bin/git-shell-verify

   1 #!/bin/sh
   2 #
   3 # Abort any push early if the pushing user doesn't have any push permissions
   4 # at all.  This avoids unnecessary traffic and unpacked object pollution.
   5 #
   6 # This script is intended for use from within the chroot jail and may or may
   7 # not work properly outside it.
   8
   9 set -e
  10
  11 # git_add_config "some.var=value"
  12 # every ' in value must be replaced with the 4-character sequence '\'' before
  13 # calling this function or Git will barf.  Will not be effective unless running
  14 # Git version 1.7.3 or later.
  15 git_add_config() {
  16         GIT_CONFIG_PARAMETERS="${GIT_CONFIG_PARAMETERS:+$GIT_CONFIG_PARAMETERS }'$1'"
  17         export GIT_CONFIG_PARAMETERS
  18 }
  19
  20 TMPDIR="/tmp"
  21 GIT_CONFIG_NOSYSTEM=1
  22 GIT_ATTR_NOSYSTEM=1
  23 GIT_NO_REPLACE_OBJECTS=1
  24 GIT_TERMINAL_PROMPT=0
  25 GIT_PAGER="cat"
  26 PAGER="cat"
  27 GIROCCO_SUPPRESS_AUTO_GC_UPDATE=1
  28
  29 if ! [ -x @perlbin@ ]; then
  30         # We are INSIDE the chroot
  31         reporoot=/@jailreporoot@
  32         XDG_CONFIG_HOME=/var/empty
  33         HOME=/etc/girocco
  34         GIT_ASKPASS=/bin/git-askpass-password
  35 else
  36         # We are NOT INSIDE the chroot
  37         reporoot=@reporoot@
  38         XDG_CONFIG_HOME=@chroot@/var/empty
  39         HOME=@chroot@/etc/girocco
  40         GIT_ASKPASS=@basedir@/bin/git-askpass-password
  41 fi
  42 mob=@mob@
  43 webadmurl=@webadmurl@
  44 ua=@git_server_ua@
  45 defined_ua=@defined_git_server_ua@
  46 cfg_git_no_mmap=@git_no_mmap@
  47 var_big_file_threshold=@big_file_threshold@
  48 var_upload_window=@upload_pack_window@
  49 cfg_fetch_stash_refs=@fetch_stash_refs@
  50 cfg_suppress_git_ssh_logging=@suppress_git_ssh_logging@
  51
  52 export XDG_CONFIG_HOME
  53 export HOME
  54 export TMPDIR
  55 export GIT_CONFIG_NOSYSTEM
  56 export GIT_ATTR_NOSYSTEM
  57 export GIT_NO_REPLACE_OBJECTS
  58 export GIT_TERMINAL_PROMPT
  59 export GIT_PAGER
  60 export PAGER
  61 export GIT_ASKPASS
  62 export GIROCCO_SUPPRESS_AUTO_GC_UPDATE
  63 unset GIT_USER_AGENT
  64 unset GIT_HTTP_USER_AGENT
  65 if [ -n "$defined_ua" ]; then
  66         GIT_USER_AGENT="$ua"
  67         export GIT_USER_AGENT
  68 fi
  69 unset GIT_CONFIG_PARAMETERS
  70 git_add_config "core.ignoreCase=false"
  71 git_add_config "core.pager=cat"
  72 if [ -n "$cfg_git_no_mmap" ]; then
  73         # Just like compiling with NO_MMAP
  74         git_add_config "core.packedGitWindowSize=1m"
  75 else
  76         # Always use the 32-bit default (32m) even on 64-bit to avoid memory blowout
  77         git_add_config "core.packedGitWindowSize=32m"
  78 fi
  79 # Always use the 32-bit default (256m) even on 64-bit to avoid memory blowout
  80 git_add_config "core.packedGitLimit=256m"
  81 [ -z "$var_big_file_threshold" ] ||
  82         git_add_config "core.bigFileThreshold=$var_big_file_threshold"
  83 git_add_config "gc.auto=0"
  84
  85 if [ "${cfg_fetch_stash_refs:-0}" = "0" ]; then
  86         git_add_config "uploadpack.hiderefs=refs/stash"
  87         git_add_config "uploadpack.hiderefs=refs/tgstash"
  88 fi
  89
  90 fromip="${SSH_CLIENT%% *}"
  91 fromip="${fromip:+$fromip }"
  92
  93 logmsg()
  94 {
  95         [ "${cfg_suppress_git_ssh_logging:-0}" = "0" ] || return 0
  96         _msg="$(LC_ALL=C tr -c '\040-\176' '[?*]' <<EOT
  97 $fromip$* $LOGNAME
  98 EOT
  99         )" && _msg="${_msg%[?]}" &&
 100         logger -t "${0##*/}[$$]" <<EOT
 101 $_msg
 102 EOT
 103 }
 104
 105 # When accessing Git via ssh, there should never be a terminal on 0, 1 or 2
 106 # The "no-pty" flag should be set in all the ssh keys files to prevent this
 107 # However, just in case, check for it here and die as a safety fallback
 108 if [ -t 0 ] || [ -t 1 ] || [ -t 2 ]; then
 109         logmsg "denied pty"
 110         echo forbidden >&2
 111         exit 1
 112 fi
 113
 114 # Only the following commands are allowed:
 115 #
 116 #   git-shell -c "git-receive-pack 'dir'"
 117 #   git-shell -c "git receive-pack 'dir'"
 118 #   git-shell -c "git-upload-pack 'dir'"
 119 #   git-shell -c "git upload-pack 'dir'"
 120 #   git-shell -c "git-upload-archive 'dir'"
 121 #   git-shell -c "git upload-archive 'dir'"
 122 #
 123 # where dir must start with $reporoot/ but a leading/trailing '/' is optional
 124 # as well as the final .git however if $dir does not start with $reporoot but
 125 # adding a $reporoot prefix makes it work then the $reporoot prefix will be
 126 # silently added.
 127
 128 if [ "$1" != "-c" ]; then
 129         echo forbidden >&2
 130         exit 1
 131 fi
 132
 133 dir="$2"
 134 type=''
 135 case "$2" in
 136         "git-receive-pack "*)   type='receive-pack';   dir="${dir#git-receive-pack }";;
 137         "git receive-pack "*)   type='receive-pack';   dir="${dir#git receive-pack }";;
 138         "git-upload-pack "*)    type='upload-pack';    dir="${dir#git-upload-pack }";;
 139         "git upload-pack "*)    type='upload-pack';    dir="${dir#git upload-pack }";;
 140         "git-upload-archive "*) type='upload-archive'; dir="${dir#git-upload-archive }";;
 141         "git upload-archive "*) type='upload-archive'; dir="${dir#git upload-archive }";;
 142         *)
 143                 echo forbidden >&2
 144                 exit 1
 145 esac
 146
 147 # valid project names only allow 0-9A-Za-z._+- plus the / separator and they
 148 # are always single quoted so the only valid directory names will always start
 149 # with a single quote and end with a single quote and not contain any internal
 150 # character that needs to be escaped.
 151
 152 case "$dir" in
 153         "'"*) :;;
 154         *)
 155                 logmsg "denied $type $dir"
 156                 echo forbidden >&2
 157                 exit 1
 158 esac
 159 case "$dir" in
 160         *"'") :;;
 161         *)
 162                 logmsg "denied $type $dir"
 163                 echo forbidden >&2
 164                 exit 1
 165 esac
 166
 167 # Some shells do not properly handle quoting after # or % so we cannot
 168 # put an explicit ' there in a way that works for all shells.  Instead
 169 # just remove a single character since we've already verified it's a '.
 170 dir="${dir#?}"; dir="${dir%?}"
 171
 172 # add a missing leading /
 173 case "$dir" in
 174         /*) :;;
 175         *)
 176                 dir="/$dir"
 177 esac
 178
 179 # remove a trailing /
 180 case "$dir" in
 181         *?/)
 182                 dir="${dir%/}"
 183 esac
 184
 185 # add a missing trailing .git
 186 case "$dir" in
 187         *.git) :;;
 188         *)
 189                 dir="$dir.git"
 190 esac
 191
 192 # do not allow any .. sequence
 193 case "$dir" in *..*)
 194         logmsg "denied $type $dir"
 195         echo forbidden >&2
 196         exit 1
 197 esac
 198
 199 odir="$dir"
 200 case "$dir" in
 201         "$reporoot/"*) :;;
 202         *)
 203                 # Allow it if prefixing with $reporoot matches an existing directory
 204                 if [ -d "$reporoot$dir" ]; then
 205                         dir="$reporoot$dir"
 206                 else
 207                         logmsg "denied $type $dir"
 208                         echo forbidden >&2
 209                         exit 1
 210                 fi
 211 esac
 212
 213 # Valid project names never end in .git (we add that automagically), so a valid
 214 # fork can never have .git at the end of any path component except the last.
 215 # We check this to avoid a situation where a certain collection of pushed refs
 216 # could be mistaken for a GIT_DIR.  Git would ultimately complain, but some
 217 # undesirable things could happen along the way.
 218
 219 # Remove the leading $reporoot and trailing .git to get a test string
 220 testpath="${dir#$reporoot/}"
 221 testpath="${testpath%.git}"
 222 case "$testpath/" in *.[Gg][Ii][Tt]/*|_*)
 223         logmsg "denied $type $odir"
 224         echo forbidden >&2
 225         exit 1
 226 esac
 227
 228 if ! [ -d "$dir" ] || ! [ -f "$dir/HEAD" ] || ! [ -d "$dir/objects" ]; then
 229         logmsg "denied $type $odir"
 230         echo forbidden >&2
 231         exit 1
 232 fi
 233
 234 proj="${dir#$reporoot/}"; projbare="${proj%.git}"
 235
 236 if [ "$type" = 'receive-pack' ] && [ "$LOGNAME" = 'git' ]; then
 237         logmsg "denied $type $odir"
 238         echo "The user '$LOGNAME' may only be used for fetches, sorry" >&2
 239         exit 3
 240 fi
 241
 242 if [ "$type" = 'receive-pack' ] && ! [ -f "$dir/.nofetch" ]; then
 243         logmsg "denied $type $odir"
 244         echo "The $proj project is a mirror and may not be pushed to, sorry" >&2
 245         exit 3
 246 fi
 247
 248 if [ "$type" = 'receive-pack' ]; then
 249         git_add_config 'receive.unpackLimit=1'
 250         # Note the git config documentation is wrong
 251         # transfer.unpackLimit, if set, overrides receive.unpackLimit
 252         git_add_config 'transfer.unpackLimit=1'
 253 fi
 254
 255 if ! [ -x @perlbin@ ] && [ "$type" = 'receive-pack' ]; then
 256         # We are INSIDE the chroot trying to push
 257
 258         if ! can_user_push "$projbare"; then
 259                 # If mob is enabled and mob has push permissions and
 260                 # the current user is not the mob then it's a personal mob push
 261                 # presuming the special mob directory has been set up
 262                 if [ "$mob" = "mob" ] && [ "$LOGNAME" != "mob" ] && [ -d "$reporoot/$proj/mob" ] &&
 263                                                                 can_user_push "$projbare" mob; then
 264                         (
 265                                 umask 113
 266                                 >"/etc/sshactive/$LOGNAME,"
 267                                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 268                                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 269                         )
 270                         logmsg "accepted $type $odir mob"
 271                         exec git-shell -c "git-receive-pack '$reporoot/$proj/mob'"
 272                         exit 1
 273                 fi
 274                 logmsg "denied $type $odir noperms"
 275                 echo "The user '$LOGNAME' does not have push permissions for project '$proj'" >&2
 276                 echo "You may adjust push permissions at $webadmurl/editproj.cgi?name=$proj" >&2
 277                 exit 3
 278         fi
 279         (
 280                 umask 113
 281                 >"/etc/sshactive/$LOGNAME,"
 282                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 283                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 284         )
 285 fi
 286
 287 [ -z "$var_upload_window" ] || [ "$type" != "upload-pack" ] ||
 288         git_add_config "pack.window=$var_upload_window"
 289
 290 logmsg "accepted $type $odir"
 291 exec git-shell -c "git-$type '$dir'"
 292 exit 1