Go 语言 AES 加密和解密的三种模式实现（CBC/ECB/CFB
package main
import (
"bytes"
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"encoding/hex"
"io"
"log"
)
func main() {
origData := []byte("Hello World") // 待加密的数据
key := []byte("ABCDEFGHIJKLMNOP") // 加密的密钥
log.Println("原文：", string(origData))
log.Println("------------------ CBC模式 --------------------")
encrypted := AesEncryptCBC(origData, key)
log.Println("密文(hex)：", hex.EncodeToString(encrypted))
log.Println("密文(base64)：", base64.StdEncoding.EncodeToString(encrypted))
decrypted := AesDecryptCBC(encrypted, key)
log.Println("解密结果：", string(decrypted))
log.Println("------------------ ECB模式 --------------------")
encrypted = AesEncryptECB(origData, key)
log.Println("密文(hex)：", hex.EncodeToString(encrypted))
log.Println("密文(base64)：", base64.StdEncoding.EncodeToString(encrypted))
decrypted = AesDecryptECB(encrypted, key)
log.Println("解密结果：", string(decrypted))
log.Println("------------------ CFB模式 --------------------")
encrypted = AesEncryptCFB(origData, key)
log.Println("密文(hex)：", hex.EncodeToString(encrypted))
log.Println("密文(base64)：", base64.StdEncoding.EncodeToString(encrypted))
decrypted = AesDecryptCFB(encrypted, key)
log.Println("解密结果：", string(decrypted))
}
// =================== CBC ======================
func AesEncryptCBC(origData []byte, key []byte) (encrypted []byte) {
// 分组秘钥
// NewCipher该函数限制了输入k的长度必须为16, 24或者32
block, _ := aes.NewCipher(key)
blockSize := block.BlockSize() // 获取秘钥块的长度
origData = pkcs5Padding(origData, blockSize) // 补全码
blockMode := cipher.NewCBCEncrypter(block, key[:blockSize]) // 加密模式
encrypted = make([]byte, len(origData)) // 创建数组
blockMode.CryptBlocks(encrypted, origData) // 加密
return encrypted
}
func AesDecryptCBC(encrypted []byte, key []byte) (decrypted []byte) {
block, _ := aes.NewCipher(key) // 分组秘钥
blockSize := block.BlockSize() // 获取秘钥块的长度
blockMode := cipher.NewCBCDecrypter(block, key[:blockSize]) // 加密模式
decrypted = make([]byte, len(encrypted)) // 创建数组
blockMode.CryptBlocks(decrypted, encrypted) // 解密
decrypted = pkcs5UnPadding(decrypted) // 去除补全码
return decrypted
}
func pkcs5Padding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
return append(ciphertext, padtext...)
}
func pkcs5UnPadding(origData []byte) []byte {
length := len(origData)
unpadding := int(origData[length-1])
return origData[length - unpadding)]
}
// =================== ECB ======================
func AesEncryptECB(origData []byte, key []byte) (encrypted []byte) {
cipher, _ := aes.NewCipher(generateKey(key))
length := (len(origData) + aes.BlockSize) / aes.BlockSize
plain := make([]byte, length*aes.BlockSize)
copy(plain, origData)
pad := byte(len(plain) - len(origData))
for i := len(origData); i < len(plain); i++ {
plain = pad
}
encrypted = make([]byte, len(plain))
// 分组分块加密
for bs, be := 0, cipher.BlockSize(); bs <= len(origData); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {
cipher.Encrypt(encrypted[bs:be], plain[bs:be])
}
return encrypted
}
func AesDecryptECB(encrypted []byte, key []byte) (decrypted []byte) {
cipher, _ := aes.NewCipher(generateKey(key))
decrypted = make([]byte, len(encrypted))
//
for bs, be := 0, cipher.BlockSize(); bs < len(encrypted); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {
cipher.Decrypt(decrypted[bs:be], encrypted[bs:be])
}
trim := 0
if len(decrypted) > 0 {
trim = len(decrypted) - int(decrypted[len(decrypted)-1])
}
return decrypted[:trim]
}
func generateKey(key []byte) (genKey []byte) {
genKey = make([]byte, 16)
copy(genKey, key)
for i := 16; i < len(key); {
for j := 0; j < 16 && i < len(key); j, i = j+1, i+1 {
genKey[j] ^= key
}
}
return genKey
}
// =================== CFB ======================
func AesEncryptCFB(origData []byte, key []byte) (encrypted []byte) {
block, err := aes.NewCipher(key)
if err != nil {
panic(err)
}
encrypted = make([]byte, aes.BlockSize+len(origData))
iv := encrypted[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
panic(err)
}
stream := cipher.NewCFBEncrypter(block, iv)
stream.XORKeyStream(encrypted[aes.BlockSize:], origData)
return encrypted
}
func AesDecryptCFB(encrypted []byte, key []byte) (decrypted []byte) {
block, _ := aes.NewCipher(key)
if len(encrypted) < aes.BlockSize {
panic("ciphertext too short")
}
iv := encrypted[:aes.BlockSize]
encrypted = encrypted[aes.BlockSize:]
stream := cipher.NewCFBDecrypter(block, iv)
stream.XORKeyStream(encrypted, encrypted)
return encrypted
}