sftp Error Code LIBSSH2_ERROR_SFTP_PROTOCOL

Posts: 3 · Miha 27 Mar 2016, 11:28

Hi,

Can you help me identify where the problem

I can upload/sync to server using sftp option MIRROR (hard drive -> sftp server)

But if I want to download with the option MIRROR (sftp server -> hard drive)
I get error msg

Error Code LIBSSH2_ERROR_SFTP_PROTOCOL: Failed opening remote file LIBSSH2_FX_PERMISSION_DENIED (libssh2_sftp_open)

This happens only on certain files.

Posts: 3 · Miha 30 Mar 2016, 07:36

Hi,

Did identify the problem

sometimes ffs uploads a file but without any permissions.

Because of that when I try to download file server will not allow it.
I did try to upload it with filezella and permissions are there so I guess this is a ffs problem.

Can you fix this?

Posts: 7212 · Zenju 30 Mar 2016, 10:34

FreeFileSync uploads all new files with read-write permissions (0666) and folders with read-write-execute (0777). Is there a problem with these defaults?

Posts: 3 · Miha 30 Mar 2016, 12:58

problem is that generally it will do 0666 or 0777
but I did encounter 9000 files from 80.000 files who had empty permissions
it looks like it sometimes skips this step

Posts: 1 · Wim 20 Jun 2016, 13:23

i'm also having similar problems: files that appear to have permission 0000. the sftp server i'm uploading to / downloading from is a laCie Cloudbox. is there any way to review in logging what happened and why?

Posts: 2 · kartom 29 Aug 2017, 07:25

FreeFileSync uploads all new files with read-write permissions (0666) and folders with read-write-execute (0777). Is there a problem with these defaults?

We are running FreeFileSync v 9.3 and it's not creating files with permission 666 for us. The new files created by FreeFileSync will get permission 644, and that is a problem for us.

On our system all new files are created with permission 664, but when we are using FreeFileSync for syncing all new files get permission 644. Is there a way of changing the default behaviour or could there be
something in our setup that makes FreeFileSync create files with the 644 permission?

Posts: 11 · xurc 31 Aug 2017, 07:47

I got the same error

Error Code LIBSSH2_ERROR_SFTP_PROTOCOL: Failed opening remote file
LIBSSH2_FX_PERMISSION_DENIED (libssh2_sftp_open)

In case when I wanted to compare folders (local to remote via SFTP )
It turned out that my ISP changed IPv4 into IPv6 and that was the issue. When they changed back to IPv4 synchronization works fine. I believe this must be problem with the library that FreeFileSync uses to connect together with IPv6

Posts: 7212 · Zenju 1 Sep 2017, 13:39

It turned out that my ISP changed IPv4 into IPv6 and that was the issue. When they changed back to IPv4 synchronization works fine.xurc, 31 Aug 2017, 07:47

In general IPv6 should work fine with SFTP. Do you have an IPv6 test server that reproduces the connection issues?

Posts: 11 · xurc 4 Sep 2017, 08:33

It turned out that my ISP changed IPv4 into IPv6 and that was the issue. When they changed back to IPv4 synchronization works fine.xurc, 31 Aug 2017, 07:47
In general IPv6 should work fine with SFTP. Do you have an IPv6 test server that reproduces the connection issues? Zenju, 01 Sep 2017, 13:39

Now I don't have. Actually I really don't know exactly whether the problem was with server or client. It worked fine until some day. I got the error as above then. I tried to change connection settings but nothing works. After a while I realized that on my router (provided by ISP) protocol version is switched to IPv6. So every machine behind the router received new IP adresses (IPv6). When I asked ISP to change it back to IPv4 synchronization started to work again. I can't change protocol by myself so I can't test it. I need to call to my ISP, but I would rather not to do this, as many other services, that I use in my network, simply does not work.

Posts: 11 · xurc 27 Oct 2017, 19:34

Hi,

I would like to back to this problem. Now I have reproducible environment. What I'm sure is:
1) The error is: Cannot open folder "sftp://xxx.ovh.net/".
LIBSSH2_ERROR_SFTP_PROTOCOL: Failed opening remote file - LIBSSH2_FX_PERMISSION_DENIED [libssh2_sftp_opendir]
2) When using FileZilla & WinSCP the connection works, so login and pass are valid
3) my new ovh server works on both IPv4 and IPv6

What I can do to get more verbose logs from the error?

Posts: 7212 · Zenju 28 Oct 2017, 10:40

Do you have a test login that allows to (at least temporarily) reproduce the connection issues from my end?

Posts: 11 · xurc 29 Oct 2017, 14:40

I can arrange that, but I would not like to public it here :) and I don't see that private messages are available. Please contact me via e-mail I used on this forum (I assume you as site admin has privileges to read that)

Posts: 11 · xurc 29 Oct 2017, 17:18

This isn't an IPv6 issue: You're trying to access an FTP server via the SFTP protocol! ;) Zenju, 29 Oct 2017, 17:09

SFTP is available on that server as weel. I can connect via SFTP using FileZilla and WinSCP, but I can't with FreeFileSync.

Posts: 7212 · Zenju 29 Oct 2017, 17:34

SFTP is available on that server as weel. I can connect via SFTP using FileZilla and WinSCP, but I can't with FreeFileSync. xurc, 29 Oct 2017, 17:18

The problem is that FFS is not allowed to access the root folder "/". If you'd manually enter the server directory "/home/username" everything works fine. So this is mostly a problem of the SFTP folder picker, which should be improved, e.g. to consider the working directory after login rather than always start form "/".