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
  82 # When accessing Git via ssh, there should never be a terminal on 0, 1 or 2
  83 # The "no-pty" flag should be set in all the ssh keys files to prevent this
  84 # However, just in case, check for it here and die as a safety fallback
  85 if [ -t 0 ] || [ -t 1 ] || [ -t 2 ]; then
  86         echo forbidden >&2
  87         exit 1
  88 fi
  89
  90 # Only the following commands are allowed:
  91 #
  92 #   git-shell -c "git-receive-pack 'dir'"
  93 #   git-shell -c "git receive-pack 'dir'"
  94 #   git-shell -c "git-upload-pack 'dir'"
  95 #   git-shell -c "git upload-pack 'dir'"
  96 #   git-shell -c "git-upload-archive 'dir'"
  97 #   git-shell -c "git upload-archive 'dir'"
  98 #
  99 # where dir must start with $reporoot/ but a leading/trailing '/' is optional
 100 # as well as the final .git however if $dir does not start with $reporoot but
 101 # adding a $reporoot prefix makes it work then the $reporoot prefix will be
 102 # silently added.
 103
 104 if [ "$1" != "-c" ]; then
 105         echo forbidden >&2
 106         exit 1
 107 fi
 108
 109 dir="$2"
 110 type=''
 111 case "$2" in
 112         "git-receive-pack "*)   type='receive-pack';   dir="${dir#git-receive-pack }";;
 113         "git receive-pack "*)   type='receive-pack';   dir="${dir#git receive-pack }";;
 114         "git-upload-pack "*)    type='upload-pack';    dir="${dir#git-upload-pack }";;
 115         "git upload-pack "*)    type='upload-pack';    dir="${dir#git upload-pack }";;
 116         "git-upload-archive "*) type='upload-archive'; dir="${dir#git-upload-archive }";;
 117         "git upload-archive "*) type='upload-archive'; dir="${dir#git upload-archive }";;
 118         *)
 119                 echo forbidden >&2
 120                 exit 1
 121 esac
 122
 123 # valid project names only allow 0-9A-Za-z._+- plus the / separator and they
 124 # are always single quoted so the only valid directory names will always start
 125 # with a single quote and end with a single quote and not contain any internal
 126 # character that needs to be escaped.
 127
 128 case "$dir" in
 129         "'"*) :;;
 130         *)
 131                 echo forbidden >&2
 132                 exit 1
 133 esac
 134 case "$dir" in
 135         *"'") :;;
 136         *)
 137                 echo forbidden >&2
 138                 exit 1
 139 esac
 140
 141 # Some shells do not properly handle quoting after # or % so we cannot
 142 # put an explicit ' there in a way that works for all shells.  Instead
 143 # just remove a single character since we've already verified it's a '.
 144 dir="${dir#?}"; dir="${dir%?}"
 145
 146 # add a missing leading /
 147 case "$dir" in
 148         /*) :;;
 149         *)
 150                 dir="/$dir"
 151 esac
 152
 153 # remove a trailing /
 154 case "$dir" in
 155         *?/)
 156                 dir="${dir%/}"
 157 esac
 158
 159 # add a missing trailing .git
 160 case "$dir" in
 161         *.git) :;;
 162         *)
 163                 dir="$dir.git"
 164 esac
 165
 166 # do not allow any .. sequence
 167 case "$dir" in *..*)
 168         echo forbidden >&2
 169         exit 1
 170 esac
 171
 172 case "$dir" in
 173         "$reporoot/"*) :;;
 174         *)
 175                 # Allow it if prefixing with $reporoot matches an existing directory
 176                 if [ -d "$reporoot$dir" ]; then
 177                         dir="$reporoot$dir"
 178                 else
 179                         echo forbidden >&2
 180                         exit 1
 181                 fi
 182 esac
 183
 184 # Valid project names never end in .git (we add that automagically), so a valid
 185 # fork can never have .git at the end of any path component except the last.
 186 # We check this to avoid a situation where a certain collection of pushed refs
 187 # could be mistaken for a GIT_DIR.  Git would ultimately complain, but some
 188 # undesirable things could happen along the way.
 189
 190 # Remove the leading $reporoot and trailing .git to get a test string
 191 testpath="${dir#$reporoot/}"
 192 testpath="${testpath%.git}"
 193 case "$testpath/" in *.[Gg][Ii][Tt]/*|_*)
 194         echo forbidden >&2
 195         exit 1
 196 esac
 197
 198 if ! [ -d "$dir" ] || ! [ -f "$dir/HEAD" ] || ! [ -d "$dir/objects" ]; then
 199         echo forbidden >&2
 200         exit 1
 201 fi
 202
 203 proj="${dir#$reporoot/}"; projbare="${proj%.git}"
 204
 205 if [ "$type" = 'receive-pack' ] && [ "$LOGNAME" = 'git' ]; then
 206         echo "The user '$LOGNAME' may only be used for fetches, sorry" >&2
 207         exit 3
 208 fi
 209
 210 if [ "$type" = 'receive-pack' ] && ! [ -f "$dir/.nofetch" ]; then
 211         echo "The $proj project is a mirror and may not be pushed to, sorry" >&2
 212         exit 3
 213 fi
 214
 215 if [ "$type" = 'receive-pack' ]; then
 216         git_add_config 'receive.unpackLimit=1'
 217         # Note the git config documentation is wrong
 218         # transfer.unpackLimit, if set, overrides receive.unpackLimit
 219         git_add_config 'transfer.unpackLimit=1'
 220 fi
 221
 222 if ! [ -x @perlbin@ ] && [ "$type" = 'receive-pack' ]; then
 223         # We are INSIDE the chroot trying to push
 224
 225         if ! can_user_push "$projbare"; then
 226                 # If mob is enabled and mob has push permissions and
 227                 # the current user is not the mob then it's a personal mob push
 228                 # presuming the special mob directory has been set up
 229                 if [ "$mob" = "mob" ] && [ "$LOGNAME" != "mob" ] && [ -d "$reporoot/$proj/mob" ] &&
 230                                                                 can_user_push "$projbare" mob; then
 231                         (
 232                                 umask 113
 233                                 >"/etc/sshactive/$LOGNAME,"
 234                                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 235                                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 236                         )
 237                         exec git-shell -c "git-receive-pack '$reporoot/$proj/mob'"
 238                         exit 1
 239                 fi
 240                 echo "The user '$LOGNAME' does not have push permissions for project '$proj'" >&2
 241                 echo "You may adjust push permissions at $webadmurl/editproj.cgi?name=$proj" >&2
 242                 exit 3
 243         fi
 244         (
 245                 umask 113
 246                 >"/etc/sshactive/$LOGNAME,"
 247                 mv -f "/etc/sshactive/$LOGNAME," "/etc/sshactive/$LOGNAME"
 248                 ! [ -e "$dir/.delaygc" ] || >"$dir/.allowgc" || :
 249         )
 250 fi
 251
 252 [ -z "$var_upload_window" ] || [ "$type" != "upload-pack" ] ||
 253         git_add_config "pack.window=$var_upload_window"
 254
 255 exec git-shell -c "git-$type '$dir'"
 256 exit 1