[9fans] encrypting 9P traffic

[9fans] encrypting 9P traffic

[John Floren]

I'm preparing to go to Defcon next week, and to help avoid getting
owned I'm planning to bring along a Plan 9 laptop. I'd like to be able
to mount, say, my home fileserver while I'm there, but 9P traffic goes
out unencrypted if you use "srv" rather than "import -E ssl". This got
me to fiddling with tlssrvtunnel and tlsclienttunnel, but I've run
into some problems:

(gozer is the cpu server, x61 is the terminal)

gozer% tlssrvtunnel tcp!gozer!564 tcp!*!12345 cert.pem # I created
cert.pem using auth/rsagen, rsa2x509, and pemencode
listen started
gozer%

# I did sha1sum of cert.pem and, on the client side, created "thumb"
containing "x509 sha1=<hash> cn=*.<myauthdomain>" where myauthdomain
is the same domain I used to create the cert
x61% tlsclienttunnel tcp!gozer!12345 tcp!*!564 thumb
x61% srv net!x61!564 x61
x61% mount /srv/x61 /n/x61
mount: mount /n/x61: EOF receiving fversion reply


I can't seem to find any mention of these programs in 9fans except for
the initial announcement of their creation. Did I do something wrong
along the way? I'm not very familiar with TLS so it's definitely
possible.

On a more general note, I've decided that probably the smartest option
will be to "import -E ssl myhomesystem /net" (because after 9 years,
import still doesn't support TLS or SSL v3) so I can essentially
tunnel all communication out that way... I'll have to use the open
wifi, since Plan 9 doesn't do WPA, and I wouldn't trust Defcon's WPA
network either in any case. Can anyone think of a problem with this
plan, besides the fact that anyone sniffing packets will figure out
that the owner of jfloren.net is quite probably in attendance?


John

Re: [9fans] encrypting 9P traffic

[Lyndon Nerenberg]

Shouldn't import and srv just default to tls?

Re: [9fans] encrypting 9P traffic

[John Floren]

On Wed, Jul 27, 2011 at 4:49 PM, Lyndon Nerenberg <lyndon@orthanc.ca> wrote:
> Shouldn't import and srv just default to tls?
>
>

x61% import -E tls gozer / /n/gozer
import: gozer: tls has not yet been implemented

As far as I can tell, srv doesn't even have an encryption option. Do a
"9fs gozer", fire up snoopy, and start reading some files--you'll see
the plaintext of the files (and all the rest of the 9p messages)
whizzing past.

John

Re: [9fans] encrypting 9P traffic

[erik quanstrom]

On Wed Jul 27 19:52:55 EDT 2011, john@jfloren.net wrote:
> On Wed, Jul 27, 2011 at 4:49 PM, Lyndon Nerenberg <lyndon@orthanc.ca> wrote:
> > Shouldn't import and srv just default to tls?
> >
> >
>
> x61% import -E tls gozer / /n/gozer
> import: gozer: tls has not yet been implemented
>
> As far as I can tell, srv doesn't even have an encryption option. Do a
> "9fs gozer", fire up snoopy, and start reading some files--you'll see
> the plaintext of the files (and all the rest of the 9p messages)
> whizzing past.

this works for me.  i've been using it for years.

	; import -k 'user=hostowner' -E ssl minooka.coraid.com / /n/coraid
	; echo bind /net/ether0>/n/coraid/dev/aoe/ctl  # ouch

- erik

Re: [9fans] encrypting 9P traffic

[erik quanstrom]

On Wed Jul 27 19:50:05 EDT 2011, lyndon@orthanc.ca wrote:
> Shouldn't import and srv just default to tls?

import, yes*.  srv, no.

- erik

---
*  thanks to its undocumented** protocol for negotiating encryption, etc.

---
** unless you count documentation like hardware vendors do.  "read the
source code".

Re: [9fans] encrypting 9P traffic

[John Floren]

On Wed, Jul 27, 2011 at 6:27 PM, erik quanstrom <quanstro@quanstro.net> wrote:
> On Wed Jul 27 19:50:05 EDT 2011, lyndon@orthanc.ca wrote:
>> Shouldn't import and srv just default to tls?
>
> import, yes*.  srv, no.
>
> - erik
>
> ---
> *  thanks to its undocumented** protocol for negotiating encryption, etc.
>
> ---
> ** unless you count documentation like hardware vendors do.  "read the
> source code".
>
>

Import defaults to unencrypted, at least for me. Import and srv
*should* default to TLS but it's not implemented. SSL is implemented
for import but it's not the default.


John

Re: [9fans] encrypting 9P traffic

[David du Colombier]

> Import defaults to unencrypted, at least for me. Import and srv
> *should* default to TLS but it's not implemented. SSL is implemented
> for import but it's not the default.

Yes, but like you said earlier, it's SSLv2, not SSLv3.

However, pushtls is here (even if not used anywhere) and it's
easy to implement it.
I recently added TLS support in exportfs, import and cpu, but
it's not finished yet.

The main difference between tlssrvtunnel and import is that
tlssrvtunnel is using the TLS handshake protocol, while import
is using a custom handshake protocol, without certificate handling.

So it depends on what you want.

--
David du Colombier

Re: [9fans] encrypting 9P traffic

[Steve Simon]

strange, cpu is definitely encrypted, and import uses cpu to start export on
the remote machine so it should be encrypted too - unless I misunderstood.

the fs protocol used by srv is not encrypted, I'am guessing because machines
need to use it to boot and adding booting over encrypted links was too much hassle.

Perhaps there where performance reasons too?

-Steve

Re: [9fans] encrypting 9P traffic

[Charles Forsyth]

>Yes, but like you said earlier, it's SSLv2, not SSLv3.

what's the advantage of using v3 for plan 9 connections?
plan 9 uses only the record format of v2.

Re: [9fans] encrypting 9P traffic

[David du Colombier]

> >Yes, but like you said earlier, it's SSLv2, not SSLv3.
>
> what's the advantage of using v3 for plan 9 connections?
> plan 9 uses only the record format of v2.

exportfs, import and cpu are the three last commands still using
devssl. When they will be migrated to devtls, devssl could be
definitely removed.

HTTP, SMTP, IMAP, POP and others already use both TLS 1.0 handshake
and record protocols.

It's easier to maintain a single encryption protocol than two.

Moreover, if you want to interact with foreign implementations,
they often don't implement SSL 2.0 anymore, or, at best, only
support the standard and weak ciphers of SSL 2.0, and not
the newest ones, standardized in TLS 1.0, 1.1, 1.2 and their
extensions (mostly AES, SHA1 and SHA2).

--
David du Colombier

Re: [9fans] encrypting 9P traffic

[erik quanstrom]

> Import defaults to unencrypted, at least for me. Import and srv
> *should* default to TLS but it's not implemented. SSL is implemented
> for import but it's not the default.

you can change the default.  i'm sure there was a performance reason to
make it not the default.  (think of the import hidden in C.)  it's probablly
not a valid reason anymore.

in fact, it would make sense to me to think about encrypting everything.
say at the level of macsec.

- erik