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 }'$1'"
  17         export GIT_CONFIG_PARAMETERS
  18 }
  19
  20 TMPDIR="/tmp"
  21 GIT_CONFIG_NOSYSTEM=1
  22 GIT_ATTR_NOSYSTEM=1
  23 GIT_NO_REPLACE_OBJECTS=1
  24 GIT_TERMINAL_PROMPT=0
  25 GIT_PAGER="cat"
  26 PAGER="cat"
  27 GIROCCO_SUPPRESS_AUTO_GC_UPDATE=1
  28
  29 if ! [ -x @perlbin@ ]; then
  30         # We are INSIDE the chroot
  31         PATH=/bin && export PATH
  32         reporoot=/@jailreporoot@
  33         XDG_CONFIG_HOME=/var/empty
  34         HOME=/etc/girocco
  35         GIT_ASKPASS=/bin/git-askpass-password
  36 else
  37         # We are NOT INSIDE the chroot
  38         reporoot=@reporoot@
  39         XDG_CONFIG_HOME=@chroot@/var/empty
  40         HOME=@chroot@/etc/girocco
  41         GIT_ASKPASS=@basedir@/bin/git-askpass-password
  42 fi
  43 mob=@mob@
  44 webadmurl=@webadmurl@
  45 ua=@git_server_ua@
  46 defined_ua=@defined_git_server_ua@
  47 cfg_git_no_mmap=@git_no_mmap@
  48 var_big_file_threshold=@big_file_threshold@
  49 var_upload_window=@upload_pack_window@
  50 cfg_fetch_stash_refs=@fetch_stash_refs@
  51 cfg_suppress_git_ssh_logging=@suppress_git_ssh_logging@
  52 cfg_max_file_size512=@max_file_size512@
  53
  54 export XDG_CONFIG_HOME
  55 export HOME
  56 export TMPDIR
  57 export GIT_CONFIG_NOSYSTEM
  58 export GIT_ATTR_NOSYSTEM
  59 export GIT_NO_REPLACE_OBJECTS
  60 export GIT_TERMINAL_PROMPT
  61 export GIT_PAGER
  62 export PAGER
  63 export GIT_ASKPASS
  64 export GIROCCO_SUPPRESS_AUTO_GC_UPDATE
  65 unset GIT_USER_AGENT
  66 unset GIT_HTTP_USER_AGENT
  67 if [ -n "$defined_ua" ]; then
  68         GIT_USER_AGENT="$ua"
  69         export GIT_USER_AGENT
  70 fi
  71 unset GIT_CONFIG_PARAMETERS
  72 git_add_config "core.ignoreCase=false"
  73 git_add_config "core.pager=cat"
  74 if [ -n "$cfg_git_no_mmap" ]; then
  75         # Just like compiling with NO_MMAP
  76         git_add_config "core.packedGitWindowSize=1m"
  77 else
  78         # Always use the 32-bit default (32m) even on 64-bit to avoid memory blowout
  79         git_add_config "core.packedGitWindowSize=32m"
  80 fi
  81 # Always use the 32-bit default (256m) even on 64-bit to avoid memory blowout
  82 git_add_config "core.packedGitLimit=256m"
  83 [ -z "$var_big_file_threshold" ] ||
  84         git_add_config "core.bigFileThreshold=$var_big_file_threshold"
  85 git_add_config "gc.auto=0"
  86
  87 if [ "${cfg_fetch_stash_refs:-0}" = "0" ]; then
  88         git_add_config "uploadpack.hiderefs=refs/stash"
  89         git_add_config "uploadpack.hiderefs=refs/tgstash"
  90 fi
  91
  92 fromip="${SSH_CLIENT%% *}"
  93 fromip="${fromip:+$fromip }"
  94
  95 logmsg()
  96 {
  97         [ "${cfg_suppress_git_ssh_logging:-0}" = "0" ] || return 0
  98         _msg="$(LC_ALL=C tr -c '\040-\176' '[?*]' <<EOT
  99 $fromip$* $LOGNAME
 100 EOT
 101         )" && _msg="${_msg%[?]}" &&
 102         logger -t "${0##*/}[$$]" <<EOT
 103 $_msg
 104 EOT
 105 }
 106
 107 # When accessing Git via ssh, there should never be a terminal on 0, 1 or 2
 108 # The "no-pty" flag should be set in all the ssh keys files to prevent this
 109 # However, just in case, check for it here and die as a safety fallback
 110 if [ -t 0 ] || [ -t 1 ] || [ -t 2 ]; then
 111         logmsg "denied pty"
 112         echo forbidden >&2
 113         exit 1
 114 fi
 115
 116 # Only the following commands are allowed:
 117 #
 118 #   git-shell -c "git-receive-pack 'dir'"
 119 #   git-shell -c "git receive-pack 'dir'"
 120 #   git-shell -c "git-upload-pack 'dir'"
 121 #   git-shell -c "git upload-pack 'dir'"
 122 #   git-shell -c "git-upload-archive 'dir'"
 123 #   git-shell -c "git upload-archive 'dir'"
 124 #
 125 # where dir must start with $reporoot/ but a leading/trailing '/' is optional
 126 # as well as the final .git however if $dir does not start with $reporoot but
 127 # adding a $reporoot prefix makes it work then the $reporoot prefix will be
 128 # silently added.
 129
 130 if [ "$1" != "-c" ]; then
 131         echo forbidden >&2
 132         exit 1
 133 fi
 134
 135 dir="$2"
 136 type=''
 137 case "$2" in
 138         "git-receive-pack "*)   type='receive-pack';   dir="${dir#git-receive-pack }";;
 139         "git receive-pack "*)   type='receive-pack';   dir="${dir#git receive-pack }";;
 140         "git-upload-pack "*)    type='upload-pack';    dir="${dir#git-upload-pack }";;
 141         "git upload-pack "*)    type='upload-pack';    dir="${dir#git upload-pack }";;
 142         "git-upload-archive "*) type='upload-archive'; dir="${dir#git-upload-archive }";;
 143         "git upload-archive "*) type='upload-archive'; dir="${dir#git upload-archive }";;
 144         *)
 145                 echo forbidden >&2
 146                 exit 1
 147 esac
 148
 149 # valid project names only allow 0-9A-Za-z._+- plus the / separator and they
 150 # are always single quoted so the only valid directory names will always start
 151 # with a single quote and end with a single quote and not contain any internal
 152 # character that needs to be escaped.
 153
 154 case "$dir" in
 155         "'"*) :;;
 156         *)
 157                 logmsg "denied $type $dir"
 158                 echo forbidden >&2
 159                 exit 1
 160 esac
 161 case "$dir" in
 162         *"'") :;;
 163         *)
 164                 logmsg "denied $type $dir"
 165                 echo forbidden >&2
 166                 exit 1
 167 esac
 168
 169 # Some shells do not properly handle quoting after # or % so we cannot
 170 # put an explicit ' there in a way that works for all shells.  Instead
 171 # just remove a single character since we've already verified it's a '.
 172 dir="${dir#?}"; dir="${dir%?}"
 173
 174 # add a missing leading /
 175 case "$dir" in
 176         /*) :;;
 177         *)
 178                 dir="/$dir"
 179 esac
 180
 181 # remove a trailing /
 182 case "$dir" in
 183         *?/)
 184                 dir="${dir%/}"
 185 esac
 186
 187 # add a missing trailing .git
 188 case "$dir" in
 189         *.git) :;;
 190         *)
 191                 dir="$dir.git"
 192 esac
 193
 194 # do not allow any .. sequence
 195 case "$dir" in *..*)
 196         logmsg "denied $type $dir"
 197         echo forbidden >&2
 198         exit 1
 199 esac
 200
 201 odir="$dir"
 202 case "$dir" in
 203         "$reporoot/"*) :;;
 204         *)
 205                 # Allow it if prefixing with $reporoot matches an existing directory
 206                 if [ -d "$reporoot$dir" ]; then
 207                         dir="$reporoot$dir"
 208                 else
 209                         logmsg "denied $type $dir"
 210                         echo forbidden >&2
 211                         exit 1
 212                 fi
 213 esac
 214
 215 # Valid project names never end in .git (we add that automagically), so a valid
 216 # fork can never have .git at the end of any path component except the last.
 217 # We check this to avoid a situation where a certain collection of pushed refs
 218 # could be mistaken for a GIT_DIR.  Git would ultimately complain, but some
 219 # undesirable things could happen along the way.
 220
 221 # Remove the leading $reporoot and trailing .git to get a test string
 222 testpath="${dir#$reporoot/}"
 223 testpath="${testpath%.git}"
 224 case "$testpath/" in *.[Gg][Ii][Tt]/*|_*)
 225         logmsg "denied $type $odir"
 226         echo forbidden >&2
 227         exit 1
 228 esac
 229
 230 if ! [ -d "$dir" ] || ! [ -f "$dir/HEAD" ] || ! [ -d "$dir/objects" ]; then
 231         logmsg "denied $type $odir"
 232         echo forbidden >&2
 233         exit 1
 234 fi
 235
 236 proj="${dir#$reporoot/}"; projbare="${proj%.git}"
 237
 238 if [ "$type" = 'receive-pack' ] && [ "$LOGNAME" = 'git' ]; then
 239         logmsg "denied $type $odir"
 240         echo "The user '$LOGNAME' may only be used for fetches, sorry" >&2
 241         exit 3
 242 fi
 243
 244 if [ "$type" = 'receive-pack' ] && ! [ -f "$dir/.nofetch" ]; then
 245         logmsg "denied $type $odir"
 246         echo "The $proj project is a mirror and may not be pushed to, sorry" >&2
 247         exit 3
 248 fi
 249
 250 GIT_SHELL='git-shell'
 251 if [ "$type" = 'receive-pack' ]; then
 252         git_add_config 'receive.unpackLimit=1'
 253         # Note the git config documentation is wrong
 254         # transfer.unpackLimit, if set, overrides receive.unpackLimit
 255         git_add_config 'transfer.unpackLimit=1'
 256         # set up the correct git-shell command if cfg_max_file_size512 > 0
 257         if [ "${cfg_max_file_size512:-0}" != "0" ]; then
 258                 GIT_SHELL='ulimit512 -i -f "$cfg_max_file_size512" -- git-shell'
 259         fi
 260 fi
 261
 262 if ! [ -x @perlbin@ ] && [ "$type" = 'receive-pack' ]; then
 263         # We are INSIDE the chroot trying to push
 264
 265         if ! can_user_push "$projbare"; then
 266                 # If mob is enabled and mob has push permissions and
 267                 # the current user is not the mob then it's a personal mob push
 268                 # presuming the special mob directory has been set up
 269                 if [ "$mob" = "mob" ] && [ "$LOGNAME" != "mob" ] && [ -d "$reporoot/$proj/mob" ] &&
 270                                                                 can_user_push "$projbare" mob; then
 271                         (
 272                                 umask 113
 273                                 >"/etc/sshactive/$LOGNAME,"
 274                                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 275                                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 276                         )
 277                         logmsg "accepted $type $odir mob"
 278                         eval 'exec '"$GIT_SHELL"' -c "git-receive-pack '\''$reporoot/$proj/mob'\''"'
 279                         exit 1
 280                 fi
 281                 logmsg "denied $type $odir noperms"
 282                 echo "The user '$LOGNAME' does not have push permissions for project '$proj'" >&2
 283                 echo "You may adjust push permissions at $webadmurl/editproj.cgi?name=$proj" >&2
 284                 exit 3
 285         fi
 286         (
 287                 umask 113
 288                 >"/etc/sshactive/$LOGNAME,"
 289                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 290                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 291         )
 292 fi
 293
 294 [ -z "$var_upload_window" ] || [ "$type" != "upload-pack" ] ||
 295         git_add_config "pack.window=$var_upload_window"
 296
 297 logmsg "accepted $type $odir"
 298 eval 'exec '"$GIT_SHELL"' -c "git-$type '\''$dir'\''"'
 299 exit 1