[C#] AES (고급 암호화 표준)

[C#] AES (고급 암호화 표준)

 

 

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
 
namespace AESWithJava.Con
{
    class Program
    {
        static void Main(string[] args)
        {
            String originalText = "plain text";
            String key = "key";
            String en = Encrypt(originalText, key);
            String de = Decrypt(en, key);
 
            Console.WriteLine("Original Text is " + originalText); 
            Console.WriteLine("Encrypted Text is " + en);
            Console.WriteLine( "Decrypted Text is " + de);
        }
 
        public static string Decrypt(string textToDecrypt, string key)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();
            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
 
            rijndaelCipher.KeySize = 128;
            rijndaelCipher.BlockSize = 128;
            byte[] encryptedData = Convert.FromBase64String(textToDecrypt);
            byte[] pwdBytes = Encoding.UTF8.GetBytes(key);
            byte[] keyBytes = new byte[16];
            int len = pwdBytes.Length;
            if (len > keyBytes.Length)
            {
                len = keyBytes.Length;
            }
            Array.Copy(pwdBytes, keyBytes, len);
            rijndaelCipher.Key = keyBytes;
            rijndaelCipher.IV = keyBytes;
            byte[] plainText = rijndaelCipher.CreateDecryptor().TransformFinalBlock(encryptedData, 0, encryptedData.Length);
            return Encoding.UTF8.GetString(plainText);
        }
 
        public static string Encrypt(string textToEncrypt, string key)
        {
            RijndaelManaged rijndaelCipher = new RijndaelManaged();
            rijndaelCipher.Mode = CipherMode.CBC;
            rijndaelCipher.Padding = PaddingMode.PKCS7;
 
            rijndaelCipher.KeySize = 128;
            rijndaelCipher.BlockSize = 128;
            byte[] pwdBytes = Encoding.UTF8.GetBytes(key);
            byte[] keyBytes = new byte[16];
            int len = pwdBytes.Length;
            if (len > keyBytes.Length)
            {
                len = keyBytes.Length;
            }
            Array.Copy(pwdBytes, keyBytes, len);
            rijndaelCipher.Key = keyBytes;
            rijndaelCipher.IV = keyBytes;
            ICryptoTransform transform = rijndaelCipher.CreateEncryptor();
            byte[] plainText = Encoding.UTF8.GetBytes(textToEncrypt);
            return Convert.ToBase64String(transform.TransformFinalBlock(plainText, 0, plainText.Length));
        }
 
    }
}