Also change the mac filename to match
The procedure remains the same, but now there's a nifty script to automate
the signing process.
Future steps:
- Build osslsigncode in the gitian-win descriptor so that the signer itself is
deterministic.
- Verify in the gitian-win-signer descriptor that the expected cert chain was
used.
Rather than fetching a signature.tar.gz from somewhere on the net, instruct
Gitian to use a signature from a tag in the bitcoin-detached-sigs repository
which corresponds to the tag of the release being built.
This changes detached-sig-apply.sh to take a dirname rather than a tarball as
an argument, though detached-sig-create.sh still outputs a tarball for
convenience.
