Unfortunately the golang.org/x/crypto/acme/autocert caching strategy is not
compatible with the SPIRE server KeyManager interface.
As such, golang.org/x/crypto/acme/autocert has been forked and modified to
facilitate key management via the KeyManager while still using the Cache to
store certificates. The specific changes are documented below the copyright in
autocert/autocert.go.
The golang.org/x/crypto/acme/autocert/acmetest package has also been forked for
use in unit-testing. It has been enhanced to provide some extra features for
deeper test coverage. The specific changes are documented below the copyright in
acmetest/ca.go.
Both packages were forked from the following go module:
golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4