narrow_widen_acl: enforce narrowacl in narrow_widen (SEC)

Reviewer note: this was sent by the author as a simple bugfix, but can be
considered a security patch, since it allows users to access things outside
of the ACL, hence the (SEC) prefix.

However, this affects the `narrow` extention which is still marked as
experimental and has relatively few users aside from large companies with
their own security layers on top from what we can gather.
We feel (Alphare: or at least, I feel) like pinging the packaging list is
enough in this case.

hgext/narrow/narrowwirepeer.py

@@ -1,155 +1,161 b''
 # narrowwirepeer.py - passes narrow spec with unbundle command
 #
 # Copyright 2017 Google, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 from mercurial import (
     bundle2,
     error,
+    exchange,
     extensions,
     hg,
     narrowspec,
     wireprototypes,
     wireprotov1peer,
     wireprotov1server,
 )
 
 from . import narrowbundle2
 
 
 def uisetup():
     wireprotov1peer.wirepeer.narrow_widen = peernarrowwiden
 
 
 def reposetup(repo):
     def wirereposetup(ui, peer):
         def wrapped(orig, cmd, *args, **kwargs):
             if cmd == b'unbundle':
                 # TODO: don't blindly add include/exclude wireproto
                 # arguments to unbundle.
                 include, exclude = repo.narrowpats
                 kwargs["includepats"] = b','.join(include)
                 kwargs["excludepats"] = b','.join(exclude)
             return orig(cmd, *args, **kwargs)
 
         extensions.wrapfunction(peer, b'_calltwowaystream', wrapped)
 
     hg.wirepeersetupfuncs.append(wirereposetup)
 
 
 @wireprotov1server.wireprotocommand(
     b'narrow_widen',
     b'oldincludes oldexcludes'
     b' newincludes newexcludes'
     b' commonheads cgversion'
     b' known ellipses',
     permission=b'pull',
 )
 def narrow_widen(
     repo,
     proto,
     oldincludes,
     oldexcludes,
     newincludes,
     newexcludes,
     commonheads,
     cgversion,
     known,
     ellipses,
 ):
     """wireprotocol command to send data when a narrow clone is widen. We will
     be sending a changegroup here.
 
     The current set of arguments which are required:
     oldincludes: the old includes of the narrow copy
     oldexcludes: the old excludes of the narrow copy
     newincludes: the new includes of the narrow copy
     newexcludes: the new excludes of the narrow copy
     commonheads: list of heads which are common between the server and client
     cgversion(maybe): the changegroup version to produce
     known: list of nodes which are known on the client (used in ellipses cases)
     ellipses: whether to send ellipses data or not
     """
 
     preferuncompressed = False
     try:
 
         def splitpaths(data):
             # work around ''.split(',') => ['']
             return data.split(b',') if data else []
 
         oldincludes = splitpaths(oldincludes)
         newincludes = splitpaths(newincludes)
         oldexcludes = splitpaths(oldexcludes)
         newexcludes = splitpaths(newexcludes)
+
+        # enforce narrow acl if set
+        if repo.ui.has_section(exchange._NARROWACL_SECTION):
+            exchange.applynarrowacl(repo, {'includepats': newincludes})
+
         # validate the patterns
         narrowspec.validatepatterns(set(oldincludes))
         narrowspec.validatepatterns(set(newincludes))
         narrowspec.validatepatterns(set(oldexcludes))
         narrowspec.validatepatterns(set(newexcludes))
 
         common = wireprototypes.decodelist(commonheads)
         known = wireprototypes.decodelist(known)
         if ellipses == b'0':
             ellipses = False
         else:
             ellipses = bool(ellipses)
         cgversion = cgversion
 
         bundler = bundle2.bundle20(repo.ui)
         newmatch = narrowspec.match(
             repo.root, include=newincludes, exclude=newexcludes
         )
         oldmatch = narrowspec.match(
             repo.root, include=oldincludes, exclude=oldexcludes
         )
         if not ellipses:
             bundle2.widen_bundle(
                 bundler,
                 repo,
                 oldmatch,
                 newmatch,
                 common,
                 known,
                 cgversion,
                 ellipses,
             )
         else:
             narrowbundle2.generate_ellipses_bundle2_for_widening(
                 bundler,
                 repo,
                 oldmatch,
                 newmatch,
                 cgversion,
                 common,
                 known,
             )
     except error.Abort as exc:
         bundler = bundle2.bundle20(repo.ui)
         manargs = [(b'message', exc.message)]
         advargs = []
         if exc.hint is not None:
             advargs.append((b'hint', exc.hint))
         bundler.addpart(bundle2.bundlepart(b'error:abort', manargs, advargs))
         preferuncompressed = True
 
     chunks = bundler.getchunks()
     return wireprototypes.streamres(
         gen=chunks, prefer_uncompressed=preferuncompressed
     )
 
 
 def peernarrowwiden(remote, **kwargs):
     for ch in ('commonheads', 'known'):
         kwargs[ch] = wireprototypes.encodelist(kwargs[ch])
 
     for ch in ('oldincludes', 'newincludes', 'oldexcludes', 'newexcludes'):
         kwargs[ch] = b','.join(kwargs[ch])
 
     kwargs['ellipses'] = b'%i' % bool(kwargs['ellipses'])
     f = remote._callcompressable(b'narrow_widen', **kwargs)
     return bundle2.getunbundler(remote.ui, f)

tests/test-narrow-acl.t

@@ -1,43 +1,79 b''
 Make a narrow clone then archive it
   $ . "$TESTDIR/narrow-library.sh"
 
   $ hg init master
   $ cd master
 
   $ for x in `$TESTDIR/seq.py 3`; do
   >   echo $x > "f$x"
   >   hg add "f$x"
   >   hg commit -m "Add $x"
   > done
   $ cat >> .hg/hgrc << EOF
   > [narrowacl]
   > default.includes=f1 f2
   > EOF
   $ hg serve -a localhost -p $HGPORT1 -d --pid-file=hg.pid
   $ cat hg.pid >> "$DAEMON_PIDS"
 
   $ cd ..
   $ hg clone http://localhost:$HGPORT1 narrowclone1
   requesting all changes
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 2 changes to 2 files
   new changesets * (glob)
   updating to branch default
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
 The clone directory should only contain f1 and f2
   $ ls -A -1 narrowclone1 | sort
   .hg
   f1
   f2
 
 Requirements should contain narrowhg
   $ hg debugrequires -R narrowclone1 | grep narrowhg
   narrowhg-experimental
 
 NarrowHG should track f1 and f2
   $ hg -R narrowclone1 tracked
   I path:f1
   I path:f2
+
+Narrow should not be able to widen to include f3
+  $ hg -R narrowclone1 tracked --addinclude f3
+  comparing with http://localhost:$HGPORT1/
+  searching for changes
+  abort: The following includes are not accessible for test: ['path:f3']
+  [255]
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  f2
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  I path:f2
+
+Narrow should allow widen to include f2
+  $ hg -R narrowclone1 tracked --removeinclude f2 > /dev/null
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  $ hg -R narrowclone1 tracked --addinclude f2
+  comparing with http://localhost:$HGPORT1/
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 0 changesets with 1 changes to 1 files
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  I path:f2
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  f2