Less of an issue with Postman, but a question to whether, by using Postman, I’d be able to see the calculated AWS Canonical request.
Out of the few tools I’ve used that offer AWS authentication methods, Postman has been the only one that has successfully matched the signature. I’d like to use Postman’s canonical request as reference.
Hi @marchap,
You can see how Postman does this here: https://github.com/postmanlabs/postman-runtime/blob/c18367f75b6aeed8950daee5183e5db76477caa7/lib/authorizer/aws4.js#L223.
Much of this is actually coming from the aws4 module on npm. You can see the code here: https://github.com/mhart/aws4/blob/master/aws4.js.
Unfortunately, I don’t think there’s a way to get access to the canonical request before it’s converted into an HMAC digest. Since it’s a hash code (not encrypted text), you can’t reverse-engineer the signature. I’d look at the code in these libraries and see if you can produce something locally that reliably gives you what you’re seeking.
Best,
Kevin