package Sm4

import (
	"crypto/cipher"
	sm4 "github.com/tjfoc/gmsm/sm4"
)

func EncryptSM4(plainText string, key string) ([]byte, error) {
	block, err := sm4.NewCipher([]byte(key))
	if err != nil {
		return nil, err
	}

	ciphertext := make([]byte, len(plainText))
	iv := []byte("UISwD9fW6cFh9SNS") // 使用16字节的初始化向量
	mode := cipher.NewCBCEncrypter(block, iv)
	mode.CryptBlocks(ciphertext, []byte(plainText))

	return ciphertext, nil
}

func DecryptSM4(ciphertext string, key string) ([]byte, error) {
	block, err := sm4.NewCipher([]byte(key))
	if err != nil {
		return nil, err
	}

	plaintext := make([]byte, len(ciphertext))
	iv := []byte("UISwD9fW6cFh9SNS") // 使用与加密相同的初始化向量
	mode := cipher.NewCBCDecrypter(block, iv)
	mode.CryptBlocks(plaintext, []byte(ciphertext))

	return plaintext, nil
}