Since last I wrote, I’ve been experimenting with Amazon Echo skills.

Getting the skill working for personal use wasn’t very difficult. Having a skill published to the whole world is more involved, because you have to pass their certification testing.

I’m not quite there yet, and I’m not really sure what I’m doing wrong.My first attempts to address the problems found in the certification phase have led to this: https://github.com/rbowen/validate-echo-request-php

That’s a PHP function that handles the validation of the request certificate, timestamp, and various other things that are part of the request. However, apparently I’m not validating the certificate correctly just yet, as the latest feedback was:

1. The skill does not validate the signature for the incoming requests and is accepting requests with invalid signature specified. Please refer to the document that describes how to build your Alexa Skill as a web service (available via this link: https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/developing-an-alexa-skill-as-a-web-service ) for tips and requirements about validating the requests (and their signatures) sent to your web service.

Furthermore, I can’t find anywhere in the documentation what you’re supposed to return on failure, so perhaps that’s what I’m doing wrong.

On the other hand, all of the skills that I’ve written work just fine for me, in developer mode, I just can’t show them to anybody else.