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 [ "$(id -u)" -ne 0 ]; then
  30                 echo >&1 "ERROR: This command can only be used by root."
  31                 exit 1
  32         fi
  33 }
  34
  35 # gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead.
  36 init_keyring() {
  37     for path; do
  38         if ! [ -e "$path" ]; then
  39             touch -- "$path"
  40             chmod 0644 -- "$path"
  41         fi
  42     done
  43 }
  44
  45 add_keys_with_verify_against_master_keyring() {
  46     ADD_KEYRING=$1
  47     MASTER=$2
  48
  49     if [ ! -f "$ADD_KEYRING" ]; then
  50         echo "ERROR: '$ADD_KEYRING' not found"
  51         return
  52     fi
  53     if [ ! -f "$MASTER" ]; then
  54         echo "ERROR: '$MASTER' not found"
  55         return
  56     fi
  57
  58     # when adding new keys, make sure that the archive-master-keyring
  59     # is honored. so:
  60     #   all keys that are exported must have a valid signature
  61     #   from a key in the $distro-master-keyring
  62     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
  63     all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5`
  64     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
  65
  66     # ensure there are no colisions LP: #857472
  67     for all_add_key in $all_add_keys; do
  68         for master_key in $master_keys; do
  69             if [ "$all_add_key" = "$master_key" ]; then
  70                 echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted"
  71                 return 1
  72             fi
  73         done
  74     done
  75
  76     for add_key in $add_keys; do
  77         # export the add keyring one-by-one
  78         rm -f $TMP_KEYRING
  79         $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key
  80         # check if signed with the master key and only add in this case
  81         ADDED=0
  82         for master_key in $master_keys; do
  83             if $GPG_CMD --keyring $MASTER --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then
  84                 $GPG --import $TMP_KEYRING
  85                 ADDED=1
  86             fi
  87         done
  88         if [ $ADDED = 0 ]; then
  89             echo >&2 "Key '$add_key' not added. It is not signed with a master key"
  90         fi
  91     done
  92     rm -f $TMP_KEYRING
  93 }
  94
  95 # update the current archive signing keyring from a network URI
  96 # the archive-keyring keys needs to be signed with the master key
  97 # (otherwise it does not make sense from a security POV)
  98 net_update() {
  99     # Disabled for now as code is insecure (LP: #1013639 (and 857472, 1013128))
 100     exit 1
 101
 102     if [ -z "$ARCHIVE_KEYRING_URI" ]; then
 103         echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set"
 104         exit 1
 105     fi
 106     requires_root
 107     # in theory we would need to depend on wget for this, but this feature
 108     # isn't useable in debian anyway as we have no keyring uri nor a master key
 109     if ! which wget >/dev/null 2>&1; then
 110         echo >&2 "ERROR: an installed wget is required for a network-based update"
 111         exit 1
 112     fi
 113     if [ ! -d /var/lib/apt/keyrings ]; then
 114         mkdir -p /var/lib/apt/keyrings
 115     fi
 116     keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING)
 117     old_mtime=0
 118     if [ -e $keyring ]; then
 119         old_mtime=$(stat -c %Y $keyring)
 120     fi
 121     (cd  /var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI)
 122     if [ ! -e $keyring ]; then
 123         return
 124     fi
 125     new_mtime=$(stat -c %Y $keyring)
 126     if [ $new_mtime -ne $old_mtime ]; then
 127         echo "Checking for new archive signing keys now"
 128         add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING
 129     fi
 130 }
 131
 132 update() {
 133     if [ ! -f $ARCHIVE_KEYRING ]; then
 134         echo >&2 "ERROR: Can't find the archive-keyring"
 135         echo >&2 "Is the ubuntu-keyring package installed?"
 136         exit 1
 137     fi
 138     requires_root
 139
 140     # add new keys from the package;
 141
 142     # we do not use add_keys_with_verify_against_master_keyring here,
 143     # because "update" is run on regular package updates.  A
 144     # attacker might as well replace the master-archive-keyring file
 145     # in the package and add his own keys. so this check wouldn't
 146     # add any security. we *need* this check on net-update though
 147     $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import
 148
 149     if [ -r "$REMOVED_KEYS" ]; then
 150         # remove no-longer supported/used keys
 151         keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5`
 152         for key in $keys; do
 153             if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then
 154                 $GPG --quiet --batch --delete-key --yes ${key}
 155             fi
 156         done
 157     else
 158         echo "Warning: removed keys keyring  $REMOVED_KEYS missing or not readable" >&2
 159     fi
 160 }
 161
 162
 163 usage() {
 164     echo "Usage: apt-key [--keyring file] [command] [arguments]"
 165     echo
 166     echo "Manage apt's list of trusted keys"
 167     echo
 168     echo "  apt-key add <file>          - add the key contained in <file> ('-' for stdin)"
 169     echo "  apt-key del <keyid>         - remove the key <keyid>"
 170     echo "  apt-key export <keyid>      - output the key <keyid>"
 171     echo "  apt-key exportall           - output all trusted keys"
 172     echo "  apt-key update              - update keys using the keyring package"
 173     echo "  apt-key net-update          - update keys using the network"
 174     echo "  apt-key list                - list keys"
 175     echo "  apt-key finger              - list fingerprints"
 176     echo "  apt-key adv                 - pass advanced options to gpg (download key)"
 177     echo
 178     echo "If no specific keyring file is given the command applies to all keyring files."
 179 }
 180
 181 # Determine on which keyring we want to work
 182 if [ "$1" = "--keyring" ]; then
 183         #echo "keyfile given"
 184         shift
 185         TRUSTEDFILE="$1"
 186         if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ] || [ "$2" = 'adv' ]; then
 187                 GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE"
 188         else
 189                 echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable"
 190                 exit 1
 191         fi
 192         shift
 193 # otherwise use the default
 194 else
 195         #echo "generate list"
 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                 #echo "parts active"
 207                 for trusted in $(run-parts --list $TRUSTEDPARTS --regex '^.*\.gpg$'); do
 208                         #echo "part -> $trusted"
 209                         GPG="$GPG --keyring $trusted"
 210                 done
 211         fi
 212 fi
 213 #echo "COMMAND: $GPG"
 214
 215 command="$1"
 216 if [ -z "$command" ]; then
 217     usage
 218     exit 1
 219 fi
 220 shift
 221
 222 if [ "$command" != "help" ] && ! which gpg >/dev/null 2>&1; then
 223     echo >&2 "Warning: gnupg does not seem to be installed."
 224     echo >&2 "Warning: apt-key requires gnupg for most operations."
 225     echo >&2
 226 fi
 227
 228 case "$command" in
 229     add)
 230         requires_root
 231         init_keyring "$TRUSTEDFILE"
 232         $GPG --quiet --batch --import "$1"
 233         echo "OK"
 234         ;;
 235     del|rm|remove)
 236         requires_root
 237         init_keyring "$TRUSTEDFILE"
 238         $GPG --quiet --batch --delete-key --yes "$1"
 239         echo "OK"
 240         ;;
 241     update)
 242         init_keyring "$TRUSTEDFILE"
 243         update
 244         ;;
 245     net-update)
 246         init_keyring "$TRUSTEDFILE"
 247         net_update
 248         ;;
 249     list)
 250         init_keyring "$TRUSTEDFILE"
 251         $GPG --batch --list-keys
 252         ;;
 253     finger*)
 254         init_keyring "$TRUSTEDFILE"
 255         $GPG --batch --fingerprint
 256         ;;
 257     export)
 258         init_keyring "$TRUSTEDFILE"
 259         $GPG --armor --export "$1"
 260         ;;
 261     exportall)
 262         init_keyring "$TRUSTEDFILE"
 263         $GPG --armor --export
 264         ;;
 265     adv*)
 266         init_keyring "$TRUSTEDFILE"
 267         echo "Executing: $GPG $*"
 268         $GPG $*
 269         ;;
 270     help)
 271         usage
 272         ;;
 273     *)
 274         usage
 275         exit 1
 276         ;;
 277 esac