[sslh] plug in =)

[Yves Rutschle]

On Fri, Feb 24, 2012 at 06:02:34PM +0100, Régis A. Despres wrote:
> In a first place, thanks regarding the way to test described above.
> It might be a good idea to place it somewhere the Home page and/or the README.

I thought about it as I was writing it :)

> Secondly, i had in mind something similar to the "regular expression
> thing" you mentionned.
> But as for testing purpose it might be something optionnal called by
> getopt (-f testing_file)

Ok, having an additional optional external file on top of
the hard-coded C probes sounds like a good solution. I'll
add that soon then.

> Afterwhat, looking a bit ahead and regarding the limitation you
> mentionned, perhaps it would be possible to define some main trigger
> (i.e. size, content, ...) and organize them as something like : [...]

Yes, but I'm just not sure how useful that would be with
regards to the amount of work to make it work. I think I'll
just use regular expressions for the time being, and we'll
extend it somehow if we really need specific tests that
can't be done with regexps.

For example a much simpler way would be to allow several
patterns that would be matched in turn until one worked:

openvpn: ^\x00[\x0D-\xFF]$
openvpn: ^\x00[\x0D-\xFF]\x38

"if the buffer is 2 characters long, and it matches, it's
openvpn. if it's 3 or longer, and it matches the second
rule, it's openvpn"

In that case sslh would just match the first packet of a
connection against each pattern in the file until one
protocol matched, if they all fail it moves to the
hard-coded rules (that way it's also possible to override
internal probes without re-compiling).

Y.