Sign x-amz-content-sha256 header

[Serzh470]

Hi!

I've tried to use evaporate to upload files from django admin (inside django-s3direct package) and have faced the problem, that request header x-amz-content-sha256 is not signed. Is any solutions to add it via evaporate interface?

server response is

<?xml version="1.0" encoding="UTF-8"?>
<Error>
  <Code>AccessDenied</Code>
  <Message>There were headers present in the request which were not signed</Message>
  <Resource>/osite-test/uploads/videos/BigBuck.mp4?uploads</Resource>
  <RequestId>e14d24f1175a9e69</RequestId>
  <HeadersNotSigned>x-amz-content-sha256</HeadersNotSigned>
</Error>

[Serzh470]

I've solved it with adding a line

addHeader('x-amz-content-sha256',  this.getPayloadSha256Content());

in method AwsSignatureV4.prototype.canonicalHeaders, but maybe there is a smater way to fix it.