cmdline/apt-key.in

   1 #!/bin/sh
   2
   3 set -e
   4 unset GREP_OPTIONS
   5
   6 APT_DIR="/"
   7 eval $(apt-config shell APT_DIR Dir)
   8
   9 MASTER_KEYRING='&keyring-master-filename;'
  10 eval $(apt-config shell MASTER_KEYRING APT::Key::MasterKeyring)
  11 ARCHIVE_KEYRING='&keyring-filename;'
  12 eval $(apt-config shell ARCHIVE_KEYRING APT::Key::ArchiveKeyring)
  13 REMOVED_KEYS='&keyring-removed-filename;'
  14 eval $(apt-config shell REMOVED_KEYS APT::Key::RemovedKeys)
  15 ARCHIVE_KEYRING_URI='&keyring-uri;'
  16 eval $(apt-config shell ARCHIVE_KEYRING_URI APT::Key::ArchiveKeyringURI)
  17
  18 aptkey_echo() { echo "$@"; }
  19
  20 requires_root() {
  21         if [ "$(id -u)" -ne 0 ]; then
  22                 echo >&2 "ERROR: This command can only be used by root."
  23                 exit 1
  24         fi
  25 }
  26
  27 get_fingerprints_of_keyring() {
  28     $GPG_CMD --keyring "$1" --with-colons --fingerprint | while read publine; do
  29         # search for a public key
  30         if [ "${publine%%:*}" != 'pub' ]; then continue; fi
  31         # search for the associated fingerprint (should be the very next line)
  32         while read fprline; do
  33            if [ "${fprline%%:*}" = 'sub' ]; then break; # should never happen
  34            elif [ "${fprline%%:*}" != 'fpr' ]; then continue; fi
  35            echo "$fprline" | cut -d':' -f 10
  36         done
  37     done
  38 }
  39
  40 add_keys_with_verify_against_master_keyring() {
  41     ADD_KEYRING=$1
  42     MASTER=$2
  43
  44     if [ ! -f "$ADD_KEYRING" ]; then
  45         echo >&2 "ERROR: '$ADD_KEYRING' not found"
  46         return
  47     fi
  48     if [ ! -f "$MASTER" ]; then
  49         echo >&2 "ERROR: '$MASTER' not found"
  50         return
  51     fi
  52
  53     # when adding new keys, make sure that the archive-master-keyring
  54     # is honored. so:
  55     #   all keys that are exported must have a valid signature
  56     #   from a key in the $distro-master-keyring
  57     add_keys="$(get_fingerprints_of_keyring "$ADD_KEYRING")"
  58     all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5`
  59     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  60
  61     # ensure there are no colisions LP: #857472
  62     for all_add_key in $all_add_keys; do
  63         for master_key in $master_keys; do
  64             if [ "$all_add_key" = "$master_key" ]; then
  65                 echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted"
  66                 return 1
  67             fi
  68         done
  69     done
  70
  71     for add_key in $add_keys; do
  72         # export the add keyring one-by-one
  73         local TMP_KEYRING="${GPGHOMEDIR}/tmp-keyring.gpg"
  74         $GPG_CMD --batch --yes --keyring "$ADD_KEYRING" --output "$TMP_KEYRING" --export "$add_key"
  75         if ! $GPG_CMD --batch --yes --keyring "$TMP_KEYRING" --import "$MASTER" > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
  76             cat "${GPGHOMEDIR}/gpgoutput.log"
  77             false
  78         fi
  79         # check if signed with the master key and only add in this case
  80         ADDED=0
  81         for master_key in $master_keys; do
  82             if $GPG_CMD --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then
  83                 $GPG_CMD --batch --yes --keyring "$ADD_KEYRING" --export "$add_key" | $GPG --batch --yes --import
  84                 ADDED=1
  85             fi
  86         done
  87         if [ $ADDED = 0 ]; then
  88             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  89         fi
  90         rm -f "${TMP_KEYRING}"
  91     done
  92 }
  93
  94 # update the current archive signing keyring from a network URI
  95 # the archive-keyring keys needs to be signed with the master key
  96 # (otherwise it does not make sense from a security POV)
  97 net_update() {
  98     # Disabled for now as code is insecure (LP: #1013639 (and 857472, 1013128))
  99     APT_KEY_NET_UPDATE_ENABLED=""
 100     eval $(apt-config shell APT_KEY_NET_UPDATE_ENABLED APT::Key::Net-Update-Enabled)
 101     if [ -z "$APT_KEY_NET_UPDATE_ENABLED" ]; then
 102         exit 1
 103     fi
 104
 105     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
 106         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
 107         exit 1
 108     fi
 109     # in theory we would need to depend on wget for this, but this feature
 110     # isn't useable in debian anyway as we have no keyring uri nor a master key
 111     if ! which wget >/dev/null 2>&1; then
 112         echo >&2 "ERROR: an installed wget is required for a network-based update"
 113         exit 1
 114     fi
 115     if [ ! -d ${APT_DIR}/var/lib/apt/keyrings ]; then
 116         mkdir -p ${APT_DIR}/var/lib/apt/keyrings
 117     fi
 118     keyring=${APT_DIR}/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING_URI)
 119     old_mtime=0
 120     if [ -e $keyring ]; then
 121         old_mtime=$(stat -c %Y $keyring)
 122     fi
 123     (cd  ${APT_DIR}/var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI)
 124     if [ ! -e $keyring ]; then
 125         return
 126     fi
 127     new_mtime=$(stat -c %Y $keyring)
 128     if [ $new_mtime -ne $old_mtime ]; then
 129         aptkey_echo "Checking for new archive signing keys now"
 130         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 131     fi
 132 }
 133
 134 update() {
 135     if [ ! -f $ARCHIVE_KEYRING ]; then
 136         echo >&2 "ERROR: Can't find the archive-keyring"
 137         echo >&2 "Is the &keyring-package; package installed?"
 138         exit 1
 139     fi
 140
 141     # add new keys from the package;
 142
 143     # we do not use add_keys_with_verify_against_master_keyring here,
 144     # because "update" is run on regular package updates.  A
 145     # attacker might as well replace the master-archive-keyring file
 146     # in the package and add his own keys. so this check wouldn't
 147     # add any security. we *need* this check on net-update though
 148     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 149
 150     if [ -r "$REMOVED_KEYS" ]; then
 151         # remove no-longer supported/used keys
 152         get_fingerprints_of_keyring "$REMOVED_KEYS" | while read key; do
 153             foreach_keyring_do 'remove_key_from_keyring' "$key"
 154         done
 155     else
 156         echo >&2 "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable"
 157     fi
 158 }
 159
 160 remove_key_from_keyring() {
 161     local KEYRINGFILE="$1"
 162     shift
 163     # non-existent keyrings have by definition no keys
 164     if [ ! -e "$KEYRINGFILE" ]; then
 165        return
 166     fi
 167
 168     local GPG="$GPG_CMD --keyring $KEYRINGFILE"
 169     for KEY in "$@"; do
 170         # check if the key is in this keyring: the key id is in the 5 column at the end
 171         if ! get_fingerprints_of_keyring "$KEYRINGFILE" | grep -q "^[0-9A-F]*${KEY}$"; then
 172             continue
 173         fi
 174         if [ ! -w "$KEYRINGFILE" ]; then
 175             echo >&2 "Key ${KEY} is in keyring ${KEYRINGFILE}, but can't be removed as it is read only."
 176             continue
 177         fi
 178         # check if it is the only key in the keyring and if so remove the keyring altogether
 179         if [ '1' = "$(get_fingerprints_of_keyring "$KEYRINGFILE" | wc -l)" ]; then
 180             mv -f "$KEYRINGFILE" "${KEYRINGFILE}~" # behave like gpg
 181             return
 182         fi
 183         # we can't just modify pointed to files as these might be in /usr or something
 184         local REALTARGET
 185         if [ -L "$KEYRINGFILE" ]; then
 186             REALTARGET="$(readlink -f "$KEYRINGFILE")"
 187             mv -f "$KEYRINGFILE" "${KEYRINGFILE}.dpkg-tmp"
 188             cp -a "$REALTARGET" "$KEYRINGFILE"
 189         fi
 190         # delete the key from the keyring
 191         $GPG --batch --delete-key --yes "$KEY"
 192         if [ -n "$REALTARGET" ]; then
 193             # the real backup is the old link, not the copy we made
 194             mv -f "${KEYRINGFILE}.dpkg-tmp" "${KEYRINGFILE}~"
 195         fi
 196     done
 197 }
 198
 199 foreach_keyring_do() {
 200    local ACTION="$1"
 201    shift
 202    # if a --keyring was given, just remove from there
 203    if [ -n "$FORCED_KEYRING" ]; then
 204         $ACTION "$FORCED_KEYRING" "$@"
 205    else
 206         # otherwise all known keyrings are up for inspection
 207         if [ -s "$TRUSTEDFILE" ]; then
 208             $ACTION "$TRUSTEDFILE" "$@"
 209         fi
 210         local TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 211         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 212         if [ -d "$TRUSTEDPARTS" ]; then
 213             # strip / suffix as gpg will double-slash in that case (#665411)
 214             local STRIPPED_TRUSTEDPARTS="${TRUSTEDPARTS%/}"
 215             if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then
 216                 TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS"
 217             fi
 218             for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do
 219                 if [ -s "$trusted" ]; then
 220                     $ACTION "$trusted" "$@"
 221                 fi
 222             done
 223         fi
 224    fi
 225 }
 226
 227 run_cmd_on_keyring() {
 228     local KEYRINGFILE="$1"
 229     shift
 230     # fingerprint and co will fail if key isn't in this keyring
 231     $GPG_CMD --keyring "$KEYRINGFILE" --batch "$@" 2>/dev/null || true
 232 }
 233
 234 import_keys_from_keyring() {
 235     local IMPORT="$1"
 236     local KEYRINGFILE="$2"
 237     if ! $GPG_CMD --keyring "$KEYRINGFILE" --batch --import "$IMPORT" > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 238         cat "${GPGHOMEDIR}/gpgoutput.log"
 239         false
 240     fi
 241 }
 242
 243 merge_keys_into_keyrings() {
 244     local KEYRINGFILE="$1"
 245     local IMPORT="$2"
 246     if ! $GPG_CMD --keyring "$KEYRINGFILE" --batch --import --import-options 'merge-only' "$IMPORT" > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 247         cat "${GPGHOMEDIR}/gpgoutput.log"
 248         false
 249     fi
 250 }
 251
 252 merge_back_changes() {
 253     if [ -n "$FORCED_KEYRING" ]; then
 254         # if the keyring was forced merge is already done
 255         return
 256     fi
 257     if [ -s "${GPGHOMEDIR}/pubring.gpg" ]; then
 258         # merge all updated keys
 259         foreach_keyring_do 'merge_keys_into_keyrings' "${GPGHOMEDIR}/pubring.gpg"
 260     fi
 261     # look for keys which were added or removed
 262     get_fingerprints_of_keyring "${GPGHOMEDIR}/pubring.orig.gpg" > "${GPGHOMEDIR}/pubring.orig.keylst"
 263     get_fingerprints_of_keyring "${GPGHOMEDIR}/pubring.gpg" > "${GPGHOMEDIR}/pubring.keylst"
 264     sort "${GPGHOMEDIR}/pubring.keylst" "${GPGHOMEDIR}/pubring.orig.keylst" | uniq --unique | while read key; do
 265         if grep -q "^${key}$" "${GPGHOMEDIR}/pubring.orig.keylst"; then
 266             # key isn't part of new keyring, so remove
 267             foreach_keyring_do 'remove_key_from_keyring' "$key"
 268         elif grep -q "^${key}$" "${GPGHOMEDIR}/pubring.keylst"; then
 269             # key is part of new keyring, so we need to import it
 270             create_new_keyring "$TRUSTEDFILE"
 271             if ! $GPG --batch --yes --export "$key" | $GPG_CMD --keyring "$TRUSTEDFILE" --batch --yes --import > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 272                cat "${GPGHOMEDIR}/gpgoutput.log"
 273                false
 274             fi
 275         else
 276             echo >&2 "Errror: Key ${key} (dis)appeared out of nowhere"
 277         fi
 278     done
 279 }
 280
 281 setup_merged_keyring() {
 282     if [ -z "$FORCED_KEYRING" ]; then
 283         foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/pubring.gpg"
 284         if [ -r "${GPGHOMEDIR}/pubring.gpg" ]; then
 285             cp -a "${GPGHOMEDIR}/pubring.gpg" "${GPGHOMEDIR}/pubring.orig.gpg"
 286         else
 287            touch "${GPGHOMEDIR}/pubring.gpg" "${GPGHOMEDIR}/pubring.orig.gpg"
 288         fi
 289         GPG="$GPG --keyring ${GPGHOMEDIR}/pubring.gpg"
 290     else
 291         GPG="$GPG --keyring $TRUSTEDFILE"
 292         create_new_keyring "$TRUSTEDFILE"
 293     fi
 294 }
 295
 296 create_new_keyring() {
 297     # gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
 298     if ! [ -e "$TRUSTEDFILE" ]; then
 299         if [ -w "$(dirname "$TRUSTEDFILE")" ]; then
 300             touch -- "$TRUSTEDFILE"
 301             chmod 0644 -- "$TRUSTEDFILE"
 302         fi
 303     fi
 304 }
 305
 306 usage() {
 307     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 308     echo
 309     echo "Manage apt's list of trusted keys"
 310     echo
 311     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 312     echo "  apt-key del <keyid>         - remove the key <keyid>"
 313     echo "  apt-key export <keyid>      - output the key <keyid>"
 314     echo "  apt-key exportall           - output all trusted keys"
 315     echo "  apt-key update              - update keys using the keyring package"
 316     echo "  apt-key net-update          - update keys using the network"
 317     echo "  apt-key list                - list keys"
 318     echo "  apt-key finger              - list fingerprints"
 319     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 320     echo
 321     echo "If no specific keyring file is given the command applies to all keyring files."
 322 }
 323
 324 while [ -n "$1" ]; do
 325    case "$1" in
 326       --keyring)
 327          shift
 328          TRUSTEDFILE="$1"
 329          FORCED_KEYRING="$1"
 330          ;;
 331       --secret-keyring)
 332          shift
 333          FORCED_SECRET_KEYRING="$1"
 334          ;;
 335       --readonly)
 336          merge_back_changes() { true; }
 337          ;;
 338       --fakeroot)
 339          requires_root() { true; }
 340          ;;
 341       --quiet)
 342          aptkey_echo() { true; }
 343          ;;
 344       --*)
 345          echo >&2 "Unknown option: $1"
 346          usage
 347          exit 1;;
 348       *)
 349          break;;
 350    esac
 351    shift
 352 done
 353
 354 if [ -z "$TRUSTEDFILE" ]; then
 355    TRUSTEDFILE="/etc/apt/trusted.gpg"
 356    eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 357    eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 358 fi
 359
 360 command="$1"
 361 if [ -z "$command" ]; then
 362     usage
 363     exit 1
 364 fi
 365 shift
 366
 367 if [ "$command" != "help" ]; then
 368     eval $(apt-config shell GPG_EXE Apt::Key::gpgcommand)
 369
 370     if [ -n "$GPG_EXE" ] && which "$GPG_EXE" >/dev/null 2>&1; then
 371         true
 372     elif which gpg >/dev/null 2>&1; then
 373         GPG_EXE="gpg"
 374     elif which gpg2 >/dev/null 2>&1; then
 375         GPG_EXE="gpg2"
 376     else
 377         echo >&2 "Error: gnupg or gnupg2 do not seem to be installed,"
 378         echo >&2 "Error: but apt-key requires gnupg or gnupg2 for operation."
 379         echo >&2
 380         exit 255
 381     fi
 382
 383     GPG_CMD="$GPG_EXE --ignore-time-conflict --no-options --no-default-keyring"
 384
 385     # gpg needs (in different versions more or less) files to function correctly,
 386     # so we give it its own homedir and generate some valid content for it
 387     GPGHOMEDIR="$(mktemp -d)"
 388     CURRENTTRAP="${CURRENTTRAP} rm -rf '${GPGHOMEDIR}';"
 389     trap "${CURRENTTRAP}" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM
 390     chmod 700 "$GPGHOMEDIR"
 391     # We don't use a secret keyring, of course, but gpg panics and
 392     # implodes if there isn't one available - and writeable for imports
 393     SECRETKEYRING="${GPGHOMEDIR}/secring.gpg"
 394     touch $SECRETKEYRING
 395     GPG_CMD="$GPG_CMD --homedir $GPGHOMEDIR"
 396     # create the trustdb with an (empty) dummy keyring
 397     # older gpgs required it, newer gpgs even warn that it isn't needed,
 398     # but require it nonetheless for some commands, so we just play safe
 399     # here for the foreseeable future and create a dummy one
 400     $GPG_CMD --quiet --check-trustdb --keyring $SECRETKEYRING >/dev/null 2>&1
 401     # tell gpg that it shouldn't try to maintain a trustdb file
 402     GPG_CMD="$GPG_CMD --no-auto-check-trustdb --trust-model always"
 403     GPG="$GPG_CMD"
 404
 405     # for advanced operations, we might really need a secret keyring after all
 406     if [ -n "$FORCED_SECRET_KEYRING" ] && [ -r "$FORCED_SECRET_KEYRING" ]; then
 407         rm -f "$SECRETKEYRING"
 408         cp -a "$FORCED_SECRET_KEYRING" "$SECRETKEYRING"
 409     fi
 410 fi
 411
 412 case "$command" in
 413     add)
 414         requires_root
 415         setup_merged_keyring
 416         $GPG --quiet --batch --import "$@"
 417         merge_back_changes
 418         aptkey_echo "OK"
 419         ;;
 420     del|rm|remove)
 421         requires_root
 422         foreach_keyring_do 'remove_key_from_keyring' "$@"
 423         aptkey_echo "OK"
 424         ;;
 425     update)
 426         requires_root
 427         setup_merged_keyring
 428         update
 429         merge_back_changes
 430         ;;
 431     net-update)
 432         requires_root
 433         setup_merged_keyring
 434         net_update
 435         merge_back_changes
 436         ;;
 437     list)
 438         foreach_keyring_do 'run_cmd_on_keyring' --list-keys "$@"
 439         ;;
 440     finger*)
 441         foreach_keyring_do 'run_cmd_on_keyring' --fingerprint "$@"
 442         ;;
 443     export|exportall)
 444         foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/pubring.gpg"
 445         $GPG_CMD --keyring "${GPGHOMEDIR}/pubring.gpg" --armor --export "$@"
 446         ;;
 447     adv*)
 448         setup_merged_keyring
 449         aptkey_echo "Executing: $GPG $*"
 450         $GPG "$@"
 451         merge_back_changes
 452         ;;
 453     verify)
 454         setup_merged_keyring
 455         if which gpgv >/dev/null 2>&1; then
 456             gpgv --homedir "${GPGHOMEDIR}" --keyring "${GPGHOMEDIR}/pubring.gpg" --ignore-time-conflict "$@"
 457         else
 458             $GPG --verify "$@"
 459         fi
 460         ;;
 461     help)
 462         usage
 463         ;;
 464     *)
 465         usage
 466         exit 1
 467         ;;
 468 esac