public class DEncryptHelper
{
#region 加密
/**/
/// <summary>
/// 加密資料
/// </summary>
/// <param name="input">加密前的字元串</param>
/// <returns>加密後的字元串</returns>
public static string Encrypt(string input)
{
// 鹽值
string saltValue = "saltValue";
// 密碼值
string pwdValue = "pwdValue";
byte[] data = UTF8Encoding.UTF8.GetBytes(input);
byte[] salt = UTF8Encoding.UTF8.GetBytes(saltValue);
// AesManaged - 進階加密标準(AES) 對稱算法的管理類
AesManaged aes = new AesManaged();
// Rfc2898DeriveBytes - 通過使用基于 HMACSHA1 的僞随機數生成器,實作基于密碼的密鑰派生功能 (PBKDF2 - 一種基于密碼的密鑰派生函數)
// 通過 密碼 和 salt 派生密鑰
Rfc2898DeriveBytes rfc = new Rfc2898DeriveBytes(pwdValue, salt);
/**/
/*
* AesManaged.BlockSize - 加密操作的塊大小(機關:bit)
* AesManaged.LegalBlockSizes - 對稱算法支援的塊大小(機關:bit)
* AesManaged.KeySize - 對稱算法的密鑰大小(機關:bit)
* AesManaged.LegalKeySizes - 對稱算法支援的密鑰大小(機關:bit)
* AesManaged.Key - 對稱算法的密鑰
* AesManaged.IV - 對稱算法的密鑰大小
* Rfc2898DeriveBytes.GetBytes(int 需要生成的僞随機密鑰位元組數) - 生成密鑰
*/
aes.BlockSize = aes.LegalBlockSizes[0].MaxSize;
aes.KeySize = aes.LegalKeySizes[0].MaxSize;
aes.Key = rfc.GetBytes(aes.KeySize / 8);
aes.IV = rfc.GetBytes(aes.BlockSize / 8);
// 用目前的 Key 屬性和初始化向量 IV 建立對稱加密器對象
ICryptoTransform encryptTransform = aes.CreateEncryptor();
// 加密後的輸出流
MemoryStream encryptStream = new MemoryStream();
// 将加密後的目标流(encryptStream)與加密轉換(encryptTransform)相連接配接
CryptoStream encryptor = new CryptoStream(encryptStream, encryptTransform, CryptoStreamMode.Write);
// 将一個位元組序列寫入目前 CryptoStream (完成加密的過程)
encryptor.Write(data, 0, data.Length);
encryptor.Close();
// 将加密後所得到的流轉換成位元組數組,再用Base64編碼将其轉換為字元串
string encryptedString = Convert.ToBase64String(encryptStream.ToArray());
return encryptedString;
}
#endregion
#region silverlight密碼解密
/**/
/// <summary>
/// 解密資料
/// </summary>
/// <param name="input">加密後的字元串</param>
/// <returns>加密前的字元串</returns>
public static string Decrypt(string input)
{
// 鹽值(與加密時設定的值一緻)
string saltValue = "saltValue";
// 密碼值(與加密時設定的值一緻)
string pwdValue = "pwdValue";
byte[] encryptBytes = Convert.FromBase64String(input);
byte[] salt = Encoding.UTF8.GetBytes(saltValue);
AesManaged aes = new AesManaged();
Rfc2898DeriveBytes rfc = new Rfc2898DeriveBytes(pwdValue, salt);
aes.BlockSize = aes.LegalBlockSizes[0].MaxSize;
aes.KeySize = aes.LegalKeySizes[0].MaxSize;
aes.Key = rfc.GetBytes(aes.KeySize / 8);
aes.IV = rfc.GetBytes(aes.BlockSize / 8);
// 用目前的 Key 屬性和初始化向量 IV 建立對稱解密器對象
ICryptoTransform decryptTransform = aes.CreateDecryptor();
// 解密後的輸出流
MemoryStream decryptStream = new MemoryStream();
// 将解密後的目标流(decryptStream)與解密轉換(decryptTransform)相連接配接
CryptoStream decryptor = new CryptoStream(decryptStream, decryptTransform, System.Security.Cryptography.CryptoStreamMode.Write);
// 将一個位元組序列寫入目前 CryptoStream (完成解密的過程)
decryptor.Write(encryptBytes, 0, encryptBytes.Length);
decryptor.Close();
// 将解密後所得到的流轉換為字元串
byte[] decryptBytes = decryptStream.ToArray();
string decryptedString = UTF8Encoding.UTF8.GetString(decryptBytes, 0, decryptBytes.Length);
return decryptedString;
}
#endregion
}