(from patchset 1, c12c890c64dd6372b3893af1e6f5ab11802c9e81, of
https://go-review.googlesource.com/c/go/+/230025/1, with merges fixes
due to parent commit's differents from its ps1..ps3)
Instead of parsing the PEM files and then storing the *Certificate
values forever, still parse them to see if they're valid and pick out
some fields, but then only store the decoded pem.Block.Bytes until
that cert is first needed.
Saves about 500K of memory on my (Debian stable) machine after doing a
tls.Dial or calling x509.SystemCertPool.
A more aggressive version of this is still possible: we can not keep
the pem.Block.Bytes in memory either, and re-read them from disk when
necessary. But dealing with files disappearing and even large
multi-cert PEM files changing (with offsets sliding around) made this
conservative version attractive. It doesn't change the
slurp-roots-on-startup semantics. It just does so with less memory
retained.
Change-Id: I3aea333f4749ae3b0026042ec3ff7ac015c72204
(from patchset 1, 7cdc3c3e7427c9ef69e19224d6036c09c5ea1723, of
https://go-review.googlesource.com/c/go/+/229917/1)
This will allow building CertPools that consume less memory. (Most
certs are never accessed. Different users/programs access different
ones, but not many.)
This CL only adds the new internal mechanism (and uses it for the
old AddCert) but does not modify any existing root pool behavior.
(That is, the default Unix roots are still all slurped into memory as
of this CL)
Change-Id: Ib3a42e4050627b5e34413c595d8ced839c7bfa14
Snapshotted from Go commit 619c7a48a38b28b521591b490fd14ccb7ea5e821
(https://go-review.googlesource.com/c/go/+/229762,
"crypto/x509: add x509omitbundledroots build tag to not embed roots")
With 975c01342a25899962969833d8b2873dc8856a4f
(https://go-review.googlesource.com/c/go/+/220721) removed, because it
depends on other stuff in Go std that doesn't yet exist in a Go
release.
Also, add a subset fork of Go's internal/testenv, for use by x509's tests.
