During testing with a region on us-west-2 I kept getting a signature mismatch error. Using the endpoint s3-us-west-2.amazonaws.com fixed the issue. Also according to the docs I think the s3.amazonaws.com endpoint is only valid for us-east-1. Why there isn't a s3-us-east-1.amazonaws.com endpoint is beyond me.
During testing with a region on us-west-2 I kept getting a signature mismatch error. Using the endpoint s3-us-west-2.amazonaws.com fixed the issue. Also according to the docs I think the s3.amazonaws.com endpoint is only valid for us-east-1. Why there isn't a s3-us-east-1.amazonaws.com endpoint is beyond me.