Make SigningInstructions public

[cholcombe973]

Motivation and Context

I'm building an s3 server in rust and I need signature verification to work from the server side when receiving requests. To do that the server needs to generate a signature and then compare it to the one that the client has already sent along. I believe that the sign module in aws-sigv4 http_request contains the functions required to do that.

Description

Exported the SigningInstructions struct in the sign module of http_request for aws-sigv4.

Testing

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[jdisanti]

Why can't you just use the aws_sigv4::http_request::sign method? Example here: https://docs.rs/aws-sigv4/0.55.3/aws_sigv4/http_request/index.html

The SigningOutput gives you access to just the signature string if that's all you need: https://docs.rs/aws-sigv4/0.55.3/aws_sigv4/struct.SigningOutput.html#method.signature

[cholcombe973]

Well I wanted to return the signing instructions from the function and I can't complete the function signature because SigningInstructions is private. I should probably elaborate a little more. I have a custom Request Body that I don't think will inter opt properly with the aws libraries so I'm trying to do a little hack where I return the signing instructions and then apply those to my Request later. It's likely this wasn't the intended use for these functions haha.

[jdisanti]

I see. I think the correct fix would be to add SigningInstructions to the export here: https://github.com/awslabs/smithy-rs/blob/b023426d1cfd05e1fd9eef2f92a21cad58b93b86/aws/rust-runtime/aws-sigv4/src/http_request/mod.rs#L59

We probably just missed that during initial implementation since I guess it works if you only need to call a function on that returned value rather than name it.

[cholcombe973]

Thanks! I'll do that in the morning

[cholcombe973]

@jdisanti I pushed that update.

[jdisanti]

Looks good. Could you also update the PR description/title and add an entry to CHANGELOG.next.toml for [[aws-sdk-rust]]?

[jdisanti]

Looks good. I'll apply a couple minor changes and get this merged. Thank you!

[cholcombe973]

@jdisanti did you want me to update the docs for the SigningInstructions as well? It looks like that's what most of these test breakages are about.

[jdisanti]

That would be great!