hgweb: fix trust of templates path (BC)
Long ago we disabled trust of the templates path with a comment
describing the (insecure) behavior before the change. At some later
refactor, the code was apparently changed back to match the comment,
unaware that the intent of the comment was to describe the behavior to
avoid.
This change disables the trust and updates the comment to explicitly
say not only what the old problem was, but also that it was in fact a
problem and the action taken to prevent it.
Impact: prior to this change, if you had a UNIX-based hgweb server
where users can write hgrc files, those users could potentially read
any file readable by the web server.
This is marked as a backwards compatibility issue because people may
have configured templates without proper trust settings. Issue spotted
by Greg Szorc.
# extension to emulate invoking 'dirstate.write()' at the time
# specified by '[fakedirstatewritetime] fakenow', only when
# 'dirstate.write()' is invoked via functions below:
#
# - 'workingctx._checklookup()' (= 'repo.status()')
# - 'committablectx.markcommitted()'
from mercurial import context, extensions, parsers, util
def pack_dirstate(fakenow, orig, dmap, copymap, pl, now):
# execute what original parsers.pack_dirstate should do actually
# for consistency
actualnow = int(now)
for f, e in dmap.iteritems():
if e[0] == 'n' and e[3] == actualnow:
e = parsers.dirstatetuple(e[0], e[1], e[2], -1)
dmap[f] = e
return orig(dmap, copymap, pl, fakenow)
def fakewrite(ui, func):
# fake "now" of 'pack_dirstate' only if it is invoked while 'func'
fakenow = ui.config('fakedirstatewritetime', 'fakenow')
if not fakenow:
# Execute original one, if fakenow isn't configured. This is
# useful to prevent subrepos from executing replaced one,
# because replacing 'parsers.pack_dirstate' is also effective
# in subrepos.
return func()
# parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
# 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
timestamp = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
fakenow = float(timestamp)
orig_pack_dirstate = parsers.pack_dirstate
wrapper = lambda *args: pack_dirstate(fakenow, orig_pack_dirstate, *args)
parsers.pack_dirstate = wrapper
try:
return func()
finally:
parsers.pack_dirstate = orig_pack_dirstate
def _checklookup(orig, workingctx, files):
ui = workingctx.repo().ui
return fakewrite(ui, lambda : orig(workingctx, files))
def markcommitted(orig, committablectx, node):
ui = committablectx.repo().ui
return fakewrite(ui, lambda : orig(committablectx, node))
def extsetup(ui):
extensions.wrapfunction(context.workingctx, '_checklookup',
_checklookup)
extensions.wrapfunction(context.committablectx, 'markcommitted',
markcommitted)