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 SECRETKEYRING="$(mktemp)"
   9 trap "rm -f '${SECRETKEYRING}'" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM
  10 GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring ${SECRETKEYRING}"
  11
  12 if [ "$(id -u)" -eq 0 ]; then
  13         # we could use a tmpfile here too, but creation of this tends to be time-consuming
  14         GPG_CMD="$GPG_CMD --trustdb-name /etc/apt/trustdb.gpg"
  15 fi
  16
  17 GPG="$GPG_CMD"
  18
  19
  20 # ubuntu keyrings
  21 MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg
  22 ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
  23 REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg
  24 ARCHIVE_KEYRING_URI=http://archive.ubuntu.com/ubuntu/project/ubuntu-archive-keyring.gpg
  25
  26
  27 requires_root() {
  28         if [ "$(id -u)" -ne 0 ]; then
  29                 echo >&1 "ERROR: This command can only be used by root."
  30                 exit 1
  31         fi
  32 }
  33
  34 add_keys_with_verify_against_master_keyring() {
  35     ADD_KEYRING=$1
  36     MASTER=$2
  37
  38     if [ ! -f "$ADD_KEYRING" ]; then
  39         echo "ERROR: '$ADD_KEYRING' not found"
  40         return
  41     fi
  42     if [ ! -f "$MASTER" ]; then
  43         echo "ERROR: '$MASTER' not found"
  44         return
  45     fi
  46
  47     # when adding new keys, make sure that the archive-master-keyring
  48     # is honored. so:
  49     #   all keys that are exported must have a valid signature
  50     #   from a key in the $distro-master-keyring
  51     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  52     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  53     # verify to ensure that there are no key id duplications that may be
  54     # used to attack the system, see LP: #857472
  55     for add_key in $add_keys; do
  56         for master_key in $master_keys; do
  57             if [ "$add_key" = "$master_key" ]; then
  58                 echo >&2 "Keyid collision for '$add_key' detected, operation aborted"
  59                 return 1
  60             fi
  61         done
  62     done
  63     # add all keys signed with any of the master key(s)
  64     for add_key in $add_keys; do
  65         ADDED=0
  66         for master_key in $master_keys; do
  67             if $GPG_CMD --keyring $ADD_KEYRING --verify-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then
  68                 $GPG_CMD --quiet --batch --keyring $ADD_KEYRING --export $add_key | $GPG --import
  69                 ADDED=1
  70             fi
  71         done
  72         if [ $ADDED = 0 ]; then
  73             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  74         fi
  75     done
  76 }
  77
  78 # update the current archive signing keyring from a network URI
  79 # the archive-keyring keys needs to be signed with the master key
  80 # (otherwise it does not make sense from a security POV)
  81 net_update() {
  82     # Disabled for now as code is insecure
  83     exit 1
  84
  85     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
  86         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
  87         exit 1
  88     fi
  89     requires_root
  90     # in theory we would need to depend on wget for this, but this feature
  91     # isn't useable in debian anyway as we have no keyring uri nor a master key
  92     if ! which wget >/dev/null 2>&1; then
  93         echo >&2 "ERROR: an installed wget is required for a network-based update"
  94         exit 1
  95     fi
  96     if [ ! -d /var/lib/apt/keyrings ]; then
  97         mkdir -p /var/lib/apt/keyrings
  98     fi
  99     keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
 100     old_mtime=0
 101     if [ -e $keyring ]; then
 102         old_mtime=$(stat -c %Y $keyring)
 103     fi
 104     (cd  /var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI)
 105     if [ ! -e $keyring ]; then
 106         return
 107     fi
 108     new_mtime=$(stat -c %Y $keyring)
 109     if [ $new_mtime -ne $old_mtime ]; then
 110         echo "Checking for new archive signing keys now"
 111         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 112     fi
 113 }
 114
 115 update() {
 116     if [ ! -f $ARCHIVE_KEYRING ]; then
 117         echo >&2 "ERROR: Can't find the archive-keyring"
 118         echo >&2 "Is the ubuntu-keyring package installed?"
 119         exit 1
 120     fi
 121     requires_root
 122
 123     # add new keys from the package;
 124
 125     # we do not use add_keys_with_verify_against_master_keyring here,
 126     # because "update" is run on regular package updates.  A
 127     # attacker might as well replace the master-archive-keyring file
 128     # in the package and add his own keys. so this check wouldn't
 129     # add any security. we *need* this check on net-update though
 130     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 131
 132     if [ -r "$REMOVED_KEYS" ]; then
 133         # remove no-longer supported/used keys
 134         keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
 135         for key in $keys; do
 136             if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
 137                 $GPG --quiet --batch --delete-key --yes ${key}
 138             fi
 139         done
 140     else
 141         echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
 142     fi
 143 }
 144
 145
 146 usage() {
 147     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 148     echo
 149     echo "Manage apt's list of trusted keys"
 150     echo
 151     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 152     echo "  apt-key del <keyid>         - remove the key <keyid>"
 153     echo "  apt-key export <keyid>      - output the key <keyid>"
 154     echo "  apt-key exportall           - output all trusted keys"
 155     echo "  apt-key update              - update keys using the keyring package"
 156     echo "  apt-key net-update          - update keys using the network"
 157     echo "  apt-key list                - list keys"
 158     echo "  apt-key finger              - list fingerprints"
 159     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 160     echo
 161     echo "If no specific keyring file is given the command applies to all keyring files."
 162 }
 163
 164 # Determine on which keyring we want to work
 165 if [ "$1" = "--keyring" ]; then
 166         #echo "keyfile given"
 167         shift
 168         TRUSTEDFILE="$1"
 169         if [ -r "$TRUSTEDFILE" ]; then
 170                 GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 171         else
 172                 echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
 173                 exit 1
 174         fi
 175         shift
 176 # otherwise use the default
 177 else
 178         #echo "generate list"
 179         TRUSTEDFILE="/etc/apt/trusted.gpg"
 180         eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 181         eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 182         if [ -r "$TRUSTEDFILE" ]; then
 183                 GPG="$GPG --keyring $TRUSTEDFILE"
 184         fi
 185         GPG="$GPG --primary-keyring $TRUSTEDFILE"
 186         TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 187         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 188         if [ -d "$TRUSTEDPARTS" ]; then
 189                 #echo "parts active"
 190                 for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
 191                         #echo "part -> $trusted"
 192                         GPG="$GPG --keyring $trusted"
 193                 done
 194         fi
 195 fi
 196 #echo "COMMAND: $GPG"
 197
 198 command="$1"
 199 if [ -z "$command" ]; then
 200     usage
 201     exit 1
 202 fi
 203 shift
 204
 205 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 206     echo >&2 "Warning: gnupg does not seem to be installed."
 207     echo >&2 "Warning: apt-key requires gnupg for most operations."
 208     echo >&2
 209 fi
 210
 211 case "$command" in
 212     add)
 213         requires_root
 214         $GPG --quiet --batch --import "$1"
 215         echo "OK"
 216         ;;
 217     del|rm|remove)
 218         requires_root
 219         $GPG --quiet --batch --delete-key --yes "$1"
 220         echo "OK"
 221         ;;
 222     update)
 223         update
 224         ;;
 225     net-update)
 226         net_update
 227         ;;
 228     list)
 229         $GPG --batch --list-keys
 230         ;;
 231     finger*)
 232         $GPG --batch --fingerprint
 233         ;;
 234     export)
 235         $GPG --armor --export "$1"
 236         ;;
 237     exportall)
 238         $GPG --armor --export
 239         ;;
 240     adv*)
 241         echo "Executing: $GPG $*"
 242         $GPG $*
 243         ;;
 244     help)
 245         usage
 246         ;;
 247     *)
 248         usage
 249         exit 1
 250         ;;
 251 esac