cmdline/apt-key.in

   1 #!/bin/sh
   2
   3 set -e
   4 unset GREP_OPTIONS
   5
   6 GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring"
   7
   8 # gpg needs (in different versions more or less) files to function correctly,
   9 # so we give it its own homedir and generate some valid content for it
  10 GPGHOMEDIR="$(mktemp -d)"
  11 CURRENTTRAP="${CURRENTTRAP} rm -rf '${GPGHOMEDIR}';"
  12 trap "${CURRENTTRAP}" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM
  13 chmod 700 "$GPGHOMEDIR"
  14 # We don't use a secret keyring, of course, but gpg panics and
  15 # implodes if there isn't one available - and writeable for imports
  16 SECRETKEYRING="${GPGHOMEDIR}/secring.gpg"
  17 touch $SECRETKEYRING
  18 GPG_CMD="$GPG_CMD --homedir $GPGHOMEDIR"
  19 # create the trustdb with an (empty) dummy keyring
  20 # older gpgs required it, newer gpgs even warn that it isn't needed,
  21 # but require it nonetheless for some commands, so we just play safe
  22 # here for the foreseeable future and create a dummy one
  23 $GPG_CMD --quiet --check-trustdb --keyring $SECRETKEYRING >/dev/null 2>&1
  24 # tell gpg that it shouldn't try to maintain a trustdb file
  25 GPG_CMD="$GPG_CMD --no-auto-check-trustdb --trust-model always"
  26 GPG="$GPG_CMD"
  27
  28 APT_DIR="/"
  29 eval $(apt-config shell APT_DIR Dir)
  30
  31 MASTER_KEYRING='&keyring-master-filename;'
  32 eval $(apt-config shell MASTER_KEYRING APT::Key::MasterKeyring)
  33 ARCHIVE_KEYRING='&keyring-filename;'
  34 eval $(apt-config shell ARCHIVE_KEYRING APT::Key::ArchiveKeyring)
  35 REMOVED_KEYS='&keyring-removed-filename;'
  36 eval $(apt-config shell REMOVED_KEYS APT::Key::RemovedKeys)
  37 ARCHIVE_KEYRING_URI='&keyring-uri;'
  38 eval $(apt-config shell ARCHIVE_KEYRING_URI APT::Key::ArchiveKeyringURI)
  39 TMP_KEYRING=${APT_DIR}/var/lib/apt/keyrings/maybe-import-keyring.gpg
  40
  41 aptkey_echo() { echo "$@"; }
  42
  43 requires_root() {
  44         if [ "$(id -u)" -ne 0 ]; then
  45                 echo >&2 "ERROR: This command can only be used by root."
  46                 exit 1
  47         fi
  48 }
  49
  50 add_keys_with_verify_against_master_keyring() {
  51     ADD_KEYRING=$1
  52     MASTER=$2
  53
  54     if [ ! -f "$ADD_KEYRING" ]; then
  55         echo >&2 "ERROR: '$ADD_KEYRING' not found"
  56         return
  57     fi
  58     if [ ! -f "$MASTER" ]; then
  59         echo >&2 "ERROR: '$MASTER' not found"
  60         return
  61     fi
  62
  63     # when adding new keys, make sure that the archive-master-keyring
  64     # is honored. so:
  65     #   all keys that are exported must have a valid signature
  66     #   from a key in the $distro-master-keyring
  67     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  68     all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5`
  69     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  70
  71     # ensure there are no colisions LP: #857472
  72     for all_add_key in $all_add_keys; do
  73         for master_key in $master_keys; do
  74             if [ "$all_add_key" = "$master_key" ]; then
  75                 echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted"
  76                 return 1
  77             fi
  78         done
  79     done
  80
  81     for add_key in $add_keys; do
  82         # export the add keyring one-by-one
  83         rm -f $TMP_KEYRING
  84         $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key
  85         # check if signed with the master key and only add in this case
  86         ADDED=0
  87         for master_key in $master_keys; do
  88             if $GPG_CMD --keyring $MASTER --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then
  89                 $GPG --import $TMP_KEYRING
  90                 ADDED=1
  91             fi
  92         done
  93         if [ $ADDED = 0 ]; then
  94             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  95         fi
  96     done
  97     rm -f $TMP_KEYRING
  98 }
  99
 100 # update the current archive signing keyring from a network URI
 101 # the archive-keyring keys needs to be signed with the master key
 102 # (otherwise it does not make sense from a security POV)
 103 net_update() {
 104     # Disabled for now as code is insecure (LP: #1013639 (and 857472, 1013128))
 105     APT_KEY_NET_UPDATE_ENABLED=""
 106     eval $(apt-config shell APT_KEY_NET_UPDATE_ENABLED APT::Key::Net-Update-Enabled)
 107     if [ -z "$APT_KEY_NET_UPDATE_ENABLED" ]; then
 108         exit 1
 109     fi
 110
 111     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
 112         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
 113         exit 1
 114     fi
 115     # in theory we would need to depend on wget for this, but this feature
 116     # isn't useable in debian anyway as we have no keyring uri nor a master key
 117     if ! which wget >/dev/null 2>&1; then
 118         echo >&2 "ERROR: an installed wget is required for a network-based update"
 119         exit 1
 120     fi
 121     if [ ! -d ${APT_DIR}/var/lib/apt/keyrings ]; then
 122         mkdir -p ${APT_DIR}/var/lib/apt/keyrings
 123     fi
 124     keyring=${APT_DIR}/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING_URI)
 125     old_mtime=0
 126     if [ -e $keyring ]; then
 127         old_mtime=$(stat -c %Y $keyring)
 128     fi
 129     (cd  ${APT_DIR}/var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI)
 130     if [ ! -e $keyring ]; then
 131         return
 132     fi
 133     new_mtime=$(stat -c %Y $keyring)
 134     if [ $new_mtime -ne $old_mtime ]; then
 135         aptkey_echo "Checking for new archive signing keys now"
 136         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 137     fi
 138 }
 139
 140 update() {
 141     if [ ! -f $ARCHIVE_KEYRING ]; then
 142         echo >&2 "ERROR: Can't find the archive-keyring"
 143         echo >&2 "Is the &keyring-package; package installed?"
 144         exit 1
 145     fi
 146
 147     # add new keys from the package;
 148
 149     # we do not use add_keys_with_verify_against_master_keyring here,
 150     # because "update" is run on regular package updates.  A
 151     # attacker might as well replace the master-archive-keyring file
 152     # in the package and add his own keys. so this check wouldn't
 153     # add any security. we *need* this check on net-update though
 154     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 155
 156     if [ -r "$REMOVED_KEYS" ]; then
 157         # remove no-longer supported/used keys
 158         $GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5 | while read key; do
 159             foreach_keyring_do 'remove_key_from_keyring' "$key"
 160         done
 161     else
 162         echo >&2 "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable"
 163     fi
 164 }
 165
 166 remove_key_from_keyring() {
 167     local KEYRINGFILE="$1"
 168     shift
 169     # non-existent keyrings have by definition no keys
 170     if [ ! -e "$KEYRINGFILE" ]; then
 171        return
 172     fi
 173
 174     local GPG="$GPG_CMD --keyring $KEYRINGFILE"
 175     while [ -n "$1" ]; do
 176        local KEY="$1"
 177        shift
 178         # check if the key is in this keyring: the key id is in the 5 column at the end
 179         if ! $GPG --with-colons --list-keys 2>&1 | grep -q "^pub:[^:]*:[^:]*:[^:]*:[0-9A-F]*${KEY}:"; then
 180             continue
 181         fi
 182         if [ ! -w "$KEYRINGFILE" ]; then
 183             echo >&2 "Key ${KEY} is in keyring ${KEYRINGFILE}, but can't be removed as it is read only."
 184             continue
 185         fi
 186         # check if it is the only key in the keyring and if so remove the keyring altogether
 187         if [ '1' = "$($GPG --with-colons --list-keys | grep "^pub:[^:]*:[^:]*:[^:]*:[0-9A-F]\+:" | wc -l)" ]; then
 188             mv -f "$KEYRINGFILE" "${KEYRINGFILE}~" # behave like gpg
 189             return
 190         fi
 191         # we can't just modify pointed to files as these might be in /usr or something
 192         local REALTARGET
 193         if [ -L "$KEYRINGFILE" ]; then
 194             REALTARGET="$(readlink -f "$KEYRINGFILE")"
 195             mv -f "$KEYRINGFILE" "${KEYRINGFILE}.dpkg-tmp"
 196             cp -a "$REALTARGET" "$KEYRINGFILE"
 197         fi
 198         # delete the key from the keyring
 199         $GPG --batch --delete-key --yes "$KEY"
 200         if [ -n "$REALTARGET" ]; then
 201             # the real backup is the old link, not the copy we made
 202             mv -f "${KEYRINGFILE}.dpkg-tmp" "${KEYRINGFILE}~"
 203         fi
 204     done
 205 }
 206
 207 foreach_keyring_do() {
 208    local ACTION="$1"
 209    shift
 210    # if a --keyring was given, just remove from there
 211    if [ -n "$FORCED_KEYRING" ]; then
 212         $ACTION "$FORCED_KEYRING" "$@"
 213    else
 214         # otherwise all known keyrings are up for inspection
 215         if [ -s "$TRUSTEDFILE" ]; then
 216             $ACTION "$TRUSTEDFILE" "$@"
 217         fi
 218         local TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 219         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 220         if [ -d "$TRUSTEDPARTS" ]; then
 221             # strip / suffix as gpg will double-slash in that case (#665411)
 222             local STRIPPED_TRUSTEDPARTS="${TRUSTEDPARTS%/}"
 223             if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then
 224                 TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS"
 225             fi
 226             for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do
 227                 if [ -s "$trusted" ]; then
 228                     $ACTION "$trusted" "$@"
 229                 fi
 230             done
 231         fi
 232    fi
 233 }
 234
 235 list_keys_from_keyring() {
 236     local KEYRINGFILE="$1"
 237     shift
 238     # don't show the error message if this keyring doesn't include the key
 239     $GPG_CMD --keyring "$KEYRINGFILE" --batch --list-keys "$@" 2>/dev/null || true
 240 }
 241
 242 fingerprint_keys_from_keyring() {
 243     local KEYRINGFILE="$1"
 244     shift
 245     # don't show the error message if this keyring doesn't include the fingerprint
 246     $GPG_CMD --keyring "$KEYRINGFILE" --batch --fingerprint "$@" 2>/dev/null || true
 247 }
 248
 249 import_keys_from_keyring() {
 250     local IMPORT="$1"
 251     local KEYRINGFILE="$2"
 252     $GPG_CMD --keyring "$KEYRINGFILE" --batch --import "$IMPORT" >/dev/null 2>&1
 253 }
 254
 255 setup_merged_keyring() {
 256     local TRUSTEDFILE_BAK="$TRUSTEDFILE"
 257     TRUSTEDFILE='/dev/null'
 258     foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/trusted.gpg"
 259     TRUSTEDFILE="$TRUSTEDFILE_BAK"
 260     # mark it as non-writeable so users get errors if gnupg tries to modify it
 261     if [ -s "${GPGHOMEDIR}/trusted.gpg" ]; then
 262         chmod -w "${GPGHOMEDIR}/trusted.gpg"
 263         GPG="$GPG --keyring ${GPGHOMEDIR}/trusted.gpg"
 264     fi
 265     if [ -r "$TRUSTEDFILE" ]; then
 266         GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 267     fi
 268 }
 269
 270
 271 usage() {
 272     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 273     echo
 274     echo "Manage apt's list of trusted keys"
 275     echo
 276     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 277     echo "  apt-key del <keyid>         - remove the key <keyid>"
 278     echo "  apt-key export <keyid>      - output the key <keyid>"
 279     echo "  apt-key exportall           - output all trusted keys"
 280     echo "  apt-key update              - update keys using the keyring package"
 281     echo "  apt-key net-update          - update keys using the network"
 282     echo "  apt-key list                - list keys"
 283     echo "  apt-key finger              - list fingerprints"
 284     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 285     echo
 286     echo "If no specific keyring file is given the command applies to all keyring files."
 287 }
 288
 289 while [ -n "$1" ]; do
 290    case "$1" in
 291       --keyring)
 292          shift
 293          TRUSTEDFILE="$1"
 294          FORCED_KEYRING="$1"
 295          shift
 296          ;;
 297       --fakeroot)
 298          requires_root() { true; }
 299          shift
 300          ;;
 301       --quiet)
 302          aptkey_echo() { true; }
 303          shift
 304          ;;
 305       --*)
 306          echo >&2 "Unknown option: $1"
 307          usage
 308          exit 1;;
 309       *)
 310          break;;
 311    esac
 312 done
 313
 314 if [ -z "$TRUSTEDFILE" ]; then
 315    TRUSTEDFILE="/etc/apt/trusted.gpg"
 316    eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 317    eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 318 fi
 319
 320 command="$1"
 321 if [ -z "$command" ]; then
 322     usage
 323     exit 1
 324 fi
 325 shift
 326
 327 if [ "$command" != "help" ]; then
 328     if ! which gpg >/dev/null 2>&1; then
 329         echo >&2 "Warning: gnupg does not seem to be installed."
 330         echo >&2 "Warning: apt-key requires gnupg for most operations."
 331         echo >&2
 332     fi
 333
 334     # gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
 335     if ! [ -e "$TRUSTEDFILE" ]; then
 336         if [ -w "$(dirname "$TRUSTEDFILE")" ]; then
 337            touch -- "$TRUSTEDFILE"
 338            chmod 0644 -- "$TRUSTEDFILE"
 339         fi
 340     fi
 341 fi
 342
 343 case "$command" in
 344     add)
 345         requires_root
 346         setup_merged_keyring
 347         $GPG --quiet --batch --import "$@"
 348         aptkey_echo "OK"
 349         ;;
 350     del|rm|remove)
 351         requires_root
 352         foreach_keyring_do 'remove_key_from_keyring' "$@"
 353         aptkey_echo "OK"
 354         ;;
 355     update)
 356         requires_root
 357         setup_merged_keyring
 358         update
 359         ;;
 360     net-update)
 361         requires_root
 362         setup_merged_keyring
 363         net_update
 364         ;;
 365     list)
 366         foreach_keyring_do 'list_keys_from_keyring' "$@"
 367         ;;
 368     finger*)
 369         foreach_keyring_do 'fingerprint_keys_from_keyring' "$@"
 370         ;;
 371     export|exportall)
 372         foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/trusted.gpg"
 373         $GPG_CMD --keyring "${GPGHOMEDIR}/trusted.gpg" --armor --export "$@"
 374         ;;
 375     adv*)
 376         setup_merged_keyring
 377         aptkey_echo "Executing: $GPG $*"
 378         $GPG "$@"
 379         ;;
 380     help)
 381         usage
 382         ;;
 383     *)
 384         usage
 385         exit 1
 386         ;;
 387 esac