blog: SLSA Build L3 for Eclipse Temurin (#2524)

* blog: SLSA Build L3 for Eclipse Temurin

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Update with references to GPG blog

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Update with SBoM download information

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Placate linter

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Update content/blog/slsabuild3-temurin/index.md

Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

* Define SBoM

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Update publish date on blog to Tuesday 9th Jan

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Adjustments since we are posting in 2024

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* Add detail on the SHA being in the components section of the SBoM

Signed-off-by: Stewart X Addison <sxa@redhat.com>

* January 2024 GA - and beyond

Signed-off-by: Stewart X Addison <sxa@redhat.com>

---------

Signed-off-by: Stewart X Addison <sxa@redhat.com>
Co-authored-by: Tim Ellison <tellison@users.noreply.github.com>

content/blog/slsabuild3-temurin/index.md

@@ -0,0 +1,112 @@
+---
+title: SLSA build level 3 compliance on Linux and macOS for Eclipse Temurin
+date: "2024-01-09T17:00:00+00:00"
+author: sxa
+description: Eclipse Temurin by Adoptium is compliant with build level 3 of the SLSA 1.0 secure development framework on Linux and macOS.
+tags:
+  - temurin
+  - security
+---
+
+## Introduction
+
+Supply-chain Levels for Software Artifacts, or [SLSA](https://slsa.dev), is a framework with individual levels that software
+producers can work towards to make their software more secure, and consumers
+can use to make decisions based on the software package’s security posture.  The
+Adoptium project has worked closely with the Eclipse Foundation security
+team to work towards making the Eclipse Temurin compliant with the SLSA
+specification's build requirements.
+
+[At the end](https://adoptium.net/blog/2022/11/slsa2-temurin/)
+[of 2022](https://newsroom.eclipse.org/eclipse-newsletter/2022/december/eclipse-temurin-slsa-level-two-compliant)
+we achieved compliance with level 2 of the SLSA v0.1 specification.  In
+April 2023 SLSA version 1.0 was released and split the specification into
+multiple "tracks", of which the build track is the only one currently
+published.  If you're not familiar with the changes, check out
+[this lightning talk](https://youtu.be/uLXzyutZEmQ?si=XjD9H6uO_GEjJVBG) from one
+of my colleagues.  We have been able to build on our work done previously to
+meet build level 3 for Linux and macOS for Eclipse Temurin's build and
+distribution.
+
+## What have you done since declaring SLSA level 2?
+
+We have built on top of the work covered in the earlier blog to meet the
+requirements of SLSA build level 3. The additional requirements were as
+follows:
+
+### Prevent runs from influencing one another, even within the same project
+
+In order to achieve independence between build runs, we perform all of our
+Linux builds in Docker containers. These containers are instantiated, the
+build is run and the results saved, and then we shut down the container.
+This way there can be no influencing from caching or from one run impacting
+a subsequent one.
+
+We have implemented a comparable system on macOS by using
+[MacStadium's Orka](https://www.macstadium.com/orka) which allows us to dynamically spin up virtual machines for each
+build run to give us a comparable level of isolation.
+
+For other operating systems that we build on - Windows, AIX and Solaris - we
+are not currently set up to do something equivalent which is why we are not
+claiming SLSA build level 3 for those builds.
+
+### Verifying provenance artifacts
+
+We have introduced a build verification step which can take the Software
+Bill of Materials (SBoM) produced as part of the build output and verify its
+contents as far as is practical.  This will do some checks to ensure that
+the fields are valid and match expectations about how the product has been
+built.  This job is stored in
+https://github.com/adoptium/temurin-build/blob/master/tooling as
+release_download_test.sh which performs SHA and GPG checks as well as
+running some basic checks on the downloads.  It also calls
+validateSBOMcontent.sh to check the SBoM contents to make sure the
+dependencies, including compilers, listed in there match expectations.  The
+SBoM contents now also includes the SHA256 checksums of all of the build
+artifacts in the `components` section.  There is information on
+programatically verifying the GPG signatures in
+[an earlier blog](https://adoptium.net/blog/2022/07/gpg-signed-releases/)
+
+In addition to all these checks we also verify after each build that the
+build code has the features enabled that it should have. This is done using
+a custom AQA test job called "smoke tests" which use the tests in the build
+repository in the
+[buildAndPackage](https://github.com/adoptium/temurin-build/tree/master/test/functional/buildAndPackage)
+directory and test various aspects of the built JDK If these checks fail
+then these will be trapped early on.
+
+We expect that all of these checks will be enhanced over time, particularly
+as we add more details into the SBoM.
+
+The current SBoM can be downloaded via the adoptium API.  If you are already
+familiar with the API for downloading JDKs, then replacing `jdk` with `sbom`
+in the URL will let you download the SBoM. For example, this will download
+the latest GA SBoM for Temurin 21 on Linux/x64:
+
+- https://api.adoptopenjdk.net/v3/binary/latest/21/ga/linux/x64/sbom/hotspot/normal/adoptopenjdk?project=jdk
+
+Note that there is an enhanced version of the SBoM which includes more
+details on the artifacts that is already in the nightly builds and will be
+included for the January 2024 GA releases and beyond.  We will not (and
+should not) regenerate the SBoM for older releases.
+
+### Prevent secret material used to sign the provenance from being accessible to user-defined build steps
+
+The signing jobs that we use are all contained within our Jenkins CI system.
+These are independent of the build jobs and run as a
+subsequent step to avoid the credentials ever being available to the build
+jobs.
+
+## What's in the future?
+
+At the moment SLSA build level 3 is the highest level available. We will
+look to keep up to date as updates to the specification are made available.
+We expect a "level 4" on the build track, and also other tracks to cover
+source code.
+
+We are also continuing to work on our [reproducible builds](https://adoptium.net/blog/2023/09/Reproducible-Comparison-Builds/) which gives an
+extra layer of confidence that any customers of Temurin are able to rebuild
+from source code in order to independently verify that nothing in our build
+systems have been tampered with or introduced any unexpected code.  Anyone
+(yes, even you!) can use our fully open-source setup and build scripts to
+rebuild the Temurin JDK, and we encourage you to give it a try!