automatic updating, digital signing?

["Mikhail T." <mi+thun%aldan.algebra.com@localhost>]

Hello!

We are evaluating different methods of package-building for our "fleet"
of systems running Solaris-8 and 10 as well RedHat (i386 and amd64).

One of the desired features of whatever model we end up picking, is the
ability to automatically update packages from a single repository --
after verifying each package's digital signature.

The RedHat's rpm/yum combo provides both of these, and porting it to
Solaris is not impossible. However, building the custom RPMs is not as
nice as dealing with the pkgsrc-tree (we would want to add custom
patches for some ports', err, packages' patches/ subdirectories, for
example).

Is there something in pkgsrc, that can do the equivalent of "yum
upgrade"? Thanks!

    -mi