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