DebTik/internal/backup/backup_test.go

package backup

import (
	"archive/zip"
	"bytes"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestCreateAndInspectBackup(t *testing.T) {
	tempDir := t.TempDir()
	debtikDir := filepath.Join(tempDir, "debtik")
	netDir := filepath.Join(tempDir, "network")
	storeDir := filepath.Join(tempDir, "backups")

	// Create test structure
	if err := os.MkdirAll(filepath.Join(debtikDir, "certs"), 0755); err != nil {
		t.Fatal(err)
	}
	if err := os.MkdirAll(netDir, 0755); err != nil {
		t.Fatal(err)
	}

	metadataContent := []byte(`{"version": 1, "description": "test"}`)
	keyContent := []byte(`super-secret-ssh-key`)
	certContent := []byte(`fake-cert-data`)
	ifacesContent := []byte(`auto eth0` + "\n" + `iface eth0 inet dhcp`)

	if err := os.WriteFile(filepath.Join(debtikDir, "metadata.json"), metadataContent, 0644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(debtikDir, "ssh_host_ed25519_key"), keyContent, 0600); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(debtikDir, "certs", "server.crt"), certContent, 0644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(netDir, "interfaces.cfg"), ifacesContent, 0644); err != nil {
		t.Fatal(err)
	}

	mgr := NewManager(debtikDir, netDir, storeDir, nil)

	// Create backup
	zipBytes, manifest, err := mgr.CreateBackup("Unit test backup")
	if err != nil {
		t.Fatalf("CreateBackup failed: %v", err)
	}

	if len(zipBytes) == 0 {
		t.Fatal("Expected non-empty zip bytes")
	}
	if manifest.Comment != "Unit test backup" {
		t.Errorf("Unexpected manifest comment: %s", manifest.Comment)
	}
	if len(manifest.Files) != 4 {
		t.Fatalf("Expected 4 files in manifest, got %d", len(manifest.Files))
	}

	// Inspect backup
	r := bytes.NewReader(zipBytes)
	inspected, err := mgr.InspectBackup(r, int64(len(zipBytes)))
	if err != nil {
		t.Fatalf("InspectBackup failed: %v", err)
	}

	if inspected.Hostname != manifest.Hostname {
		t.Errorf("Hostname mismatch: %s != %s", inspected.Hostname, manifest.Hostname)
	}
	if len(inspected.Files) != 4 {
		t.Errorf("Expected 4 files in inspected manifest, got %d", len(inspected.Files))
	}
}

func TestRestoreBackup(t *testing.T) {
	tempDir := t.TempDir()
	debtikDir := filepath.Join(tempDir, "debtik")
	netDir := filepath.Join(tempDir, "network")
	storeDir := filepath.Join(tempDir, "backups")

	_ = os.MkdirAll(debtikDir, 0755)
	_ = os.MkdirAll(netDir, 0755)

	origMetadata := []byte(`{"version": "orig"}`)
	origKey := []byte(`private-key-123`)
	origIfaces := []byte(`auto eth0`)

	_ = os.WriteFile(filepath.Join(debtikDir, "metadata.json"), origMetadata, 0644)
	_ = os.WriteFile(filepath.Join(debtikDir, "ssh_host_ed25519_key"), origKey, 0600)
	_ = os.WriteFile(filepath.Join(netDir, "interfaces.cfg"), origIfaces, 0644)

	restarted := false
	restartHook := func() error {
		restarted = true
		return nil
	}

	mgr := NewManager(debtikDir, netDir, storeDir, restartHook)
	_ = restarted

	// 1. Create backup
	zipBytes, _, err := mgr.CreateBackup("Pre-modify backup")
	if err != nil {
		t.Fatalf("CreateBackup failed: %v", err)
	}

	// 2. Modify live files
	_ = os.WriteFile(filepath.Join(debtikDir, "metadata.json"), []byte(`{"version": "modified"}`), 0644)
	_ = os.WriteFile(filepath.Join(debtikDir, "rogue.json"), []byte(`rogue data`), 0644)
	_ = os.WriteFile(filepath.Join(netDir, "interfaces.cfg"), []byte(`modified eth0`), 0644)

	// 3. Restore backup
	r := bytes.NewReader(zipBytes)
	res, err := mgr.RestoreBackup(r, int64(len(zipBytes)))
	if err != nil {
		t.Fatalf("RestoreBackup failed: %v", err)
	}

	if !res.Success {
		t.Fatal("Expected restore success true")
	}

	// 4. Verify original metadata was restored
	restoredMeta, err := os.ReadFile(filepath.Join(debtikDir, "metadata.json"))
	if err != nil {
		t.Fatalf("Failed reading restored metadata: %v", err)
	}
	if string(restoredMeta) != string(origMetadata) {
		t.Errorf("Metadata mismatch: got %q, want %q", string(restoredMeta), string(origMetadata))
	}

	// 5. Verify rogue file was removed during sync
	if _, err := os.Stat(filepath.Join(debtikDir, "rogue.json")); !os.IsNotExist(err) {
		t.Error("Expected rogue.json to be cleaned up after restore")
	}

	// 6. Verify key permissions are 0600
	keyInfo, err := os.Stat(filepath.Join(debtikDir, "ssh_host_ed25519_key"))
	if err != nil {
		t.Fatalf("Failed reading restored key: %v", err)
	}
	if keyInfo.Mode().Perm() != 0600 {
		t.Errorf("Expected 0600 perm on private key, got %v", keyInfo.Mode().Perm())
	}

	// 7. Verify pre-restore fallback backup exists in storeDir
	if res.SafetyBackup == "" {
		t.Error("Expected non-empty SafetyBackup path")
	}
	if _, err := os.Stat(res.SafetyBackup); err != nil {
		t.Errorf("Safety backup file does not exist: %v", err)
	}
}

func TestZipSlipPrevention(t *testing.T) {
	tempDir := t.TempDir()
	debtikDir := filepath.Join(tempDir, "debtik")
	netDir := filepath.Join(tempDir, "network")
	storeDir := filepath.Join(tempDir, "backups")

	mgr := NewManager(debtikDir, netDir, storeDir, nil)

	// Create malicious zip with traversal path
	buf := new(bytes.Buffer)
	zw := zip.NewWriter(buf)

	// Valid manifest
	mf, err := zw.Create("manifest.json")
	if err != nil {
		t.Fatal(err)
	}
	_, _ = mf.Write([]byte(`{"version": "1.0", "files": []}`))

	// Malicious traversal file
	malicious, err := zw.Create("../../../etc/evil.conf")
	if err != nil {
		t.Fatal(err)
	}
	_, _ = malicious.Write([]byte(`malicious payload`))
	_ = zw.Close()

	r := bytes.NewReader(buf.Bytes())
	_, err = mgr.InspectBackup(r, int64(buf.Len()))
	if err == nil {
		t.Fatal("Expected InspectBackup to fail on Zip Slip traversal entry")
	}
	if !strings.Contains(err.Error(), "illegal entry path") {
		t.Errorf("Expected illegal entry path error, got %v", err)
	}

	// Attempt restore
	_, err = mgr.RestoreBackup(r, int64(buf.Len()))
	if err == nil {
		t.Fatal("Expected RestoreBackup to fail on Zip Slip entry")
	}
}

func TestLocalBackupsAndPruning(t *testing.T) {
	tempDir := t.TempDir()
	debtikDir := filepath.Join(tempDir, "debtik")
	netDir := filepath.Join(tempDir, "network")
	storeDir := filepath.Join(tempDir, "backups")

	_ = os.MkdirAll(debtikDir, 0755)
	_ = os.WriteFile(filepath.Join(debtikDir, "dummy.json"), []byte("{}"), 0644)

	mgr := NewManager(debtikDir, netDir, storeDir, nil)

	// Create 7 pre-restore backups
	for i := 0; i < 7; i++ {
		_, err := mgr.CreatePreRestoreBackup()
		if err != nil {
			t.Fatalf("Failed creating pre-restore backup %d: %v", i, err)
		}
	}

	// List backups
	list, err := mgr.ListLocalBackups()
	if err != nil {
		t.Fatalf("ListLocalBackups failed: %v", err)
	}

	// Pre-restore backups should be pruned to keep 5
	if len(list) != 5 {
		t.Errorf("Expected 5 backups after pruning, got %d", len(list))
	}

	// Test GetLocalBackup
	savedFile := list[0].Filename
	path, err := mgr.GetLocalBackup(savedFile)
	if err != nil {
		t.Fatalf("GetLocalBackup failed: %v", err)
	}
	if _, err := os.Stat(path); err != nil {
		t.Fatalf("File does not exist: %v", err)
	}

	// Test GetLocalBackup traversal reject
	_, err = mgr.GetLocalBackup("../../evil.zip")
	if err == nil {
		t.Error("Expected error on traversal filename")
	}
}