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
 155 usage() {
 156     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 157     echo
 158     echo "Manage apt's list of trusted keys"
 159     echo
 160     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 161     echo "  apt-key del <keyid>         - remove the key <keyid>"
 162     echo "  apt-key export <keyid>      - output the key <keyid>"
 163     echo "  apt-key exportall           - output all trusted keys"
 164     echo "  apt-key update              - update keys using the keyring package"
 165     echo "  apt-key net-update          - update keys using the network"
 166     echo "  apt-key list                - list keys"
 167     echo "  apt-key finger              - list fingerprints"
 168     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 169     echo
 170     echo "If no specific keyring file is given the command applies to all keyring files."
 171 }
 172
 173 while [ -n "$1" ]; do
 174    case "$1" in
 175       --keyring)
 176          shift
 177          TRUSTEDFILE="$1"
 178          if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ] || [ "$2" = 'adv' ]; then
 179             GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 180          else
 181             echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
 182             exit 1
 183          fi
 184          shift
 185          ;;
 186       --fakeroot)
 187          requires_root() { true; }
 188          shift
 189          ;;
 190       --*)
 191          echo >&2 "Unknown option: $1"
 192          usage
 193          exit 1;;
 194       *)
 195          break;;
 196    esac
 197 done
 198
 199 if [ -z "$TRUSTEDFILE" ]; then
 200    TRUSTEDFILE="/etc/apt/trusted.gpg"
 201    eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 202    eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 203    if [ -r "$TRUSTEDFILE" ]; then
 204       GPG="$GPG --keyring $TRUSTEDFILE"
 205    fi
 206    GPG="$GPG --primary-keyring $TRUSTEDFILE"
 207    TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 208    eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 209    if [ -d "$TRUSTEDPARTS" ]; then
 210       # strip / suffix as gpg will double-slash in that case (#665411)
 211       STRIPPED_TRUSTEDPARTS="${TRUSTEDPARTS%/}"
 212       if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then
 213          TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS"
 214       fi
 215       for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do
 216          GPG="$GPG --keyring $trusted"
 217       done
 218    fi
 219 fi
 220
 221 command="$1"
 222 if [ -z "$command" ]; then
 223     usage
 224     exit 1
 225 fi
 226 shift
 227
 228 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 229     echo >&2 "Warning: gnupg does not seem to be installed."
 230     echo >&2 "Warning: apt-key requires gnupg for most operations."
 231     echo >&2
 232 fi
 233
 234 case "$command" in
 235     add)
 236         requires_root
 237         init_keyring "$TRUSTEDFILE"
 238         $GPG --quiet --batch --import "$1"
 239         echo "OK"
 240         ;;
 241     del|rm|remove)
 242         requires_root
 243         init_keyring "$TRUSTEDFILE"
 244         $GPG --quiet --batch --delete-key --yes "$1"
 245         echo "OK"
 246         ;;
 247     update)
 248         init_keyring "$TRUSTEDFILE"
 249         update
 250         ;;
 251     net-update)
 252         init_keyring "$TRUSTEDFILE"
 253         net_update
 254         ;;
 255     list)
 256         init_keyring "$TRUSTEDFILE"
 257         $GPG --batch --list-keys
 258         ;;
 259     finger*)
 260         init_keyring "$TRUSTEDFILE"
 261         $GPG --batch --fingerprint
 262         ;;
 263     export)
 264         init_keyring "$TRUSTEDFILE"
 265         $GPG --armor --export "$1"
 266         ;;
 267     exportall)
 268         init_keyring "$TRUSTEDFILE"
 269         $GPG --armor --export
 270         ;;
 271     adv*)
 272         init_keyring "$TRUSTEDFILE"
 273         echo "Executing: $GPG $*"
 274         $GPG $*
 275         ;;
 276     help)
 277         usage
 278         ;;
 279     *)
 280         usage
 281         exit 1
 282         ;;
 283 esac