密码学-CFB

CFB算法

密码算法可以分为分组密码和流密码两种，之前所学的DES，3DES和AES都是分组密码。CFB和OFB都是流密码，而CFB和OFB使用方法也基本相同，所以只以CFB进行讲解：

package main

//通过CFB模式进行AES加密
import (
    "crypto/aes"
    "io"
    "crypto/rand"
    "crypto/cipher"
    "fmt"
)

//加密
func AESEncrypt(plaintext, key []byte) []byte {
    //分组秘钥
    block, _ := aes.NewCipher(key)
    //创建数组，存放加密后的密文
    ciphertext := make([]byte, aes.BlockSize+len(plaintext))
    //设置内存空间可读
    iv := ciphertext[:aes.BlockSize]
    io.ReadFull(rand.Reader, iv)
    //设置加密方式
    stream := cipher.NewCFBEncrypter(block, iv)
    //加密(利用ciphertext[aes.BlockSize:]与plaintext做异或)
    stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintext)
    return ciphertext
}

//解密
func AesDecrypt(ciphertext, key []byte) []byte {
    block, _ := aes.NewCipher(key)
    iv := ciphertext[:aes.BlockSize]
    ciphertext = ciphertext[aes.BlockSize:]
    //设置解密方式
    stream := cipher.NewCFBDecrypter(block, iv)
    //解密
    stream.XORKeyStream(ciphertext, ciphertext)
    return ciphertext
}
func main() {
    encryptcode := AESEncrypt([]byte("sanyang"), []byte("123456789abcdefg"))
    fmt.Printf("%x\n", encryptcode)
    decryptcode := AesDecrypt(encryptcode, []byte("123456789abcdefg"))
    fmt.Println(string(decryptcode))
    //fmt.Println(base64.StdEncoding.EncodeToString(decryptcode))
}