I earlier thought this saved a second of CPU even on a fast machine,
but I think when I was previously measuring, I still had a 4096 bit
RSA key being generated in the code I was measuring.
Measuring again for this, it's plenty fast.
Prep for using this package more, for derp, etc.
Updates #16315
Change-Id: I4c9008efa9aa88a3d65409d6ffd7b3807f4d75e9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If you had HTTPS_PROXY=https://some-valid-cert.example.com running a
CONNECT proxy, we should've been able to do a TLS CONNECT request to
e.g. controlplane.tailscale.com:443 through that, and I'm pretty sure
it used to work, but refactorings and lack of integration tests made
it regress.
It probably regressed when we added the baked-in LetsEncrypt root cert
validation fallback code, which was testing against the wrong hostname
(the ultimate one, not the one which we were being asked to validate)
Fixes#16222
Change-Id: If014e395f830e2f87f056f588edacad5c15e91bc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>