cmdline/apt-key

   1 #!/bin/sh
   2
   3 set -e
   4 unset GREP_OPTIONS
   5
   6 # We don't use a secret keyring, of course, but gpg panics and
   7 # implodes if there isn't one available
   8
   9 GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg"
  10 GPG="$GPG_CMD --keyring /etc/apt/trusted.gpg"
  11
  12
  13 MASTER_KEYRING=""
  14 ARCHIVE_KEYRING_URI=""
  15 #MASTER_KEYRING=/usr/share/keyrings/debian-master-keyring.gpg
  16 #ARCHIVE_KEYRING_URI=http://ftp.debian.org/debian/debian-archive-keyring.gpg
  17
  18 ARCHIVE_KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg
  19 REMOVED_KEYS=/usr/share/keyrings/debian-archive-removed-keys.gpg
  20
  21 add_keys_with_verify_against_master_keyring() {
  22     ADD_KEYRING=$1
  23     MASTER=$2
  24
  25     if [ ! -f "$ADD_KEYRING" ]; then
  26         echo "ERROR: '$ADD_KEYRING' not found"
  27         return
  28     fi
  29     if [ ! -f "$MASTER" ]; then
  30         echo "ERROR: '$MASTER' not found"
  31         return
  32     fi
  33
  34     # when adding new keys, make sure that the archive-master-keyring
  35     # is honored. so:
  36     #   all keys that are exported must have a valid signature
  37     #   from a key in the $distro-master-keyring
  38     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  39     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  40     for add_key in $add_keys; do
  41         ADDED=0
  42         for master_key in $master_keys; do
  43             if $GPG_CMD --keyring $ADD_KEYRING --list-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then
  44                 $GPG_CMD --quiet --batch --keyring $ADD_KEYRING --export $add_key | $GPG --import
  45                 ADDED=1
  46             fi
  47         done
  48         if [ $ADDED = 0 ]; then
  49             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  50         fi
  51     done
  52 }
  53
  54 # update the current archive signing keyring from a network URI
  55 # the archive-keyring keys needs to be signed with the master key
  56 # (otherwise it does not make sense from a security POV)
  57 net_update() {
  58     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
  59         echo "ERROR: no location for the archive-keyring given"
  60         exit 1
  61     fi
  62     # in theory we would need to depend on wget for this, but this feature
  63     # isn't useable in debian anyway as we have no keyring uri nor a master key
  64     if ! which wget >/dev/null 2>&1; then
  65         echo "ERROR: an installed wget is required for a network-based update"
  66         exit 1
  67     fi
  68     if [ ! -d /var/lib/apt/keyrings ]; then
  69         mkdir -p /var/lib/apt/keyrings
  70     fi
  71     keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
  72     old_mtime=0
  73     if [ -e $keyring ]; then
  74         old_mtime=$(stat -c %Y $keyring)
  75     fi
  76     (cd  /var/lib/apt/keyrings; wget -q -N $ARCHIVE_KEYRING_URI)
  77     if [ ! -e $keyring ]; then
  78         return
  79     fi
  80     new_mtime=$(stat -c %Y $keyring)
  81     if [ $new_mtime -ne $old_mtime ]; then
  82         echo "Checking for new archive signing keys now"
  83         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
  84     fi
  85 }
  86
  87 update() {
  88     if [ ! -f $ARCHIVE_KEYRING ]; then
  89         echo >&2 "ERROR: Can't find the archive-keyring"
  90         echo >&2 "Is the debian-archive-keyring package installed?"
  91         exit 1
  92     fi
  93
  94     # add new keys from the package;
  95
  96     # we do not use add_keys_with_verify_against_master_keyring here,
  97     # because "update" is run on regular package updates.  A
  98     # attacker might as well replace the master-archive-keyring file
  99     # in the package and add his own keys. so this check wouldn't
 100     # add any security. we *need* this check on net-update though
 101     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 102
 103     if [ -r "$REMOVED_KEYS" ]; then
 104         # remove no-longer supported/used keys
 105         keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
 106         for key in $keys; do
 107             if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
 108                 $GPG --quiet --batch --delete-key --yes ${key}
 109             fi
 110         done
 111     else
 112         echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
 113     fi
 114 }
 115
 116
 117 usage() {
 118     echo "Usage: apt-key [command] [arguments]"
 119     echo
 120     echo "Manage apt's list of trusted keys"
 121     echo
 122     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 123     echo "  apt-key del <keyid>         - remove the key <keyid>"
 124     echo "  apt-key export <keyid>      - output the key <keyid>"
 125     echo "  apt-key exportall           - output all trusted keys"
 126     echo "  apt-key update              - update keys using the keyring package"
 127     echo "  apt-key net-update          - update keys using the network"
 128     echo "  apt-key list                - list keys"
 129     echo "  apt-key finger              - list fingerprints"
 130     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 131     echo
 132 }
 133
 134 command="$1"
 135 if [ -z "$command" ]; then
 136     usage
 137     exit 1
 138 fi
 139 shift
 140
 141 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 142     echo >&2 "Warning: gnupg does not seem to be installed."
 143     echo >&2 "Warning: apt-key requires gnupg for most operations."
 144     echo >&2
 145 fi
 146
 147 case "$command" in
 148     add)
 149         $GPG --quiet --batch --import "$1"
 150         echo "OK"
 151         ;;
 152     del|rm|remove)
 153         $GPG --quiet --batch --delete-key --yes "$1"
 154         echo "OK"
 155         ;;
 156     update)
 157         update
 158         ;;
 159     net-update)
 160         net_update
 161         ;;
 162     list)
 163         $GPG --batch --list-keys
 164         ;;
 165     finger*)
 166         $GPG --batch --fingerprint
 167         ;;
 168     export)
 169         $GPG --armor --export "$1"
 170         ;;
 171     exportall)
 172         $GPG --armor --export
 173         ;;
 174     adv*)
 175         echo "Executing: $GPG $*"
 176         $GPG $*
 177         ;;
 178     help)
 179         usage
 180         ;;
 181     *)
 182         usage
 183         exit 1
 184         ;;
 185 esac