sha1 hmac hexdigest signature

sha1_dgst_main.go

package main

import (
	"crypto/hmac"
	"crypto/sha1"
	"crypto/subtle"
	"encoding/hex"
	"fmt"
	"os"
)

func generateSignature(secretToken, payloadBody string) string {
	mac := hmac.New(sha1.New, []byte(secretToken))
	mac.Write([]byte(payloadBody))
	expectedMAC := mac.Sum(nil)
	return "sha1=" + hex.EncodeToString(expectedMAC)
}

func verifySignature(secretToken, payloadBody string, signatureToCompareWith string) bool {
	signature := generateSignature(secretToken, payloadBody)
	return subtle.ConstantTimeCompare([]byte(signature), []byte(signatureToCompareWith)) == 1
}

func main() {
	testPayloadBody := `{"message":"test content"}`
	testSignatureToCompareWith := `sha1=33a08e9b5e9c8d5e944d9288e9b499abb298344d`

	fmt.Println("signature match? :", verifySignature(os.Getenv("SECRET_TOKEN"), testPayloadBody, testSignatureToCompareWith))
}