s3proxy - proxy with encryption

Modified https://github.com/abustany/s3proxy

See changes

INFO: Multipart uploads are not supported. It's difficult to encrypt separate parts, instead of whole unencrypted file, and decrypt file back in original consistent state. Looks like it's a big challenge for now. Maybe later there will be a solution for this problem.

How to build and run s3proxy

signature_v4 - examples of code for AWS signature V4

Additional information:

https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_sigv-create-signed-request.html

https://github.com/mhart/aws4/tree/master?tab=readme-ov-file