GitLab

Deal with ssl/nossl clients; at Chad's suggestion add a small handshake
tag to ssl enabled tmcc/tmcd which tells tmcd that it needs to enter
full SSL mode. This allows old tmcc to connect to an ssl enabled tmcd,
and still work okay.

I've also ironed out the verification stuff. At the client, we make sure
that the CommonName field of the peer cert maps to the same address that
we connected to (bossnode).

At the server, we check the OU field of the cert (we create the client
certs with the OU field set to the node type; a convention I made up!).
It must match the type of the node, as we get it from the nodes table.
Also check the CommonName to make sure it matches our hostname. This is
by no means bulletproof, but perfection is costly, and we don't have the
money!

Also cleaned up the REDIRECT testmode stuff. Instead of ifdef'ed under
TESTMODE, leave it compiled in all the time, but only allow it from the
local node (where tmcd is running). Mere users will not be able to
access it, but testbed people can use it since they have accounts on the
boss node.

by smarter brains by me (I have asked Dave to look it over). Anyway ...

I added a top level ssl directory which has a bunch of goo for
creating certificates and keys.  I currently create a Certificate
Authority, a server certificate, and a client certificate. The private
keys for all three are unencrypted, so no password is required. All
key/cert combos can be installed on boss. The client side needs the
key/cert pair (in one file), and the CA cert (no key!). There are
install targets to do this. NOTE, you do not want to create/install
these without being careful, since you could instantly invalidate all
the clients!

I have added the necessary SSL routines to tmcd/tmcc. See the ssl.c
and ssl.h file. I have set it up so that with all you need to do is
uncomment three lines in the makefile, and accept,connect,read,write,
and close are redirected to SSL'ified versions in ssl.c. The current
security model is that the client and server both "demand" certificate
verification from the other side (as opposed to just server side
verification). tmcd reads in server.pem, while tmcc reads in
client.pem. Both read in the emulab.pem (CA cert with no private
key).

Initial testing indicates I have done this at least partially
correctly. Whoever invented this stuff has a really twisted mind
though. There are some questions at the top of ssl.c that need to be
answered.

Oh, also redid all the syslog stuff throughout tmcd.