RE: Some servers do not forward X11, but I do not know why.

2005-12-12 Thread Mark Senior
Interesting... Do you have lsof available on the hosts where you can't get X forwarding? lsof -i should tell you all the processes with ports open, you can verify if there is some process hogging all 999 ports... If not, some versions of netstat can also show you the PID of the process that has

RE: Restricting sftp commands

2005-12-21 Thread Mark Senior
Probably the most robust thing would be to use file-system ACLs to restrict users to the desired actions. They could always try a "get" command, but it would fail if they tried to download a file to which they lacked read permissions. That would also have the advantage of working regardless of wh

Re: X11 tuneling: a hard to fix problem

2006-04-20 Thread Mark Senior
No, don't use xhost + The entire point of using ssh for X11 forwarding is that the ssh connection comes from a local process - you don't have to accept outside X11 connections. xhost + is used specifically for accepting X11 connections that _don't_ come from a local process (e.g not over your SSH

Re: Need some education: Man-in-the-Middle Attacks

2006-08-31 Thread Mark Senior
On 8/29/06, Christ, Bryan wrote: All, Please pardon my naivete. I was looking at the diagram on the URL listed below and contemplating how host fingerprinting prevents MITM attacks. http://www.vandyke.com/solutions/ssh_overview/ssh_overview_threats.html So my question is this... Given the ill

Re: Decrypting an ssh session knowing the private key?

2006-10-07 Thread Mark Senior
I would like to write a program that could deycrypt ssh communication by using the private key of the server computer. This should be possable right? I don't believe that is the case. SSH uses its private key only to certify its identity to the client. So knowing the private key lets you do a

Re: Scp & sftp with no shell access or restricted access

2006-11-16 Thread Mark Senior
I have a feeling that might not be very robust if you're allowing sftp or scp to anywhere a user normally has access to - a user could then download their own authorized_keys file, edit it to give themselves shell access, and then upload it. Another option might be to use the Match option in Open

Re: How to restrict remote forwarding ports in SSH2?

2006-11-30 Thread Mark Senior
You're quite right. Netcat is included in most unices (to get full bidirectional port forwarding, you would actually need two shell commands & a pipeline). Socat is quite a bit more versatile, and would do the forward in a single command. I think it's available by default in some unices, and sh

Re: TCP_NODELAY

2007-01-17 Thread Mark Senior
It can also be set per socket with setsockopt(2). How to do something similar in an ssh subsystem, I'm afraid I don't know Regards Mark On 1/15/07, olaf weiser wrote: Hallo to all, so far I know, this is a system wide parameter You could set this per interface or for all connections

Re: /tmp rather than /home, attacks?

2007-03-20 Thread Mark Senior
On 13 Mar 2007 00:41:45 +0100, Thomas Hafner wrote: Hello, having an option like ControlPath ~/.ssh/control/[EMAIL PROTECTED]:%p is probably not a good idea, if the user's home directory is shared by different machines (name collision for similiar outgoing SSH connections). Something like that