public bool EncryptAndSaveFile(string filePath, MemoryStream ms, string passwordString, CryptoProgress progress)
{
FileStream fs = null;
try
{
CryptoProgressHandler progressHandler = null;
if (string.IsNullOrEmpty(passwordString))
{
throw new Exception("Password can not be null or empty");
}
if (File.Exists(filePath))
{
fs = new FileStream(filePath, FileMode.Truncate);
}
else
{
fs = new FileStream(filePath, FileMode.CreateNew);
}
// fs = new FileStream(filePath, FileMode.Truncate); //File.Create(filePath);
if (progress != null)
{
progressHandler = new CryptoProgressHandler {
EncodedBytes = 0, TotalBytes = ms.Length, Text = "Starting ecryption"
};
progress.Report(progressHandler);
}
using (Aes aesAlg = Aes.Create())
{
var rfc2898DeriveBytes = new Rfc2898DeriveBytes(passwordString, SALT, 1000);
Debug.Assert(aesAlg != null, nameof(aesAlg) + " != null");
aesAlg.BlockSize = 128;
aesAlg.KeySize = 256;
aesAlg.Padding = PaddingMode.PKCS7;
aesAlg.Mode = CipherMode.CBC;
aesAlg.Key = rfc2898DeriveBytes.GetBytes(32);
aesAlg.IV = rfc2898DeriveBytes.GetBytes(16);
// Create a encrypt transform
ICryptoTransform encrypt = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
int bufferSize = (int)Math.Min(MaxBufferSize, ms.Length);
var buffer = new byte[bufferSize];
ms.Position = 0;
using (var csEncrypt = new CryptoStream(fs, encrypt, CryptoStreamMode.Write))
{
int bytesRead;
while ((bytesRead = ms.Read(buffer, 0, buffer.Length)) > 0)
{
csEncrypt.Write(buffer, 0, bytesRead);
if (progressHandler == null)
{
continue;
}
progressHandler.EncodedBytes += bytesRead;
progress.Report(progressHandler);
}
csEncrypt.FlushFinalBlock();
fs.Flush();
}
}
}
catch (Exception ex)
{
Log.Error(ex, "Error in EncryptionManager.EncryptAndSaveFile");
return(false);
}
finally
{
fs?.Close();
progress?.Report(new CryptoProgressHandler {
EncodedBytes = ms.Length, TotalBytes = ms.Length, Text = "Encryption completed"
});
}
return(true);
}
public MemoryStream DecryptFileToMemoryStream(string filePath, string passwordString, CryptoProgress progress)
{
var ms = new MemoryStream();
FileStream fs = null;
try
{
CryptoProgressHandler progressHandler = null;
if (string.IsNullOrEmpty(passwordString))
{
throw new Exception("Password can not be null or empty");
}
fs = File.OpenRead(filePath);
fs.Position = 0;
if (progress != null)
{
progressHandler = new CryptoProgressHandler {
EncodedBytes = 0, TotalBytes = fs.Length, Text = "Starting decryption"
};
progress.Report(progressHandler);
}
// Create an AesCryptoServiceProvider object
using (Aes aesAlg = Aes.Create())
{
var rfc2898DeriveBytes = new Rfc2898DeriveBytes(passwordString, SALT, 1000);
aesAlg.BlockSize = 128;
aesAlg.KeySize = 256;
aesAlg.Padding = PaddingMode.PKCS7;
aesAlg.Mode = CipherMode.CBC;
aesAlg.Key = rfc2898DeriveBytes.GetBytes(32);
aesAlg.IV = rfc2898DeriveBytes.GetBytes(16);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
int bufferSize = Math.Min(MaxBufferSize, (int)fs.Length);
var plainTextBytes = new byte[bufferSize];
using (var csDecrypt = new CryptoStream(fs, decryptor, CryptoStreamMode.Read))
{
int decryptedByteCount;
while ((decryptedByteCount = csDecrypt.Read(plainTextBytes, 0, plainTextBytes.Length)) > 0)
{
ms.Write(plainTextBytes, 0, decryptedByteCount);
if (progressHandler == null)
{
continue;
}
progressHandler.EncodedBytes += decryptedByteCount;
progress.Report(progressHandler);
}
}
}
}
catch (Exception ex)
{
Log.Error(ex, "Error in EncryptionManager.EncryptAndSaveFile");
return(null);
}
finally
{
fs?.Close();
progress?.Report(new CryptoProgressHandler {
EncodedBytes = ms.Length, TotalBytes = ms.Length, Text = "Decryption completed"
});
}
return(ms);
}