Add support for encryption on objects uploaded to S3

Our S3 bucket has a policy that forces AES (or KMS) encryption on all uploaded objects. This means that the current version of sleet doesn’t work as it doesn’t specify encryption.

As for the solution, I’ve got it working for our AES encryption case by adding ServerSideEncryptionMethod = ServerSideEncryptionMethod.AES256 to:

https://github.com/emgarten/Sleet/blob/d19f2eaf4ae02e6ab1262462312342d490afaa62/src/SleetLib/FileSystem/AmazonS3FileSystemAbstraction.cs#L26-L31

and

https://github.com/emgarten/Sleet/blob/d19f2eaf4ae02e6ab1262462312342d490afaa62/src/SleetLib/FileSystem/AmazonS3FileSystemAbstraction.cs#L131-L139

but of course it needs to be configurable.

However, there are a lot of possible options that as you can see in the AWS docs.

I can submit a PR tomorrow probably, are you happy if it just supports AES for now and throws for any of the other options? So the user could only specify AES256 or None (current behaviour which would stay the default).

[mungojam]

I don’t forsee needing other request options for myself in future as I now have it working with just that one, so up to you if you want to leave it open for other options in a nested structure.

I probably won’t get back to this till next weekend by the way. It’s a bit of a side project. I’m trying to do the same for python at the same time but that has other complications 🙂

[emgarten]

I don’t forsee needing other request options for myself in future as I now have it working with just that one, so up to you if you want to leave it open for other options in a nested structure.

Top level would be fine then. I appreciate the PRs 😄