AWS API calls

This question is about calling AWS REST APIs. Based on:

http://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html

AWS requires REST clients to call their APIs using Signature Version 4 which in case you don't know what I am talking about is a pain in the neck.  Here comes the question:

Has anybody, by any chance implemented the v4 signing alg. in COS? If yes, would she or he have the kind heart to share?

Thanks,

Chris