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