public static void EncryptionErasure(string filePath, BackgroundWorker bgwShredFiles)
{
try
{
string encryptedFilePath = AnonymousRename.GetAnonymousFileName(filePath);
using (var ciphertext = new FileStream(encryptedFilePath, FileMode.Create, FileAccess.ReadWrite, FileShare.Read))
using (var plaintext = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read))
{
byte[] fileBytes = FileHandling.GetBufferSize(plaintext);
byte[] key = SodiumCore.GetRandomBytes(Constants.EncryptionKeySize);
byte[] nonce = SodiumCore.GetRandomBytes(Constants.XChaChaNonceLength);
StreamCiphers.Encrypt(plaintext, ciphertext, 0, fileBytes, nonce, key, bgwShredFiles);
Utilities.ZeroArray(key);
Utilities.ZeroArray(nonce);
}
// Overwrite the original file
File.Copy(encryptedFilePath, filePath, true);
ShredFiles.EraseFileMetadata(encryptedFilePath);
File.Delete(encryptedFilePath);
}
catch (Exception ex) when(ex is CryptographicException || ExceptionFilters.FileAccessExceptions(ex))
{
Logging.LogException(ex.ToString(), Logging.Severity.High);
DisplayMessage.ErrorResultsText(filePath, ex.GetType().Name, "'Encryption' erasure failed.");
}
}
public static void PseudorandomData(string filePath, BackgroundWorker bgwShredFiles)
{
try
{
using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read))
{
byte[] randomBytes = FileHandling.GetBufferSize(fileStream);
while (fileStream.Position < fileStream.Length)
{
randomBytes = SodiumCore.GetRandomBytes(randomBytes.Length);
fileStream.Write(randomBytes, 0, randomBytes.Length);
ReportProgress.ReportEncryptionProgress(fileStream.Position, fileStream.Length, bgwShredFiles);
}
}
}
catch (Exception ex) when(ExceptionFilters.FileAccessExceptions(ex))
{
Logging.LogException(ex.ToString(), Logging.Severity.High);
DisplayMessage.ErrorResultsText(filePath, ex.GetType().Name, "'1 Pass' erasure failed.");
}
}
public static void ZeroFill(string filePath, bool useOnes, BackgroundWorker bgwShredFiles)
{
try
{
using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read))
{
byte[] zeroes = FileHandling.GetBufferSize(fileStream);
if (useOnes == true)
{
zeroes = FillArrayWithOnes(zeroes);
}
while (fileStream.Position < fileStream.Length)
{
fileStream.Write(zeroes, 0, zeroes.Length);
ReportProgress.ReportEncryptionProgress(fileStream.Position, fileStream.Length, bgwShredFiles);
}
}
}
catch (Exception ex) when(ExceptionFilters.FileAccessExceptions(ex))
{
Logging.LogException(ex.ToString(), Logging.Severity.High);
DisplayMessage.ErrorResultsText(filePath, ex.GetType().Name, "'Zero fill' erasure failed.");
}
}