LetsEncrypt announced its new "Generation Y" root hierarchy on
2025-11-24 and switched its default ACME profile to issue from the new
roots in May 2026. Our baked-in fallback root store only contained the
Generation X roots (ISRG Root X1 and X2), so chains terminating at the
new ISRG Root YE (ECDSA P-384) or ISRG Root YR (RSA 4096) roots failed
to verify when the system roots were also missing them.
Add both new self-signed roots, fetched from
https://letsencrypt.org/certificates/ (valid 2025-09-03 to 2045-09-02).
Also add a live network test, run by default in CI only (or with
--run-live-lets-encrypt-test), that verifies the baked-in roots alone
are sufficient to validate LetsEncrypt's per-root test endpoints for
X1, X2, YE, and YR.
Fixes#20527
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: Ic69076d8ae5aae08db167095745e92c53357afe3
This file was never truly necessary and has never actually been used in
the history of Tailscale's open source releases.
A Brief History of AUTHORS files
---
The AUTHORS file was a pattern developed at Google, originally for
Chromium, then adopted by Go and a bunch of other projects. The problem
was that Chromium originally had a copyright line only recognizing
Google as the copyright holder. Because Google (and most open source
projects) do not require copyright assignemnt for contributions, each
contributor maintains their copyright. Some large corporate contributors
then tried to add their own name to the copyright line in the LICENSE
file or in file headers. This quickly becomes unwieldy, and puts a
tremendous burden on anyone building on top of Chromium, since the
license requires that they keep all copyright lines intact.
The compromise was to create an AUTHORS file that would list all of the
copyright holders. The LICENSE file and source file headers would then
include that list by reference, listing the copyright holder as "The
Chromium Authors".
This also become cumbersome to simply keep the file up to date with a
high rate of new contributors. Plus it's not always obvious who the
copyright holder is. Sometimes it is the individual making the
contribution, but many times it may be their employer. There is no way
for the proejct maintainer to know.
Eventually, Google changed their policy to no longer recommend trying to
keep the AUTHORS file up to date proactively, and instead to only add to
it when requested: https://opensource.google/docs/releasing/authors.
They are also clear that:
> Adding contributors to the AUTHORS file is entirely within the
> project's discretion and has no implications for copyright ownership.
It was primarily added to appease a small number of large contributors
that insisted that they be recognized as copyright holders (which was
entirely their right to do). But it's not truly necessary, and not even
the most accurate way of identifying contributors and/or copyright
holders.
In practice, we've never added anyone to our AUTHORS file. It only lists
Tailscale, so it's not really serving any purpose. It also causes
confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header
in other open source repos which don't actually have an AUTHORS file, so
it's ambiguous what that means.
Instead, we just acknowledge that the contributors to Tailscale (whoever
they are) are copyright holders for their individual contributions. We
also have the benefit of using the DCO (developercertificate.org) which
provides some additional certification of their right to make the
contribution.
The source file changes were purely mechanical with:
git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g'
Updates #cleanup
Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>
We previously baked in the LetsEncrypt x509 root CA for our tlsdial
package.
This moves that out into a new "bakedroots" package and is now also
shared by ipn/ipnlocal's cert validation code (validCertPEM) that
decides whether it's time to fetch a new cert.
Otherwise, a machine without LetsEncrypt roots locally in its system
roots is unable to use tailscale cert/serve and fetch certs.
Fixes#14690
Change-Id: Ic88b3bdaabe25d56b9ff07ada56a27e3f11d7159
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Brad FitzpatrickandBrad Fitzpatrick
Will NorrisandWill Norris