Golang 实现sha256 加密

先贴出PHP代码：

$string = "1234";
$key = "abcd";
$signature = hash_hmac('sha256', $string, $key);

然后是Golang：

package main

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

func main() {
	s := []byte("1234")
	key := []byte("abcd")
	m := hmac.New(sha256.New, key )
	m.Write( s )
	signature := hex.EncodeToString(m.Sum(nil))
	fmt.Print(signature + "\n\r")
}

得出签名都是：d219a3dd877f943be0ee65ef6a34129778d2fd0568ce2d9a8f37fea9d7fcaca3