Mostly cribbed from encoding/asn1.parseUTCTime. Fixes golang/go#45411 Change-Id: I6c6ab2a2ad7c05a7f8bd81ecce4fcbb4e608e8db Reviewed-on: https://go-review.googlesource.com/c/crypto/+/273286 Trust: Roland Shoemaker <roland@golang.org> Trust: Katie Hockman <katie@golang.org> Run-TryBot: Roland Shoemaker <roland@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Katie Hockman <katie@golang.org>