sslutil: reference appropriate config section in messaging
Error messages reference the config section defining the host
fingerprint. Now that we have multiple sections where this config
setting could live, we need to point the user at the appropriate
one.
We default to the new "hostsecurity" section. But we will still
refer them to the "hostfingerprint" section if a value is defined
there.
There are some corner cases where the messaging might be off. e.g.
they could define a SHA-1 fingerprint in both sections. IMO the
messaging needs a massive overhaul. I plan to do this as part
of future refactoring to security settings.
Test for CVE-2016-3630
$ hg init
>>> open("a.i", "w").write(
... """eJxjYGZgZIAAYQYGxhgom+k/FMx8YKx9ZUaKSOyqo4cnuKb8mbqHV5cBCVTMWb1Cwqkhe4Gsg9AD
... Joa3dYtcYYYBAQ8Qr4OqZAYRICPTSr5WKd/42rV36d+8/VmrNpv7NP1jQAXrQE4BqQUARngwVA=="""
... .decode("base64").decode("zlib"))
$ hg debugindex a.i
rev offset length delta linkrev nodeid p1 p2
0 0 19 -1 2 99e0332bd498 000000000000 000000000000
1 19 12 0 3 6674f57a23d8 99e0332bd498 000000000000
$ hg debugdata a.i 1 2>&1 | egrep 'Error:.*decoded'
(mercurial.mpatch.)?mpatchError: patch cannot be decoded (re)