Golang Verify Slack

working_verify_slack.go

package middlewares

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"

	"github.com/gin-gonic/gin"
)

const (
	signingKey = "SLACK_SECRET_HERE"
)

// VerifySlackMiddleware is responsible for verifying the X-Slack-Signature
// in a request against our secret.
func VerifySlackMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		rTimestamp := c.Request.Header.Get("X-Slack-Request-Timestamp")
		expectedSig := c.Request.Header.Get("X-Slack-Signature")
		rawBody, err := c.GetRawData()
		if err != nil {
			c.AbortWithStatusJSON(502, gin.H{"text": "Unexpected error."})
		}

		sigBaseString := "v0:" + rTimestamp + ":" + string(rawBody)

		h := hmac.New(sha256.New, []byte(signingKey))
		h.Write([]byte(sigBaseString))
		computedSig := "v0=" + hex.EncodeToString(h.Sum(nil))

		if expectedSig != computedSig {
			c.AbortWithStatusJSON(401, gin.H{"text": "You shall not pass."})
		}

		c.Next()
	}
}

did it work ?