view tests/test-extdiff.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.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "extdiff=" >> $HGRCPATH

  $ hg init a
  $ cd a
  $ echo a > a
  $ echo b > b
  $ hg add
  adding a
  adding b

Should diff cloned directories:

  $ hg extdiff -o -r $opt
  Only in a: a
  Only in a: b
  [1]

  $ cat <<EOF >> $HGRCPATH
  > [extdiff]
  > cmd.falabala = echo
  > opts.falabala = diffing
  > cmd.edspace = echo
  > opts.edspace = "name  <[e-mail]>"
  > EOF

  $ hg falabala
  diffing a.000000000000 a
  [1]

  $ hg help falabala
  hg falabala [OPTION]... [FILE]...
  
  use external program to diff repository (or selected files)
  
      Show differences between revisions for the specified files, using the
      following program:
  
        'echo'
  
      When two revision arguments are given, then changes are shown between
      those revisions. If only one revision is specified then that revision is
      compared to the working directory, and, when no revisions are specified,
      the working directory files are compared to its parent.
  
  options ([+] can be repeated):
  
   -o --option OPT [+]      pass option to comparison program
   -r --rev REV [+]         revision
   -c --change REV          change made by revision
      --patch               compare patches for two revisions
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -S --subrepos            recurse into subrepositories
  
  (some details hidden, use --verbose to show complete help)

  $ hg ci -d '0 0' -mtest1

  $ echo b >> a
  $ hg ci -d '1 0' -mtest2

Should diff cloned files directly:

  $ hg falabala -r 0:1
  diffing "*\\extdiff.*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  diffing */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

Specifying an empty revision should abort.

  $ hg extdiff -p diff --patch --rev 'ancestor()' --rev 1
  abort: empty revision on one side of range
  [255]

Test diff during merge:

  $ hg update -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo c >> c
  $ hg add c
  $ hg ci -m "new branch" -d '1 0'
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Should diff cloned file against wc file:

  $ hg falabala
  diffing "*\\extdiff.*\\a.2a13a4d2da36\\a" "*\\a\\a" (glob) (windows !)
  diffing */extdiff.*/a.2a13a4d2da36/a */a/a (glob) (no-windows !)
  [1]


Test --change option:

  $ hg ci -d '2 0' -mtest3

  $ hg falabala -c 1
  diffing "*\\extdiff.*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  diffing */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

Check diff are made from the first parent:

  $ hg falabala -c 3 || echo "diff-like tools yield a non-zero exit code"
  diffing "*\\extdiff.*\\a.2a13a4d2da36\\a" "a.46c0e4daeb72\\a" (glob) (windows !)
  diffing */extdiff.*/a.2a13a4d2da36/a a.46c0e4daeb72/a (glob) (no-windows !)
  diff-like tools yield a non-zero exit code

issue3153: ensure using extdiff with removed subrepos doesn't crash:

  $ hg init suba
  $ cd suba
  $ echo suba > suba
  $ hg add
  adding suba
  $ hg ci -m "adding suba file"
  $ cd ..
  $ echo suba=suba > .hgsub
  $ hg add
  adding .hgsub
  $ hg ci -Sm "adding subrepo"
  $ echo > .hgsub
  $ hg ci -m "removing subrepo"
  $ hg falabala -r 4 -r 5 -S
  diffing a.398e36faf9c6 a.5ab95fb166c4
  [1]

issue4463: usage of command line configuration without additional quoting

  $ cat <<EOF >> $HGRCPATH
  > [extdiff]
  > cmd.4463a = echo
  > opts.4463a = a-naked 'single quoted' "double quoted"
  > 4463b = echo b-naked 'single quoted' "double quoted"
  > echo =
  > EOF
  $ hg update -q -C 0
  $ echo a >> a

  $ hg --debug 4463a | grep '^running'
  running 'echo a-naked \'single quoted\' "double quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running 'echo a-naked \'single quoted\' "double quoted" */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)
  $ hg --debug 4463b | grep '^running'
  running 'echo b-naked \'single quoted\' "double quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running 'echo b-naked \'single quoted\' "double quoted" */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)
  $ hg --debug echo | grep '^running'
  running '*echo* "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running '*echo */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)

(getting options from other than extdiff section)

  $ cat <<EOF >> $HGRCPATH
  > [extdiff]
  > # using diff-tools diffargs
  > 4463b2 = echo
  > # using merge-tools diffargs
  > 4463b3 = echo
  > # no diffargs
  > 4463b4 = echo
  > [diff-tools]
  > 4463b2.diffargs = b2-naked 'single quoted' "double quoted"
  > [merge-tools]
  > 4463b3.diffargs = b3-naked 'single quoted' "double quoted"
  > EOF

  $ hg --debug 4463b2 | grep '^running'
  running 'echo b2-naked \'single quoted\' "double quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running 'echo b2-naked \'single quoted\' "double quoted" */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)
  $ hg --debug 4463b3 | grep '^running'
  running 'echo b3-naked \'single quoted\' "double quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running 'echo b3-naked \'single quoted\' "double quoted" */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)
  $ hg --debug 4463b4 | grep '^running'
  running 'echo "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running 'echo */a $TESTTMP/a/a' in */extdiff.* (glob) (no-windows !)
  $ hg --debug 4463b4 --option b4-naked --option 'being quoted' | grep '^running'
  running 'echo b4-naked "being quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running "echo b4-naked 'being quoted' */a $TESTTMP/a/a" in */extdiff.* (glob) (no-windows !)
  $ hg --debug extdiff -p echo --option echo-naked --option 'being quoted' | grep '^running'
  running 'echo echo-naked "being quoted" "*\\a" "*\\a"' in */extdiff.* (glob) (windows !)
  running "echo echo-naked 'being quoted' */a $TESTTMP/a/a" in */extdiff.* (glob) (no-windows !)

  $ touch 'sp ace'
  $ hg add 'sp ace'
  $ hg ci -m 'sp ace'
  created new head
  $ echo > 'sp ace'

Test pre-72a89cf86fcd backward compatibility with half-baked manual quoting

  $ cat <<EOF >> $HGRCPATH
  > [extdiff]
  > odd =
  > [merge-tools]
  > odd.diffargs = --foo='\$clabel' '\$clabel' "--bar=\$clabel" "\$clabel"
  > odd.executable = echo
  > EOF

  $ hg --debug odd | grep '^running'
  running '"*\\echo.exe" --foo="sp ace" "sp ace" --bar="sp ace" "sp ace"' in * (glob) (windows !)
  running "*/echo --foo='sp ace' 'sp ace' --bar='sp ace' 'sp ace'" in * (glob) (no-windows !)

Empty argument must be quoted

  $ cat <<EOF >> $HGRCPATH
  > [extdiff]
  > kdiff3 = echo
  > [merge-tools]
  > kdiff3.diffargs=--L1 \$plabel1 --L2 \$clabel \$parent \$child
  > EOF

  $ hg --debug kdiff3 -r0 | grep '^running'
  running 'echo --L1 "@0" --L2 "" a.8a5febb7f867 a' in * (glob) (windows !)
  running "echo --L1 '@0' --L2 '' a.8a5febb7f867 a" in * (glob) (no-windows !)


Test extdiff of multiple files in tmp dir:

  $ hg update -C 0 > /dev/null
  $ echo changed > a
  $ echo changed > b
#if execbit
  $ chmod +x b
#endif

Diff in working directory, before:

  $ hg diff --git
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -a
  +changed
  diff --git a/b b/b
  old mode 100644 (execbit !)
  new mode 100755 (execbit !)
  --- a/b
  +++ b/b
  @@ -1,1 +1,1 @@
  -b
  +changed


Edit with extdiff -p:

Prepare custom diff/edit tool:

  $ cat > 'diff tool.py' << EOT
  > #!$PYTHON
  > import time
  > time.sleep(1) # avoid unchanged-timestamp problems
  > file('a/a', 'ab').write('edited\n')
  > file('a/b', 'ab').write('edited\n')
  > EOT

#if execbit
  $ chmod +x 'diff tool.py'
#endif

will change to /tmp/extdiff.TMP and populate directories a.TMP and a
and start tool

#if windows
  $ cat > 'diff tool.bat' << EOF
  > @$PYTHON "`pwd`/diff tool.py"
  > EOF
  $ hg extdiff -p "`pwd`/diff tool.bat"
  [1]
#else
  $ hg extdiff -p "`pwd`/diff tool.py"
  [1]
#endif

Diff in working directory, after:

  $ hg diff --git
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
  -a
  +changed
  +edited
  diff --git a/b b/b
  old mode 100644 (execbit !)
  new mode 100755 (execbit !)
  --- a/b
  +++ b/b
  @@ -1,1 +1,2 @@
  -b
  +changed
  +edited

Test extdiff with --option:

  $ hg extdiff -p echo -o this -c 1
  this "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  this */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

  $ hg falabala -o this -c 1
  diffing this "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  diffing this */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

Test extdiff's handling of options with spaces in them:

  $ hg edspace -c 1
  "name  <[e-mail]>" "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  name  <[e-mail]> */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

  $ hg extdiff -p echo -o "name  <[e-mail]>" -c 1
  "name  <[e-mail]>" "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  name  <[e-mail]> */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

Test with revsets:

  $ hg extdif -p echo -c "rev(1)"
  "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

  $ hg extdif -p echo -r "0::1"
  "*\\a.8a5febb7f867\\a" "a.34eed99112ab\\a" (glob) (windows !)
  */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob) (no-windows !)
  [1]

Fallback to merge-tools.tool.executable|regkey
  $ mkdir dir
  $ cat > 'dir/tool.sh' << 'EOF'
  > #!/bin/sh
  > # Mimic a tool that syncs all attrs, including mtime
  > cp $1/a $2/a
  > touch -r $1/a $2/a
  > chmod +x $2/a
  > echo "** custom diff **"
  > EOF
#if execbit
  $ chmod +x dir/tool.sh
#endif

Windows can't run *.sh directly, so create a shim executable that can be.
Without something executable, the next hg command will try to run `tl` instead
of $tool (and fail).
#if windows
  $ cat > dir/tool.bat <<EOF
  > @sh -c "`pwd`/dir/tool.sh %1 %2"
  > EOF
  $ tool=`pwd`/dir/tool.bat
#else
  $ tool=`pwd`/dir/tool.sh
#endif

  $ cat a
  changed
  edited
  $ hg --debug tl --config extdiff.tl= --config merge-tools.tl.executable=$tool
  making snapshot of 2 files from rev * (glob)
    a
    b
  making snapshot of 2 files from working directory
    a
    b
  running '$TESTTMP/a/dir/tool.bat a.* a' in */extdiff.* (glob) (windows !)
  running '$TESTTMP/a/dir/tool.sh a.* a' in */extdiff.* (glob) (no-windows !)
  ** custom diff **
  file changed while diffing. Overwriting: $TESTTMP/a/a (src: */extdiff.*/a/a) (glob)
  cleaning up temp directory
  [1]
  $ cat a
  a

#if execbit
  $ [ -x a ]

  $ cat > 'dir/tool.sh' << 'EOF'
  > #!/bin/sh
  > chmod -x $2/a
  > echo "** custom diff **"
  > EOF

  $ hg --debug tl --config extdiff.tl= --config merge-tools.tl.executable=$tool
  making snapshot of 2 files from rev * (glob)
    a
    b
  making snapshot of 2 files from working directory
    a
    b
  running '$TESTTMP/a/dir/tool.sh a.* a' in */extdiff.* (glob)
  ** custom diff **
  file changed while diffing. Overwriting: $TESTTMP/a/a (src: */extdiff.*/a/a) (glob)
  cleaning up temp directory
  [1]

  $ [ -x a ]
  [1]
#endif

  $ cd ..

#if symlink

Test symlinks handling (issue1909)

  $ hg init testsymlinks
  $ cd testsymlinks
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ echo a >> a
  $ ln -s missing linka
  $ hg add linka
  $ hg falabala -r 0 --traceback
  diffing testsymlinks.07f494440405 testsymlinks
  [1]
  $ cd ..

#endif

Test handling of non-ASCII paths in generated docstrings (issue5301)

  >>> open("u", "w").write("\xa5\xa5")
  $ U=`cat u`

  $ HGPLAIN=1 hg --config hgext.extdiff= --config extdiff.cmd.td=hi help -k xyzzy
  abort: no matches
  (try 'hg help' for a list of topics)
  [255]

  $ HGPLAIN=1 hg --config hgext.extdiff= --config extdiff.cmd.td=hi help td > /dev/null

  $ LC_MESSAGES=ja_JP.UTF-8 hg --config hgext.extdiff= --config extdiff.cmd.td=$U help -k xyzzy
  abort: no matches
  (try 'hg help' for a list of topics)
  [255]

  $ LC_MESSAGES=ja_JP.UTF-8 hg --config hgext.extdiff= --config extdiff.cmd.td=$U help td \
  > | grep "^      '"
        '\xa5\xa5'