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         eval $(apt-config shell TRUSTDBDIR Dir::Etc/d)
  15         GPG_CMD="$GPG_CMD --trustdb-name ${TRUSTDBDIR}/trustdb.gpg"
  16 fi
  17
  18 GPG="$GPG_CMD"
  19
  20
  21 # ubuntu keyrings
  22 MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg
  23 ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
  24 REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg
  25 ARCHIVE_KEYRING_URI=http://archive.ubuntu.com/ubuntu/project/ubuntu-archive-keyring.gpg
  26 TMP_KEYRING=/var/lib/apt/keyrings/maybe-import-keyring.gpg
  27
  28 requires_root() {
  29         if [ "$(id -u)" -ne 0 ]; then
  30                 echo >&1 "ERROR: This command can only be used by root."
  31                 exit 1
  32         fi
  33 }
  34
  35 add_keys_with_verify_against_master_keyring() {
  36     ADD_KEYRING=$1
  37     MASTER=$2
  38
  39     if [ ! -f "$ADD_KEYRING" ]; then
  40         echo "ERROR: '$ADD_KEYRING' not found"
  41         return
  42     fi
  43     if [ ! -f "$MASTER" ]; then
  44         echo "ERROR: '$MASTER' not found"
  45         return
  46     fi
  47
  48     # when adding new keys, make sure that the archive-master-keyring
  49     # is honored. so:
  50     #   all keys that are exported must have a valid signature
  51     #   from a key in the $distro-master-keyring
  52     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  53     all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5`
  54     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  55
  56     # ensure there are no colisions LP: #857472
  57     for all_add_key in $all_add_keys; do
  58         for master_key in $master_keys; do
  59             if [ "$all_add_key" = "$master_key" ]; then
  60                 echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted"
  61                 return 1
  62             fi
  63         done
  64     done
  65
  66     for add_key in $add_keys; do
  67         # export the add keyring one-by-one
  68         rm -f $TMP_KEYRING
  69         $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key
  70         # check if signed with the master key and only add in this case
  71         ADDED=0
  72         for master_key in $master_keys; do
  73             if $GPG_CMD --keyring $MASTER --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then
  74                 $GPG --import $TMP_KEYRING
  75                 ADDED=1
  76             fi
  77         done
  78         if [ $ADDED = 0 ]; then
  79             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  80         fi
  81     done
  82     rm -f $TMP_KEYRING
  83 }
  84
  85 # update the current archive signing keyring from a network URI
  86 # the archive-keyring keys needs to be signed with the master key
  87 # (otherwise it does not make sense from a security POV)
  88 net_update() {
  89
  90     if [ -z "$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 --timeout=90 -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 ubuntu-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 # Determine on which keyring we want to work
 170 if [ "$1" = "--keyring" ]; then
 171         #echo "keyfile given"
 172         shift
 173         TRUSTEDFILE="$1"
 174         if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ]; then
 175                 GPG="$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 # otherwise use the default
 182 else
 183         #echo "generate list"
 184         TRUSTEDFILE="/etc/apt/trusted.gpg"
 185         eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 186         eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 187         if [ -r "$TRUSTEDFILE" ]; then
 188                 GPG="$GPG --keyring $TRUSTEDFILE"
 189         fi
 190         GPG="$GPG --primary-keyring $TRUSTEDFILE"
 191         TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 192         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 193         if [ -d "$TRUSTEDPARTS" ]; then
 194                 #echo "parts active"
 195                 for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
 196                         #echo "part -> $trusted"
 197                         GPG="$GPG --keyring $trusted"
 198                 done
 199         fi
 200 fi
 201 #echo "COMMAND: $GPG"
 202
 203 command="$1"
 204 if [ -z "$command" ]; then
 205     usage
 206     exit 1
 207 fi
 208 shift
 209
 210 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 211     echo >&2 "Warning: gnupg does not seem to be installed."
 212     echo >&2 "Warning: apt-key requires gnupg for most operations."
 213     echo >&2
 214 fi
 215
 216 case "$command" in
 217     add)
 218         requires_root
 219         $GPG --quiet --batch --import "$1"
 220         echo "OK"
 221         ;;
 222     del|rm|remove)
 223         requires_root
 224         $GPG --quiet --batch --delete-key --yes "$1"
 225         echo "OK"
 226         ;;
 227     update)
 228         update
 229         ;;
 230     net-update)
 231         net_update
 232         ;;
 233     list)
 234         $GPG --batch --list-keys
 235         ;;
 236     finger*)
 237         $GPG --batch --fingerprint
 238         ;;
 239     export)
 240         $GPG --armor --export "$1"
 241         ;;
 242     exportall)
 243         $GPG --armor --export
 244         ;;
 245     adv*)
 246         echo "Executing: $GPG $*"
 247         $GPG $*
 248         ;;
 249     help)
 250         usage
 251         ;;
 252     *)
 253         usage
 254         exit 1
 255         ;;
 256 esac