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>
a64ca7a5b4