If a node can prove its Ed25519 identity, don't consider connections
to it canonical unless they match both identities.
Includes link handshake changes needed to avoid crashing with bug
warnings, since the tests now reach more parts of the code.
Closes ticket 20355
One is fixed by disabling the -Wredundant-decls warnings around
openssl headers here, because of the old double-declaration of
SSL_get_selected_srtp_profile().
One is fixed by including compat.h before or.h so that we get the
winsock2.h include before the windows.h include.
This was a stopgap method, designed on the theory that some routers
might support it before they could support Ed25519. But it looks
like everybody who supports RFC5705 will also have an Ed25519 key,
so there's not a lot of reason to have this even supported.
In particular, these functions are the ones that set the identity of
a given connection or channel, and/or confirm that we have learned
said IDs.
There's a lot of stub code here: we don't actually need to use the
new keys till we start looking up connections/channels by Ed25519
IDs. Still, we want to start passing the Ed25519 IDs in now, so it
makes sense to add these stubs as part of 15055.
Previously, you needed to store the previous log severity in a local
variable, and it wasn't clear if you were allowed to call these
functions more than once.
This is a big-ish patch, but it's very straightforward. Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it. The cases where we
violated this rule fall into three roughly equal groups:
* Stuff that should have been static.
* Stuff that was global but where the extern was local to some
other C file.
* Stuff that was only global when built for the unit tests, that
needed a conditional extern in the headers.
The first two were IMO genuine problems; the last is a wart of how
we build tests.
An earlier version of these tests was broken; now they're a nicer,
more robust, more black-box set of tests. The key is to have each
test check a handshake message that is wrong in _one_ way.
