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