public static class EncryptAndDecrypt
{
//加密
public static string Encrypt(string input)
{
// 鹽值
string saltValue = "saltValue";
// 密碼值
string pwdValue = "pwdValue";
byte[] data = System.Text.UTF8Encoding.UTF8.GetBytes(input);
byte[] salt = System.Text.UTF8Encoding.UTF8.GetBytes(saltValue);
// AesManaged - 高級加密標準(AES) 對稱算法的管理類
System.Security.Cryptography.AesManaged aes = new System.Security.Cryptography.AesManaged();
// Rfc2898DeriveBytes - 通過使用基于 HMACSHA1 的偽隨機數生成器，實現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
System.Security.Cryptography.Rfc2898DeriveBytes rfc = new System.Security.Cryptography.Rfc2898DeriveBytes(pwdValue, salt);
/**/
/*
* AesManaged.BlockSize - 加密操作的塊大小（單位：bit）
* AesManaged.LegalBlockSizes - 對稱算法支持的塊大小（單位：bit）
* AesManaged.KeySize - 對稱算法的密鑰大小（單位：bit）
* AesManaged.LegalKeySizes - 對稱算法支持的密鑰大小（單位：bit）
* AesManaged.Key - 對稱算法的密鑰
* AesManaged.IV - 對稱算法的密鑰大小
* Rfc2898DeriveBytes.GetBytes(int 需要生成的偽隨機密鑰字節數) - 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);
// 用當前的 Key 屬性和初始化向量 IV 創建對稱加密器對象
System.Security.Cryptography.ICryptoTransform encryptTransform = aes.CreateEncryptor();
// 加密后的輸出流
System.IO.MemoryStream encryptStream = new System.IO.MemoryStream();
// 將加密后的目標流（encryptStream）與加密轉換（encryptTransform）相連接
System.Security.Cryptography.CryptoStream encryptor = new System.Security.Cryptography.CryptoStream
(encryptStream, encryptTransform, System.Security.Cryptography.CryptoStreamMode.Write);
// 將一個字節序列寫入當前 CryptoStream （完成加密的過程）
encryptor.Write(data, 0, data.Length);
encryptor.Close();
// 將加密后所得到的流轉換成字節數組，再用Base64編碼將其轉換為字符串
string encryptedString = Convert.ToBase64String(encryptStream.ToArray());
return encryptedString;
}
#region silverlight密碼解密
/**/
/// <summary>
/// 解密數據
/// </summary>
/// <param name="input">加密后的字符串</param>
/// <returns>加密前的字符串</returns>
public static string Decrypt(string input)
{
// 鹽值（與加密時設置的值一致）
string saltValue = "saltValue";
// 密碼值（與加密時設置的值一致）
string pwdValue = "pwdValue";
byte[] encryptBytes = Convert.FromBase64String(input);
byte[] salt = Encoding.UTF8.GetBytes(saltValue);
System.Security.Cryptography.AesManaged aes = new System.Security.Cryptography.AesManaged();
System.Security.Cryptography.Rfc2898DeriveBytes rfc = new System.Security.Cryptography.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);
// 用當前的 Key 屬性和初始化向量 IV 創建對稱解密器對象
System.Security.Cryptography.ICryptoTransform decryptTransform = aes.CreateDecryptor();
// 解密后的輸出流
MemoryStream decryptStream = new MemoryStream();
// 將解密后的目標流（decryptStream）與解密轉換（decryptTransform）相連接
System.Security.Cryptography.CryptoStream decryptor = new System.Security.Cryptography.CryptoStream(
decryptStream, decryptTransform, System.Security.Cryptography.CryptoStreamMode.Write);
// 將一個字節序列寫入當前 CryptoStream （完成解密的過程）
decryptor.Write(encryptBytes, 0, encryptBytes.Length);
decryptor.Close();
// 將解密后所得到的流轉換為字符串
byte[] decryptBytes = decryptStream.ToArray();
string decryptedString = UTF8Encoding.UTF8.GetString(decryptBytes, 0, decryptBytes.Length);
return decryptedString;
}
#endregion
}
