Implemented from RFC4960 with test vectors from RFC3720. Bug: webrtc:12614 Change-Id: If03a41d1ac4acecc3e5840c015878df271b14a1b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/213344 Commit-Queue: Victor Boivie <boivie@webrtc.org> Reviewed-by: Tommi <tommi@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33606}