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