Interoperability with SSH Tectia Server

[cyberduck]

1424955 created the issue

Handle not found listing directory failure

I can no longer log in using SFTP as I have before to the same server. I get text:

Handle not found, file: ???

1 REALPATH
2 OPENDIR
3 READDIR

[cyberduck]

@dkocher commented

Please check the default path set in the bookmark.

[cyberduck]

1424955 commented

My default directory is empty. What should it be?

[cyberduck]

1424955 commented

Replying to [comment:1 dkocher]:

Please check the default path set in the bookmark.

I made a YouTube video about the problem:

http://www.youtube.com/watch?v=zMhyFmbWn-I

[cyberduck]

@dkocher commented

Do you know the SSH server product used?

[cyberduck]

@dkocher commented

Replying to [comment:5 dkocher]:

Do you know the SSH server product used?
I suspect this is an interoperability issue with Tectia SSH Server.

[cyberduck]

1424955 commented

My school uses Tectia on class computers:

http://www.google.com/search?num=50&newwindow=1&q=Tectia+site%3Auta.fi&oq=Tectia+site%3Auta.fi

But I have been able to use people.uta.fi with Cyberduck on my Mac so far.

And SSH is not allowed on people.uta.fi, because that server is for student home pages only, not for anything else.

[cyberduck]

@dkocher commented

Replying to [comment:7 tomihasa]:

And SSH is not allowed on people.uta.fi, because that server is for student home pages only, not for anything else.

The server identifies itself as

debug1: Remote protocol version 2.0, remote software version 6.4.5.90 SSH Tectia Server

[cyberduck]

@dkocher commented

Replying to [comment:7 tomihasa]:

But I have been able to use people.uta.fi with Cyberduck on my Mac so far.

The issue is new as we replaced our SSH implementation in version 4.5.

[cyberduck]

1424955 commented

This additional info may or may not help. At least earlier this year we have been able to use for example WinSCP (free software, Windows), but I prefer Mac over Windows, so I haven't much used WinSCP:

http://www.google.com/search?hl=en&as_q=WinSCP&as_qdr=y&as_sitesearch=uta.fi&as_occt=any

o o o

This info might be totally unrelated. With some services with some servers my school is starting to use Microsoft Office 365 this year:

http://www.uta.fi/hallinto/yliopistopalvelut/tietohallinto/office365/index.html

[cyberduck]

@dkocher commented

Handed over to Tectia support as Case TECT32879.

[cyberduck]

ef32726 commented

I would like this ticket to be reopened, as it seems to me a CyberDuck issue.

Apparently it seems that the Tectia SSH server creates a handle for the OpenDIR operation and gives it to the CyberDuck client.
When doing ReadDir, Cyberduck client sends back that handle modified to the Tectia SSH server, so the Tectia SSH server is not able to fulfill the operation.

The SSH File Transfer Protocol clearly states:
http://tools.ietf.org/html/draft-ietf-secsh-filexfer-01

"The SSH_FXP_HANDLE response has the following format:

uint32 id

string handle

where id' is the request identifier, and handle' is an arbitrary string that identifies an open file or directory on the server. The handle is opaque to the client; the client MUST NOT attempt to interpret or modify it in any way. The length of the handle string MUST NOT exceed 256 data bytes."

Checking at the SSHJ code (sshj-0.8.1.zip) it seems that the code assumes the incoming string is UTF-8, and the code does some conversions that will fail if applied against a binary string. Tectia SSH Server sends binary strings, so, Cyberduck does some conversion resulting in a modified handle when requesting for ReadDir…

I have taken the liberty to modify the SSHJ code a bit, just by changing the type of the “handle” as “byte[]” and using readBytes/writeBytes function and it seems to correct the problem.

I am not sure, though, what version of sshj CyberDuck is using, but I have seen a similar behavior.

To my eyes, Tectia SSH Server works as specified, and Cyberduck is violating clearly the protocol. Please, correct me if I am wrong.

[cyberduck]

@dkocher commented

Fix in d37b54b1fd2ba7aa495c01a03a6b92bc104633bb.

[cyberduck]

@dkocher commented

In 3a42af7.

[cyberduck]

1424955 commented

I updated Cyberduck today (v4.5.2). I still get the same error message as I have shown on my YouTube video mentioned in this topic. But I'm sure you will get it fixed!