diff options
Diffstat (limited to 'src/Agent.Windows')
| -rw-r--r-- | src/Agent.Windows/Recovery/RecoveryManager.cs | 13 | ||||
| -rw-r--r-- | src/Agent.Windows/Recovery/TransactionalFileEditor.cs | 41 | ||||
| -rw-r--r-- | src/Agent.Windows/Tools/TextFileDetector.cs | 141 | ||||
| -rw-r--r-- | src/Agent.Windows/Tools/WindowsToolBackend.cs | 16 |
4 files changed, 209 insertions, 2 deletions
diff --git a/src/Agent.Windows/Recovery/RecoveryManager.cs b/src/Agent.Windows/Recovery/RecoveryManager.cs index 8fd7368..c9b28bf 100644 --- a/src/Agent.Windows/Recovery/RecoveryManager.cs +++ b/src/Agent.Windows/Recovery/RecoveryManager.cs @@ -49,6 +49,7 @@ public sealed class RecoveryManager(string journalDirectory, ISecurityAuditSink { case "file.replace": RecoverFile(entry); break; case "file.delete": RecoverDeletedFile(entry); break; + case "file.rename": RecoverRenamedFile(entry); break; case "dir.mkdir": RecoverMkdir(entry); break; case "dir.rmdir": RecoverRmdir(entry); break; case "acl": RecoverAcl(entry); break; @@ -96,6 +97,18 @@ public sealed class RecoveryManager(string journalDirectory, ISecurityAuditSink File.WriteAllBytes(entry.Target, original); } + private static void RecoverRenamedFile(JournalEntry entry) + { + string destination = entry.Data["destination_path"]; + string sourceHash = entry.Data["source_sha256"]; + if (!File.Exists(destination)) return; // Already rolled back or destination missing — skip. + if (!Hash(destination).Equals(sourceHash, StringComparison.Ordinal)) + throw new InvalidOperationException($"Renamed destination '{destination}' hash does not match journal record; automatic recovery refused."); + if (File.Exists(entry.Target)) + throw new InvalidOperationException($"Source path '{entry.Target}' was recreated after crash; automatic recovery refused."); + File.Move(destination, entry.Target); + } + private static void RecoverMkdir(JournalEntry entry) { if (!Directory.Exists(entry.Target)) return; diff --git a/src/Agent.Windows/Recovery/TransactionalFileEditor.cs b/src/Agent.Windows/Recovery/TransactionalFileEditor.cs index 805a069..25c949d 100644 --- a/src/Agent.Windows/Recovery/TransactionalFileEditor.cs +++ b/src/Agent.Windows/Recovery/TransactionalFileEditor.cs @@ -93,6 +93,26 @@ public sealed class TransactionalFileEditor(TaskResourceJournal journal, string return new(journal, entryId, canonical); } + public FileRenameTransaction Rename(string sourcePath, string destinationPath) + { + string source = CanonicalPath.Resolve(sourcePath); + string destination = CanonicalPath.Resolve(destinationPath, requireExisting: false); + if (!File.Exists(source)) throw new FileNotFoundException($"Source file does not exist: '{source}'."); + if (File.Exists(destination)) throw new ToolValidationException($"Destination already exists: '{destination}'. Rename overwrite is not allowed."); + if (!source.StartsWith(System.IO.Path.GetPathRoot(source)!, StringComparison.OrdinalIgnoreCase) || + !destination.StartsWith(System.IO.Path.GetPathRoot(source)!, StringComparison.OrdinalIgnoreCase)) + throw new ToolValidationException("Cross-volume rename is not supported."); + byte[] content = File.ReadAllBytes(source); + string sourceHash = Convert.ToHexString(SHA256.HashData(content)); + Guid entryId = journal.Prepare("file.rename", source, new Dictionary<string, string> + { + ["destination_path"] = destination, ["source_sha256"] = sourceHash + }); + File.Move(source, destination); + journal.MarkApplied(entryId); + return new(journal, entryId, source, destination, sourceHash); + } + private static string NormalizeHash(string hash) => hash.Replace("-", string.Empty, StringComparison.Ordinal).Trim().ToUpperInvariant(); } @@ -144,6 +164,27 @@ public sealed class DirectoryRmdirTransaction(TaskResourceJournal journal, Guid } } +public sealed class FileRenameTransaction(TaskResourceJournal journal, Guid entryId, string sourcePath, string destinationPath, string sourceHash) +{ + private bool _finished; + public void Commit() { if (_finished) return; journal.MarkCleaned(entryId); _finished = true; } + public void Rollback() + { + if (_finished) return; + if (!File.Exists(destinationPath)) throw new InvalidOperationException("Rollback refused because the destination file is missing."); + if (!Hash(destinationPath).Equals(sourceHash, StringComparison.Ordinal)) + throw new InvalidDataException("Rollback refused because the destination file hash does not match the original source hash."); + File.Move(destinationPath, sourcePath); + journal.MarkCleaned(entryId); + _finished = true; + } + private static string Hash(string target) + { + using FileStream stream = File.OpenRead(target); + return Convert.ToHexString(SHA256.HashData(stream)); + } +} + public sealed class FileEditTransaction( TaskResourceJournal journal, Guid entryId, string path, string originalHash, string replacementHash, string backupPath, string originalBase64, bool originallyExisted) diff --git a/src/Agent.Windows/Tools/TextFileDetector.cs b/src/Agent.Windows/Tools/TextFileDetector.cs new file mode 100644 index 0000000..9a5778b --- /dev/null +++ b/src/Agent.Windows/Tools/TextFileDetector.cs @@ -0,0 +1,141 @@ +using System.IO; +using System.Text; + +namespace Agent.Windows.Tools; + +/// <summary> +/// Detects whether a file is text or binary by reading only a small sample from the beginning. +/// Uses BOM detection, UTF-16 validation, and UTF-8 strict decode — not NUL-byte-only detection +/// (which would incorrectly reject valid UTF-16 text). +/// </summary> +public static class TextFileDetector +{ + private const int SampleSize = 4096; + + /// <summary> + /// Returns true if the file at <paramref name="path"/> appears to contain valid text + /// (UTF-8, UTF-8 with BOM, UTF-16 LE, or UTF-16 BE). Reads at most <see cref="SampleSize"/> bytes. + /// </summary> + public static bool IsText(string path) + { + using var stream = File.OpenRead(path); + return IsText(stream); + } + + /// <summary> + /// Returns true if the stream's content appears to be valid text. + /// Reads at most <see cref="SampleSize"/> bytes from the current position. + /// </summary> + public static bool IsText(Stream stream) + { + byte[] buffer = new byte[SampleSize]; + int read = stream.Read(buffer, 0, SampleSize); + if (read == 0) return true; // Empty file is considered text. + + Span<byte> sample = buffer.AsSpan(0, read); + + // 1. Check BOM. + if (sample.StartsWith(Encoding.UTF8.Preamble)) + return TryDecodeUtf8(sample[3..]); + if (sample.StartsWith(Encoding.Unicode.Preamble)) // UTF-16 LE + return TryDecodeUtf16(sample[2..], bigEndian: false); + if (sample.StartsWith(Encoding.BigEndianUnicode.Preamble)) // UTF-16 BE + return TryDecodeUtf16(sample[2..], bigEndian: true); + + // 2. No BOM — try UTF-8 strict decode. + return TryDecodeUtf8(sample); + } + + private static bool TryDecodeUtf8(ReadOnlySpan<byte> data) + { + // Validate UTF-8 byte sequences manually to detect invalid bytes. + return TryDecodeUtf8Core(data); + } + + private static bool TryDecodeUtf8Core(ReadOnlySpan<byte> data) + { + // Validate UTF-8 byte sequences manually to detect invalid bytes. + int i = 0; + while (i < data.Length) + { + byte b = data[i]; + if (b < 0x80) // ASCII + { + i++; + } + else if (b < 0xC2) // Invalid leading byte + { + return false; + } + else if (b < 0xE0) // 2-byte sequence + { + if (i + 1 >= data.Length) break; // Truncated at sample boundary — assume valid. + if (!IsContinuationByte(data[i + 1])) return false; + i += 2; + } + else if (b < 0xF0) // 3-byte sequence + { + if (i + 2 >= data.Length) break; + if (!IsContinuationByte(data[i + 1]) || !IsContinuationByte(data[i + 2])) return false; + // Check for overlong encodings and surrogate halves. + if (b == 0xE0 && data[i + 1] < 0xA0) return false; // Overlong. + if (b == 0xED && data[i + 1] >= 0xA0) return false; // Surrogate half. + i += 3; + } + else if (b < 0xF5) // 4-byte sequence + { + if (i + 3 >= data.Length) break; + if (!IsContinuationByte(data[i + 1]) || !IsContinuationByte(data[i + 2]) || !IsContinuationByte(data[i + 3])) return false; + if (b == 0xF0 && data[i + 1] < 0x90) return false; // Overlong. + if (b == 0xF4 && data[i + 1] >= 0x90) return false; // Out of range. + i += 4; + } + else + { + return false; + } + } + return true; + } + + private static bool TryDecodeUtf16(ReadOnlySpan<byte> data, bool bigEndian) + { + // UTF-16: every code unit is 2 bytes. Validate that surrogates are properly paired. + if (data.Length % 2 != 0) + { + // Odd byte count at sample boundary — check the pairs we have. + } + + int i = 0; + while (i + 1 < data.Length) + { + ushort codeUnit = bigEndian + ? (ushort)((data[i] << 8) | data[i + 1]) + : (ushort)((data[i + 1] << 8) | data[i]); + + if (codeUnit < 0xD800 || codeUnit > 0xDFFF) + { + // BMP character — valid. + i += 2; + } + else if (codeUnit >= 0xD800 && codeUnit <= 0xDBFF) + { + // High surrogate — must be followed by a low surrogate. + if (i + 3 >= data.Length) break; // Truncated at sample boundary — assume valid. + ushort next = bigEndian + ? (ushort)((data[i + 2] << 8) | data[i + 3]) + : (ushort)((data[i + 3] << 8) | data[i + 2]); + if (next < 0xDC00 || next > 0xDFFF) return false; + i += 4; + } + else + { + // Low surrogate without preceding high surrogate — invalid. + return false; + } + } + return true; + } + + private static bool IsContinuationByte(byte b) => b >= 0x80 && b <= 0xBF; +}
\ No newline at end of file diff --git a/src/Agent.Windows/Tools/WindowsToolBackend.cs b/src/Agent.Windows/Tools/WindowsToolBackend.cs index bb54c6e..936bcbd 100644 --- a/src/Agent.Windows/Tools/WindowsToolBackend.cs +++ b/src/Agent.Windows/Tools/WindowsToolBackend.cs @@ -104,6 +104,7 @@ public sealed class WindowsToolBackend(WindowsSandboxSettings settings, ISecurit int lines = arguments.TryGetProperty("tail_lines", out JsonElement lineElement) ? lineElement.GetInt32() : 100; lines = Math.Min(lines, settings.TailLineLimit); if (new FileInfo(canonical).Length > settings.WholeReadLimitBytes * 16) throw new IOException("Tail input is too large."); + if (!TextFileDetector.IsText(canonical)) throw new ToolValidationException("File appears to be binary; tail mode is text-only."); string[] content = File.ReadLines(canonical).TakeLast(lines).ToArray(); return Success(JsonSerializer.Serialize(content)); } @@ -160,6 +161,14 @@ public sealed class WindowsToolBackend(WindowsSandboxSettings settings, ISecurit FileDeleteTransaction transaction = editor.Delete(path, expected); transaction.Commit(); } + else if (operation == "rename") + { + string newPath = arguments.GetProperty("new_path").GetString()!; + _paths.Demand(path, FileCapability.Write); + _paths.Demand(newPath, FileCapability.Write); + FileRenameTransaction transaction = editor.Rename(path, newPath); + transaction.Commit(); + } else { _paths.Demand(path, FileCapability.Write); @@ -169,8 +178,11 @@ public sealed class WindowsToolBackend(WindowsSandboxSettings settings, ISecurit FileEditTransaction transaction = editor.Replace(path, replacement, expected); transaction.Commit(); } - audit.Write(new(DateTimeOffset.UtcNow, context.Journal.TaskId, "file." + operation, "completed", new Dictionary<string, string> { ["path"] = Path.GetFullPath(path) })); - return Success($"{operation} completed for {Path.GetFullPath(path)}", externalEffect: true); + string auditPath = operation == "rename" + ? $"{Path.GetFullPath(path)} -> {Path.GetFullPath(arguments.GetProperty("new_path").GetString()!)}" + : Path.GetFullPath(path); + audit.Write(new(DateTimeOffset.UtcNow, context.Journal.TaskId, "file." + operation, "completed", new Dictionary<string, string> { ["path"] = auditPath })); + return Success($"{operation} completed for {auditPath}", externalEffect: true); } private ToolExecutionResult DirectoryOp(TaskContext context, JsonElement arguments) |