sslutil: issue warning when [hostfingerprint] is used
Mercurial 3.9 added the [hostsecurity] section, which is better
than [hostfingerprints] in every way.
One of the ways that [hostsecurity] is better is that it supports
SHA-256 and SHA-512 fingerprints, not just SHA-1 fingerprints.
The world is moving away from SHA-1 because it is borderline
secure. Mercurial should be part of that movement.
This patch adds a warning when a valid SHA-1 fingerprint from
the [hostfingerprints] section is being used. The warning informs
users to switch to [hostsecurity]. It even prints the config
option they should set. It uses the SHA-256 fingerprint because
recommending a SHA-1 fingerprint in 2017 would be ill-advised.
The warning will print itself on every connection to a server until
it is fixed. There is no way to suppress the warning. I admit this
is annoying. But given the security implications of sticking with
SHA-1, I think this is justified. If this patch is accepted,
I'll likely send a follow-up to start warning on SHA-1
certificates in [hostsecurity] as well. Then sometime down
the road, we can drop support for SHA-1 fingerprints.
Credit for this idea comes from timeless in issue 5466.
# extension to emulate invoking 'patch.internalpatch()' at the time
# specified by '[fakepatchtime] fakenow'
from __future__ import absolute_import
from mercurial import (
extensions,
patch as patchmod,
util,
)
def internalpatch(orig, ui, repo, patchobj, strip,
prefix='', files=None,
eolmode='strict', similarity=0):
if files is None:
files = set()
r = orig(ui, repo, patchobj, strip,
prefix=prefix, files=files,
eolmode=eolmode, similarity=similarity)
fakenow = ui.config('fakepatchtime', 'fakenow')
if fakenow:
# parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
# 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
fakenow = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
for f in files:
repo.wvfs.utime(f, (fakenow, fakenow))
return r
def extsetup(ui):
extensions.wrapfunction(patchmod, 'internalpatch', internalpatch)