D3Ext-Hooka/utils/aes.go

package utils

import (
  "crypto/aes"
  "crypto/cipher"
  "crypto/rand"
  "errors"
  "bytes"
)

func AESEncrypt(plaintext []byte, iv []byte, key []byte) ([]byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}

	if string(plaintext) == "" {
		return nil, errors.New("string to encrypt is empty")
	}

	ecb := cipher.NewCBCEncrypter(block, iv)
	content := []byte(plaintext)
	content = PKCS5Padding(content, block.BlockSize())
	crypted := make([]byte, len(content))
	ecb.CryptBlocks(crypted, content)

	return crypted, nil
}

func AESDecrypt(ciphertext []byte, iv []byte, key []byte) ([]byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}

	if len(ciphertext) == 0 {
		return nil, errors.New("ciphertext cannot be empty")
	}

	ecb := cipher.NewCBCDecrypter(block, iv)
	decrypted := make([]byte, len(ciphertext))
	ecb.CryptBlocks(decrypted, ciphertext)

	return PKCS5Trimming(decrypted), nil
}

func GenerateIV() ([]byte, error) {
	iv := make([]byte, aes.BlockSize)
	_, err := rand.Read(iv)
	if err != nil {
		return nil, err
	}

	return iv, nil
}

func PKCS5Trimming(encrypt []byte) []byte {
	padding := encrypt[len(encrypt)-1]
	return encrypt[:len(encrypt)-int(padding)]
}

func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(ciphertext, padtext...)
}