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