aws-sdk-ruby: S3 presigned urls using response_expires convert values to ISO8601 instead of http-date

Confirm by changing [ ] to [x] below to ensure that it’s a bug:

• I’ve gone though Developer Guide for v3 and API reference
• I’ve checked AWS Forums and StackOverflow for answers
• I’ve searched for previous similar issues and didn’t find any solution

Describe the bug

For S3 presigned URL generation, supplying the response_expires param will result in a presigned URL asking for a response-expires value in iso8601 format, which results in a subsequent S3 response with an HTTP Expires header with a value in ISO8601 format. Eg, 2015-10-21T07:28:00Z.

This is not a legal value for the Expires header, which should be in http-date format instead. Eg Wed, 21 Oct 2015 07:28:00 GMT

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Expires

Gem name (‘aws-sdk’, ‘aws-sdk-resources’ or service gems like ‘aws-sdk-s3’) and its version

aws-sdk-s3 1.81.1

Version of Ruby, OS environment

ruby 2.6.6p146 (2020-03-31 revision 67876) [x86_64-darwin19]

To Reproduce (observed behavior)

bucket.object(object_key).presigned_url(:get, response_expires: "Wed, 21 Oct 2015 07:28:00 GMT")

This results in a presigned URL which has in it the query param response-expires=2015-10-21T07%3A28%3A00Z

When this URL is requested from s3, the response has a header Expires: 2015-10-21T07:28:00Z

Expected behavior

The response-expires query in the generated URL, which is used to create the signature as well, should be in http-date format, not ISO8601 format. The query param for above example should look instead like: response-expires=Wed%2C%2021%20Oct%202015%2007%3A28%3A00%20GMT

In order to result in a response from S3 with a standards-compliant Expires header that will be interpreted by user-agents as intended, Expires: Wed, 21 Oct 2015 07:28:00 GMT