city_chips/pkg/helper/aes/aes.go

package aes

import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"encoding/base64"
	"encoding/hex"
	"errors"
	"fmt"
	"io"
)

// KEY_ALGORITHM 密钥算法
const KEY_ALGORITHM = "AES"

// DEFAULT_CIPHER_ALGORITHM 默认加密算法/工作模式/填充方式
const DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding"

// InitSecretKey 初始化密钥
func InitSecretKey() ([]byte, error) {
	key := make([]byte, 16) // AES-128
	if _, err := io.ReadFull(rand.Reader, key); err != nil {
		return nil, fmt.Errorf("生成随机密钥失败: %v", err)
	}
	return key, nil
}

// ToKey 转换密钥
func ToKey(key []byte) cipher.Block {
	block, _ := aes.NewCipher(key)
	return block
}

// Encrypt 加密
func Encrypt(data, key []byte) ([]byte, error) {
	return EncryptWithAlgorithm(data, key, DEFAULT_CIPHER_ALGORITHM)
}

// EncryptWithAlgorithm 使用指定算法加密
func EncryptWithAlgorithm(data, key []byte, cipherAlgorithm string) ([]byte, error) {
	block := ToKey(key)

	// PKCS5填充
	data = PKCS5Padding(data, block.BlockSize())

	ciphertext := make([]byte, len(data))
	for bs, be := 0, block.BlockSize(); bs < len(data); bs, be = bs+block.BlockSize(), be+block.BlockSize() {
		block.Encrypt(ciphertext[bs:be], data[bs:be])
	}

	return ciphertext, nil
}

// Decrypt 解密
func Decrypt(data, key []byte) ([]byte, error) {
	return DecryptWithAlgorithm(data, key, DEFAULT_CIPHER_ALGORITHM)
}

// DecryptWithAlgorithm 使用指定算法解密
func DecryptWithAlgorithm(data, key []byte, cipherAlgorithm string) ([]byte, error) {
	block := ToKey(key)

	plaintext := make([]byte, len(data))
	for bs, be := 0, block.BlockSize(); bs < len(data); bs, be = bs+block.BlockSize(), be+block.BlockSize() {
		block.Decrypt(plaintext[bs:be], data[bs:be])
	}

	// PKCS5去除填充
	plaintext = PKCS5UnPadding(plaintext)

	return plaintext, nil
}

// ShowByteArray 显示字节数组
func ShowByteArray(data []byte) string {
	if data == nil {
		return "nil"
	}
	var buf bytes.Buffer
	buf.WriteString("{")
	for i, b := range data {
		if i > 0 {
			buf.WriteString(",")
		}
		buf.WriteString(fmt.Sprintf("%d", b))
	}
	buf.WriteString("}")
	return buf.String()
}

// ParseHexStr2Byte 将16进制转换为二进制
func ParseHexStr2Byte(hexStr string) ([]byte, error) {
	if len(hexStr) < 1 {
		return nil, errors.New("hex string too short")
	}
	return hex.DecodeString(hexStr)
}

// ParseByte2HexStr 将二进制转换成16进制
func ParseByte2HexStr(data []byte) string {
	return hex.EncodeToString(data)
}

// AESEncryptString 加密字符串
func AESEncryptString(str, key string) (string, error) {
	if str == "" || key == "" {
		return "", errors.New("input string or key is empty")
	}

	keyBytes := []byte(key)
	if len(keyBytes) != 16 && len(keyBytes) != 24 && len(keyBytes) != 32 {
		return "", errors.New("key length must be 16, 24 or 32 bytes")
	}

	block, err := aes.NewCipher(keyBytes)
	if err != nil {
		return "", fmt.Errorf("创建AES加密块失败: %v", err)
	}

	// PKCS5填充
	data := PKCS5Padding([]byte(str), block.BlockSize())

	ciphertext := make([]byte, len(data))
	for bs, be := 0, block.BlockSize(); bs < len(data); bs, be = bs+block.BlockSize(), be+block.BlockSize() {
		block.Encrypt(ciphertext[bs:be], data[bs:be])
	}

	return base64.StdEncoding.EncodeToString(ciphertext), nil
}

// AESDecryptString 解密字符串
func AESDecryptString(str, key string) (string, error) {
	if str == "" || key == "" {
		return "", errors.New("input string or key is empty")
	}

	keyBytes := []byte(key)
	if len(keyBytes) != 16 && len(keyBytes) != 24 && len(keyBytes) != 32 {
		return "", errors.New("key length must be 16, 24 or 32 bytes")
	}

	ciphertext, err := base64.StdEncoding.DecodeString(str)
	if err != nil {
		return "", fmt.Errorf("base64解码失败: %v", err)
	}

	block, err := aes.NewCipher(keyBytes)
	if err != nil {
		return "", fmt.Errorf("创建AES加密块失败: %v", err)
	}

	plaintext := make([]byte, len(ciphertext))
	for bs, be := 0, block.BlockSize(); bs < len(ciphertext); bs, be = bs+block.BlockSize(), be+block.BlockSize() {
		block.Decrypt(plaintext[bs:be], ciphertext[bs:be])
	}

	// PKCS5去除填充
	plaintext = PKCS5UnPadding(plaintext)

	return string(plaintext), nil
}

// PKCS5Padding PKCS5填充
func PKCS5Padding(data []byte, blockSize int) []byte {
	padding := blockSize - len(data)%blockSize
	padText := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(data, padText...)
}

// PKCS5UnPadding PKCS5去除填充
func PKCS5UnPadding(data []byte) []byte {
	length := len(data)
	unPadding := int(data[length-1])
	return data[:(length - unPadding)]
}

// ExampleUsage 示例用法
func ExampleUsage() {
	// 示例密钥(与Java示例中的密钥一致)
	exampleKeyBase64 := "9iEepr1twrizIEKrs1hs2A=="
	exampleKey, _ := base64.StdEncoding.DecodeString(exampleKeyBase64)

	// 示例数据
	exampleData := `{"requestName":"BeforeIn","requestValue":{"carCode":"浙AD0V07","inTime":"2016-09-29 10:06:03","inChannelId":"4","GUID":"1403970b-4eb2-46bc-8f2b-eeec91ddcd5f","inOrOut":"0"},"Type":"0"}`

	fmt.Printf("加密前数据: string: %s\n", exampleData)
	fmt.Printf("加密前数据: byte[]: %s\n", ShowByteArray([]byte(exampleData)))
	fmt.Println()

	// 加密
	encryptData, err := Encrypt([]byte(exampleData), exampleKey)
	if err != nil {
		fmt.Printf("加密失败: %v\n", err)
		return
	}
	encryptStr := ParseByte2HexStr(encryptData)

	fmt.Printf("加密后数据: byte[]: %s\n", ShowByteArray(encryptData))
	fmt.Printf("加密后数据: Byte2HexStr: %s\n", encryptStr)
	fmt.Println()

	// 解密
	decryptData, err := Decrypt(encryptData, exampleKey)
	if err != nil {
		fmt.Printf("解密失败: %v\n", err)
		return
	}

	fmt.Printf("解密后数据: byte[]: %s\n", ShowByteArray(decryptData))
	fmt.Printf("解密后数据: string: %s\n", string(decryptData))
}