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Software components for data protection, secure storage and transfer

SFTP Symlink access

Also by EldoS: BizCrypto
Components for BizTalk® and SQL Server® Integration Services that let you securely store and transfer information in your business automation solutions.
#11963
Posted: 12/18/2009 11:53:40
by Claudiu Popescu (Basic support level)
Joined: 12/18/2009
Posts: 6

Hello,

I'm new to this forum and to this component.
I wanna decide which component to use in order to build a software, at this time ip*works ssh/sftp worked up to one point, now I tested SecureBlackbox.
The problem with it is that I can't download a symlinked file, for example: /proc/sys/kernel/osrelease
Your demo client failed also, it downloaded a empty file.
Is there a way to read data from this files?

Thank you for taking the time in reading this.
#11964
Posted: 12/18/2009 12:05:36
by Eugene Mayevski (EldoS Corp.)

The issue might be server-dependent. What is the contents of ServerSoftwareName property after connection is made?


Sincerely yours
Eugene Mayevski
#11965
Posted: 12/18/2009 12:27:49
by Claudiu Popescu (Basic support level)
Joined: 12/18/2009
Posts: 6

ServerSoftwareName is: OpenSSH_5.2
I tested this on a different server with the same result.
#11966
Posted: 12/18/2009 13:50:21
by Eugene Mayevski (EldoS Corp.)

Thank you for checking. The developers will take a look at the issue tomorrow. However, for me your file doesn't look like a symlink. Did you try downloading actual files referenced by symlinks, not /proc information?


Sincerely yours
Eugene Mayevski
#11967
Posted: 12/18/2009 14:22:26
by Claudiu Popescu (Basic support level)
Joined: 12/18/2009
Posts: 6

I only downloaded /proc files.
And I must agree with you, that file is not a symlink.
I'm waiting your reply regarding this issue.
#11968
Posted: 12/19/2009 00:28:34
by Ken Ivanov (EldoS Corp.)

Thank you for the report.

Can you please clarify, are you trying to download a /proc/sys/kernel/osrelease file or a symbolic link that points to this file?

I performed several checks with OpenSSH. It appears that the server (at least the versions I have) returns 0 size in a stat response for symbolic link files, while returning the correct sizes of the linked files within directory listings responses. Not sure if this is correct behavior for the server, but as OpenSSH is used widely we will probably need to implement a special workaround.
#11969
Posted: 12/19/2009 03:21:13
by Claudiu Popescu (Basic support level)
Joined: 12/18/2009
Posts: 6

What I'm trying to do is to access data from /proc files, this is vital for what I plan to do with my program.
A alternative would be to access the data via ssh exec but that's not what I planed from the beginning.
OpenSSH is used on all major linux distributions.
What I need is a way to access the data from this files or download them to a stream.
What I know is that ip*works can download this files without any kind of problem, but after I tested there trial version I tend to go for your component.
With SecureBlackbox I have a few options that ip*works doesn't have.
To be honest by now the only thing missing is this, /proc files are reported as 0bits in size and empty.
From what I know this directory is a virtual file system used by the kernel, so this may be the problem.
#11970
Posted: 12/19/2009 05:16:09
by Ken Ivanov (EldoS Corp.)

Thank you for the explanation.

The reason why I am asking is that /proc directory is usually not accessible via SFTP (which defaults to file system subtree that starts from user's home directory). So I assume that you use symbolic links to reference files outside of the home subtree. Do I understand you right?

Quote
To be honest by now the only thing missing is this, /proc files are reported as 0bits in size and empty.

Yes, zero size of those files (reported by the file system) is the reason. We have already implemented the workaround, it will be available within the future build update.
#11971
Posted: 12/19/2009 07:51:59
by Claudiu Popescu (Basic support level)
Joined: 12/18/2009
Posts: 6

I'm only trying to access this files via sftp and as a example WinSCP can access them without any problems.
I'm waiting your future release in order to test it, at this time I can't progress with my application due to this limitation.
#11972
Posted: 12/19/2009 08:04:31
by Ken Ivanov (EldoS Corp.)

Can you please specify the edition you are evaluating? If it is the .NET one, we can provide you with an unofficial build that introduces the fix.
Also by EldoS: CallbackProcess
A component to control process creation and termination in Windows and .NET applications.

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