X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/b08f3f535b7c55202345ae44143a202fa186afea..f87338d2da95ba7d55a1a67b4506717e94d49bca:/cmdline/apt-key?ds=sidebyside diff --git a/cmdline/apt-key b/cmdline/apt-key index 533193901..64cf5a6f4 100755 --- a/cmdline/apt-key +++ b/cmdline/apt-key @@ -1,23 +1,61 @@ #!/bin/sh set -e +unset GREP_OPTIONS -# We don't use a secret keyring, of course, but gpg panics and -# implodes if there isn't one available +GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring" -GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg" -GPG="$GPG_CMD --keyring /etc/apt/trusted.gpg" +# gpg needs a trustdb to function, but it can't be invalid (not even empty) +# so we create a temporary directory to store our fresh readable trustdb in +TRUSTDBDIR="$(mktemp -d)" +CURRENTTRAP="${CURRENTTRAP} rm -rf '${TRUSTDBDIR}';" +trap "${CURRENTTRAP}" 0 HUP INT QUIT ILL ABRT FPE SEGV PIPE TERM +chmod 700 "$TRUSTDBDIR" +# We also don't use a secret keyring, of course, but gpg panics and +# implodes if there isn't one available - and writeable for imports +SECRETKEYRING="${TRUSTDBDIR}/secring.gpg" +touch $SECRETKEYRING +GPG_CMD="$GPG_CMD --secret-keyring $SECRETKEYRING" +GPG_CMD="$GPG_CMD --trustdb-name ${TRUSTDBDIR}/trustdb.gpg" +# now create the trustdb with an (empty) dummy keyring +$GPG_CMD --quiet --check-trustdb --keyring $SECRETKEYRING +# and make sure that gpg isn't trying to update the file +GPG_CMD="$GPG_CMD --no-auto-check-trustdb --trust-model always" -MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg -ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg -REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg -ARCHIVE_KEYRING_URI=http://archive.ubuntu.com/ubuntu/ubuntu-archive-keyring.gpg +GPG="$GPG_CMD" + +MASTER_KEYRING='' +eval $(apt-config shell MASTER_KEYRING APT::Key::MasterKeyring) +ARCHIVE_KEYRING='/usr/share/keyrings/debian-archive-keyring.gpg' +eval $(apt-config shell ARCHIVE_KEYRING APT::Key::ArchiveKeyring) +REMOVED_KEYS='/usr/share/keyrings/debian-archive-removed-keys.gpg' +eval $(apt-config shell REMOVED_KEYS APT::Key::RemovedKeys) +ARCHIVE_KEYRING_URI='' +eval $(apt-config shell ARCHIVE_KEYRING_URI APT::Key::ArchiveKeyringURI) +TMP_KEYRING=/var/lib/apt/keyrings/maybe-import-keyring.gpg + +requires_root() { + if [ "$(id -u)" -ne 0 ]; then + echo >&1 "ERROR: This command can only be used by root." + exit 1 + fi +} + +# gpg defaults to mode 0600 for new keyrings. Create one with 0644 instead. +init_keyring() { + for path; do + if ! [ -e "$path" ]; then + touch -- "$path" + chmod 0644 -- "$path" + fi + done +} add_keys_with_verify_against_master_keyring() { ADD_KEYRING=$1 MASTER=$2 - + if [ ! -f "$ADD_KEYRING" ]; then echo "ERROR: '$ADD_KEYRING' not found" return @@ -29,16 +67,31 @@ add_keys_with_verify_against_master_keyring() { # when adding new keys, make sure that the archive-master-keyring # is honored. so: - # all keys that are exported and have the name - # "Ubuntu Archive Automatic Signing Key" must have a valid signature - # from a key in the ubuntu-master-keyring + # all keys that are exported must have a valid signature + # from a key in the $distro-master-keyring add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5` + all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5` master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5` + + # ensure there are no colisions LP: #857472 + for all_add_key in $all_add_keys; do + for master_key in $master_keys; do + if [ "$all_add_key" = "$master_key" ]; then + echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted" + return 1 + fi + done + done + for add_key in $add_keys; do - ADDED=0 + # export the add keyring one-by-one + rm -f $TMP_KEYRING + $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key + # check if signed with the master key and only add in this case + ADDED=0 for master_key in $master_keys; do - if $GPG_CMD --keyring $ADD_KEYRING --list-sigs --with-colons $add_key | grep ^sig | cut -d: -f5 | grep -q $master_key; then - $GPG_CMD --quiet --batch --keyring $ADD_KEYRING --export $add_key | $GPG --import + if $GPG_CMD --keyring $MASTER --keyring $TMP_KEYRING --check-sigs --with-colons $add_key | grep '^sig:!:' | cut -d: -f5 | grep -q $master_key; then + $GPG --import $TMP_KEYRING ADDED=1 fi done @@ -46,49 +99,133 @@ add_keys_with_verify_against_master_keyring() { echo >&2 "Key '$add_key' not added. It is not signed with a master key" fi done + rm -f $TMP_KEYRING } # update the current archive signing keyring from a network URI # the archive-keyring keys needs to be signed with the master key # (otherwise it does not make sense from a security POV) net_update() { + # Disabled for now as code is insecure (LP: #1013639 (and 857472, 1013128)) + exit 1 + if [ -z "$ARCHIVE_KEYRING_URI" ]; then - echo "ERROR: no location for the archive-keyring given" + echo >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set" + exit 1 + fi + requires_root + # in theory we would need to depend on wget for this, but this feature + # isn't useable in debian anyway as we have no keyring uri nor a master key + if ! which wget >/dev/null 2>&1; then + echo >&2 "ERROR: an installed wget is required for a network-based update" + exit 1 fi if [ ! -d /var/lib/apt/keyrings ]; then mkdir -p /var/lib/apt/keyrings fi - (cd /var/lib/apt/keyrings; wget -q -N $ARCHIVE_KEYRING_URI) - add_keys_with_verify_against_master_keyring /var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING) $MASTER_KEYRING + keyring=/var/lib/apt/keyrings/$(basename $ARCHIVE_KEYRING) + old_mtime=0 + if [ -e $keyring ]; then + old_mtime=$(stat -c %Y $keyring) + fi + (cd /var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI) + if [ ! -e $keyring ]; then + return + fi + new_mtime=$(stat -c %Y $keyring) + if [ $new_mtime -ne $old_mtime ]; then + echo "Checking for new archive signing keys now" + add_keys_with_verify_against_master_keyring $keyring $MASTER_KEYRING + fi } update() { if [ ! -f $ARCHIVE_KEYRING ]; then echo >&2 "ERROR: Can't find the archive-keyring" - echo >&2 "Is the ubuntu-keyring package installed?" + echo >&2 "Is the debian-archive-keyring package installed?" exit 1 fi + requires_root + + # add new keys from the package; - # add new keys, if no MASTER_KEYRING is used, use the traditional - # way - if [ -z "$MASTER_KEYRING" ]; then - $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import + # we do not use add_keys_with_verify_against_master_keyring here, + # because "update" is run on regular package updates. A + # attacker might as well replace the master-archive-keyring file + # in the package and add his own keys. so this check wouldn't + # add any security. we *need* this check on net-update though + $GPG_CMD --quiet --batch --keyring $ARCHIVE_KEYRING --export | $GPG --import + + if [ -r "$REMOVED_KEYS" ]; then + # remove no-longer supported/used keys + keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5` + for key in $keys; do + if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then + $GPG --quiet --batch --delete-key --yes ${key} + fi + done else - add_keys_with_verify_against_master_keyring $ARCHIVE_KEYRING $MASTER_KEYRING + echo "Warning: removed keys keyring $REMOVED_KEYS missing or not readable" >&2 + fi +} + +remove_key_from_keyring() { + local GPG="$GPG_CMD --keyring $1" + # check if the key is in this keyring: the key id is in the 5 column at the end + if ! $GPG --with-colons --list-keys 2>&1 | grep -q "^pub:[^:]*:[^:]*:[^:]*:[0-9A-F]\+$2:"; then + return + fi + if [ ! -w "$1" ]; then + echo >&2 "Key ${2} is in keyring ${1}, but can't be removed as it is read only." + return + fi + # check if it is the only key in the keyring and if so remove the keyring alltogether + if [ '1' = "$($GPG --with-colons --list-keys | grep "^pub:[^:]*:[^:]*:[^:]*:[0-9A-F]\+:" | wc -l)" ]; then + mv -f "$1" "${1}~" # behave like gpg + return fi + # we can't just modify pointed to files as these might be in /usr or something + local REALTARGET + if [ -L "$1" ]; then + REALTARGET="$(readlink -f "$1")" + mv -f "$1" "${1}.dpkg-tmp" + cp -a "$REALTARGET" "$1" + ls "$(dirname $1)" + fi + # delete the key from the keyring + $GPG --batch --delete-key --yes "$2" + if [ -n "$REALTARGET" ]; then + # the real backup is the old link, not the copy we made + mv -f "${1}.dpkg-tmp" "${1}~" + fi +} - # remove no-longer supported/used keys - keys=`$GPG_CMD --keyring $REMOVED_KEYS --with-colons --list-keys | grep ^pub | cut -d: -f5` - for key in $keys; do - if $GPG --list-keys --with-colons | grep ^pub | cut -d: -f5 | grep -q $key; then - $GPG --quiet --batch --delete-key --yes ${key} +remove_key() { + requires_root + + # if a --keyring was given, just remove from there + if [ -n "$FORCED_KEYRING" ]; then + remove_key_from_keyring "$FORCED_KEYRING" "$1" + else + # otherwise all known keyrings are up for inspection + local TRUSTEDFILE="/etc/apt/trusted.gpg" + eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring) + eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f) + remove_key_from_keyring "$TRUSTEDFILE" "$1" + TRUSTEDPARTS="/etc/apt/trusted.gpg.d" + eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d) + if [ -d "$TRUSTEDPARTS" ]; then + for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do + remove_key_from_keyring "$trusted" "$1" + done fi - done + fi + echo "OK" } usage() { - echo "Usage: apt-key [command] [arguments]" + echo "Usage: apt-key [--keyring file] [command] [arguments]" echo echo "Manage apt's list of trusted keys" echo @@ -99,9 +236,61 @@ usage() { echo " apt-key update - update keys using the keyring package" echo " apt-key net-update - update keys using the network" echo " apt-key list - list keys" + echo " apt-key finger - list fingerprints" + echo " apt-key adv - pass advanced options to gpg (download key)" echo + echo "If no specific keyring file is given the command applies to all keyring files." } +while [ -n "$1" ]; do + case "$1" in + --keyring) + shift + TRUSTEDFILE="$1" + FORCED_KEYRING="$1" + if [ -r "$TRUSTEDFILE" ] || [ "$2" = 'add' ] || [ "$2" = 'adv' ]; then + GPG="$GPG --keyring $TRUSTEDFILE --primary-keyring $TRUSTEDFILE" + else + echo >&2 "Error: The specified keyring »$TRUSTEDFILE« is missing or not readable" + exit 1 + fi + shift + ;; + --fakeroot) + requires_root() { true; } + shift + ;; + --*) + echo >&2 "Unknown option: $1" + usage + exit 1;; + *) + break;; + esac +done + +if [ -z "$TRUSTEDFILE" ]; then + TRUSTEDFILE="/etc/apt/trusted.gpg" + eval $(apt-config shell TRUSTEDFILE Apt::GPGV::TrustedKeyring) + eval $(apt-config shell TRUSTEDFILE Dir::Etc::Trusted/f) + if [ -r "$TRUSTEDFILE" ]; then + GPG="$GPG --keyring $TRUSTEDFILE" + fi + GPG="$GPG --primary-keyring $TRUSTEDFILE" + TRUSTEDPARTS="/etc/apt/trusted.gpg.d" + eval $(apt-config shell TRUSTEDPARTS Dir::Etc::TrustedParts/d) + if [ -d "$TRUSTEDPARTS" ]; then + # strip / suffix as gpg will double-slash in that case (#665411) + STRIPPED_TRUSTEDPARTS="${TRUSTEDPARTS%/}" + if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then + TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS" + fi + for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do + GPG="$GPG --keyring $trusted" + done + fi +fi + command="$1" if [ -z "$command" ]; then usage @@ -117,32 +306,41 @@ fi case "$command" in add) + requires_root + init_keyring "$TRUSTEDFILE" $GPG --quiet --batch --import "$1" echo "OK" ;; del|rm|remove) - $GPG --quiet --batch --delete-key --yes "$1" - echo "OK" + init_keyring "$TRUSTEDFILE" + remove_key "$1" ;; update) + init_keyring "$TRUSTEDFILE" update ;; net-update) + init_keyring "$TRUSTEDFILE" net_update ;; list) + init_keyring "$TRUSTEDFILE" $GPG --batch --list-keys ;; finger*) + init_keyring "$TRUSTEDFILE" $GPG --batch --fingerprint ;; export) + init_keyring "$TRUSTEDFILE" $GPG --armor --export "$1" ;; exportall) + init_keyring "$TRUSTEDFILE" $GPG --armor --export ;; adv*) + init_keyring "$TRUSTEDFILE" echo "Executing: $GPG $*" $GPG $* ;;