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="$GPG_CMD"
  27
  28 MASTER_KEYRING=""
  29 ARCHIVE_KEYRING_URI=""
  30 #MASTER_KEYRING=/usr/share/keyrings/debian-master-keyring.gpg
  31 #ARCHIVE_KEYRING_URI=http://ftp.debian.org/debian/debian-archive-keyring.gpg
  32
  33 ARCHIVE_KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg
  34 REMOVED_KEYS=/usr/share/keyrings/debian-archive-removed-keys.gpg
  35
  36 requires_root() {
  37         if [ "$(id -u)" -ne 0 ]; then
  38                 echo >&1 "ERROR: This command can only be used by root."
  39                 exit 1
  40         fi
  41 }
  42
  43 # gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
  44 init_keyring() {
  45     for path; do
  46         if ! [ -e "$path" ]; then
  47             touch -- "$path"
  48             chmod 0644 -- "$path"
  49         fi
  50     done
  51 }
  52
  53 add_keys_with_verify_against_master_keyring() {
  54     ADD_KEYRING=$1
  55     MASTER=$2
  56
  57     if [ ! -f "$ADD_KEYRING" ]; then
  58         echo "ERROR: '$ADD_KEYRING' not found"
  59         return
  60     fi
  61     if [ ! -f "$MASTER" ]; then
  62         echo "ERROR: '$MASTER' not found"
  63         return
  64     fi
  65
  66     # when adding new keys, make sure that the archive-master-keyring
  67     # is honored. so:
  68     #   all keys that are exported must have a valid signature
  69     #   from a key in the $distro-master-keyring
  70     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  71     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  72     for add_key in $add_keys; do
  73         ADDED=0
  74         for master_key in $master_keys; do
  75             if $GPG_CMD --keyring $ADD_KEYRING --list-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then
  76                 $GPG_CMD --quiet --batch --keyring $ADD_KEYRING --export $add_key | $GPG --import
  77                 ADDED=1
  78             fi
  79         done
  80         if [ $ADDED = 0 ]; then
  81             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  82         fi
  83     done
  84 }
  85
  86 # update the current archive signing keyring from a network URI
  87 # the archive-keyring keys needs to be signed with the master key
  88 # (otherwise it does not make sense from a security POV)
  89 net_update() {
  90     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
  91         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
  92         exit 1
  93     fi
  94     requires_root
  95     # in theory we would need to depend on wget for this, but this feature
  96     # isn't useable in debian anyway as we have no keyring uri nor a master key
  97     if ! which wget >/dev/null 2>&1; then
  98         echo >&2 "ERROR: an installed wget is required for a network-based update"
  99         exit 1
 100     fi
 101     if [ ! -d /var/lib/apt/keyrings ]; then
 102         mkdir -p /var/lib/apt/keyrings
 103     fi
 104     keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
 105     old_mtime=0
 106     if [ -e $keyring ]; then
 107         old_mtime=$(stat -c %Y $keyring)
 108     fi
 109     (cd  /var/lib/apt/keyrings; wget -q -N $ARCHIVE_KEYRING_URI)
 110     if [ ! -e $keyring ]; then
 111         return
 112     fi
 113     new_mtime=$(stat -c %Y $keyring)
 114     if [ $new_mtime -ne $old_mtime ]; then
 115         echo "Checking for new archive signing keys now"
 116         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 117     fi
 118 }
 119
 120 update() {
 121     if [ ! -f $ARCHIVE_KEYRING ]; then
 122         echo >&2 "ERROR: Can't find the archive-keyring"
 123         echo >&2 "Is the debian-archive-keyring package installed?"
 124         exit 1
 125     fi
 126     requires_root
 127
 128     # add new keys from the package;
 129
 130     # we do not use add_keys_with_verify_against_master_keyring here,
 131     # because "update" is run on regular package updates.  A
 132     # attacker might as well replace the master-archive-keyring file
 133     # in the package and add his own keys. so this check wouldn't
 134     # add any security. we *need* this check on net-update though
 135     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 136
 137     if [ -r "$REMOVED_KEYS" ]; then
 138         # remove no-longer supported/used keys
 139         keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
 140         for key in $keys; do
 141             if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
 142                 $GPG --quiet --batch --delete-key --yes ${key}
 143             fi
 144         done
 145     else
 146         echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
 147     fi
 148 }
 149
 150
 151 usage() {
 152     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 153     echo
 154     echo "Manage apt's list of trusted keys"
 155     echo
 156     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 157     echo "  apt-key del <keyid>         - remove the key <keyid>"
 158     echo "  apt-key export <keyid>      - output the key <keyid>"
 159     echo "  apt-key exportall           - output all trusted keys"
 160     echo "  apt-key update              - update keys using the keyring package"
 161     echo "  apt-key net-update          - update keys using the network"
 162     echo "  apt-key list                - list keys"
 163     echo "  apt-key finger              - list fingerprints"
 164     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 165     echo
 166     echo "If no specific keyring file is given the command applies to all keyring files."
 167 }
 168
 169 while [ -n "$1" ]; do
 170    case "$1" in
 171       --keyring)
 172          shift
 173          TRUSTEDFILE="$1"
 174          if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ] || [ "$2" = 'adv' ]; then
 175             GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 176          else
 177             echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
 178             exit 1
 179          fi
 180          shift
 181          ;;
 182       --fakeroot)
 183          requires_root() { true; }
 184          shift
 185          ;;
 186       --*)
 187          echo >&2 "Unknown option: $1"
 188          usage
 189          exit 1;;
 190       *)
 191          break;;
 192    esac
 193 done
 194
 195 if [ -z "$TRUSTEDFILE" ]; then
 196    TRUSTEDFILE="/etc/apt/trusted.gpg"
 197    eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 198    eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 199    if [ -r "$TRUSTEDFILE" ]; then
 200       GPG="$GPG --keyring $TRUSTEDFILE"
 201    fi
 202    GPG="$GPG --primary-keyring $TRUSTEDFILE"
 203    TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 204    eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 205    if [ -d "$TRUSTEDPARTS" ]; then
 206       for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
 207          GPG="$GPG --keyring $trusted"
 208       done
 209    fi
 210 fi
 211
 212 command="$1"
 213 if [ -z "$command" ]; then
 214     usage
 215     exit 1
 216 fi
 217 shift
 218
 219 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 220     echo >&2 "Warning: gnupg does not seem to be installed."
 221     echo >&2 "Warning: apt-key requires gnupg for most operations."
 222     echo >&2
 223 fi
 224
 225 case "$command" in
 226     add)
 227         requires_root
 228         init_keyring "$TRUSTEDFILE"
 229         $GPG --quiet --batch --import "$1"
 230         echo "OK"
 231         ;;
 232     del|rm|remove)
 233         requires_root
 234         init_keyring "$TRUSTEDFILE"
 235         $GPG --quiet --batch --delete-key --yes "$1"
 236         echo "OK"
 237         ;;
 238     update)
 239         init_keyring "$TRUSTEDFILE"
 240         update
 241         ;;
 242     net-update)
 243         init_keyring "$TRUSTEDFILE"
 244         net_update
 245         ;;
 246     list)
 247         init_keyring "$TRUSTEDFILE"
 248         $GPG --batch --list-keys
 249         ;;
 250     finger*)
 251         init_keyring "$TRUSTEDFILE"
 252         $GPG --batch --fingerprint
 253         ;;
 254     export)
 255         init_keyring "$TRUSTEDFILE"
 256         $GPG --armor --export "$1"
 257         ;;
 258     exportall)
 259         init_keyring "$TRUSTEDFILE"
 260         $GPG --armor --export
 261         ;;
 262     adv*)
 263         init_keyring "$TRUSTEDFILE"
 264         echo "Executing: $GPG $*"
 265         $GPG $*
 266         ;;
 267     help)
 268         usage
 269         ;;
 270     *)
 271         usage
 272         exit 1
 273         ;;
 274 esac