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