Operation not permitted
[19:14:59] [R] List Error

After 2 or 3 minutes, I got the same 425 error when listing a folder.

I tried every TLS/SSL settings combinations I could, always the same problem.
Tried to enable keep alives, same problem.

The server's administrator, who I also opened an ticket with, only told me to reboot my hosted box but it doesn't change anything. I asked him if config has changed and waiting for his answer.

Thanks,
David.

[diez.david]

Hi,

Issue is resolved after FTP admin has changed "TLSOptions NoSessionReuseRequired" setting in ProFTPd.
See http://www.proftpd.org/docs/RELEASE_NOTES-1.3.3a

Thank you for your support.

Regards,
David.