openssh unix dev - Mar 2008 - Command-based ssh_config declarations

How difficult would it be to enhance the client ssh_config file to allow 
command-based declarations similar to that provided by the "Host"
keyword?

The main reason I need something like this is when ssh is used via CVS and 
Subversion.  I want all CVS/Subversion traffic to use a different SSH port 
and different authentication options.

So... you might have an ssh_config file that contained:

   Command '*cvs.mydomain.com cvs server' '*svn.mydomain.com
svnserve -t'
     Port 2200
     Protocol 2
     BatchMode yes
     PasswordAuthentication no
     PubkeyAuthentication yes

Where the string matched against the pattern is the complete command line 
passed to the ssh client.

This would allow all CVS traffic to use one setting, but normal SSH 
traffic to the same host could use different settings.

Circa 2008-03-06 19:06 dixit petesea at bigfoot.com:

: How difficult would it be to enhance the client ssh_config file to allow 
: command-based declarations similar to that provided by the "Host"
keyword?

Not necessary; see below.

: The main reason I need something like this is when ssh is used via CVS and 
: Subversion.  I want all CVS/Subversion traffic to use a different SSH port 
: and different authentication options.

  [...]

This is where the 'HostName' directive is your friend.  Your ssh_config
file can look like this:

    Host svn.example.com
        HostName server.example.com
        Port 2200
        BatchMode yes
        # etc.

    Host *
        Protocol 2
        # etc.

Now, for your Subversion commands, use
'svn+ssh://svn.example.com/repository' as the repository specification,
rather than 'svn+ssh://server.example.com/repository'.  You can even use
a different identity for pubkey authentication, if you wish.

This is mainly a matter of discipline or policy in what name is used to
access the Subversion or CVS server.  The names in the Host stanzas
aren't even required to be valid DNS names, as long as the HostName
directive contains a either a valid IP address or a name that's
defined in DNS or /etc/hosts or whatever your system uses.

If you have more than one such host running a Subversion or CVS server,
you can add a Host stanza for each one into ssh_config.  If you have
thousands of them, you should consider using a wrapper script for the
'ssh' command instead.

-- 
jim knoble  |  jmknoble at pobox.com  |  http://www.pobox.com/~jmknoble/
(GnuPG key ID: 6F39C2CC  >>>>>> 
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