Generate Microsoft Azure Storage account shared access signature with Golang

azure_sas.go

package main

import (
    "crypto/hmac"
    "crypto/sha256"
    "fmt"
    "encoding/base64"
    "strings"
)

const (
  AZURE_ACCOUNT_NAME    = "",
  AZURE_ACCESS_KEY      = "",
  AZURE_CONTAINER_NAME  = "",
  
)

func main() {
  blob := fmt.Sprintf("/%s/%s/%s", AZURE_ACCOUNT_NAME, AZURE_CONTAINER_NAME, "filename.jpg")
  sA := []string{"r", // permissions
                 "", 
                 "2019-02-10T00:00:00Z", // expiry time
                 blob, 
                 "", 
                 "2019-02-09", // API version
                 "", "", "", "", ""}
  toSign := strings.Join(sA, "\n")
  decodingAccessKey, _ := base64.StdEncoding.DecodeString(AZURE_ACCESS_KEY)
  h := hmac.New(sha256.New, []byte(decodingAccessKey))
  h.Write([]byte(toSign))
  signature := base64.StdEncoding.EncodeToString(h.Sum(nil))
  fmt.Println("s: " + signature)
}