view tests/test-convert-svn-encoding.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 svn svn-bindings

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert =
  > EOF

  $ svnadmin create svn-repo
  $ svnadmin load -q svn-repo < "$TESTDIR/svn/encoding.svndump"

Convert while testing all possible outputs

  $ hg --debug convert svn-repo A-hg --config progress.debug=1
  initializing destination A-hg repository
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  run hg sink pre-conversion action
  scanning source...
  found trunk at 'trunk'
  found tags at 'tags'
  found branches at 'branches'
  found branch branch\xc3\xa9 at 5 (esc)
  found branch branch\xc3\xa9e at 6 (esc)
  scanning: 1/4 revisions (25.00%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  fetching revision log for "/trunk" from 4 to 0
  parsing revision 4 (2 changes)
  parsing revision 3 (4 changes)
  parsing revision 2 (3 changes)
  parsing revision 1 (3 changes)
  no copyfrom path, don't know what to do.
  '/branches' is not under '/trunk', ignoring
  '/tags' is not under '/trunk', ignoring
  scanning: 2/4 revisions (50.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  fetching revision log for "/branches/branch\xc3\xa9" from 5 to 0 (esc)
  parsing revision 5 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  found parent of branch /branches/branch\xc3\xa9 at 4: /trunk (esc)
  scanning: 3/4 revisions (75.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  fetching revision log for "/branches/branch\xc3\xa9e" from 6 to 0 (esc)
  parsing revision 6 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  found parent of branch /branches/branch\xc3\xa9e at 5: /branches/branch\xc3\xa9 (esc)
  scanning: 4/4 revisions (100.00%)
  scanning: 5/4 revisions (125.00%)
  scanning: 6/4 revisions (150.00%)
  sorting...
  converting...
  5 init projA
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@1
  converting: 0/6 revisions (0.00%)
  committing changelog
  updating the branch cache
  4 hello
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@2
  converting: 1/6 revisions (16.67%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa0 0/3 paths (0.00%) (esc)
  scanning paths: /trunk/\xc3\xa0/e\xcc\x81 1/3 paths (33.33%) (esc)
  scanning paths: /trunk/\xc3\xa9 2/3 paths (66.67%) (esc)
  committing files:
  \xc3\xa0/e\xcc\x81 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/2 files (50.00%) (esc)
  \xc3\xa9 (esc)
  getting files: \xc3\xa9 2/2 files (100.00%) (esc)
  committing manifest
  committing changelog
  updating the branch cache
  3 copy files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@3
  converting: 2/6 revisions (33.33%)
  scanning paths: /trunk/\xc3\xa0 0/4 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa8 1/4 paths (25.00%) (esc)
  copied to \xc3\xa8 from \xc3\xa9@2 (esc)
  scanning paths: /trunk/\xc3\xa9 2/4 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 3/4 paths (75.00%) (esc)
  mark /trunk/\xc3\xb9 came from \xc3\xa0:2 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/4 files (25.00%) (esc)
  getting files: \xc3\xa9 2/4 files (50.00%) (esc)
  committing files:
  \xc3\xa8 (esc)
  getting files: \xc3\xa8 3/4 files (75.00%) (esc)
   \xc3\xa8: copy \xc3\xa9:6b67ccefd5ce6de77e7ead4f5292843a0255329f (esc)
  \xc3\xb9/e\xcc\x81 (esc)
  getting files: \xc3\xb9/e\xcc\x81 4/4 files (100.00%) (esc)
   \xc3\xb9/e\xcc\x81: copy \xc3\xa0/e\xcc\x81:a9092a3d84a37b9993b5c73576f6de29b7ea50f6 (esc)
  committing manifest
  committing changelog
  updating the branch cache
  2 remove files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@4
  converting: 3/6 revisions (50.00%)
  scanning paths: /trunk/\xc3\xa8 0/2 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 1/2 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  getting files: \xc3\xa8 1/2 files (50.00%) (esc)
  getting files: \xc3\xb9/e\xcc\x81 2/2 files (100.00%) (esc)
  committing files:
  committing manifest
  committing changelog
  updating the branch cache
  1 branch to branch?
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?@5
  converting: 4/6 revisions (66.67%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  scanning paths: /branches/branch\xc3\xa9 0/1 paths (0.00%) (esc)
  committing changelog
  updating the branch cache
  0 branch to branch?e
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?e@6
  converting: 5/6 revisions (83.33%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  scanning paths: /branches/branch\xc3\xa9e 0/1 paths (0.00%) (esc)
  committing changelog
  updating the branch cache
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  updating tags
  committing files:
  .hgtags
  committing manifest
  committing changelog
  updating the branch cache
  run hg sink post-conversion action
  $ cd A-hg
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Check tags are in UTF-8

  $ cat .hgtags
  e94e4422020e715add80525e8f0f46c9968689f1 branch\xc3\xa9e (esc)
  f7e66f98380ed1e53a797c5c7a7a2616a7ab377d branch\xc3\xa9 (esc)

  $ cd ..