Auth/signature problem with Aws_sdb

[smondet]

With this:

let region = "us-east-1" in
let access_key =  env_exn "AWS_KEY_ID" in
let secret_key =  env_exn "AWS_SECRET_KEY" in
Aws_lwt.Runtime.run_request
  ~region ~access_key ~secret_key
  (module Aws_sdb.CreateDomain)
  (Aws_sdb.Types.CreateDomainRequest.make
     ~domain_name:"smondet-test" ())

I get

HttpError(401 - AwsError): [AuthFailure: AWS was not able to authenticate the request: access credentials are missing]

but the exact same credentials work well with the Aws_ec2 module.

And with AWS-CLI: aws sdb create-domain --domain-name smondet-test0 also works.

---

Aws.sign_request
seems to be using “Version 4” of the protocol.

And issue aws/aws-sdk-cpp#372
says that SDB is using “Version 2”?

And this doc
http://docs.aws.amazon.com/AmazonSimpleDB/latest/DeveloperGuide/HMACAuth.html
seems to confirm:

This section describes how to create the signature. The method described in
the following procedure is known as signature version 2, and uses the
HMAC-SHA256 signing method.