/// <summary>
/// 流数据加密
/// </summary>
/// <param name="data">数据</param>
/// <param name="proEntity">加密配置</param>
/// <returns>加密后流数据，返回MemoryStream</returns>
/// <exception cref="ArgumentNullException">当加密配置为null时抛出此异常</exception>
/// <exception cref="Exception">此方法只支持对称加密，如果使用非对称配置，抛出此异常</exception>
public static Stream Encrypt(Stream data, EncryptionConfigEntity proEntity)
{
if (proEntity == null)
{
throw new ArgumentNullException("proEntity");
}
if (proEntity.SymmetricAlgorithm == false)
{
throw new Exception("This method id not intended for asymmetric encryption");
}
//retrive the secret key and iv information
var provider = proEntity.AlgorithmProvider.CreateInstance <SymmetricAlgorithm>();
provider.Key = Decryption.Base64ToBytes(proEntity.ExtentProperty["Key"]);
provider.IV = Decryption.Base64ToBytes(proEntity.ExtentProperty["IV"]);
var encryptor = provider.CreateEncryptor();
var encrypted = new MemoryStream();
//encrypt the stream symmetrically
var encStream = new CryptoStream(encrypted, encryptor, CryptoStreamMode.Write);
var buffer = new byte[1024];
int count;
while ((count = data.Read(buffer, 0, 1024)) > 0)
{
encStream.Write(buffer, 0, count);
}
encStream.FlushFinalBlock();
encrypted.Position = 0;
return(encrypted);
}
/// <summary>
/// 解密数据
/// </summary>
/// <param name="data">待解密流数据</param>
/// <param name="proEntity">解密配置</param>
/// <returns>解密后流数据，返回MemoryStream</returns>
/// <exception cref="ArgumentNullException">当解密配置为null时抛出此异常</exception>
/// <exception cref="Exception">此方法只支持对称解密，如果使用非对称配置，抛出此异常</exception>
public static Stream Decrypt(Stream data, EncryptionConfigEntity proEntity)
{
if (proEntity == null)
{
throw new ArgumentNullException("proEntity");
}
if (proEntity.SymmetricAlgorithm != true)
{
throw new Exception("This method id not intended for asymmetric encryption");
}
//retrieve the secret key and iv from the configuration file
var provider = proEntity.AlgorithmProvider.CreateInstance <SymmetricAlgorithm>();
var key = proEntity.ExtentProperty["Key"];
var iv = proEntity.ExtentProperty["IV"];
provider.Key = Decryption.Base64ToBytes(key);
provider.IV = Decryption.Base64ToBytes(iv);
var decryptor = provider.CreateDecryptor();
//decrypt the stream
var decStream = new CryptoStream(data, decryptor, CryptoStreamMode.Read);
var decrypted = new MemoryStream();
var buffer = new byte[2048];
int count;
while ((count = decStream.Read(buffer, 0, buffer.Length)) != 0)
{
decrypted.Write(buffer, 0, count);
}
decrypted.Position = 0;
return(decrypted);
}
