view tests/test-static-http.t @ 36755:ff4bc0ab6740 stable

wireproto: check permissions when executing "batch" command (BC) (SEC)

For as long as the "batch" command has existed (introduced by
bd88561afb4b and first released as part of Mercurial 1.9), that command
(like most wire commands introduced after 2008) lacked an entry in
the hgweb permissions table. And since we don't verify permissions if
an entry is missing from the permissions table, this meant that
executing a command via "batch" would bypass all permissions
checks.

The security implications are significant: a Mercurial HTTP server
would allow writes via "batch" wire protocol commands as long as
the HTTP request were processed by Mercurial and the process running
the Mercurial HTTP server had write access to the repository. The
Mercurial defaults of servers being read-only and the various web.*
config options to define access control were bypassed.

In addition, "batch" could be used to exfiltrate data from servers
that were configured to not allow read access.

Both forms of permissions bypass could be mitigated to some extent
by using HTTP authentication. This would prevent HTTP requests from
hitting Mercurial's server logic. However, any authenticated request
would still be able to bypass permissions checks via "batch" commands.

The easiest exploit was to send "pushkey" commands via "batch" and
modify the state of bookmarks, phases, and obsolescence markers.
However, I suspect a well-crafted HTTP request could trick the server
into running the "unbundle" wire protocol command, effectively
performing a full `hg push` to create new changesets on the remote.

This commit plugs this gaping security hole by having the "batch"
command perform permissions checking on each sub-command that is
being batched. We do this by threading a permissions checking
callable all the way to the protocol handler. The threading is a
bit hacky from a code perspective. But it preserves API compatibility,
which is the proper thing to do on the stable branch.

One of the subtle things we do is assume that a command with an
undefined permission is a "push" command. This is the safest thing to
do from a security perspective: we don't want to take chances that
a command could perform a write even though the server is configured
to not allow writes.

As the test changes demonstrate, it is no longer possible to bypass
permissions via the "batch" wire protocol command.

.. bc::

   The "batch" wire protocol command now enforces permissions of
   each invoked sub-command. Wire protocol commands must define
   their operation type or the "batch" command will assume they
   can write data and will prevent their execution on HTTP servers
   unless the HTTP request method is POST, the server is configured
   to allow pushes, and the (possibly authenticated) HTTP user is
   authorized to perform a push.

#require killdaemons

  $ hg clone http://localhost:$HGPORT/ copy
  abort: * (glob)
  [255]
  $ test -d copy
  [1]

This server doesn't do range requests so it's basically only good for
one pull

  $ $PYTHON "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid \
  > --logfile server.log
  $ cat dumb.pid >> $DAEMON_PIDS
  $ hg init remote
  $ cd remote
  $ echo foo > bar
  $ echo c2 > '.dotfile with spaces'
  $ hg add
  adding .dotfile with spaces
  adding bar
  $ hg commit -m"test"
  $ hg tip
  changeset:   0:02770d679fb8
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     test
  
  $ cd ..
  $ hg clone static-http://localhost:$HGPORT/remote local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 02770d679fb8
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 1 changesets, 2 total revisions
  $ cat bar
  foo
  $ cd ../remote
  $ echo baz > quux
  $ hg commit -A -mtest2
  adding quux

check for HTTP opener failures when cachefile does not exist

  $ rm .hg/cache/*
  $ cd ../local
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup"
  > EOF
  $ hg pull
  pulling from static-http://localhost:$HGPORT/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 4ac2e3648604
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_NODE_LAST=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=http://localhost:$HGPORT/remote
  (run 'hg update' to get a working copy)

trying to push

  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo more foo >> bar
  $ hg commit -m"test"
  $ hg push
  pushing to static-http://localhost:$HGPORT/remote
  abort: destination does not support push
  [255]

trying clone -r

  $ cd ..
  $ hg clone -r doesnotexist static-http://localhost:$HGPORT/remote local0
  abort: unknown revision 'doesnotexist'!
  [255]
  $ hg clone -r 0 static-http://localhost:$HGPORT/remote local0
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 02770d679fb8
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

test with "/" URI (issue747) and subrepo

  $ hg init
  $ hg init sub
  $ touch sub/test
  $ hg -R sub commit -A -m "test"
  adding test
  $ hg -R sub tag not-empty
  $ echo sub=sub > .hgsub
  $ echo a > a
  $ hg add a .hgsub
  $ hg -q ci -ma
  $ hg clone static-http://localhost:$HGPORT/ local2
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 3 changes to 3 files
  new changesets a9ebfbe8e587
  updating to branch default
  cloning subrepo sub from static-http://localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  new changesets be090ea66256:322ea90975df
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local2
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  3 files, 1 changesets, 3 total revisions
  checking subrepo links
  $ cat a
  a
  $ hg paths
  default = static-http://localhost:$HGPORT/

test with empty repo (issue965)

  $ cd ..
  $ hg init remotempty
  $ hg clone static-http://localhost:$HGPORT/remotempty local3
  no changes found
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local3
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions
  $ hg paths
  default = static-http://localhost:$HGPORT/remotempty

test with non-repo

  $ cd ..
  $ mkdir notarepo
  $ hg clone static-http://localhost:$HGPORT/notarepo local3
  abort: 'http://localhost:$HGPORT/notarepo' does not appear to be an hg repository!
  [255]

Clone with tags and branches works

  $ hg init remote-with-names
  $ cd remote-with-names
  $ echo 0 > foo
  $ hg -q commit -A -m initial
  $ echo 1 > foo
  $ hg commit -m 'commit 1'
  $ hg -q up 0
  $ hg branch mybranch
  marked working directory as branch mybranch
  (branches are permanent and global, did you want a bookmark?)
  $ echo 2 > foo
  $ hg commit -m 'commit 2 (mybranch)'
  $ hg tag -r 1 'default-tag'
  $ hg tag -r 2 'branch-tag'

  $ cd ..

  $ hg clone static-http://localhost:$HGPORT/remote-with-names local-with-names
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 5 changes to 2 files (+1 heads)
  new changesets 68986213bd44:0c325bd2b5a7
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Clone a specific branch works

  $ hg clone -r mybranch static-http://localhost:$HGPORT/remote-with-names local-with-names-branch
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 2 files
  new changesets 68986213bd44:0c325bd2b5a7
  updating to branch mybranch
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Clone a specific tag works

  $ hg clone -r default-tag static-http://localhost:$HGPORT/remote-with-names local-with-names-tag
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets 68986213bd44:4ee3fcef1c80
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ killdaemons.py

List of files accessed over HTTP:

  $ cat server.log | sed -n -e 's|.*GET \(/[^ ]*\).*|\1|p' | sort -u
  /.hg/bookmarks
  /.hg/bookmarks.current
  /.hg/cache/hgtagsfnodes1
  /.hg/requires
  /.hg/store/00changelog.i
  /.hg/store/00manifest.i
  /.hg/store/data/%7E2ehgsub.i
  /.hg/store/data/%7E2ehgsubstate.i
  /.hg/store/data/a.i
  /notarepo/.hg/00changelog.i
  /notarepo/.hg/requires
  /remote-with-names/.hg/bookmarks
  /remote-with-names/.hg/bookmarks.current
  /remote-with-names/.hg/cache/branch2-served
  /remote-with-names/.hg/cache/hgtagsfnodes1
  /remote-with-names/.hg/cache/tags2-served
  /remote-with-names/.hg/localtags
  /remote-with-names/.hg/requires
  /remote-with-names/.hg/store/00changelog.i
  /remote-with-names/.hg/store/00manifest.i
  /remote-with-names/.hg/store/data/%7E2ehgtags.i
  /remote-with-names/.hg/store/data/foo.i
  /remote/.hg/bookmarks
  /remote/.hg/bookmarks.current
  /remote/.hg/cache/branch2-base
  /remote/.hg/cache/branch2-immutable
  /remote/.hg/cache/branch2-served
  /remote/.hg/cache/hgtagsfnodes1
  /remote/.hg/cache/rbc-names-v1
  /remote/.hg/cache/tags2-served
  /remote/.hg/localtags
  /remote/.hg/requires
  /remote/.hg/store/00changelog.i
  /remote/.hg/store/00manifest.i
  /remote/.hg/store/data/%7E2edotfile%20with%20spaces.i
  /remote/.hg/store/data/%7E2ehgtags.i
  /remote/.hg/store/data/bar.i
  /remote/.hg/store/data/quux.i
  /remotempty/.hg/bookmarks
  /remotempty/.hg/bookmarks.current
  /remotempty/.hg/requires
  /remotempty/.hg/store/00changelog.i
  /remotempty/.hg/store/00manifest.i
  /sub/.hg/bookmarks
  /sub/.hg/bookmarks.current
  /sub/.hg/cache/hgtagsfnodes1
  /sub/.hg/requires
  /sub/.hg/store/00changelog.i
  /sub/.hg/store/00manifest.i
  /sub/.hg/store/data/%7E2ehgtags.i
  /sub/.hg/store/data/test.i