如何在 ASP.Net Core Mvc 应用程序中验证 Slack Events API 请求 URL？

Question

I'm working on Slack integration in an ASP.Net Core MVC 2 application.

I have done it for Searching and Posting messages to Slack channels. Now I'm stuck at integrating Events API in this application. Basically, at the moment I'm not able to verify my Request Url as mentioned here Events API Subscription

Following is my action method that we have give to Slack where they will send the verification json object which will be mapped to request parameter of my action and is as follows:

{
"token": "Jhj5dZrVaK7ZwHHjRyZWjbDl",
"challenge": "3eZbrw1aBm2rZgRNFdxV2595E9CY3gmdALWMmHkvFXO7tYXAYM8P",
"type": "url_verification"
}

[HttpPost]
    public IActionResult Event(EventsRequest request)
    {
        if (request != null)
        {
            if (request.type.Equals("url_verification"))
                return Content(request.challenge);
            else
                ViewBag.Challenge = request.challenge;
        }
        return View();
    }

Here is my EventsRequest class:

public class EventsRequest
{
    public string token { get; set; }
    public string challenge { get; set; }
    public string type { get; set; }
}

I have deployed this application locally on IIS and have applied InBound rules to make it accessible publicly and it is accessible. But issues arise when I give the following URL to Slack for verification:

http://IP_Address/Slack/Event

Following is the screenshot of the response that Slack gives

Can someone tell what's wrong here? I tried to hit this URL with Postman and I was able to get the desired results.

Answer 1

You can try these:

1. As suggested in https://api.slack.com/events-api#subscriptions

Your Event Request URL must be confirmed before saving this form. If your server takes some time to "wake up" and your initial attempt at URL verification fails due to a timeout, use the retry button to attempt verification again.

If it fails at first attempt make sure server is up & running and try next time.

2. After you've completed typing your URL, we'll dispatch a HTTP POST to your request URL. We'll verify your SSL certificate and we'll send a application/json POST body containing three fields:

   { "token": "Jhj5dZrVaK7ZwHHjRyZWjbDl", "challenge": "3eZbrw1aBm2rZgRNFdxV2595E9CY3gmdALWMmHkvFXO7tYXAYM8P", "type": "url_verification" }

You need to replace example json with the real values generated for you url configuration and verification.

Make sure url for verification is set correctly before generating challenge and is not changed afterwards.

3. Make sure no mismatch in url scheme like http in one place and https at other.

Try adding from body in post request:

[HttpPost]
public IActionResult Event([FromBody]EventsRequest request)