dispatch: protect against malicious 'hg serve --stdio' invocations (sec) Some shared-ssh installations assume that 'hg serve --stdio' is a safe command to run for minimally trusted users. Unfortunately, the messy implementation of argument parsing here meant that trying to access a repo named '--debugger' would give the user a pdb prompt, thereby sidestepping any hoped-for sandboxing. Serving repositories over HTTP(S) is unaffected. We're not currently hardening any subcommands other than 'serve'. If your service exposes other commands to users with arbitrary repository names, it is imperative that you defend against repository names of '--debugger' and anything starting with '--config'. The read-only mode of hg-ssh stopped working because it provided its hook configuration to "hg serve --stdio" via --config parameter. This is banned for security reasons now. This patch switches it to directly call ui.setconfig(). If your custom hosting infrastructure relies on passing --config to "hg serve --stdio", you'll need to find a different way to get that configuration into Mercurial, either by using ui.setconfig() as hg-ssh does in this patch, or by placing an hgrc file someplace where Mercurial will read it. mitrandir@fb.com provided some extra fixes for the dispatch code and for hg-ssh in places that I overlooked.

     1

#!/bin/sh

     2

#

     3

# This is an example of using HGEDITOR to create of diff to review the

     4

# changes while committing.

     5

     6

# If you want to pass your favourite editor some other parameters

     7

# only for Mercurial, modify this:

     8

case "${EDITOR}" in

     9

    "")

    10

        EDITOR="vi"

    11

        ;;

    12

    emacs)

    13

        EDITOR="$EDITOR -nw"

    14

        ;;

    15

    gvim|vim)

    16

        EDITOR="$EDITOR -f -o"

    17

        ;;

    18

esac

    19

    20

    21

HGTMP=""

    22

cleanup_exit() {

    23

    rm -rf "$HGTMP"

    24

}

    25

    26

# Remove temporary files even if we get interrupted

    27

trap "cleanup_exit" 0 # normal exit

    28

trap "exit 255" HUP INT QUIT ABRT TERM

    29

    30

HGTMP=$(mktemp -d ${TMPDIR-/tmp}/hgeditor.XXXXXX)

    31

[ x$HGTMP != x -a -d $HGTMP ] || {

    32

  echo "Could not create temporary directory! Exiting." 1>&2

    33

  exit 1

    34

}

    35

    36

(

    37

    grep '^HG: changed' "$1" | cut -b 13- | while read changed; do

    38

        "$HG" diff "$changed" >> "$HGTMP/diff"

    39

    done

    40

)

    41

    42

cat "$1" > "$HGTMP/msg"

    43

    44

MD5=$(which md5sum 2>/dev/null) || \

    45

    MD5=$(which md5 2>/dev/null)

    46

[ -x "${MD5}" ] && CHECKSUM=`${MD5} "$HGTMP/msg"`

    47

if [ -s "$HGTMP/diff" ]; then

    48

    $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?

    49

else

    50

    $EDITOR "$HGTMP/msg" || exit $?

    51

fi

    52

[ -x "${MD5}" ] && (echo "$CHECKSUM" | ${MD5} -c >/dev/null 2>&1 && exit 13)

    53

    54

mv "$HGTMP/msg" "$1"

    55

    56

exit $?