(feature): changed files checksum algorythm, padded files descriptor with encryption and integrity check, handling secret in env var or text file fallback
This commit is contained in:
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commit
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@ -9,6 +9,8 @@ using MaksIT.LTO.Core;
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using MaksIT.LTO.Backup.Entities;
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using MaksIT.LTO.Core.MassStorage;
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using MaksIT.LTO.Core.Networking;
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using MaksIT.LTO.Core.Utilities;
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using MaksIT.LTO.Core.Helpers;
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namespace MaksIT.LTO.Backup;
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@ -16,16 +18,19 @@ namespace MaksIT.LTO.Backup;
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public class Application {
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private const string _descriptoFileName = "descriptor.json";
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private const string _secretFileName = "secret.txt";
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private readonly string appPath = AppDomain.CurrentDomain.BaseDirectory;
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private readonly string _tapePath;
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private readonly string _descriptorFilePath;
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private readonly string _secretFilePath;
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private readonly ILogger<Application> _logger;
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private readonly ILogger<TapeDeviceHandler> _tapeDeviceLogger;
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private readonly ILogger<NetworkConnection> _networkConnectionLogger;
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private readonly Configuration _configuration;
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private readonly string _secret;
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public Application(
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ILogger<Application> logger,
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@ -37,9 +42,26 @@ public class Application {
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_networkConnectionLogger = loggerFactory.CreateLogger<NetworkConnection>();
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_descriptorFilePath = Path.Combine(appPath, _descriptoFileName);
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_secretFilePath = Path.Combine(appPath, _secretFileName);
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_configuration = configuration.Value;
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_tapePath = _configuration.TapePath;
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var secret = Environment.GetEnvironmentVariable("LTO_BACKUP_SECRET")
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?? Environment.GetEnvironmentVariable("LTO_BACKUP_SECRET", EnvironmentVariableTarget.Machine);
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if (!string.IsNullOrWhiteSpace(secret))
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_secret = secret;
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else if (!File.Exists(_secretFilePath)) {
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_secret = AESGCMUtility.GenerateKeyBase64();
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File.WriteAllText(_secretFilePath, _secret);
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}
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else
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_secret = File.ReadAllText(_secretFilePath);
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if (string.IsNullOrWhiteSpace(_secret)) {
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throw new InvalidOperationException("Secret is required for encryption.");
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}
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}
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public void Run() {
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@ -95,31 +117,31 @@ public class Application {
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}
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}
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public void LoadTape() {
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private void LoadTape() {
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using var handler = new TapeDeviceHandler(_tapeDeviceLogger, _tapePath);
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LoadTape(handler);
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}
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public void LoadTape(TapeDeviceHandler handler) {
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private void LoadTape(TapeDeviceHandler handler) {
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handler.Prepare(TapeDeviceHandler.TAPE_LOAD);
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Thread.Sleep(2000);
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_logger.LogInformation("Tape loaded.");
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}
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public void EjectTape() {
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private void EjectTape() {
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using var handler = new TapeDeviceHandler(_tapeDeviceLogger, _tapePath);
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EjectTape(handler);
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}
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public void EjectTape(TapeDeviceHandler handler) {
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private void EjectTape(TapeDeviceHandler handler) {
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handler.Prepare(TapeDeviceHandler.TAPE_UNLOAD);
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Thread.Sleep(2000);
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_logger.LogInformation("Tape ejected.");
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}
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public void TapeErase() {
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private void TapeErase() {
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using var handler = new TapeDeviceHandler(_tapeDeviceLogger, _tapePath);
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LoadTape(handler);
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@ -143,12 +165,12 @@ public class Application {
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_logger.LogInformation("Tape erased.");
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}
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public void GetDeviceStatus() {
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private void GetDeviceStatus() {
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using var handler = new TapeDeviceHandler(_tapeDeviceLogger, _tapePath);
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handler.GetStatus();
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}
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public void PathAccessWrapper(WorkingFolder workingFolder, Action<string> myAction) {
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private void PathAccessWrapper(WorkingFolder workingFolder, Action<string> myAction) {
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if (workingFolder.LocalPath != null) {
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var localPath = workingFolder.LocalPath.Path;
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@ -182,7 +204,7 @@ public class Application {
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}
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}
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public void CreateDescriptor(WorkingFolder workingFolder, string descriptorFilePath, uint blockSize) {
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private void CreateDescriptor(WorkingFolder workingFolder, string descriptorFilePath, uint blockSize) {
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PathAccessWrapper(workingFolder, (directoryPath) => {
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var files = Directory.GetFiles(directoryPath, "*.*", SearchOption.AllDirectories);
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@ -196,18 +218,8 @@ public class Application {
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var relativePath = Path.GetRelativePath(directoryPath, filePath);
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var numberOfBlocks = (uint)((fileInfo.Length + blockSize - 1) / blockSize);
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// Optional: Calculate a simple hash for file integrity (e.g., MD5)
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using var md5 = System.Security.Cryptography.MD5.Create();
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using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
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using var bufferedStream = new BufferedStream(fileStream, (int)blockSize);
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byte[] buffer = new byte[blockSize];
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int bytesRead;
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while ((bytesRead = bufferedStream.Read(buffer, 0, buffer.Length)) > 0) {
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md5.TransformBlock(buffer, 0, bytesRead, null, 0);
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}
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md5.TransformFinalBlock(Array.Empty<byte>(), 0, 0);
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string fileHash = BitConverter.ToString(md5.Hash).Replace("-", "").ToLower();
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// Calculate CRC32 checksum for file integrity
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string fileHash = ChecksumUtility.CalculateCRC32ChecksumFromFileInChunks(filePath, (int)blockSize);
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descriptor.Add(new FileDescriptor {
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StartBlock = currentTapeBlock, // Position of the file on the tape
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@ -247,7 +259,17 @@ public class Application {
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}
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}
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public void WriteFilesToTape(WorkingFolder workingFolder, string descriptorFilePath, uint blockSize) {
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private byte[] AddPadding(byte[] data, int blockSize) {
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int paddingSize = blockSize - (data.Length % blockSize);
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byte[] paddedData = new byte[data.Length + paddingSize];
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Array.Copy(data, paddedData, data.Length);
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for (int i = data.Length; i < paddedData.Length; i++) {
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paddedData[i] = (byte)paddingSize;
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}
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return paddedData;
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}
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private void WriteFilesToTape(WorkingFolder workingFolder, string descriptorFilePath, uint blockSize) {
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PathAccessWrapper(workingFolder, (directoryPath) => {
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_logger.LogInformation($"Writing files to tape from: {directoryPath}.");
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_logger.LogInformation($"Block Size: {blockSize}.");
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@ -279,9 +301,6 @@ public class Application {
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var currentTapeBlock = (descriptorJson.Length + blockSize - 1) / blockSize;
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int writeError = 0;
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foreach (var file in descriptor.Files) {
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var filePath = Path.Combine(directoryPath, file.FilePath);
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using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
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@ -296,7 +315,7 @@ public class Application {
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Array.Clear(buffer, bytesRead, buffer.Length - bytesRead);
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}
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writeError = handler.WriteData(buffer);
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var writeError = handler.WriteData(buffer);
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if (writeError != 0) {
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_logger.LogInformation($"Failed to write file: {filePath}");
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return;
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@ -314,14 +333,35 @@ public class Application {
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// write descriptor to tape
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var descriptorData = Encoding.UTF8.GetBytes(descriptorJson);
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var descriptorBlocks = (descriptorData.Length + blockSize - 1) / blockSize;
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for (int i = 0; i < descriptorBlocks; i++) {
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descriptorData = AESGCMUtility.EncryptData(descriptorData, _secret);
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// calculate the padding size
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var paddingSize = blockSize - (descriptorData.Length % blockSize);
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if (paddingSize == blockSize) {
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paddingSize = 0;
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}
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// add padding to the descriptor data
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var paddedDescriptorData = new byte[descriptorData.Length + paddingSize + 1];
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Array.Copy(descriptorData, paddedDescriptorData, descriptorData.Length);
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// fill the padding with a specific value (e.g., 0x00)
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for (int i = descriptorData.Length; i < paddedDescriptorData.Length - 1; i++) {
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paddedDescriptorData[i] = 0x00;
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}
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// append the padding size at the end
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paddedDescriptorData[paddedDescriptorData.Length - 1] = (byte)paddingSize;
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// calculate the number of blocks needed
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var descriptorBlocks = (paddedDescriptorData.Length + blockSize - 1) / blockSize;
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for (var i = 0; i < descriptorBlocks; i++) {
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var startIndex = i * blockSize;
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var length = Math.Min(blockSize, descriptorData.Length - startIndex);
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byte[] block = new byte[blockSize]; // Initialized with zeros by default
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Array.Copy(descriptorData, startIndex, block, 0, length);
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writeError = handler.WriteData(block);
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var length = Math.Min(blockSize, paddedDescriptorData.Length - startIndex);
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var block = new byte[blockSize]; // Initialized with zeros by default
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Array.Copy(paddedDescriptorData, startIndex, block, 0, length);
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var writeError = handler.WriteData(block);
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if (writeError != 0)
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return;
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@ -329,8 +369,9 @@ public class Application {
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Thread.Sleep(_configuration.WriteDelay); // Small delay between blocks
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}
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// write 3 0 filled blocks to indicate end of backup
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ZeroFillBlocks(handler, 3, blockSize);
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// write mark to indicate end of files
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handler.WriteMarks(TapeDeviceHandler.TAPE_FILEMARKS, 2);
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Thread.Sleep(_configuration.WriteDelay);
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handler.Prepare(TapeDeviceHandler.TAPE_UNLOCK);
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Thread.Sleep(2000);
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@ -341,7 +382,7 @@ public class Application {
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});
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}
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public BackupDescriptor? FindDescriptor(uint blockSize) {
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private BackupDescriptor? FindDescriptor(uint blockSize) {
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_logger.LogInformation("Searching for descriptor on tape...");
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_logger.LogInformation($"Block Size: {blockSize}.");
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@ -357,34 +398,55 @@ public class Application {
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handler.SetPosition(TapeDeviceHandler.TAPE_SPACE_FILEMARKS, 0, 1);
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Thread.Sleep(2000);
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handler.WaitForTapeReady();
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var position = handler.GetPosition(TapeDeviceHandler.TAPE_ABSOLUTE_BLOCK);
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if (position.Error != null)
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return null;
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// Read data from tape until 3 zero-filled blocks are found
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var desctiptorBlocks = position.OffsetLow;
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handler.SetPosition(TapeDeviceHandler.TAPE_SPACE_FILEMARKS, 0, 2);
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Thread.Sleep(2000);
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position = handler.GetPosition(TapeDeviceHandler.TAPE_ABSOLUTE_BLOCK);
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if (position.Error != null)
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return null;
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desctiptorBlocks = position.OffsetLow - desctiptorBlocks;
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var padding = handler.ReadData(blockSize);
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handler.SetPosition(TapeDeviceHandler.TAPE_SPACE_FILEMARKS, 0, 1);
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Thread.Sleep(2000);
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// read data from descriptorBlocks
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var buffer = new List<byte>();
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byte[] data;
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var zeroBlocks = 0;
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do {
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data = handler.ReadData(blockSize);
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for (var i = 0; i < desctiptorBlocks; i++) {
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var data = handler.ReadData(blockSize);
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buffer.AddRange(data);
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if (data.All(b => b == 0)) {
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zeroBlocks++;
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}
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else {
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zeroBlocks = 0;
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}
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} while (zeroBlocks < 3);
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// Remove the last 3 zero-filled blocks from the buffer
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var totalZeroBlocksSize = (int)(3 * blockSize);
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if (buffer.Count >= totalZeroBlocksSize) {
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buffer.RemoveRange(buffer.Count - totalZeroBlocksSize, totalZeroBlocksSize);
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}
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// Convert buffer to byte array
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var byteArray = buffer.ToArray();
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// Convert buffer to array
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var paddedData = buffer.ToArray();
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// Retrieve the padding size from the last byte
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int paddingSize = paddedData[^1];
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// Calculate the length of the original data
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int originalDataLength = paddedData.Length - paddingSize - 1;
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// Ensure the padding size is valid
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if (paddingSize < 0 || paddingSize >= paddedData.Length || originalDataLength < 0)
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return null;
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// Create a new array for the original data
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var descriptorData = new byte[originalDataLength];
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Array.Copy(paddedData, descriptorData, originalDataLength);
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descriptorData = AESGCMUtility.DecryptData(descriptorData, _secret);
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// Convert byte array to string and trim ending zeros
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var json = Encoding.UTF8.GetString(byteArray).TrimEnd('\0');
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var json = Encoding.UTF8.GetString(descriptorData);
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try {
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var descriptor = JsonSerializer.Deserialize<BackupDescriptor>(json);
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@ -395,9 +457,9 @@ public class Application {
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}
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catch (JsonException ex) {
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_logger.LogInformation($"Failed to parse descriptor JSON: {ex.Message}");
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return null;
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}
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handler.Prepare(TapeDeviceHandler.TAPE_UNLOCK);
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Thread.Sleep(2000);
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@ -407,7 +469,7 @@ public class Application {
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return null;
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}
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public void RestoreDirectory(BackupDescriptor descriptor, WorkingFolder workingFolder) {
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private void RestoreDirectory(BackupDescriptor descriptor, WorkingFolder workingFolder) {
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PathAccessWrapper(workingFolder, (restoreDirectoryPath) => {
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_logger.LogInformation("Restoring files to directory: " + restoreDirectoryPath);
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@ -448,20 +510,11 @@ public class Application {
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}
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}
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// check md5 checksum of restored file with the one in descriptor
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using (var md5 = System.Security.Cryptography.MD5.Create()) {
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using (var fileStreamRead = new FileStream(filePath, FileMode.Open, FileAccess.Read)) {
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var fileHash = md5.ComputeHash(fileStreamRead);
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var fileHashString = BitConverter.ToString(fileHash).Replace("-", "").ToLower();
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if (fileHashString != file.FileHash) {
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_logger.LogInformation($"Checksum mismatch for file: {filePath}");
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}
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else {
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_logger.LogInformation($"Restored file: {filePath}");
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}
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}
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}
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// check checksum of restored file with the one in descriptor
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if (ChecksumUtility.VerifyCRC32ChecksumFromFileInChunks(filePath, file.FileHash, (int)descriptor.BlockSize))
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_logger.LogInformation($"Restored file: {filePath}");
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else
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_logger.LogInformation($"Checksum mismatch for file: {filePath}");
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}
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handler.SetPosition(TapeDeviceHandler.TAPE_REWIND);
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@ -469,7 +522,7 @@ public class Application {
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});
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}
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public int CheckMediaSize(string ltoGen) {
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private int CheckMediaSize(string ltoGen) {
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var descriptor = JsonSerializer.Deserialize<BackupDescriptor>(File.ReadAllText(_descriptorFilePath));
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if (descriptor == null) {
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_logger.LogInformation("Failed to read descriptor.");
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@ -498,7 +551,7 @@ public class Application {
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return 0;
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}
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public void Backup() {
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private void Backup() {
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while (true) {
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_logger.LogInformation("\nSelect a backup to perform:");
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for (int i = 0; i < _configuration.Backups.Count; i++) {
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@ -539,7 +592,7 @@ public class Application {
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}
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}
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public void Restore() {
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private void Restore() {
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while (true) {
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_logger.LogInformation("\nSelect a backup to restore:");
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for (int i = 0; i < _configuration.Backups.Count; i++) {
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@ -582,4 +635,3 @@ public class Application {
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}
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}
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}
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@ -5,6 +5,7 @@
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<TargetFramework>net8.0</TargetFramework>
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<ImplicitUsings>enable</ImplicitUsings>
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<Nullable>enable</Nullable>
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<Version>0.0.2</Version>
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</PropertyGroup>
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<ItemGroup>
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@ -23,6 +24,9 @@
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<None Update="configuration.json">
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<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
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</None>
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<None Update="secret.txt">
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<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
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</None>
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</ItemGroup>
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</Project>
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@ -5,6 +5,7 @@
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<ImplicitUsings>enable</ImplicitUsings>
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<Nullable>enable</Nullable>
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<DefineConstants>NTDDI_VERSION_05010000;NTDDI_WINXP_05010000</DefineConstants>
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<Version>0.0.2</Version>
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</PropertyGroup>
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<ItemGroup>
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57
src/MaksIT.LTO.Core/Utilities/AESGCMUtility.cs
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57
src/MaksIT.LTO.Core/Utilities/AESGCMUtility.cs
Normal file
@ -0,0 +1,57 @@
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using System.Security.Cryptography;
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namespace MaksIT.LTO.Core.Utilities;
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public static class AESGCMUtility {
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private const int IvLength = 12; // 12 bytes for AES-GCM IV
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private const int TagLength = 16; // 16 bytes for AES-GCM Tag
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public static byte[] EncryptData(byte[] data, string base64Key) {
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var key = Convert.FromBase64String(base64Key);
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using (AesGcm aesGcm = new AesGcm(key, AesGcm.TagByteSizes.MaxSize)) {
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var iv = new byte[IvLength];
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RandomNumberGenerator.Fill(iv);
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var cipherText = new byte[data.Length];
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var tag = new byte[TagLength];
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aesGcm.Encrypt(iv, data, cipherText, tag);
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// Concatenate cipherText, tag, and iv
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var result = new byte[cipherText.Length + tag.Length + iv.Length];
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Buffer.BlockCopy(cipherText, 0, result, 0, cipherText.Length);
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Buffer.BlockCopy(tag, 0, result, cipherText.Length, tag.Length);
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Buffer.BlockCopy(iv, 0, result, cipherText.Length + tag.Length, iv.Length);
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return result;
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}
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}
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public static byte[] DecryptData(byte[] data, string base64Key) {
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var key = Convert.FromBase64String(base64Key);
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// Extract cipherText, tag, and iv
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var cipherTextLength = data.Length - IvLength - TagLength;
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var cipherText = new byte[cipherTextLength];
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var tag = new byte[TagLength];
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var iv = new byte[IvLength];
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||||
Buffer.BlockCopy(data, 0, cipherText, 0, cipherTextLength);
|
||||
Buffer.BlockCopy(data, cipherTextLength, tag, 0, TagLength);
|
||||
Buffer.BlockCopy(data, cipherTextLength + TagLength, iv, 0, IvLength);
|
||||
|
||||
using (AesGcm aesGcm = new AesGcm(key, AesGcm.TagByteSizes.MaxSize)) {
|
||||
var decryptedData = new byte[cipherText.Length];
|
||||
aesGcm.Decrypt(iv, cipherText, tag, decryptedData);
|
||||
return decryptedData;
|
||||
}
|
||||
}
|
||||
|
||||
public static string GenerateKeyBase64() {
|
||||
var key = new byte[32]; // 256-bit key for AES-256
|
||||
RandomNumberGenerator.Fill(key);
|
||||
return Convert.ToBase64String(key);
|
||||
}
|
||||
}
|
||||
130
src/MaksIT.LTO.Core/Utilities/ChecksumUtility.cs
Normal file
130
src/MaksIT.LTO.Core/Utilities/ChecksumUtility.cs
Normal file
@ -0,0 +1,130 @@
|
||||
using System.IO;
|
||||
using System.Security.Cryptography;
|
||||
|
||||
namespace MaksIT.LTO.Core.Helpers;
|
||||
|
||||
public static class ChecksumUtility {
|
||||
public static string CalculateCRC32Checksum(byte[] data) {
|
||||
using var crc32 = new Crc32();
|
||||
byte[] hashBytes = crc32.ComputeHash(data);
|
||||
return BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
|
||||
}
|
||||
|
||||
public static string CalculateCRC32ChecksumFromFile(string filePath) {
|
||||
using var crc32 = new Crc32();
|
||||
using var stream = File.OpenRead(filePath);
|
||||
byte[] hashBytes = crc32.ComputeHash(stream);
|
||||
return BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
|
||||
}
|
||||
|
||||
public static string CalculateCRC32ChecksumFromFileInChunks(string filePath, int chunkSize = 8192) {
|
||||
using var crc32 = new Crc32();
|
||||
using var stream = File.OpenRead(filePath);
|
||||
var buffer = new byte[chunkSize];
|
||||
int bytesRead;
|
||||
while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) > 0) {
|
||||
crc32.TransformBlock(buffer, 0, bytesRead, null, 0);
|
||||
}
|
||||
crc32.TransformFinalBlock(buffer, 0, 0);
|
||||
byte[] hashBytes = crc32.Hash;
|
||||
return BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
|
||||
}
|
||||
|
||||
public static bool VerifyCRC32Checksum(byte[] data, string expectedChecksum) {
|
||||
string calculatedChecksum = CalculateCRC32Checksum(data);
|
||||
return string.Equals(calculatedChecksum, expectedChecksum, StringComparison.OrdinalIgnoreCase);
|
||||
}
|
||||
|
||||
public static bool VerifyCRC32ChecksumFromFile(string filePath, string expectedChecksum) {
|
||||
string calculatedChecksum = CalculateCRC32ChecksumFromFile(filePath);
|
||||
return string.Equals(calculatedChecksum, expectedChecksum, StringComparison.OrdinalIgnoreCase);
|
||||
}
|
||||
|
||||
public static bool VerifyCRC32ChecksumFromFileInChunks(string filePath, string expectedChecksum, int chunkSize = 8192) {
|
||||
string calculatedChecksum = CalculateCRC32ChecksumFromFileInChunks(filePath, chunkSize);
|
||||
return string.Equals(calculatedChecksum, expectedChecksum, StringComparison.OrdinalIgnoreCase);
|
||||
}
|
||||
}
|
||||
|
||||
public class Crc32 : HashAlgorithm {
|
||||
public const uint DefaultPolynomial = 0xedb88320;
|
||||
public const uint DefaultSeed = 0xffffffff;
|
||||
|
||||
private static uint[]? defaultTable;
|
||||
|
||||
private readonly uint seed;
|
||||
private readonly uint[] table;
|
||||
private uint hash;
|
||||
|
||||
public Crc32()
|
||||
: this(DefaultPolynomial, DefaultSeed) {
|
||||
}
|
||||
|
||||
public Crc32(uint polynomial, uint seed) {
|
||||
table = InitializeTable(polynomial);
|
||||
this.seed = hash = seed;
|
||||
}
|
||||
|
||||
public override void Initialize() {
|
||||
hash = seed;
|
||||
}
|
||||
|
||||
protected override void HashCore(byte[] buffer, int start, int length) {
|
||||
hash = CalculateHash(table, hash, buffer, start, length);
|
||||
}
|
||||
|
||||
protected override byte[] HashFinal() {
|
||||
var hashBuffer = UInt32ToBigEndianBytes(~hash);
|
||||
HashValue = hashBuffer;
|
||||
return hashBuffer;
|
||||
}
|
||||
|
||||
public override int HashSize => 32;
|
||||
|
||||
public static uint Compute(byte[] buffer) {
|
||||
return Compute(DefaultPolynomial, DefaultSeed, buffer);
|
||||
}
|
||||
|
||||
public static uint Compute(uint seed, byte[] buffer) {
|
||||
return Compute(DefaultPolynomial, seed, buffer);
|
||||
}
|
||||
|
||||
public static uint Compute(uint polynomial, uint seed, byte[] buffer) {
|
||||
return ~CalculateHash(InitializeTable(polynomial), seed, buffer, 0, buffer.Length);
|
||||
}
|
||||
|
||||
private static uint[] InitializeTable(uint polynomial) {
|
||||
if (polynomial == DefaultPolynomial && defaultTable != null)
|
||||
return defaultTable;
|
||||
|
||||
var createTable = new uint[256];
|
||||
for (var i = 0; i < 256; i++) {
|
||||
var entry = (uint)i;
|
||||
for (var j = 0; j < 8; j++)
|
||||
if ((entry & 1) == 1)
|
||||
entry = (entry >> 1) ^ polynomial;
|
||||
else
|
||||
entry >>= 1;
|
||||
createTable[i] = entry;
|
||||
}
|
||||
|
||||
if (polynomial == DefaultPolynomial)
|
||||
defaultTable = createTable;
|
||||
|
||||
return createTable;
|
||||
}
|
||||
|
||||
private static uint CalculateHash(uint[] table, uint seed, byte[] buffer, int start, int size) {
|
||||
var crc = seed;
|
||||
for (var i = start; i < size - start; i++)
|
||||
crc = (crc >> 8) ^ table[buffer[i] ^ crc & 0xff];
|
||||
return crc;
|
||||
}
|
||||
|
||||
private static byte[] UInt32ToBigEndianBytes(uint x) => [
|
||||
(byte)((x >> 24) & 0xff),
|
||||
(byte)((x >> 16) & 0xff),
|
||||
(byte)((x >> 8) & 0xff),
|
||||
(byte)(x & 0xff)
|
||||
];
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user