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 $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  53     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  54
  55     for add_key in $add_keys; do
  56
  57         # ensure there are no colisions LP: #857472
  58         for master_key in $master_keys; do
  59             if [ "$add_key" = "$master_key" ]; then
  60                 echo >&2 "Keyid collision for '$add_key' detected, operation aborted"
  61                 return 1
  62             fi
  63         done
  64
  65         # export the add keyring one-by-one
  66         rm -f $TMP_KEYRING
  67         $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key
  68         # check if signed with the master key and only add in this case
  69         ADDED=0
  70         for master_key in $master_keys; do
  71             if $GPG_CMD --keyring $MASTER --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then
  72                 $GPG --import $TMP_KEYRING
  73                 ADDED=1
  74             fi
  75         done
  76         if [ $ADDED = 0 ]; then
  77             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  78         fi
  79     done
  80     rm -f $TMP_KEYRING
  81 }
  82
  83 # update the current archive signing keyring from a network URI
  84 # the archive-keyring keys needs to be signed with the master key
  85 # (otherwise it does not make sense from a security POV)
  86 net_update() {
  87
  88     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
  89         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
  90         exit 1
  91     fi
  92     requires_root
  93     # in theory we would need to depend on wget for this, but this feature
  94     # isn't useable in debian anyway as we have no keyring uri nor a master key
  95     if ! which wget >/dev/null 2>&1; then
  96         echo >&2 "ERROR: an installed wget is required for a network-based update"
  97         exit 1
  98     fi
  99     if [ ! -d /var/lib/apt/keyrings ]; then
 100         mkdir -p /var/lib/apt/keyrings
 101     fi
 102     keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
 103     old_mtime=0
 104     if [ -e $keyring ]; then
 105         old_mtime=$(stat -c %Y $keyring)
 106     fi
 107     (cd  /var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI)
 108     if [ ! -e $keyring ]; then
 109         return
 110     fi
 111     new_mtime=$(stat -c %Y $keyring)
 112     if [ $new_mtime -ne $old_mtime ]; then
 113         echo "Checking for new archive signing keys now"
 114         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 115     fi
 116 }
 117
 118 update() {
 119     if [ ! -f $ARCHIVE_KEYRING ]; then
 120         echo >&2 "ERROR: Can't find the archive-keyring"
 121         echo >&2 "Is the ubuntu-keyring package installed?"
 122         exit 1
 123     fi
 124     requires_root
 125
 126     # add new keys from the package;
 127
 128     # we do not use add_keys_with_verify_against_master_keyring here,
 129     # because "update" is run on regular package updates.  A
 130     # attacker might as well replace the master-archive-keyring file
 131     # in the package and add his own keys. so this check wouldn't
 132     # add any security. we *need* this check on net-update though
 133     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 134
 135     if [ -r "$REMOVED_KEYS" ]; then
 136         # remove no-longer supported/used keys
 137         keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
 138         for key in $keys; do
 139             if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
 140                 $GPG --quiet --batch --delete-key --yes ${key}
 141             fi
 142         done
 143     else
 144         echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
 145     fi
 146 }
 147
 148
 149 usage() {
 150     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 151     echo
 152     echo "Manage apt's list of trusted keys"
 153     echo
 154     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 155     echo "  apt-key del <keyid>         - remove the key <keyid>"
 156     echo "  apt-key export <keyid>      - output the key <keyid>"
 157     echo "  apt-key exportall           - output all trusted keys"
 158     echo "  apt-key update              - update keys using the keyring package"
 159     echo "  apt-key net-update          - update keys using the network"
 160     echo "  apt-key list                - list keys"
 161     echo "  apt-key finger              - list fingerprints"
 162     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 163     echo
 164     echo "If no specific keyring file is given the command applies to all keyring files."
 165 }
 166
 167 # Determine on which keyring we want to work
 168 if [ "$1" = "--keyring" ]; then
 169         #echo "keyfile given"
 170         shift
 171         TRUSTEDFILE="$1"
 172         if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ]; then
 173                 GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 174         else
 175                 echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
 176                 exit 1
 177         fi
 178         shift
 179 # otherwise use the default
 180 else
 181         #echo "generate list"
 182         TRUSTEDFILE="/etc/apt/trusted.gpg"
 183         eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring)
 184         eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f)
 185         if [ -r "$TRUSTEDFILE" ]; then
 186                 GPG="$GPG --keyring $TRUSTEDFILE"
 187         fi
 188         GPG="$GPG --primary-keyring $TRUSTEDFILE"
 189         TRUSTEDPARTS="/etc/apt/trusted.gpg.d"
 190         eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d)
 191         if [ -d "$TRUSTEDPARTS" ]; then
 192                 #echo "parts active"
 193                 for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
 194                         #echo "part -> $trusted"
 195                         GPG="$GPG --keyring $trusted"
 196                 done
 197         fi
 198 fi
 199 #echo "COMMAND: $GPG"
 200
 201 command="$1"
 202 if [ -z "$command" ]; then
 203     usage
 204     exit 1
 205 fi
 206 shift
 207
 208 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 209     echo >&2 "Warning: gnupg does not seem to be installed."
 210     echo >&2 "Warning: apt-key requires gnupg for most operations."
 211     echo >&2
 212 fi
 213
 214 case "$command" in
 215     add)
 216         requires_root
 217         $GPG --quiet --batch --import "$1"
 218         echo "OK"
 219         ;;
 220     del|rm|remove)
 221         requires_root
 222         $GPG --quiet --batch --delete-key --yes "$1"
 223         echo "OK"
 224         ;;
 225     update)
 226         update
 227         ;;
 228     net-update)
 229         net_update
 230         ;;
 231     list)
 232         $GPG --batch --list-keys
 233         ;;
 234     finger*)
 235         $GPG --batch --fingerprint
 236         ;;
 237     export)
 238         $GPG --armor --export "$1"
 239         ;;
 240     exportall)
 241         $GPG --armor --export
 242         ;;
 243     adv*)
 244         echo "Executing: $GPG $*"
 245         $GPG $*
 246         ;;
 247     help)
 248         usage
 249         ;;
 250     *)
 251         usage
 252         exit 1
 253         ;;
 254 esac