Verifying a subversion checkout

[C. P. Ghost]

Hello,

is there a way to automatically verify that the checkout
of a random subversion revision of /usr/src hasn't been
tampered with?

I'm worried about the possibility of
  1/ an MitM attack while fetching the sources
  2/ changes to the local /usr/src for whatever reasons

2/ isn't so critical; there's always the possibility to check
them from another machine, provided checksums were
created immediately after the svn update. It's 1/ that's
bothering me.

Or, asked differently, does SVN protocol support some
kind of authentication that thwarts man-in-the-middle
attacks?

Of course, at release points, we always have checksums
for the ISO images. That's security-wise the only point
where I'm sure that I'm running from genuine sources.
It's what's in-between releases that I'm asking about.

Thanks,
-cpghost.

-- 
Cordula's Web. http://www.cordula.ws/