apt/test/integration/test-apt-update-nofallback

#!/bin/sh
#
# ensure we never fallback from a signed to a unsigned repo
# 
# hash checks are done in 
# 
set -e

simulate_mitm_and_inject_evil_package()
{
    rm -f $APTARCHIVE/dists/unstable/InRelease
    rm -f $APTARCHIVE/dists/unstable/Release.gpg
    inject_evil_package
}

inject_evil_package()
{
    cat > $APTARCHIVE/dists/unstable/main/binary-i386/Packages <<EOF
Package: evil
Installed-Size: 29
Maintainer: Joe Sixpack <joe@example.org>
Architecture: all
Version: 1.0
Filename: pool/evil_1.0_all.deb
Size: 1270
Description: an autogenerated evil package
EOF
    # avoid ims hit
    touch -d '+1hour' aptarchive/dists/unstable/main/binary-i386/Packages
}

assert_update_is_refused_and_last_good_state_used()
{
    testequal "E: The repository 'file: unstable Release.gpg' is no longer signed." aptget update -qq

    assert_repo_is_intact
}

assert_repo_is_intact()
{
    testequal "foo/unstable 2.0 all" apt list -q
    testsuccess "" aptget install -y -s foo
    testfailure "" aptget install -y evil

    LISTDIR=rootdir/var/lib/apt/lists
    if ! ( ls $LISTDIR/*InRelease >/dev/null 2>&1 || 
            ls $LISTDIR/*Release.gpg >/dev/null 2>&1 ); then
        echo "Can not find InRelease/Release.gpg in $(ls $LISTDIR)"
        msgfail
    fi
}

setupaptarchive_with_lists_clean()
{
    setupaptarchive --no-update
    rm -f rootdir/var/lib/apt/lists/_*
    #rm -rf rootdir/var/lib/apt/lists
}

test_from_inrelease_to_unsigned()
{
    # setup archive with InRelease file
    setupaptarchive_with_lists_clean
    testsuccess aptget update

    simulate_mitm_and_inject_evil_package
    assert_update_is_refused_and_last_good_state_used
}

test_from_release_gpg_to_unsigned()
{
    # setup archive with Release/Release.gpg (but no InRelease)
    setupaptarchive_with_lists_clean
    rm $APTARCHIVE/dists/unstable/InRelease
    testsuccess aptget update

    simulate_mitm_and_inject_evil_package
    assert_update_is_refused_and_last_good_state_used
}

test_from_inrelease_to_unsigned_with_override()
{
    # setup archive with InRelease file
    setupaptarchive_with_lists_clean
    testsuccess aptget update

    # simulate moving to a unsigned but otherwise valid repo
    simulate_mitm_and_inject_evil_package
    generatereleasefiles

    # and ensure we can update to it (with enough force) 
    testsuccess aptget update --allow-insecure-repositories \
        -o Acquire::AllowDowngradeToInsecureRepositories=1
    # but that the individual packages are still considered untrusted
    testequal "WARNING: The following packages cannot be authenticated!
  evil
E: There are problems and -y was used without --force-yes" aptget install -qq -y evil
}

test_cve_2012_0214()
{
    # see https://bugs.launchpad.net/ubuntu/+source/apt/+bug/947108
    #
    # it was possible to MITM the download so that InRelease/Release.gpg
    # are not delivered (404) and a altered Release file was send
    #
    # apt left the old InRelease file in /var/lib/apt/lists and downloaded
    # the unauthenticated Release file too giving the false impression that
    # Release was authenticated
    #
    # Note that this is pretty much impossible nowdays because:
    # a) InRelease is left as is, not split to InRelease/Release as it was 
    #    in the old days
    # b) we refuse to go from signed->unsigned
    #
    # Still worth having a regression test the simulates the condition

    # setup archive with InRelease
    setupaptarchive_with_lists_clean
    testsuccess aptget update

    # do what CVE-2012-0214 did
    rm $APTARCHIVE/dists/unstable/InRelease
    rm $APTARCHIVE/dists/unstable/Release.gpg
    inject_evil_package
    # build valid Release file
    aptftparchive -qq release ./aptarchive > aptarchive/dists/unstable/Release 

    assert_update_is_refused_and_last_good_state_used

    # ensure there is no _Release file downloaded
    testfailure ls rootdir/var/lib/apt/lists/*_Release
}

test_subvert_inrelease()
{
    # setup archive with InRelease
    setupaptarchive_with_lists_clean
    testsuccess aptget update

    # replace InRelease with something else
    mv $APTARCHIVE/dists/unstable/Release $APTARCHIVE/dists/unstable/InRelease

    testequal "W: Failed to fetch file:${APTARCHIVE}/dists/unstable/InRelease  Does not start with a cleartext signature

E: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq

    # ensure we keep the repo
    assert_repo_is_intact
}

test_inrelease_to_invalid_inrelease()
{
    # setup archive with InRelease
    setupaptarchive_with_lists_clean
    testsuccess aptget update

    # now remove InRelease and subvert Release do no longer verify
    sed -i 's/Codename.*/Codename: evil!'/ $APTARCHIVE/dists/unstable/InRelease
    inject_evil_package

    testequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file: unstable InRelease: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>

W: Failed to fetch file:${APTARCHIVE}/dists/unstable/InRelease  

W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq

    # ensure we keep the repo
    assert_repo_is_intact
    testfailure grep "evil" rootdir/var/lib/apt/lists/*InRelease
}

test_release_gpg_to_invalid_release_release_gpg()
{
    # setup archive with InRelease
    setupaptarchive_with_lists_clean
    rm $APTARCHIVE/dists/unstable/InRelease
    testsuccess aptget update

    # now subvert Release do no longer verify
    echo "Some evil data" >>  $APTARCHIVE/dists/unstable/Release
    inject_evil_package

    testequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file: unstable Release.gpg: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>

W: Failed to fetch file:${APTARCHIVE}/dists/unstable/Release.gpg  

W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq

    assert_repo_is_intact
    testfailure grep "evil" rootdir/var/lib/apt/lists/*Release
}


TESTDIR=$(readlink -f $(dirname $0))
. $TESTDIR/framework

setupenvironment
configarchitecture "i386"

# a "normal" package with source and binary
buildsimplenativepackage 'foo' 'all' '2.0'

# setup the archive and ensure we have a single package that installs fine
setupaptarchive
APTARCHIVE=$(readlink -f ./aptarchive)
assert_repo_is_intact

# test the various cases where a repo may go from signed->unsigned
msgmsg "test_from_inrelease_to_unsigned"
test_from_inrelease_to_unsigned

msgmsg "test_from_release_gpg_to_unsigned"
test_from_release_gpg_to_unsigned

# ensure we do not regress on CVE-2012-0214
msgmsg "test_cve_2012_0214"
test_cve_2012_0214

# ensure InRelase can not be subverted
msgmsg "test_subvert_inrelease"
test_subvert_inrelease

# ensure we revert to last good state if InRelease does not verify
msgmsg "test_inrelease_to_invalid_inrelease"
test_inrelease_to_invalid_inrelease

# ensure we revert to last good state if Release/Release.gpg does not verify
msgmsg "test_release_gpg_to_invalid_release_release_gpg"
test_release_gpg_to_invalid_release_release_gpg

# ensure we can ovveride the downgrade error
msgmsg "test_from_inrelease_to_unsigned"
test_from_inrelease_to_unsigned_with_override