openssh unix dev - Apr 2002 - OpenSSH server stops returning data from a server module

Hi all

I've written a client/server application using OpenSSH for securing 
the transactions. The server is written as OpenSSH server module 
(same as sftp) while the client is a seperate application invoking 
the ssh client. My application and the ssh client are connected by 
socketpairs the same way as the OpenSSH server and the server module 
are.

After the connection between the ssh client and the server is 
established, the user is authenticated and the server module is 
loaded, the application starts sending messages to the server module. 
The server module then responds to the former request. After around 
1K of data returned by the server module, the OpenSSH server stops 
forwarding the data returned by the server module, so the failure is 
deterministic.

I've done several tests to exclude a mistake made by myself. The 
server module and the client application seperately work correctly on 
the same data. If I connect the client and the server module directly 
by replacing the execution of the ssh client in the client 
application with the execution of the server module, then there is no 
problem at all.

My tests have shown this behaviour from OpenSSH version 2.9 to 3.1. 
Is there any known problem related to this observation?

TIA


Norbert

do you have example code to reproduce this problem?

On Wed, Apr 10, 2002 at 06:26:15PM +0200, Norbert Sendetzky
wrote:
> Hi all
> 
> I've written a client/server application using OpenSSH for securing 
> the transactions. The server is written as OpenSSH server module 
> (same as sftp) while the client is a seperate application invoking 
> the ssh client. My application and the ssh client are connected by 
> socketpairs the same way as the OpenSSH server and the server module 
> are.
> 
> After the connection between the ssh client and the server is 
> established, the user is authenticated and the server module is 
> loaded, the application starts sending messages to the server module. 
> The server module then responds to the former request. After around 
> 1K of data returned by the server module, the OpenSSH server stops 
> forwarding the data returned by the server module, so the failure is 
> deterministic.
> 
> I've done several tests to exclude a mistake made by myself. The 
> server module and the client application seperately work correctly on 
> the same data. If I connect the client and the server module directly 
> by replacing the execution of the ssh client in the client 
> application with the execution of the server module, then there is no 
> problem at all.
> 
> My tests have shown this behaviour from OpenSSH version 2.9 to 3.1. 
> Is there any known problem related to this observation?
> 
> TIA
> 
> 
> Norbert
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> openssh-unix-dev at mindrot.org mailing list
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