public static void DecryptFile(FileStream fileStreamToRead, string encryptionKey, string tempDecryptedFilePath)
{
using (fileStreamToRead)
{
using (CryptoStream decryptionStream = DataProtection.GetDecryptionStream((Stream)fileStreamToRead, encryptionKey))
{
using (FileStream fileStream = File.Create(tempDecryptedFilePath))
{
byte[] buffer = new byte[4096];
int count;
do
{
count = decryptionStream.Read(buffer, 0, buffer.Length);
if (count > 0)
{
fileStream.Write(buffer, 0, count);
}
}while (count > 0);
}
}
}
}