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