Cloud AWS client side encryption

[GlenRSmith]

See elasticsearch-cloud-aws PR 118 from @NicolasTr
elastic/elasticsearch-cloud-aws#118

[NicolasTr]

Thanks for creating this @GlenRSmith

I'll port the code as soon as I can. Hopefully this month, more realistically somewhere in November.

Did the structure of the project change when the cloud aws plugin was moved to elasticsearch?

@dadoonet

[xuzha]

@NicolasTr Yes, thecloud-awsplugin has been split into two separate plugins : repository-s3 and discovery-ec2. I think this PR is only related to Repository-s3.

[dadoonet]

@NicolasTr IIRC you told us that you want to port your changes to this repository. Is it still your plan? Thanks!

[samcday]

It's kinda a bummer that by the looks of things @NicolasTr had a totally functional, reviewed, tested PR that was even run through the CLA gauntlet, and it didn't end up making it into the project! :(

[xuzha]

The PR has been reverted, reopen this