From: David Kalnischkies Date: Sat, 30 Nov 2013 22:07:20 +0000 (+0100) Subject: cherry-pick ubuntus (disabled) net-update fixes X-Git-Tag: 0.9.14~17 X-Git-Url: http://git.hcoop.net/ntk/apt.git/commitdiff_plain/f87338d2da95ba7d55a1a67b4506717e94d49bca cherry-pick ubuntus (disabled) net-update fixes With the net-update command a special keyring can be downloaded and imported into apt, which must be signed by a master key. Its is currently disabled because of security problems with it – and the only known user before that was Ubuntu. --- diff --git a/cmdline/apt-key b/cmdline/apt-key index 713a41c0..64cf5a6f 100755 --- a/cmdline/apt-key +++ b/cmdline/apt-key @@ -25,17 +25,15 @@ GPG_CMD="$GPG_CMD --no-auto-check-trustdb --trust-model always" GPG="$GPG_CMD" -MASTER_KEYRING="" -#MASTER_KEYRING=/usr/share/keyrings/debian-master-keyring.gpg +MASTER_KEYRING='' eval $(apt-config shell MASTER_KEYRING APT::Key::MasterKeyring) -ARCHIVE_KEYRING_URI="" -#ARCHIVE_KEYRING_URI=http://ftp.debian.org/debian/debian-archive-keyring.gpg -eval $(apt-config shell ARCHIVE_KEYRING_URI APT::Key::ArchiveKeyringURI) - -ARCHIVE_KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg +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 +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 @@ -57,7 +55,7 @@ init_keyring() { add_keys_with_verify_against_master_keyring() { ADD_KEYRING=$1 MASTER=$2 - + if [ ! -f "$ADD_KEYRING" ]; then echo "ERROR: '$ADD_KEYRING' not found" return @@ -72,12 +70,28 @@ add_keys_with_verify_against_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 $TMP_KEYRING ADDED=1 fi done @@ -85,12 +99,16 @@ add_keys_with_verify_against_master_keyring() { echo >&2 "Key '$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 >&2 "ERROR: Your distribution is not supported in net-update as no uri for the archive-keyring is set" exit 1 @@ -110,7 +128,7 @@ net_update() { if [ -e $keyring ]; then old_mtime=$(stat -c %Y $keyring) fi - (cd /var/lib/apt/keyrings; wget -q -N $ARCHIVE_KEYRING_URI) + (cd /var/lib/apt/keyrings; wget --timeout=90 -q -N $ARCHIVE_KEYRING_URI) if [ ! -e $keyring ]; then return fi diff --git a/test/integration/exploid-keyring-with-dupe-keys.pub b/test/integration/exploid-keyring-with-dupe-keys.pub new file mode 100644 index 00000000..642952a4 Binary files /dev/null and b/test/integration/exploid-keyring-with-dupe-keys.pub differ diff --git a/test/integration/exploid-keyring-with-dupe-subkeys.pub b/test/integration/exploid-keyring-with-dupe-subkeys.pub new file mode 100644 index 00000000..02d4e6ee Binary files /dev/null and b/test/integration/exploid-keyring-with-dupe-subkeys.pub differ diff --git a/test/integration/test-apt-key-net-update b/test/integration/test-apt-key-net-update new file mode 100755 index 00000000..d5205836 --- /dev/null +++ b/test/integration/test-apt-key-net-update @@ -0,0 +1,95 @@ +#!/bin/sh +set -e + +TESTDIR=$(readlink -f $(dirname $0)) +. $TESTDIR/framework + +setupenvironment +configarchitecture "i386" + +# mock +requires_root() { + return 0 +} + +# extract net_update() and import it +func=$( sed -n -e '/^add_keys_with_verify_against_master_keyring/,/^}/p' ${BUILDDIRECTORY}/apt-key ) +eval "$func" + +mkdir -p ./etc/apt +TRUSTEDFILE=./etc/apt/trusted.gpg +mkdir -p ./var/lib/apt/keyrings +TMP_KEYRING=./var/lib/apt/keyrings/maybe-import-keyring.gpg +GPG_CMD="gpg --ignore-time-conflict --no-options --no-default-keyring" +GPG="$GPG_CMD --keyring $TRUSTEDFILE" +MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg + + +msgtest "add_keys_with_verify_against_master_keyring" +if [ ! -e $MASTER_KEYRING ]; then + echo -n "No $MASTER_KEYRING found" + msgskip + exit 0 +fi + +# test bad keyring and ensure its not added (LP: #857472) +ADD_KEYRING=./keys/exploid-keyring-with-dupe-keys.pub +if add_keys_with_verify_against_master_keyring $ADD_KEYRING $MASTER_KEYRING; then + msgfail +else + msgpass +fi + +# ensure the keyring is still empty +gpg_out=$($GPG --list-keys) +msgtest "Test if keyring is empty" +if [ -n "" ]; then + msgfail +else + msgpass +fi + + +# test another possible attack vector using subkeys (LP: #1013128) +msgtest "add_keys_with_verify_against_master_keyring with subkey attack" +ADD_KEYRING=./keys/exploid-keyring-with-dupe-subkeys.pub +if add_keys_with_verify_against_master_keyring $ADD_KEYRING $MASTER_KEYRING; then + msgfail +else + msgpass +fi + +# ensure the keyring is still empty +gpg_out=$($GPG --list-keys) +msgtest "Test if keyring is empty" +if [ -n "" ]; then + msgfail +else + msgpass +fi + + +# test good keyring and ensure we get no errors +ADD_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg +if add_keys_with_verify_against_master_keyring $ADD_KEYRING $MASTER_KEYRING; then + msgpass +else + msgfail +fi + +testequal './etc/apt/trusted.gpg +--------------------- +pub 1024D/437D05B5 2004-09-12 +uid Ubuntu Archive Automatic Signing Key +sub 2048g/79164387 2004-09-12 + +pub 1024D/FBB75451 2004-12-30 +uid Ubuntu CD Image Automatic Signing Key + +pub 4096R/C0B21F32 2012-05-11 +uid Ubuntu Archive Automatic Signing Key (2012) + +pub 4096R/EFE21092 2012-05-11 +uid Ubuntu CD Image Automatic Signing Key (2012) +' $GPG --list-keys +