view tests/test-pull.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 serve

  $ hg init test
  $ cd test

  $ echo foo>foo
  $ hg addremove
  adding foo
  $ hg commit -m 1

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 1 changesets, 1 total revisions

  $ hg serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

  $ hg clone --pull http://foo:bar@localhost:$HGPORT/ copy
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 340e38bdcde4
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd copy
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 1 changesets, 1 total revisions

  $ hg co
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat foo
  foo

  $ hg manifest --debug
  2ed2a3912a0b24502043eae84ee4b279c18b90dd 644   foo

  $ hg pull
  pulling from http://foo@localhost:$HGPORT/
  searching for changes
  no changes found

  $ hg rollback --dry-run --verbose
  repository tip rolled back to revision -1 (undo pull: http://foo:***@localhost:$HGPORT/)

Test pull of non-existing 20 character revision specification, making sure plain ascii identifiers
not are encoded like a node:

  $ hg pull -r 'xxxxxxxxxxxxxxxxxxxy'
  pulling from http://foo@localhost:$HGPORT/
  abort: unknown revision 'xxxxxxxxxxxxxxxxxxxy'!
  [255]
  $ hg pull -r 'xxxxxxxxxxxxxxxxxx y'
  pulling from http://foo@localhost:$HGPORT/
  abort: unknown revision '7878787878787878787878787878787878782079'!
  [255]

Issue622: hg init && hg pull -u URL doesn't checkout default branch

  $ cd ..
  $ hg init empty
  $ cd empty
  $ hg pull -u ../test
  pulling from ../test
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 340e38bdcde4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Test 'file:' uri handling:

  $ hg pull -q file://../test-does-not-exist
  abort: file:// URLs can only refer to localhost
  [255]

  $ hg pull -q file://../test
  abort: file:// URLs can only refer to localhost
  [255]

MSYS changes 'file:' into 'file;'

#if no-msys
  $ hg pull -q file:../test  # no-msys
#endif

It's tricky to make file:// URLs working on every platform with
regular shell commands.

  $ URL=`$PYTHON -c "import os; print 'file://foobar' + ('/' + os.getcwd().replace(os.sep, '/')).replace('//', '/') + '/../test'"`
  $ hg pull -q "$URL"
  abort: file:// URLs can only refer to localhost
  [255]

  $ URL=`$PYTHON -c "import os; print 'file://localhost' + ('/' + os.getcwd().replace(os.sep, '/')).replace('//', '/') + '/../test'"`
  $ hg pull -q "$URL"

SEC: check for unsafe ssh url

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > ssh = sh -c "read l; read l; read l"
  > EOF

  $ hg pull 'ssh://-oProxyCommand=touch${IFS}owned/path'
  pulling from ssh://-oProxyCommand%3Dtouch%24%7BIFS%7Downed/path
  abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path'
  [255]
  $ hg pull 'ssh://%2DoProxyCommand=touch${IFS}owned/path'
  pulling from ssh://-oProxyCommand%3Dtouch%24%7BIFS%7Downed/path
  abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path'
  [255]
  $ hg pull 'ssh://fakehost|touch${IFS}owned/path'
  pulling from ssh://fakehost%7Ctouch%24%7BIFS%7Downed/path
  abort: no suitable response from remote hg!
  [255]
  $ hg pull 'ssh://fakehost%7Ctouch%20owned/path'
  pulling from ssh://fakehost%7Ctouch%20owned/path
  abort: no suitable response from remote hg!
  [255]

  $ [ ! -f owned ] || echo 'you got owned'

  $ cd ..