The libsecp change broke signature checking. Disable it for now,
with a big FIXME. The next version should have a method for S value
checking, and also compact serialization.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Our current proto_to_locktime actually handles relative locktimes,
and HTLCs use absolute. Fix that.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The even-S check was based on https://github.com/sipa/bitcoin/commit/a81cd9680
which was replaced by a low-S check in commit e0e14e43d9586409e42919f6cb955540134cda2a
Abstract out and fix the check.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>