cmdline/apt-key

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