Go实战--go中使用hmac sha256(The way to go)

声明不止，继续 go go go !!!

上一篇blog介绍了base64加密，今天继续介绍一下关于加密方面的实战应用，也就是hmac sha256.

何为hmac？

wiki：
In cryptography, a keyed-hash message authentication code (HMAC) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key.

百度百科：
HMAC是**相关的哈希运算消息认证码，HMAC运算利用哈希算法，以一个**和一个消息为输入，生成一个消息摘要作为输出。

主要用于验证接口签名~

何为sha256？

哈希值用作表示大量数据的固定大小的唯一值。数据的少量更改会在哈希值中产生不可预知的大量更改。
SHA256 算法的哈希值大小为 256 位。

crypto/hmac

Package hmac implements the Keyed-Hash Message Authentication Code (HMAC) as defined in U.S. Federal Information Processing Standards Publication 198. An HMAC is a cryptographic hash that uses a key to sign a message. The receiver verifies the hash by recomputing it using the same key.

func New

func New(h func() hash.Hash, key []byte) hash.Hash

New returns a new HMAC hash using the given hash.Hash type and key.

crypto/sha256

Package sha256 implements the SHA224 and SHA256 hash algorithms as defined in FIPS 180-4.

func New

func New() hash.Hash

New returns a new hash.Hash computing the SHA256 checksum.

使用：

package main

import (
    "crypto/sha256"
    "fmt"
)

func main() {
    h := sha256.New()
    h.Write([]byte("hello world\n"))
    fmt.Printf("%x", h.Sum(nil))
}

应用

package main

import (
    "crypto/hmac"
    "crypto/sha256"
    "fmt"
    "io"
)

func main() {
    c := getSha256Code("[e-mail]")
    fmt.Println(c)

    c = getHmacCode("[e-mail]")
    fmt.Println(c)
}

func getHmacCode(s string) string {
    h := hmac.New(sha256.New, []byte("ourkey"))
    io.WriteString(h, s)
    return fmt.Sprintf("%x", h.Sum(nil))
}

func getSha256Code(s string) string {
    h := sha256.New()
    h.Write([]byte(s))
    return fmt.Sprintf("%x", h.Sum(nil))
}

输出：
973dfe463ec85785f5f95af5ba3906eedb2d931c24e69824a89ea65dba4e813b
453159a62580804892cc90a27dfb8bfdf2309107336445dcfd0186674111ee71