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     while [ -n "$1" ]; do
 170        local KEY="$1"
 171        shift
 172         # check if the key is in this keyring: the key id is in the 5 column at the end
 173         if ! get_fingerprints_of_keyring "$KEYRINGFILE" | grep -q "^[0-9A-F]*${KEY}$"; then
 174             continue
 175         fi
 176         if [ ! -w "$KEYRINGFILE" ]; then
 177             echo >&2 "Key ${KEY} is in keyring ${KEYRINGFILE}, but can't be removed as it is read only."
 178             continue
 179         fi
 180         # check if it is the only key in the keyring and if so remove the keyring altogether
 181         if [ '1' = "$(get_fingerprints_of_keyring "$KEYRINGFILE" | wc -l)" ]; then
 182             mv -f "$KEYRINGFILE" "${KEYRINGFILE}~" # behave like gpg
 183             return
 184         fi
 185         # we can't just modify pointed to files as these might be in /usr or something
 186         local REALTARGET
 187         if [ -L "$KEYRINGFILE" ]; then
 188             REALTARGET="$(readlink -f "$KEYRINGFILE")"
 189             mv -f "$KEYRINGFILE" "${KEYRINGFILE}.dpkg-tmp"
 190             cp -a "$REALTARGET" "$KEYRINGFILE"
 191         fi
 192         # delete the key from the keyring
 193         $GPG --batch --delete-key --yes "$KEY"
 194         if [ -n "$REALTARGET" ]; then
 195             # the real backup is the old link, not the copy we made
 196             mv -f "${KEYRINGFILE}.dpkg-tmp" "${KEYRINGFILE}~"
 197         fi
 198     done
 199 }
 200
 201 foreach_keyring_do() {
 202    local ACTION="$1"
 203    shift
 204    # if a --keyring was given, just remove from there
 205    if [ -n "$FORCED_KEYRING" ]; then
 206         $ACTION "$FORCED_KEYRING" "$@"
 207    else
 208         # otherwise all known keyrings are up for inspection
 209         if [ -s "$TRUSTEDFILE" ]; then
 210             $ACTION "$TRUSTEDFILE" "$@"
 211         fi
 212         local TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 213         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 214         if [ -d "$TRUSTEDPARTS" ]; then
 215             # strip / suffix as gpg will double-slash in that case (#665411)
 216             local STRIPPED_TRUSTEDPARTS="${TRUSTEDPARTS%/}"
 217             if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then
 218                 TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS"
 219             fi
 220             for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do
 221                 if [ -s "$trusted" ]; then
 222                     $ACTION "$trusted" "$@"
 223                 fi
 224             done
 225         fi
 226    fi
 227 }
 228
 229 list_keys_from_keyring() {
 230     local KEYRINGFILE="$1"
 231     shift
 232     # don't show the error message if this keyring doesn't include the key
 233     $GPG_CMD --keyring "$KEYRINGFILE" --batch --list-keys "$@" 2>/dev/null || true
 234 }
 235
 236 fingerprint_keys_from_keyring() {
 237     local KEYRINGFILE="$1"
 238     shift
 239     # don't show the error message if this keyring doesn't include the fingerprint
 240     $GPG_CMD --keyring "$KEYRINGFILE" --batch --fingerprint "$@" 2>/dev/null || true
 241 }
 242
 243 import_keys_from_keyring() {
 244     local IMPORT="$1"
 245     local KEYRINGFILE="$2"
 246     if ! $GPG_CMD --keyring "$KEYRINGFILE" --batch --import "$IMPORT" > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 247         cat "${GPGHOMEDIR}/gpgoutput.log"
 248         false
 249     fi
 250 }
 251
 252 merge_keys_into_keyrings() {
 253     local KEYRINGFILE="$1"
 254     local IMPORT="$2"
 255     if ! $GPG_CMD --keyring "$KEYRINGFILE" --batch --import --import-options 'merge-only' "$IMPORT" > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 256         cat "${GPGHOMEDIR}/gpgoutput.log"
 257         false
 258     fi
 259 }
 260
 261 merge_back_changes() {
 262     if [ -n "$FORCED_KEYRING" ]; then
 263         # if the keyring was forced merge is already done
 264         return
 265     fi
 266     if [ -s "${GPGHOMEDIR}/pubring.gpg" ]; then
 267         # merge all updated keys
 268         foreach_keyring_do 'merge_keys_into_keyrings' "${GPGHOMEDIR}/pubring.gpg"
 269     fi
 270     # no look for keys which were added or removed
 271     get_fingerprints_of_keyring "${GPGHOMEDIR}/pubring.orig.gpg" > "${GPGHOMEDIR}/pubring.orig.keylst"
 272     get_fingerprints_of_keyring "${GPGHOMEDIR}/pubring.gpg" > "${GPGHOMEDIR}/pubring.keylst"
 273     #echo >&2 "MERGE BACK"
 274     sort "${GPGHOMEDIR}/pubring.keylst" "${GPGHOMEDIR}/pubring.orig.keylst" | uniq --unique | while read key; do
 275         if grep -q "^${key}$" "${GPGHOMEDIR}/pubring.orig.keylst"; then
 276             # key isn't part of new keyring, so remove
 277             foreach_keyring_do 'remove_key_from_keyring' "$key"
 278         elif grep -q "^${key}$" "${GPGHOMEDIR}/pubring.keylst"; then
 279             # key is part of new keyring, so we need to import it
 280             create_new_keyring "$TRUSTEDFILE"
 281             if ! $GPG --batch --yes --export "$key" | $GPG_CMD --keyring "$TRUSTEDFILE" --batch --yes --import > "${GPGHOMEDIR}/gpgoutput.log" 2>&1; then
 282                cat "${GPGHOMEDIR}/gpgoutput.log"
 283                false
 284             fi
 285         else
 286             echo >&2 "Errror: Key ${key} (dis)appeared out of nowhere"
 287         fi
 288     done
 289 }
 290
 291 setup_merged_keyring() {
 292     if [ -z "$FORCED_KEYRING" ]; then
 293         foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/pubring.gpg"
 294         if [ -r "${GPGHOMEDIR}/pubring.gpg" ]; then
 295             cp -a "${GPGHOMEDIR}/pubring.gpg" "${GPGHOMEDIR}/pubring.orig.gpg"
 296         else
 297            touch "${GPGHOMEDIR}/pubring.gpg" "${GPGHOMEDIR}/pubring.orig.gpg"
 298         fi
 299         GPG="$GPG --keyring ${GPGHOMEDIR}/pubring.gpg"
 300     else
 301         GPG="$GPG --keyring $TRUSTEDFILE"
 302         create_new_keyring "$TRUSTEDFILE"
 303     fi
 304 }
 305
 306 create_new_keyring() {
 307     # gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
 308     if ! [ -e "$TRUSTEDFILE" ]; then
 309         if [ -w "$(dirname "$TRUSTEDFILE")" ]; then
 310             touch -- "$TRUSTEDFILE"
 311             chmod 0644 -- "$TRUSTEDFILE"
 312         fi
 313     fi
 314 }
 315
 316 usage() {
 317     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 318     echo
 319     echo "Manage apt's list of trusted keys"
 320     echo
 321     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 322     echo "  apt-key del <keyid>         - remove the key <keyid>"
 323     echo "  apt-key export <keyid>      - output the key <keyid>"
 324     echo "  apt-key exportall           - output all trusted keys"
 325     echo "  apt-key update              - update keys using the keyring package"
 326     echo "  apt-key net-update          - update keys using the network"
 327     echo "  apt-key list                - list keys"
 328     echo "  apt-key finger              - list fingerprints"
 329     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 330     echo
 331     echo "If no specific keyring file is given the command applies to all keyring files."
 332 }
 333
 334 while [ -n "$1" ]; do
 335    case "$1" in
 336       --keyring)
 337          shift
 338          TRUSTEDFILE="$1"
 339          FORCED_KEYRING="$1"
 340          shift
 341          ;;
 342       --secret-keyring)
 343          shift
 344          FORCED_SECRET_KEYRING="$1"
 345          shift
 346          ;;
 347       --fakeroot)
 348          requires_root() { true; }
 349          shift
 350          ;;
 351       --quiet)
 352          aptkey_echo() { true; }
 353          shift
 354          ;;
 355       --*)
 356          echo >&2 "Unknown option: $1"
 357          usage
 358          exit 1;;
 359       *)
 360          break;;
 361    esac
 362 done
 363
 364 if [ -z "$TRUSTEDFILE" ]; then
 365    TRUSTEDFILE="/etc/apt/trusted.gpg"
 366    eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 367    eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 368 fi
 369
 370 command="$1"
 371 if [ -z "$command" ]; then
 372     usage
 373     exit 1
 374 fi
 375 shift
 376
 377 if [ "$command" != "help" ]; then
 378     eval $(apt-config shell GPG_EXE Apt::Key::gpgcommand)
 379
 380     if [ -n "$GPG_EXE" ] && which "$GPG_EXE" >/dev/null 2>&1; then
 381         true
 382     elif which gpg >/dev/null 2>&1; then
 383         GPG_EXE="gpg"
 384     elif which gpg2 >/dev/null 2>&1; then
 385         GPG_EXE="gpg2"
 386     else
 387         echo >&2 "Error: gnupg or gnupg2 do not seem to be installed,"
 388         echo >&2 "Error: but apt-key requires gnupg or gnupg2 for operation."
 389         echo >&2
 390         exit 255
 391     fi
 392
 393     GPG_CMD="$GPG_EXE --ignore-time-conflict --no-options --no-default-keyring"
 394
 395     # gpg needs (in different versions more or less) files to function correctly,
 396     # so we give it its own homedir and generate some valid content for it
 397     GPGHOMEDIR="$(mktemp -d)"
 398     CURRENTTRAP="${CURRENTTRAP} rm -rf '${GPGHOMEDIR}';"
 399     trap "${CURRENTTRAP}" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM
 400     chmod 700 "$GPGHOMEDIR"
 401     # We don't use a secret keyring, of course, but gpg panics and
 402     # implodes if there isn't one available - and writeable for imports
 403     SECRETKEYRING="${GPGHOMEDIR}/secring.gpg"
 404     touch $SECRETKEYRING
 405     GPG_CMD="$GPG_CMD --homedir $GPGHOMEDIR"
 406     # create the trustdb with an (empty) dummy keyring
 407     # older gpgs required it, newer gpgs even warn that it isn't needed,
 408     # but require it nonetheless for some commands, so we just play safe
 409     # here for the foreseeable future and create a dummy one
 410     $GPG_CMD --quiet --check-trustdb --keyring $SECRETKEYRING >/dev/null 2>&1
 411     # tell gpg that it shouldn't try to maintain a trustdb file
 412     GPG_CMD="$GPG_CMD --no-auto-check-trustdb --trust-model always"
 413     GPG="$GPG_CMD"
 414
 415     # for advanced operations, we might really need a secret keyring after all
 416     if [ -n "$FORCED_SECRET_KEYRING" ] && [ -r "$FORCED_SECRET_KEYRING" ]; then
 417         rm -f "$SECRETKEYRING"
 418         cp -a "$FORCED_SECRET_KEYRING" "$SECRETKEYRING"
 419     fi
 420 fi
 421
 422 case "$command" in
 423     add)
 424         requires_root
 425         setup_merged_keyring
 426         $GPG --quiet --batch --import "$@"
 427         merge_back_changes
 428         aptkey_echo "OK"
 429         ;;
 430     del|rm|remove)
 431         requires_root
 432         foreach_keyring_do 'remove_key_from_keyring' "$@"
 433         merge_back_changes
 434         aptkey_echo "OK"
 435         ;;
 436     update)
 437         requires_root
 438         setup_merged_keyring
 439         update
 440         merge_back_changes
 441         ;;
 442     net-update)
 443         requires_root
 444         setup_merged_keyring
 445         net_update
 446         merge_back_changes
 447         ;;
 448     list)
 449         foreach_keyring_do 'list_keys_from_keyring' "$@"
 450         ;;
 451     finger*)
 452         foreach_keyring_do 'fingerprint_keys_from_keyring' "$@"
 453         ;;
 454     export|exportall)
 455         foreach_keyring_do 'import_keys_from_keyring' "${GPGHOMEDIR}/pubring.gpg"
 456         $GPG_CMD --keyring "${GPGHOMEDIR}/pubring.gpg" --armor --export "$@"
 457         ;;
 458     adv*)
 459         setup_merged_keyring
 460         aptkey_echo "Executing: $GPG $*"
 461         $GPG "$@"
 462         merge_back_changes
 463         ;;
 464     help)
 465         usage
 466         ;;
 467     *)
 468         usage
 469         exit 1
 470         ;;
 471 esac