[Info-vax] Potential loss of data problem in sftp client in TCP/IP Services ?

[Simon Clubley]

On 2012-03-12, Jan-Erik Soderholm <jan-erik.soderholm at telia.com> wrote:
> Simon Clubley wrote 2012-03-12 18:02:
>> On 2012-03-12, Jan-Erik Soderholm<jan-erik.soderholm at telia.com>  wrote:
>>>
>>> Should I read that as not the latest *released* version ?
>>>
>>
>> Correct. I was asked to install the latest engineering image to
>> test my original problem against before they would work on my
>> original sftp problem.
>>
>> Although I am still on V5.6 ECO5, the Engineering supplied sftp
>> image has significant enhanced functionality. I don't know how
>> much of that functionality (namely the ascii mode conversion) is
>> present in V5.7 ECO3 which is the latest released version. If this
>> new functionality is present in ECO3, I don't know if that version
>> works correctly or not.
>>
>>> And is it your opinion that this is a specific issue
>>> in the sftp image as such?
>>>
>>> Just trying to get the context right. We are planning for
>>> an 8.2 =>  8.4 upgrade with the latest 5.7 ECO3 TCPIP...
>>
>> That's a very good question; I don't know if ECO3 is affected.
>> It's what I am trying to find out by asking my questions here.
>>
>
> OK. I have currently 8.4 and TCPIP 5.7 ECO3 in my office/hobbyist
> system, but I do not know what is needed to run a reproducer. And
> I do not think that I have the right server to run against.
>

Although my more detailed testing was against a local Linux server,
I have also seen the same failure against a Windows based sftp
server as well.

To try and reproduce:

1) On the VMS sftp client system, identify a small text file a few
blocks long; this file should be a variable length file in order to
reproduce my test environment as closely as possible. I have found
the problem does not occur when the input file is a stream_lf file.

I used my ~4 blocks long login.com file for detailed testing, but make
sure the file doesn't exist on the destination system (I don't want to
be responsible for you destroying one of your files by mistake while
following my instructions. :-)).

(BTW, input files other than stream_lf are supposed to be fully
supported. They certainly worked just fine, but with a forced
conversion to stream_lf during transfer, using V5.6 ECO 5)

2) sftp username at remote.system.domain.name

(You may need to use quotes around the parameter.)

Supply password when prompted.

3) At the "sftp> " prompt enter "put filename".

4) On the remote system, look to see if the last few bytes of the
file are missing after transfer.

> If you do have some publicaly reachable server system, I could
> give you access to my 5.7 ECO3 system if you'd like to run
> some tests.
>

Unfortunately, the servers I am using are either local access only
or have very strict security policies, so this won't be possible.
Thanks for the offer though.

> B.t.w, I'm on Alpha, I do not remember what you where running
> (of if it matters).
>

Alpha V8.3, TCP/IP V5.6 ECO 5, but with the sftp and ssh client images
replaced by the latest TCP/IP Engineering images.

> Anyway,
> thanks for your clarifications about "Engineering image". :-)
>

You are welcome. :-)

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
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