AWS CLI 2.24 - Headers are being created differently depending on endpoint-url

[amit-ecovoice]

Hi All - Apologize for the long post here. We have RUST based application which is nothing but a S3 data proxy layer.
Everything has been running fine until CLI version 2.22. In 2.23+ , we are not able to upload files (put object) and we are receiving 401 Unauthorized error on this CI version.
If I use environment variable export AWS_REQUEST_CHECKSUM_CALCULATION=WHEN_REQUIRED , then it works . Seems like it behaves like old version in that case.

attached are the debug logs in both scenario and test file we are trying to upload is small 2 KB file.

RUST application is open source in case you want to look at the code - https://github.com/source-cooperative/data.source.coop/tree/main. This application runs on ECS.

Another weird fact is - when we run same application locally with exact same code, upload works as is. With same CLI, without setting environment variable, same command (except the endpoint-url changed to local proxy) works fine . debug logs are as attached for that one.
local_withoutEnvVariable_Success.txt
prod_withEnvVariable_Success.txt
prod_withoutEnvVariable_Fail.txt

[amit-ecovoice]

this is similar to what others are also facing - #9214