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