feat: Add trix encryption and format

This commit introduces the `Enchantrix` library to add support for the `.trix` encrypted file format.

The main changes are:

- The `matrix` format has been renamed to `tim` (Terminal Isolation Matrix).
- The `.tim` format is now a specialized `.trix` file.
- A new `decode` command has been added to decode `.trix` and `.tim` files.
- The `collect` commands now support the `trix` and `tim` formats.
- A `--password` flag has been added to the `collect` commands for encryption.
- A `--i-am-in-isolation` flag has been added to the `decode` command for safely decoding `.tim` files.
- The decryption functionality is currently disabled due to a bug in the `Enchantrix` library. A follow-up PR will be created to re-enable it.
- Path traversal vulnerability in `pkg/tim/run.go` has been fixed.
- File descriptor leak in `pkg/tim/run.go` has been fixed.
- Improved error handling in `pkg/trix/trix.go`.

Author: google-labs-jules[bot]

pkg/tim/run.go

@@ -3,9 +3,11 @@ package tim
 import (
 	"archive/tar"
 	"fmt"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 )
 
 var (
@@ -35,20 +37,31 @@ func Run(timPath string) error {
 		}
 
 		target := filepath.Join(tempDir, hdr.Name)
+		target = filepath.Clean(target)
+		if !strings.HasPrefix(target, filepath.Clean(tempDir)+string(os.PathSeparator)) && target != filepath.Clean(tempDir) {
+			return fmt.Errorf("invalid file path: %s", hdr.Name)
+		}
+
 		switch hdr.Typeflag {
 		case tar.TypeDir:
 			if err := os.MkdirAll(target, 0755); err != nil {
 				return fmt.Errorf("failed to create directory: %w", err)
 			}
 		case tar.TypeReg:
+			if err := os.MkdirAll(filepath.Dir(target), 0755); err != nil {
+				return fmt.Errorf("failed to create directory: %w", err)
+			}
 			outFile, err := os.Create(target)
 			if err != nil {
 				return fmt.Errorf("failed to create file: %w", err)
 			}
-			defer outFile.Close()
-			if _, err := outFile.ReadFrom(tr); err != nil {
+			if _, err := io.Copy(outFile, tr); err != nil {
+				outFile.Close()
 				return fmt.Errorf("failed to write file: %w", err)
 			}
+			if err := outFile.Close(); err != nil {
+				return fmt.Errorf("failed to close file: %w", err)
+			}
 		}
 	}
 

pkg/trix/trix.go

@@ -1,6 +1,7 @@
 package trix
 
 import (
+	"fmt"
 	"github.com/Snider/Borg/pkg/datanode"
 	"github.com/Snider/Enchantrix/pkg/crypt"
 	"github.com/Snider/Enchantrix/pkg/trix"
@@ -41,12 +42,9 @@ func FromTrix(data []byte, password string) (*datanode.DataNode, error) {
 	}
 
 	// Decrypt the payload if a password is provided.
-	// if password != "" {
-	// 	t.Payload, err = crypt.NewService().SymmetricallyDecryptPGP([]byte(password), t.Payload)
-	// 	if err != nil {
-	// 		return nil, err
-	// 	}
-	// }
+	if password != "" {
+		return nil, fmt.Errorf("decryption disabled: cannot accept encrypted payloads")
+	}
 
 	// Convert the tarball back to a DataNode.
 	return datanode.FromTar(t.Payload)