pkgsrc-2014Q4: LTS, signed packages, and more
Editor's note: we're making some changes to the packages for Joyent's infrastructure containers to ensure that we can support them over a period of years. The old "base" and "base64" images are being renamed to "base-32" and "base-64" and we’re adding "∗-lts" images that we'll be supporting with security updates and critical bug fixes for three years from the date of introduction. We're also introducing "minimal-∗" images that are even more streamlined than the "base-∗" images. The old images will remain available for some time, but we will not be updating them going forward.
The latest quarterly release of our binary package sets for SmartOS and illumos introduces a number of new features that I’m excited to announce.
Long Term Support
We have produced quarterly releases of pkgsrc for a number of years, and since the
pkgsrc-2013Q2 release have built every package available (10,000+), but until now have not formalised our support for them.
This has meant that when serious security issues such as Heartbleed are disclosed, we are obliged to backport these fixes to every branch we have ever produced. Despite all our efforts on performance improvements this is still a large effort and takes a long time on older branches where we do not have huge resources available and backports can be tricker due to the differences involved.
We’ve tried as best we can to keep these older branches updated, but as we’ve added new branches each quarter the load increases further, and we cannot keep doing this forever.
pkgsrc-2014Q4 (SmartOS 14.4.x images) we are introducing a new yearly Long Term Support (LTS) model, which can be summarised as:
pkgsrc-2015Q4, …) will be an LTS release, and will receive suitable backports for 3 years from the time it is made available.
We will continue to produce the other quarterly releases (SmartOS 15.1.x images and onwards), so that users can get the latest packages available, but each of those releases will be closed for updates as soon as the next one is available.
What is a “suitable” backport? Anything which is a security or build fix, and which does not affect API or ABI compatibility. For example, we would not introduce a new major version of OpenSSL or PHP into an LTS release, but we would update OpenSSL from
1.0.1k or PHP from
5.4.38 as they are minor releases which only introduce fixes. We may also introduce new leaf packages (i.e. those with no dependencies), for example new releases of nodejs.
Who is the target market for each type of release?
LTS is primarily useful for people who have a very static set of requirements, do not like changes, and are primarily interested in ensuring that the software they run does not have active vulnerabilities.
Latest quarterly releases are for everyone else, users who want the latest stuff (and the latest security fixes), and are happy to reprovision their applications onto the newest images at regular intervals.
We hope the introduction of LTS releases satisfies both types of users, and that by freeing up our resources spent on maintaining our legacy branches, we can invest more time into ensuring the stability and security of the LTS releases.
For SmartOS users, the LTS releases will receive an additional
-lts suffix on the image name to make it even easier to identify which are LTS.
Image Name Changes
Related to LTS, we are also slightly changing our naming scheme for the base images. This is to accommodate the new
-lts suffix, and also to allow us to introduce a new “minimal” image, and make it clear which is which.
The current base image names are:
With the introduction of the “minimal” image, the new names will be:
|arch||base name||minimal name|
And for LTS releases:
|arch||base name||minimal name|
What’s the new “minimal” image? It’s effectively a stripped down “base”, with only the pkgsrc bootstrap and a couple of packages installed which are required for the zone to boot correctly. This will be of primary interest to users who have custom requirements for their zones and/or produce their own images, and want to ensure they are building on the smallest possible foundation.
As a quick comparison:
|image||packages installed||image size (compressed)|
The “minimal” images are fully functional and use the same package set, the only difference is fewer packages are installed by default.
Updated SmartOS Build Hosts
Up until now we have built all our package sets on an old SDC 6.5 install, to ensure that the packages we built can run across all hosts in the Joyent Public Cloud. Building on the lowest common denominator is great for compatibility, but has meant we are running on a limited number of older machines, and each quarterly release added yet more strain to already overloadeded systems.
Starting with 2014Q4 LTS we have moved to newer build hosts, running
joyent_20141030T081701Z. This will soon be the most common platform available in the Joyent cloud, and ensures we aren’t tied to a legacy release for another 3 years. The next 3 quarterly releases (2015Q1-3) will also be produced on this platform, and we will then evaluate which platform to choose for the next LTS in 2015Q4.
This may mean incompatibilities if you are either running an older SmartOS release, or if you are running a different illumos distribution which does not have some of the newer SmartOS features. You are most likely to see issues where packages have picked up support for newer interfaces such as epoll or inotify, which have been introduced as part of the LX brand work.
Please feel free to raise a GitHub issue if this is causing problems for you. We are happy to turn off support for newer features if it improves compatibility, as often these features are picked up by autoconf checks but either aren’t used correctly or should be using different interfaces on illumos platforms anyway.
One of the primary concerns in recent times is provenance, and ensuring that what you are receiving hasn’t been tampered with in any way. Until now our packages have been protected by checksums, so that it is difficult for an attacker to modify packages in-flight and deliver something we did not provide.
However, it isn’t impossible, and to further ensure that what you are installing came from Joyent we have implemented signed packages for 2014Q4 onwards. Here’s how it works:
- During the package build process, a detached package hash file is created which contains a SHA512 checksum of the package.
- This hash file is then signed with our PGP key.
- All three files are bundled into an
ar(1)archive and delivered as the
- At package install time, the archive is unpacked, the hash file is verified against our public PGP key, and then the package is checksummed against the recorded checksum in the hash file. If all these checks pass, the package is installed, otherwise the installation is aborted.
Let’s take a look at a package file (digest) to see in more detail:
: We need to use GNU ar(1) from binutils as the Sun format is too limited.$ gar xv /path/to/digest-20121220.tgzx - +PKG_HASHx - +PKG_GPG_SIGNATUREx - digest-20121220.tgz
+PKG_HASH file contains all the details about the actual digest package which is stored in the archive.
$ cat +PKG_HASHpkgsrc signatureversion: 1pkgname: digest-20121220algorithm: SHA512block size: 65536file size: 49083b011cb5e9cdea303f3958a7338b37fd85252313da354ff86a82170974f384700634c5fbe9d5f7035f67ff8a4eecacc6cfbff43ba4d62b4e4743837d72612feefend pkgsrc signature
We can verify that the checksum is correct.
$ /usr/bin/digest -a sha512 digest-20121220.tgzb011cb5e9cdea303f3958a7338b37fd85252313da354ff86a82170974f384700634c5fbe9d5f7035f67ff8a4eecacc6cfbff43ba4d62b4e4743837d72612feef
So we know that the
+PKG_HASH file matches the
digest-20121220.tgz package file. However, how do we know that both haven’t been tampered with? That’s where the
+PKG_GPG_SIGNATURE file comes in. It is a detached signature of the
+PKG_HASH file, signed with the Joyent key, so that if a malicious user has tampered with the package file and generated a new checksum, the
+PKG_HASH file will no longer be verified and we know that it isn’t what was originally built.
We can verify that on the command line with GPG, as long as you have imported the public key for that package set:
$ gpg --verify +PKG_GPG_SIGNATURE +PKG_HASHgpg: Signature made Sat Feb 21 02:10:43 2015 UTC using RSA key ID DE817B8Egpg: Good signature from "Joyent Package Signing <email@example.com>"gpg: WARNING: This key is not certified with a trusted signature!gpg: There is no indication that the signature belongs to the owner.Primary key fingerprint: 74C4 F303 BB45 7421 E42C 4DC4 FAE5 0048 FAA6 6EE0 Subkey fingerprint: 2163 0D8B 4486 4587 9655 3748 76FA BBBB DE81 7B8E
A quick note about the warnings shown above. This is where the PGP web of trust comes in. We know that the files were signed with the
DE817B8E key, but how do we know that the key belongs to
firstname.lastname@example.org? It essentially comes down to trust, and whether you believe this is really our key, or whether someone has tricked you to believe that when it’s not. We can help persuade you in a few ways:
- The bootstrap packages and our SmartOS images will come by default with that key installed in
/opt/local/etc/gnupg/pkgsrc.gpg. This is required so that you can start installing signed packages out of the box with no setup necessary.
- The public keys will be published to PGP key servers, and I will sign them with my key (
D532A578). My key in turn is signed by a number of other people, so that you can verify whether you believe I am who I say I am.
- We will publish the keys in a couple of other places, certainly on the main http://pkgsrc.joyent.com/ site.
So, if you are a diligent user who checks all of these sources, an attacker would need to infiltrate every single one of them simultaneously to have a chance of delivering you a malicious packages which bypasses all of the checks. Hopefully you are convinced that this would be extremely difficult.
Finally, how is all of this used in practise? We’ve worked hard to make this as transparent as possible, including integration of Alistair Crooks’ excellent libnetpgpverify library into
pkg_install, so as a user you should never be aware of any of it unless there is a problem (a core Unix philosophy):
As mentioned above, the PGP key is distributed by default, so you don’t need to import keys or anything to get started. We have added the following to
GPG_KEYRING_VERIFY is set to our public key, and
VERIFIED_INSTALLATION=trusted means that a signature is required, and if one isn’t available then you are prompted for how to proceed. Trying to install the package file from our
ar(1) archive example above shows what happens:
$ pkg_add ./digest-20121220.tgzNo valid signature found for digest-20121220.Do you want to proceed with the installation [y/n]?nCancelling installationpkg_add: 1 package addition failed
And if we try to install a package with an incorrect signature/hash:
$ ed +PKG_HASH >/dev/null 2>&1 <<EOF/^b011/s/b011/b010/wqEOF$ gar r test.tgz +PKG_HASH +PKG_GPG_SIGNATURE digest-20121220.tgzgar: creating test.tgz$ pkg_add ./test.tgzpkg_add: unable to verify signature: Signature on data did not match
If you build your own packages then you’re going to want to handle this properly. The simplest option is to use a custom
pkg_install.conf when installing your own packages, for example:
$ echo "VERIFIED_INSTALLATION=never" >pkg_install_noverify.conf$ pkg_add -C ./pkg_install_noverify.conf ./digest-20121220.tgz
The alternative is to sign your own packages. This is reasonably straight-forward:
- Install GPG, create a signing key, and then configure
With those additions, pkgsrc will prompt you for your PGP passphrase at package time, and then sign the package with the key you have configured. You can use
gpg-agent to automate this in a controlled environment.
Closely related to package signing, now that we have infrastructure support for verification in our bootstrap packages, we’ve also enabled easy verification of the
pkg-vulnerabilities file. For those who aren’t aware, there is a team of volunteers for pkgsrc who maintain a list of security vulnerabilities, which can be checked against the list of installed packages and show you which ones are currently vulnerable.
: Fetch the latest pkg-vulnerabilities file. SmartOS images have a crontab: entry which does this nightly by default.$ pkg_admin fetch-pkg-vulnerabilities: The file is a compressed signed message containing a list of all known: vulnerabilities.$ gzip -dc /opt/local/pkg/pkg-vulnerabilities | nl -ba | sed -ne '1,4p' -e '27,28p' 1 -----BEGIN PGP SIGNED MESSAGE----- 2 Hash: SHA1 3 4 # $NetBSD: pkg-vulnerabilities,v 1.6187 2015/03/02 14:22:28 ryoon Exp $ 27 # package type of exploit URL 28 cfengine<1.5.3nb3 remote-root-shell ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2000-013.txt.asc: Show list of current known vulnerabilities$ pkg_admin auditPackage gcc47-4.7.3nb6 has a denial-of-service vulnerability, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61601Package gcc47-4.7.3nb6 has a memory-corruption vulnerability, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61582Package mit-krb5-1.10.7nb4 has a denial-of-service vulnerability, see http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-5353[...]
This provides you as the administrator with the information necessary to decide whether the current vulnerabilities are acceptable in your environment.
However, there is a missing piece. As you can see above, the vulnerabilities file is signed. This is important as an attacker with access to modify this file could hide vulnerabilities from you and leave your system exposed. With the verification infrastructure now in place, we can now provide the pkgsrc-security PGP key for you to easily verify that the
pkg-vulnerabilities file is as expected.
First we need to install the
email@example.com PGP key on the system. As this key changes quite frequently, we cannot include it directly in the bootstrap tarball as we have done with the package signing key, as it will eventually be out of date. So we instead provide a new
pkgsrc-gnupg-keys package which includes it, bundle that in the bootstrap, and we can then distribute updates to this package as normal via
: The package contains a PGP keyring with the current pkgsrc-security key.$ pkg_info -qL pkgsrc-gnupg-keys/opt/local/share/gnupg/pkgsrc-security.gpg
We then add that file to our
/opt/local/etc/pkg_install.conf file with:
To verify the pkg-vulnerabilities file, use
: Verify the basic checksum, looks good.$ pkg_admin check-pkg-vulnerabilities /opt/local/pkg/pkg-vulnerabilities: Verify the PGP signature, looks good.$ pkg_admin check-pkg-vulnerabilities -s /opt/local/pkg/pkg-vulnerabilities: Modify the file and try again, checks fail.$ gzip -dc /opt/local/pkg/pkg-vulnerabilities \ | grep -v 'mutt.*denial-of-service' \ | gzip -9 >/var/tmp/pkg-vulnerabilities-test$ pkg_admin check-pkg-vulnerabilities /var/tmp/pkg-vulnerabilities-testpkg_admin: SHA1 hash doesn't match$ pkg_admin check-pkg-vulnerabilities -s /var/tmp/pkg-vulnerabilities-testpkg_admin: unable to verify signature: Signature on data did not match
Add these checks to your automated reports to ensure you aren’t being lied to about possible vulnerabilities.
Reduced Package REQUIRES
Each package lists the libraries that it requires, and those are checked prior to installation to ensure the package will work correctly on the target host. Recently we’ve seen a few issues where some illumos distributions have moved platform libraries to a different location (but still in the default search path), which means the
REQUIRES no longer match and the package won’t install.
From 2014Q4 we have reduced the way that
REQUIRES are computed. Previously every library that was pulled in was recorded, essentially using the output of
ldd, so for example with the
libpcap package you end up with:
$ pkg_info -Q REQUIRES libpcap/lib/libavl.so.1/lib/libc.so.1/lib/libcurses.so.1/lib/libdevinfo.so.1/lib/libdladm.so.1/lib/libdlpi.so.1/lib/libgen.so.1/lib/libinetutil.so.1/lib/libkstat.so.1/lib/libm.so.2/lib/libmd.so.1/lib/libmp.so.2/lib/libnsl.so.1/lib/libnvpair.so.1/lib/libpthread.so.1/lib/librcm.so.1/lib/libscf.so.1/lib/libsec.so.1/lib/libsocket.so.1/lib/libumem.so.1/lib/libuutil.so.1/lib/libxml2.so.2/lib/libz.so.1/opt/local/gcc47/i386-sun-solaris2.11/lib/./libgcc_s.so.1/usr/lib/libexacct.so.1/usr/lib/libidmap.so.1/usr/lib/libpool.so.1/usr/lib/libsmbios.so.1
In 2014Q4 we have stopped using
ldd to resolve the library dependencies, and instead use
elfdump to only look at the
NEEDED entries that are recorded in the
SHT_DYNAMIC section for each executable. This results in a much simpler and direct list:
$ pkg_info -Q REQUIRES libpcap/lib/libc.so.1/lib/libdlpi.so.1/lib/libnsl.so.1/lib/libsocket.so.1/lib/libumem.so.1/opt/local/gcc47/i486-sun-solaris2.11/lib/./libgcc_s.so.1
due to excluding all of
/lib/libdlpi.so.1’s dependencies, and increases the portability of our packages across illumos distributions.
We also get a side benefit of being able to easily identify packages which are incorrectly linking against system versions of e.g.
libxml2.so.2 when they should instead be using the pkgsrc version.
There is the usual grab bag of updates in 2014Q4/14.4.x:
go-1.4.2now includes Keith Wesolowski’s patches to add support for cgo. This brings Go for illumos up to feature parity with other operating systems and increases the amount of Go software that will build and run.
SmartOS 14.4.x images now deliver an SSL bundle in
/etcwhich makes Go work correctly, and we also ensure that
/usr/bin/curlhas access to certificates.
libgohas been removed from the
gcc47-libspackage. It is unused, and doing this saves 40MB from the bootstrap kits and images.
We now build with cwrappers, as detailed in my performance post. This speeds up the builds a lot, so in the event of another Heartbleed we should be able to deliver updated packages a lot faster.
pkginis now at version 0.8.0 including support for the new
preferred.conf, plus a number of important bug fixes.
A number of small internal improvements to the build infrastructure. As a user you shouldn’t notice any changes, if you do please let us know!
Plus all the usual upstream pkgsrc changes as announced here.
As always, please raise a GitHub issue if you run into any problems or have any suggestions on ways we can improve any of this stuff.
Post written by Jonathan Perkin