Turns out that introduction points don't care about the INTRODUCE2 cell
format as long as the top field is LEGACY_KEY_ID as expected. So let's
use a single INTRODUCE format regardless of the introduction point being
legacy or not.
This also removes the polymorphic void* situation.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Add the entry point from the circuit subsystem of "circuit has opened" which
is for all type of hidden service circuits. For the introduction point, this
commit actually adds the support for handling those circuits when opened and
sending ESTABLISH_INTRO on a circuit.
Rendevzou point circuit aren't supported yet at this commit.
Signed-off-by: David Goulet <dgoulet@torproject.org>
