Add AWS request signing callback

[jaguililla]

Create an HTTP callback to sign HTTP requests using the AWS signing request algorithm.

Callbacks already developed in the http/http_server module (on the com/hexagonkt/http/server/callbacks package) can be used as reference for development and testing of such components.

There is also an example of a callback used in the HTTP client as opposed to the callbacks used in the server (the class name is com.hexagonkt.rest.SerializeRequestCallback).

Note that the callback should be of before type and to pass the modified request, the request method should be used instead send.

The callback should be added to the http/rest_tools module on the com.hexagonkt.rest.tools.aws package.

A previous Java implementation can be checked at: https://github.com/jaguililla/sabina/blob/master/bali/src/main/java/co/there4/bali/Aws.java

The callback must pass the most of the AWS signing V4 Test Suite cases, and at least implement the tests included here: https://github.com/jaguililla/sabina/tree/master/bali/src/test/resources/aws-sig-v4-test-suite

Previous Java implementation tests can be found at: https://github.com/jaguililla/sabina/blob/master/bali/src/test/groovy/co/there4/bali/AwsTest.groovy

For information on how to build the project and pass the tests please refer to the contributing guide.

If you have any question or suggestion, please feel free to use this issue's comments to discuss them 🙂

[manuelkour]

Hi! I'd like to work on this issue if it's still up to grab.

[jaguililla]

Absolutely, it's all yours. I'll update the task's status.

Thanks for your cooperation and if you need anything, just write me :)

[manuelkour]

I have a question regarding some of the parameters required to sign an AWS request. (This is the reference from the AWS documentation I've been following so far.)
To calculate the signing key, the AWS (secret) access key, region and service are required. Are we expecting the HttpContext passed to the callback to contain these or in what other way could this be done?
If there's a misunderstanding on how the callback is supposed to work, could you please show me to the correct part in the documentation to read up on this?
Thanks in advance!

[jaguililla]

Ok, as the callback is a class. Could you pass those values as parameters in the constructor?

The user then will be forced to supply values for those parameters at callback instantiation time (at the application start up or routing definition).

The user could fetch those values from environment, configuration files, etc. before passing them to the callback (decoupling the AWS signing from the configuration/environment).

What do you think? does this make sense to you?

[manuelkour]

Passing it to the constructor makes it easy then, thanks!

[jaguililla]

Hello, the Hexagon GitHub organization has been renamed to https://github.com/hexagontk. You will need to change your local clone remotes to reflect this change. Thanks and sorry for the inconvenience.