v5.8.12: Fix config loading for non-standard home directories

- Config now searches: ./ → ~/ → /etc/dbbackup.conf → /etc/dbbackup/dbbackup.conf
- Works for postgres user with home at /var/lib/postgresql
- Added ConfigSearchPaths() and LoadLocalConfigWithPath()
- Log shows which config path was loaded

CHANGELOG.md

@@ -5,6 +5,36 @@ All notable changes to dbbackup will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [5.8.12] - 2026-02-04
+
+### Fixed
+- **Config Loading**: Fixed config not loading for users without standard home directories
+  - Now searches: current dir → home dir → /etc/dbbackup.conf → /etc/dbbackup/dbbackup.conf
+  - Works for postgres user with home at /var/lib/postgresql
+  - Added `ConfigSearchPaths()` and `LoadLocalConfigWithPath()` functions
+  - Log now shows which config path was actually loaded
+
+## [5.8.11] - 2026-02-04
+
+### Fixed
+- **TUI Deadlock**: Fixed goroutine leaks in pgxpool connection handling
+  - Removed redundant goroutines waiting on ctx.Done() in postgresql.go and parallel_restore.go
+  - These were causing WaitGroup deadlocks when BubbleTea tried to shutdown
+
+### Added
+- **systemd-run Resource Isolation**: New `internal/cleanup/cgroups.go` for long-running jobs
+  - `RunWithResourceLimits()` wraps commands in systemd-run scopes
+  - Configurable: MemoryHigh, MemoryMax, CPUQuota, IOWeight, Nice, Slice
+  - Automatic cleanup on context cancellation
+- **Restore Dry-Run Checks**: New `internal/restore/dryrun.go` with 10 pre-restore validations
+  - Archive access, format, connectivity, permissions, target conflicts
+  - Disk space, work directory, required tools, lock settings, memory estimation
+  - Returns pass/warning/fail status with detailed messages
+- **Audit Log Signing**: Enhanced `internal/security/audit.go` with Ed25519 cryptographic signing
+  - `SignedAuditEntry` with sequence numbers, hash chains, and signatures
+  - `GenerateSigningKeys()`, `SavePrivateKey()`, `LoadPublicKey()`
+  - `EnableSigning()`, `ExportSignedLog()`, `VerifyAuditLog()` for tamper detection
+
 ## [5.7.10] - 2026-02-03
 
 ### Fixed

cmd/native_backup.go

@@ -11,6 +11,7 @@ import (
 
 	"dbbackup/internal/database"
 	"dbbackup/internal/engine/native"
+	"dbbackup/internal/metadata"
 	"dbbackup/internal/notify"
 
 	"github.com/klauspost/pgzip"
@@ -163,6 +164,54 @@ func runNativeBackup(ctx context.Context, db database.Database, databaseName, ba
 		"duration", backupDuration,
 		"engine", result.EngineUsed)
 
+	// Get actual file size from disk
+	fileInfo, err := os.Stat(outputFile)
+	var actualSize int64
+	if err == nil {
+		actualSize = fileInfo.Size()
+	} else {
+		actualSize = result.BytesProcessed
+	}
+
+	// Calculate SHA256 checksum
+	sha256sum, err := metadata.CalculateSHA256(outputFile)
+	if err != nil {
+		log.Warn("Failed to calculate SHA256", "error", err)
+		sha256sum = ""
+	}
+
+	// Create and save metadata file
+	meta := &metadata.BackupMetadata{
+		Version:      "1.0",
+		Timestamp:    backupStartTime,
+		Database:     databaseName,
+		DatabaseType: dbType,
+		Host:         cfg.Host,
+		Port:         cfg.Port,
+		User:         cfg.User,
+		BackupFile:   filepath.Base(outputFile),
+		SizeBytes:    actualSize,
+		SHA256:       sha256sum,
+		Compression:  "gzip",
+		BackupType:   backupType,
+		Duration:     backupDuration.Seconds(),
+		ExtraInfo: map[string]string{
+			"engine":            result.EngineUsed,
+			"objects_processed": fmt.Sprintf("%d", result.ObjectsProcessed),
+		},
+	}
+
+	if cfg.CompressionLevel == 0 {
+		meta.Compression = "none"
+	}
+
+	metaPath := outputFile + ".meta.json"
+	if err := metadata.Save(metaPath, meta); err != nil {
+		log.Warn("Failed to save metadata", "error", err)
+	} else {
+		log.Debug("Metadata saved", "path", metaPath)
+	}
+
 	// Audit log: backup completed
 	auditLogger.LogBackupComplete(user, databaseName, cfg.BackupDir, result.BytesProcessed)
 

cmd/root.go

@@ -15,11 +15,11 @@ import (
 )
 
 var (
-	cfg              *config.Config
-	log              logger.Logger
-	auditLogger      *security.AuditLogger
-	rateLimiter      *security.RateLimiter
-	notifyManager    *notify.Manager
+	cfg                *config.Config
+	log                logger.Logger
+	auditLogger        *security.AuditLogger
+	rateLimiter        *security.RateLimiter
+	notifyManager      *notify.Manager
 	deprecatedPassword string
 )
 
@@ -61,22 +61,24 @@ For help with specific commands, use: dbbackup [command] --help`,
 
 		// Load local config if not disabled
 		if !cfg.NoLoadConfig {
-			// Use custom config path if specified, otherwise default to current directory
+			// Use custom config path if specified, otherwise search standard locations
 			var localCfg *config.LocalConfig
+			var configPath string
 			var err error
 			if cfg.ConfigPath != "" {
 				localCfg, err = config.LoadLocalConfigFromPath(cfg.ConfigPath)
+				configPath = cfg.ConfigPath
 				if err != nil {
 					log.Warn("Failed to load config from specified path", "path", cfg.ConfigPath, "error", err)
 				} else if localCfg != nil {
 					log.Info("Loaded configuration", "path", cfg.ConfigPath)
 				}
 			} else {
-				localCfg, err = config.LoadLocalConfig()
+				localCfg, configPath, err = config.LoadLocalConfigWithPath()
 				if err != nil {
-					log.Warn("Failed to load local config", "error", err)
+					log.Warn("Failed to load config", "error", err)
 				} else if localCfg != nil {
-					log.Info("Loaded configuration from .dbbackup.conf")
+					log.Info("Loaded configuration", "path", configPath)
 				}
 			}
 

internal/cleanup/cgroups.go

@@ -0,0 +1,236 @@
+package cleanup
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"dbbackup/internal/logger"
+)
+
+// ResourceLimits defines resource constraints for long-running operations
+type ResourceLimits struct {
+	// MemoryHigh is the high memory limit (e.g., "4G", "2048M")
+	// When exceeded, kernel will throttle and reclaim memory aggressively
+	MemoryHigh string
+
+	// MemoryMax is the hard memory limit (e.g., "6G")
+	// Process is killed if exceeded
+	MemoryMax string
+
+	// CPUQuota limits CPU usage (e.g., "70%" for 70% of one CPU)
+	CPUQuota string
+
+	// IOWeight sets I/O priority (1-10000, default 100)
+	IOWeight int
+
+	// Nice sets process priority (-20 to 19)
+	Nice int
+
+	// Slice is the systemd slice to run under (e.g., "dbbackup.slice")
+	Slice string
+}
+
+// DefaultResourceLimits returns sensible defaults for backup/restore operations
+func DefaultResourceLimits() *ResourceLimits {
+	return &ResourceLimits{
+		MemoryHigh: "4G",
+		MemoryMax:  "6G",
+		CPUQuota:   "80%",
+		IOWeight:   100, // Default priority
+		Nice:       10,  // Slightly lower priority than interactive processes
+		Slice:      "dbbackup.slice",
+	}
+}
+
+// SystemdRunAvailable checks if systemd-run is available on this system
+func SystemdRunAvailable() bool {
+	if runtime.GOOS != "linux" {
+		return false
+	}
+	_, err := exec.LookPath("systemd-run")
+	return err == nil
+}
+
+// RunWithResourceLimits executes a command with resource limits via systemd-run
+// Falls back to direct execution if systemd-run is not available
+func RunWithResourceLimits(ctx context.Context, log logger.Logger, limits *ResourceLimits, name string, args ...string) error {
+	if limits == nil {
+		limits = DefaultResourceLimits()
+	}
+
+	// If systemd-run not available, fall back to direct execution
+	if !SystemdRunAvailable() {
+		log.Debug("systemd-run not available, running without resource limits")
+		cmd := exec.CommandContext(ctx, name, args...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+
+	// Build systemd-run command
+	systemdArgs := buildSystemdArgs(limits, name, args)
+
+	log.Info("Running with systemd resource limits",
+		"command", name,
+		"memory_high", limits.MemoryHigh,
+		"cpu_quota", limits.CPUQuota)
+
+	cmd := exec.CommandContext(ctx, "systemd-run", systemdArgs...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}
+
+// RunWithResourceLimitsOutput executes with limits and returns combined output
+func RunWithResourceLimitsOutput(ctx context.Context, log logger.Logger, limits *ResourceLimits, name string, args ...string) ([]byte, error) {
+	if limits == nil {
+		limits = DefaultResourceLimits()
+	}
+
+	// If systemd-run not available, fall back to direct execution
+	if !SystemdRunAvailable() {
+		log.Debug("systemd-run not available, running without resource limits")
+		cmd := exec.CommandContext(ctx, name, args...)
+		return cmd.CombinedOutput()
+	}
+
+	// Build systemd-run command
+	systemdArgs := buildSystemdArgs(limits, name, args)
+
+	log.Debug("Running with systemd resource limits",
+		"command", name,
+		"memory_high", limits.MemoryHigh)
+
+	cmd := exec.CommandContext(ctx, "systemd-run", systemdArgs...)
+	return cmd.CombinedOutput()
+}
+
+// buildSystemdArgs constructs the systemd-run argument list
+func buildSystemdArgs(limits *ResourceLimits, name string, args []string) []string {
+	systemdArgs := []string{
+		"--scope",   // Run as transient scope (not service)
+		"--user",    // Run in user session (no root required)
+		"--quiet",   // Reduce systemd noise
+		"--collect", // Automatically clean up after exit
+	}
+
+	// Add description for easier identification
+	systemdArgs = append(systemdArgs, fmt.Sprintf("--description=dbbackup: %s", name))
+
+	// Add resource properties
+	if limits.MemoryHigh != "" {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--property=MemoryHigh=%s", limits.MemoryHigh))
+	}
+
+	if limits.MemoryMax != "" {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--property=MemoryMax=%s", limits.MemoryMax))
+	}
+
+	if limits.CPUQuota != "" {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--property=CPUQuota=%s", limits.CPUQuota))
+	}
+
+	if limits.IOWeight > 0 {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--property=IOWeight=%d", limits.IOWeight))
+	}
+
+	if limits.Nice != 0 {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--property=Nice=%d", limits.Nice))
+	}
+
+	if limits.Slice != "" {
+		systemdArgs = append(systemdArgs, fmt.Sprintf("--slice=%s", limits.Slice))
+	}
+
+	// Add separator and command
+	systemdArgs = append(systemdArgs, "--")
+	systemdArgs = append(systemdArgs, name)
+	systemdArgs = append(systemdArgs, args...)
+
+	return systemdArgs
+}
+
+// WrapCommand creates an exec.Cmd that runs with resource limits
+// This allows the caller to customize stdin/stdout/stderr before running
+func WrapCommand(ctx context.Context, log logger.Logger, limits *ResourceLimits, name string, args ...string) *exec.Cmd {
+	if limits == nil {
+		limits = DefaultResourceLimits()
+	}
+
+	// If systemd-run not available, return direct command
+	if !SystemdRunAvailable() {
+		log.Debug("systemd-run not available, returning unwrapped command")
+		return exec.CommandContext(ctx, name, args...)
+	}
+
+	// Build systemd-run command
+	systemdArgs := buildSystemdArgs(limits, name, args)
+
+	log.Debug("Wrapping command with systemd resource limits",
+		"command", name,
+		"memory_high", limits.MemoryHigh)
+
+	return exec.CommandContext(ctx, "systemd-run", systemdArgs...)
+}
+
+// ResourceLimitsFromConfig creates resource limits from size estimates
+// Useful for dynamically setting limits based on backup/restore size
+func ResourceLimitsFromConfig(estimatedSizeBytes int64, isRestore bool) *ResourceLimits {
+	limits := DefaultResourceLimits()
+
+	// Estimate memory needs based on data size
+	// Restore needs more memory than backup
+	var memoryMultiplier float64 = 0.1 // 10% of data size for backup
+	if isRestore {
+		memoryMultiplier = 0.2 // 20% of data size for restore
+	}
+
+	estimatedMemMB := int64(float64(estimatedSizeBytes/1024/1024) * memoryMultiplier)
+
+	// Clamp to reasonable values
+	if estimatedMemMB < 512 {
+		estimatedMemMB = 512 // Minimum 512MB
+	}
+	if estimatedMemMB > 16384 {
+		estimatedMemMB = 16384 // Maximum 16GB
+	}
+
+	limits.MemoryHigh = fmt.Sprintf("%dM", estimatedMemMB)
+	limits.MemoryMax = fmt.Sprintf("%dM", estimatedMemMB*2) // 2x high limit
+
+	return limits
+}
+
+// GetActiveResourceUsage returns current resource usage if running in systemd scope
+func GetActiveResourceUsage() (string, error) {
+	if !SystemdRunAvailable() {
+		return "", fmt.Errorf("systemd not available")
+	}
+
+	// Check if we're running in a scope
+	cmd := exec.Command("systemctl", "--user", "status", "--no-pager")
+	output, err := cmd.Output()
+	if err != nil {
+		return "", fmt.Errorf("failed to get systemd status: %w", err)
+	}
+
+	// Extract dbbackup-related scopes
+	lines := strings.Split(string(output), "\n")
+	var dbbackupLines []string
+	for _, line := range lines {
+		if strings.Contains(line, "dbbackup") {
+			dbbackupLines = append(dbbackupLines, strings.TrimSpace(line))
+		}
+	}
+
+	if len(dbbackupLines) == 0 {
+		return "No active dbbackup scopes", nil
+	}
+
+	return strings.Join(dbbackupLines, "\n"), nil
+}

internal/config/persist.go

@@ -41,9 +41,53 @@ type LocalConfig struct {
 	MaxRetries    int
 }
 
-// LoadLocalConfig loads configuration from .dbbackup.conf in current directory
+// ConfigSearchPaths returns all paths where config files are searched, in order of priority
+func ConfigSearchPaths() []string {
+	paths := []string{
+		filepath.Join(".", ConfigFileName), // Current directory (highest priority)
+	}
+
+	// User's home directory
+	if home, err := os.UserHomeDir(); err == nil && home != "" {
+		paths = append(paths, filepath.Join(home, ConfigFileName))
+	}
+
+	// System-wide config locations
+	paths = append(paths,
+		"/etc/dbbackup.conf",
+		"/etc/dbbackup/dbbackup.conf",
+	)
+
+	return paths
+}
+
+// LoadLocalConfig loads configuration from .dbbackup.conf
+// Search order: 1) current directory, 2) user's home directory, 3) /etc/dbbackup.conf, 4) /etc/dbbackup/dbbackup.conf
 func LoadLocalConfig() (*LocalConfig, error) {
-	return LoadLocalConfigFromPath(filepath.Join(".", ConfigFileName))
+	for _, path := range ConfigSearchPaths() {
+		cfg, err := LoadLocalConfigFromPath(path)
+		if err != nil {
+			return nil, err
+		}
+		if cfg != nil {
+			return cfg, nil
+		}
+	}
+	return nil, nil
+}
+
+// LoadLocalConfigWithPath loads configuration and returns the path it was loaded from
+func LoadLocalConfigWithPath() (*LocalConfig, string, error) {
+	for _, path := range ConfigSearchPaths() {
+		cfg, err := LoadLocalConfigFromPath(path)
+		if err != nil {
+			return nil, "", err
+		}
+		if cfg != nil {
+			return cfg, path, nil
+		}
+	}
+	return nil, "", nil
 }
 
 // LoadLocalConfigFromPath loads configuration from a specific path

internal/database/postgresql.go

@@ -74,7 +74,7 @@ func (p *PostgreSQL) Connect(ctx context.Context) error {
 	config.MinConns = 2                        // Keep minimum connections ready
 	config.MaxConnLifetime = 0                 // No limit on connection lifetime
 	config.MaxConnIdleTime = 0                 // No idle timeout
-	config.HealthCheckPeriod = 1 * time.Minute // Health check every minute
+	config.HealthCheckPeriod = 5 * time.Second // Faster health check for quicker shutdown on Ctrl+C
 
 	// Optimize for large query results (BLOB data)
 	config.ConnConfig.RuntimeParams["work_mem"] = "64MB"
@@ -97,6 +97,14 @@ func (p *PostgreSQL) Connect(ctx context.Context) error {
 
 	p.pool = pool
 	p.db = db
+
+	// NOTE: We intentionally do NOT start a goroutine to close the pool on context cancellation.
+	// The pool is closed via defer dbClient.Close() in the caller, which is the correct pattern.
+	// Starting a goroutine here causes goroutine leaks and potential double-close issues when:
+	// 1. The caller's defer runs first (normal case)
+	// 2. Then context is cancelled and the goroutine tries to close an already-closed pool
+	// This was causing deadlocks in the TUI when tea.Batch was waiting for commands to complete.
+
 	p.log.Info("Connected to PostgreSQL successfully", "driver", "pgx", "max_conns", config.MaxConns)
 	return nil
 }

internal/engine/native/parallel_restore.go

@@ -28,6 +28,9 @@ type ParallelRestoreEngine struct {
 
 	// Configuration
 	parallelWorkers int
+
+	// Internal cancel channel to stop the pool cleanup goroutine
+	closeCh chan struct{}
 }
 
 // ParallelRestoreOptions configures parallel restore behavior
@@ -101,18 +104,35 @@ func NewParallelRestoreEngineWithContext(ctx context.Context, config *PostgreSQL
 	poolConfig.MaxConns = int32(workers + 2)
 	poolConfig.MinConns = int32(workers)
 
+	// CRITICAL: Reduce health check period to allow faster shutdown
+	// Default is 1 minute which causes hangs on Ctrl+C
+	poolConfig.HealthCheckPeriod = 5 * time.Second
+
 	// Use the provided context so pool health checks stop when context is cancelled
 	pool, err := pgxpool.NewWithConfig(ctx, poolConfig)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create connection pool: %w", err)
 	}
 
-	return &ParallelRestoreEngine{
+	closeCh := make(chan struct{})
+
+	engine := &ParallelRestoreEngine{
 		config:          config,
 		pool:            pool,
 		log:             log,
 		parallelWorkers: workers,
-	}, nil
+		closeCh:         closeCh,
+	}
+
+	// NOTE: We intentionally do NOT start a goroutine to close the pool on context cancellation.
+	// The pool is closed via defer parallelEngine.Close() in the caller (restore/engine.go).
+	// The Close() method properly signals closeCh and closes the pool.
+	// Starting a goroutine here can cause:
+	// 1. Race conditions with explicit Close() calls
+	// 2. Goroutine leaks if neither ctx nor Close() fires
+	// 3. Deadlocks with BubbleTea's event loop
+
+	return engine, nil
 }
 
 // RestoreFile restores from a SQL file with parallel execution
@@ -510,8 +530,13 @@ func (e *ParallelRestoreEngine) executeCopy(ctx context.Context, stmt *SQLStatem
 	return tag.RowsAffected(), nil
 }
 
-// Close closes the connection pool
+// Close closes the connection pool and stops the cleanup goroutine
 func (e *ParallelRestoreEngine) Close() error {
+	// Signal the cleanup goroutine to exit
+	if e.closeCh != nil {
+		close(e.closeCh)
+	}
+	// Close the pool
 	if e.pool != nil {
 		e.pool.Close()
 	}

internal/restore/dryrun.go

@@ -0,0 +1,666 @@
+package restore
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"time"
+
+	"dbbackup/internal/cleanup"
+	"dbbackup/internal/config"
+	"dbbackup/internal/logger"
+)
+
+// DryRunCheck represents a single dry-run check result
+type DryRunCheck struct {
+	Name     string
+	Status   DryRunStatus
+	Message  string
+	Details  string
+	Critical bool // If true, restore will definitely fail
+}
+
+// DryRunStatus represents the status of a dry-run check
+type DryRunStatus int
+
+const (
+	DryRunPassed DryRunStatus = iota
+	DryRunWarning
+	DryRunFailed
+	DryRunSkipped
+)
+
+func (s DryRunStatus) String() string {
+	switch s {
+	case DryRunPassed:
+		return "PASS"
+	case DryRunWarning:
+		return "WARN"
+	case DryRunFailed:
+		return "FAIL"
+	case DryRunSkipped:
+		return "SKIP"
+	default:
+		return "UNKNOWN"
+	}
+}
+
+func (s DryRunStatus) Icon() string {
+	switch s {
+	case DryRunPassed:
+		return "[+]"
+	case DryRunWarning:
+		return "[!]"
+	case DryRunFailed:
+		return "[-]"
+	case DryRunSkipped:
+		return "[ ]"
+	default:
+		return "[?]"
+	}
+}
+
+// DryRunResult contains all dry-run check results
+type DryRunResult struct {
+	Checks          []DryRunCheck
+	CanProceed      bool
+	HasWarnings     bool
+	CriticalCount   int
+	WarningCount    int
+	EstimatedTime   time.Duration
+	RequiredDiskMB  int64
+	AvailableDiskMB int64
+}
+
+// RestoreDryRun performs comprehensive pre-restore validation
+type RestoreDryRun struct {
+	cfg     *config.Config
+	log     logger.Logger
+	safety  *Safety
+	archive string
+	target  string
+}
+
+// NewRestoreDryRun creates a new restore dry-run validator
+func NewRestoreDryRun(cfg *config.Config, log logger.Logger, archivePath, targetDB string) *RestoreDryRun {
+	return &RestoreDryRun{
+		cfg:     cfg,
+		log:     log,
+		safety:  NewSafety(cfg, log),
+		archive: archivePath,
+		target:  targetDB,
+	}
+}
+
+// Run executes all dry-run checks
+func (r *RestoreDryRun) Run(ctx context.Context) (*DryRunResult, error) {
+	result := &DryRunResult{
+		Checks:     make([]DryRunCheck, 0, 10),
+		CanProceed: true,
+	}
+
+	r.log.Info("Running restore dry-run checks",
+		"archive", r.archive,
+		"target", r.target)
+
+	// 1. Archive existence and accessibility
+	result.Checks = append(result.Checks, r.checkArchiveAccess())
+
+	// 2. Archive format validation
+	result.Checks = append(result.Checks, r.checkArchiveFormat())
+
+	// 3. Database connectivity
+	result.Checks = append(result.Checks, r.checkDatabaseConnectivity(ctx))
+
+	// 4. User permissions (CREATE DATABASE, DROP, etc.)
+	result.Checks = append(result.Checks, r.checkUserPermissions(ctx))
+
+	// 5. Target database conflicts
+	result.Checks = append(result.Checks, r.checkTargetConflicts(ctx))
+
+	// 6. Disk space requirements
+	diskCheck, requiredMB, availableMB := r.checkDiskSpace()
+	result.Checks = append(result.Checks, diskCheck)
+	result.RequiredDiskMB = requiredMB
+	result.AvailableDiskMB = availableMB
+
+	// 7. Work directory permissions
+	result.Checks = append(result.Checks, r.checkWorkDirectory())
+
+	// 8. Required tools availability
+	result.Checks = append(result.Checks, r.checkRequiredTools())
+
+	// 9. PostgreSQL lock settings (for parallel restore)
+	result.Checks = append(result.Checks, r.checkLockSettings(ctx))
+
+	// 10. Memory availability
+	result.Checks = append(result.Checks, r.checkMemoryAvailability())
+
+	// Calculate summary
+	for _, check := range result.Checks {
+		switch check.Status {
+		case DryRunFailed:
+			if check.Critical {
+				result.CriticalCount++
+				result.CanProceed = false
+			} else {
+				result.WarningCount++
+				result.HasWarnings = true
+			}
+		case DryRunWarning:
+			result.WarningCount++
+			result.HasWarnings = true
+		}
+	}
+
+	// Estimate restore time based on archive size
+	result.EstimatedTime = r.estimateRestoreTime()
+
+	return result, nil
+}
+
+// checkArchiveAccess verifies the archive file is accessible
+func (r *RestoreDryRun) checkArchiveAccess() DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Archive Access",
+		Critical: true,
+	}
+
+	info, err := os.Stat(r.archive)
+	if err != nil {
+		if os.IsNotExist(err) {
+			check.Status = DryRunFailed
+			check.Message = "Archive file not found"
+			check.Details = r.archive
+		} else if os.IsPermission(err) {
+			check.Status = DryRunFailed
+			check.Message = "Permission denied reading archive"
+			check.Details = err.Error()
+		} else {
+			check.Status = DryRunFailed
+			check.Message = "Cannot access archive"
+			check.Details = err.Error()
+		}
+		return check
+	}
+
+	if info.Size() == 0 {
+		check.Status = DryRunFailed
+		check.Message = "Archive file is empty"
+		return check
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Archive accessible (%s)", formatBytesSize(info.Size()))
+	return check
+}
+
+// checkArchiveFormat validates the archive format
+func (r *RestoreDryRun) checkArchiveFormat() DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Archive Format",
+		Critical: true,
+	}
+
+	err := r.safety.ValidateArchive(r.archive)
+	if err != nil {
+		check.Status = DryRunFailed
+		check.Message = "Invalid archive format"
+		check.Details = err.Error()
+		return check
+	}
+
+	format := DetectArchiveFormat(r.archive)
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Valid %s format", format.String())
+	return check
+}
+
+// checkDatabaseConnectivity tests database connection
+func (r *RestoreDryRun) checkDatabaseConnectivity(ctx context.Context) DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Database Connectivity",
+		Critical: true,
+	}
+
+	// Try to list databases as a connectivity check
+	_, err := r.safety.ListUserDatabases(ctx)
+	if err != nil {
+		check.Status = DryRunFailed
+		check.Message = "Cannot connect to database server"
+		check.Details = err.Error()
+		return check
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Connected to %s:%d", r.cfg.Host, r.cfg.Port)
+	return check
+}
+
+// checkUserPermissions verifies required database permissions
+func (r *RestoreDryRun) checkUserPermissions(ctx context.Context) DryRunCheck {
+	check := DryRunCheck{
+		Name:     "User Permissions",
+		Critical: true,
+	}
+
+	if r.cfg.DatabaseType != "postgres" {
+		check.Status = DryRunSkipped
+		check.Message = "Permission check only implemented for PostgreSQL"
+		return check
+	}
+
+	// Check if user has CREATEDB privilege
+	query := `SELECT rolcreatedb, rolsuper FROM pg_roles WHERE rolname = current_user`
+
+	args := []string{
+		"-h", r.cfg.Host,
+		"-p", fmt.Sprintf("%d", r.cfg.Port),
+		"-U", r.cfg.User,
+		"-d", "postgres",
+		"-tA",
+		"-c", query,
+	}
+
+	cmd := cleanup.SafeCommand(ctx, "psql", args...)
+	if r.cfg.Password != "" {
+		cmd.Env = append(os.Environ(), fmt.Sprintf("PGPASSWORD=%s", r.cfg.Password))
+	}
+
+	output, err := cmd.Output()
+	if err != nil {
+		check.Status = DryRunWarning
+		check.Message = "Could not verify permissions"
+		check.Details = err.Error()
+		return check
+	}
+
+	result := strings.TrimSpace(string(output))
+	parts := strings.Split(result, "|")
+
+	if len(parts) >= 2 {
+		canCreate := parts[0] == "t"
+		isSuper := parts[1] == "t"
+
+		if isSuper {
+			check.Status = DryRunPassed
+			check.Message = "User is superuser (full permissions)"
+			return check
+		}
+
+		if canCreate {
+			check.Status = DryRunPassed
+			check.Message = "User has CREATEDB privilege"
+			return check
+		}
+	}
+
+	check.Status = DryRunFailed
+	check.Message = "User lacks CREATEDB privilege"
+	check.Details = "Required for creating target database. Run: ALTER USER " + r.cfg.User + " CREATEDB;"
+	return check
+}
+
+// checkTargetConflicts checks if target database already exists
+func (r *RestoreDryRun) checkTargetConflicts(ctx context.Context) DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Target Database",
+		Critical: false, // Not critical - can be overwritten with --clean
+	}
+
+	if r.target == "" {
+		check.Status = DryRunSkipped
+		check.Message = "Cluster restore - checking multiple databases"
+		return check
+	}
+
+	databases, err := r.safety.ListUserDatabases(ctx)
+	if err != nil {
+		check.Status = DryRunWarning
+		check.Message = "Could not check existing databases"
+		check.Details = err.Error()
+		return check
+	}
+
+	for _, db := range databases {
+		if db == r.target {
+			check.Status = DryRunWarning
+			check.Message = fmt.Sprintf("Database '%s' already exists", r.target)
+			check.Details = "Use --clean to drop and recreate, or choose different target"
+			return check
+		}
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Target '%s' is available", r.target)
+	return check
+}
+
+// checkDiskSpace verifies sufficient disk space
+func (r *RestoreDryRun) checkDiskSpace() (DryRunCheck, int64, int64) {
+	check := DryRunCheck{
+		Name:     "Disk Space",
+		Critical: true,
+	}
+
+	// Get archive size
+	info, err := os.Stat(r.archive)
+	if err != nil {
+		check.Status = DryRunSkipped
+		check.Message = "Cannot determine archive size"
+		return check, 0, 0
+	}
+
+	// Estimate uncompressed size (assume 3x compression ratio)
+	archiveSizeMB := info.Size() / 1024 / 1024
+	estimatedUncompressedMB := archiveSizeMB * 3
+
+	// Need space for: work dir extraction + restored database
+	// Work dir: full uncompressed size
+	// Database: roughly same as uncompressed SQL
+	requiredMB := estimatedUncompressedMB * 2
+
+	// Check available disk space in work directory
+	workDir := r.cfg.GetEffectiveWorkDir()
+	if workDir == "" {
+		workDir = r.cfg.BackupDir
+	}
+
+	var stat syscall.Statfs_t
+	if err := syscall.Statfs(workDir, &stat); err != nil {
+		check.Status = DryRunWarning
+		check.Message = "Cannot check disk space"
+		check.Details = err.Error()
+		return check, requiredMB, 0
+	}
+
+	availableMB := int64(stat.Bavail*uint64(stat.Bsize)) / 1024 / 1024
+
+	if availableMB < requiredMB {
+		check.Status = DryRunFailed
+		check.Message = fmt.Sprintf("Insufficient disk space: need %d MB, have %d MB", requiredMB, availableMB)
+		check.Details = fmt.Sprintf("Work directory: %s", workDir)
+		return check, requiredMB, availableMB
+	}
+
+	// Warn if less than 20% buffer
+	if availableMB < requiredMB*12/10 {
+		check.Status = DryRunWarning
+		check.Message = fmt.Sprintf("Low disk space margin: need %d MB, have %d MB", requiredMB, availableMB)
+		return check, requiredMB, availableMB
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Sufficient space: need ~%d MB, have %d MB", requiredMB, availableMB)
+	return check, requiredMB, availableMB
+}
+
+// checkWorkDirectory verifies work directory is writable
+func (r *RestoreDryRun) checkWorkDirectory() DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Work Directory",
+		Critical: true,
+	}
+
+	workDir := r.cfg.GetEffectiveWorkDir()
+	if workDir == "" {
+		workDir = r.cfg.BackupDir
+	}
+
+	// Check if directory exists
+	info, err := os.Stat(workDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			check.Status = DryRunFailed
+			check.Message = "Work directory does not exist"
+			check.Details = workDir
+		} else {
+			check.Status = DryRunFailed
+			check.Message = "Cannot access work directory"
+			check.Details = err.Error()
+		}
+		return check
+	}
+
+	if !info.IsDir() {
+		check.Status = DryRunFailed
+		check.Message = "Work path is not a directory"
+		check.Details = workDir
+		return check
+	}
+
+	// Try to create a test file
+	testFile := filepath.Join(workDir, ".dbbackup-dryrun-test")
+	f, err := os.Create(testFile)
+	if err != nil {
+		check.Status = DryRunFailed
+		check.Message = "Work directory is not writable"
+		check.Details = err.Error()
+		return check
+	}
+	f.Close()
+	os.Remove(testFile)
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Work directory writable: %s", workDir)
+	return check
+}
+
+// checkRequiredTools verifies required CLI tools are available
+func (r *RestoreDryRun) checkRequiredTools() DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Required Tools",
+		Critical: true,
+	}
+
+	var required []string
+	switch r.cfg.DatabaseType {
+	case "postgres":
+		required = []string{"pg_restore", "psql", "createdb"}
+	case "mysql", "mariadb":
+		required = []string{"mysql", "mysqldump"}
+	default:
+		check.Status = DryRunSkipped
+		check.Message = "Unknown database type"
+		return check
+	}
+
+	missing := []string{}
+	for _, tool := range required {
+		if _, err := LookPath(tool); err != nil {
+			missing = append(missing, tool)
+		}
+	}
+
+	if len(missing) > 0 {
+		check.Status = DryRunFailed
+		check.Message = fmt.Sprintf("Missing tools: %s", strings.Join(missing, ", "))
+		check.Details = "Install the database client tools package"
+		return check
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("All tools available: %s", strings.Join(required, ", "))
+	return check
+}
+
+// checkLockSettings checks PostgreSQL lock settings for parallel restore
+func (r *RestoreDryRun) checkLockSettings(ctx context.Context) DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Lock Settings",
+		Critical: false,
+	}
+
+	if r.cfg.DatabaseType != "postgres" {
+		check.Status = DryRunSkipped
+		check.Message = "Lock check only for PostgreSQL"
+		return check
+	}
+
+	// Check max_locks_per_transaction
+	query := `SHOW max_locks_per_transaction`
+	args := []string{
+		"-h", r.cfg.Host,
+		"-p", fmt.Sprintf("%d", r.cfg.Port),
+		"-U", r.cfg.User,
+		"-d", "postgres",
+		"-tA",
+		"-c", query,
+	}
+
+	cmd := cleanup.SafeCommand(ctx, "psql", args...)
+	if r.cfg.Password != "" {
+		cmd.Env = append(os.Environ(), fmt.Sprintf("PGPASSWORD=%s", r.cfg.Password))
+	}
+
+	output, err := cmd.Output()
+	if err != nil {
+		check.Status = DryRunWarning
+		check.Message = "Could not check lock settings"
+		return check
+	}
+
+	locks := strings.TrimSpace(string(output))
+	if locks == "" {
+		check.Status = DryRunWarning
+		check.Message = "Could not determine max_locks_per_transaction"
+		return check
+	}
+
+	// Default is 64, recommend at least 128 for parallel restores
+	var lockCount int
+	fmt.Sscanf(locks, "%d", &lockCount)
+
+	if lockCount < 128 {
+		check.Status = DryRunWarning
+		check.Message = fmt.Sprintf("max_locks_per_transaction=%d (recommend 128+ for parallel)", lockCount)
+		check.Details = "Set: ALTER SYSTEM SET max_locks_per_transaction = 128; then restart PostgreSQL"
+		return check
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("max_locks_per_transaction=%d (sufficient)", lockCount)
+	return check
+}
+
+// checkMemoryAvailability checks if enough memory is available
+func (r *RestoreDryRun) checkMemoryAvailability() DryRunCheck {
+	check := DryRunCheck{
+		Name:     "Memory Availability",
+		Critical: false,
+	}
+
+	// Read /proc/meminfo on Linux
+	data, err := os.ReadFile("/proc/meminfo")
+	if err != nil {
+		check.Status = DryRunSkipped
+		check.Message = "Cannot check memory (non-Linux?)"
+		return check
+	}
+
+	var availableKB int64
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.HasPrefix(line, "MemAvailable:") {
+			fmt.Sscanf(line, "MemAvailable: %d kB", &availableKB)
+			break
+		}
+	}
+
+	availableMB := availableKB / 1024
+
+	// Recommend at least 1GB for restore operations
+	if availableMB < 1024 {
+		check.Status = DryRunWarning
+		check.Message = fmt.Sprintf("Low available memory: %d MB", availableMB)
+		check.Details = "Restore may be slow or fail. Consider closing other applications."
+		return check
+	}
+
+	check.Status = DryRunPassed
+	check.Message = fmt.Sprintf("Available memory: %d MB", availableMB)
+	return check
+}
+
+// estimateRestoreTime estimates restore duration based on archive size
+func (r *RestoreDryRun) estimateRestoreTime() time.Duration {
+	info, err := os.Stat(r.archive)
+	if err != nil {
+		return 0
+	}
+
+	// Rough estimate: 100 MB/minute for restore operations
+	// This accounts for decompression, SQL parsing, and database writes
+	sizeMB := info.Size() / 1024 / 1024
+	minutes := sizeMB / 100
+	if minutes < 1 {
+		minutes = 1
+	}
+
+	return time.Duration(minutes) * time.Minute
+}
+
+// formatBytesSize formats bytes to human-readable string
+func formatBytesSize(bytes int64) string {
+	const (
+		KB = 1024
+		MB = KB * 1024
+		GB = MB * 1024
+	)
+
+	switch {
+	case bytes >= GB:
+		return fmt.Sprintf("%.1f GB", float64(bytes)/GB)
+	case bytes >= MB:
+		return fmt.Sprintf("%.1f MB", float64(bytes)/MB)
+	case bytes >= KB:
+		return fmt.Sprintf("%.1f KB", float64(bytes)/KB)
+	default:
+		return fmt.Sprintf("%d B", bytes)
+	}
+}
+
+// LookPath is a wrapper around exec.LookPath for testing
+var LookPath = func(file string) (string, error) {
+	return exec.LookPath(file)
+}
+
+// PrintDryRunResult prints a formatted dry-run result
+func PrintDryRunResult(result *DryRunResult) {
+	fmt.Println("\n" + strings.Repeat("=", 60))
+	fmt.Println("RESTORE DRY-RUN RESULTS")
+	fmt.Println(strings.Repeat("=", 60))
+
+	for _, check := range result.Checks {
+		fmt.Printf("%s %-20s %s\n", check.Status.Icon(), check.Name+":", check.Message)
+		if check.Details != "" {
+			fmt.Printf("    └─ %s\n", check.Details)
+		}
+	}
+
+	fmt.Println(strings.Repeat("-", 60))
+
+	if result.EstimatedTime > 0 {
+		fmt.Printf("Estimated restore time: %s\n", result.EstimatedTime)
+	}
+
+	if result.RequiredDiskMB > 0 {
+		fmt.Printf("Disk space: %d MB required, %d MB available\n",
+			result.RequiredDiskMB, result.AvailableDiskMB)
+	}
+
+	fmt.Println()
+	if result.CanProceed {
+		if result.HasWarnings {
+			fmt.Println("⚠️  DRY-RUN: PASSED with warnings - restore can proceed")
+		} else {
+			fmt.Println("✅ DRY-RUN: PASSED - restore can proceed")
+		}
+	} else {
+		fmt.Printf("❌ DRY-RUN: FAILED - %d critical issue(s) must be resolved\n", result.CriticalCount)
+	}
+	fmt.Println()
+}

internal/security/audit.go

@@ -1,7 +1,15 @@
 package security
 
 import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
 	"os"
+	"sync"
 	"time"
 
 	"dbbackup/internal/logger"
@@ -21,13 +29,36 @@ type AuditEvent struct {
 type AuditLogger struct {
 	log     logger.Logger
 	enabled bool
+
+	// For signed audit log support
+	mu         sync.Mutex
+	entries    []SignedAuditEntry
+	privateKey ed25519.PrivateKey
+	publicKey  ed25519.PublicKey
+	prevHash   string // Hash of previous entry for chaining
+}
+
+// SignedAuditEntry represents an audit entry with cryptographic signature
+type SignedAuditEntry struct {
+	Sequence  int64  `json:"seq"`
+	Timestamp string `json:"ts"`
+	User      string `json:"user"`
+	Action    string `json:"action"`
+	Resource  string `json:"resource"`
+	Result    string `json:"result"`
+	Details   string `json:"details,omitempty"`
+	PrevHash  string `json:"prev_hash"` // Hash chain for tamper detection
+	Hash      string `json:"hash"`      // SHA-256 of this entry (without signature)
+	Signature string `json:"sig"`       // Ed25519 signature of Hash
 }
 
 // NewAuditLogger creates a new audit logger
 func NewAuditLogger(log logger.Logger, enabled bool) *AuditLogger {
 	return &AuditLogger{
-		log:     log,
-		enabled: enabled,
+		log:      log,
+		enabled:  enabled,
+		entries:  make([]SignedAuditEntry, 0),
+		prevHash: "genesis", // Initial hash for first entry
 	}
 }
 
@@ -232,3 +263,337 @@ func GetCurrentUser() string {
 	}
 	return "unknown"
 }
+
+// =============================================================================
+// Audit Log Signing and Verification
+// =============================================================================
+
+// GenerateSigningKeys generates a new Ed25519 key pair for audit log signing
+func GenerateSigningKeys() (privateKey ed25519.PrivateKey, publicKey ed25519.PublicKey, err error) {
+	publicKey, privateKey, err = ed25519.GenerateKey(rand.Reader)
+	return
+}
+
+// SavePrivateKey saves the private key to a file (PEM-like format)
+func SavePrivateKey(path string, key ed25519.PrivateKey) error {
+	encoded := base64.StdEncoding.EncodeToString(key)
+	content := fmt.Sprintf("-----BEGIN DBBACKUP AUDIT PRIVATE KEY-----\n%s\n-----END DBBACKUP AUDIT PRIVATE KEY-----\n", encoded)
+	return os.WriteFile(path, []byte(content), 0600) // Restrictive permissions
+}
+
+// SavePublicKey saves the public key to a file (PEM-like format)
+func SavePublicKey(path string, key ed25519.PublicKey) error {
+	encoded := base64.StdEncoding.EncodeToString(key)
+	content := fmt.Sprintf("-----BEGIN DBBACKUP AUDIT PUBLIC KEY-----\n%s\n-----END DBBACKUP AUDIT PUBLIC KEY-----\n", encoded)
+	return os.WriteFile(path, []byte(content), 0644)
+}
+
+// LoadPrivateKey loads a private key from file
+func LoadPrivateKey(path string) (ed25519.PrivateKey, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read private key: %w", err)
+	}
+
+	// Extract base64 content between PEM markers
+	content := extractPEMContent(string(data))
+	if content == "" {
+		return nil, fmt.Errorf("invalid private key format")
+	}
+
+	decoded, err := base64.StdEncoding.DecodeString(content)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode private key: %w", err)
+	}
+
+	if len(decoded) != ed25519.PrivateKeySize {
+		return nil, fmt.Errorf("invalid private key size")
+	}
+
+	return ed25519.PrivateKey(decoded), nil
+}
+
+// LoadPublicKey loads a public key from file
+func LoadPublicKey(path string) (ed25519.PublicKey, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read public key: %w", err)
+	}
+
+	content := extractPEMContent(string(data))
+	if content == "" {
+		return nil, fmt.Errorf("invalid public key format")
+	}
+
+	decoded, err := base64.StdEncoding.DecodeString(content)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode public key: %w", err)
+	}
+
+	if len(decoded) != ed25519.PublicKeySize {
+		return nil, fmt.Errorf("invalid public key size")
+	}
+
+	return ed25519.PublicKey(decoded), nil
+}
+
+// extractPEMContent extracts base64 content from PEM-like format
+func extractPEMContent(data string) string {
+	// Simple extraction - find content between markers
+	start := 0
+	for i := 0; i < len(data); i++ {
+		if data[i] == '\n' && i > 0 && data[i-1] == '-' {
+			start = i + 1
+			break
+		}
+	}
+
+	end := len(data)
+	for i := len(data) - 1; i > start; i-- {
+		if data[i] == '\n' && i+1 < len(data) && data[i+1] == '-' {
+			end = i
+			break
+		}
+	}
+
+	if start >= end {
+		return ""
+	}
+
+	// Remove whitespace
+	result := ""
+	for _, c := range data[start:end] {
+		if c != '\n' && c != '\r' && c != ' ' {
+			result += string(c)
+		}
+	}
+	return result
+}
+
+// EnableSigning enables cryptographic signing for audit entries
+func (a *AuditLogger) EnableSigning(privateKey ed25519.PrivateKey) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	a.privateKey = privateKey
+	a.publicKey = privateKey.Public().(ed25519.PublicKey)
+}
+
+// AddSignedEntry adds a signed entry to the audit log
+func (a *AuditLogger) AddSignedEntry(event AuditEvent) error {
+	if !a.enabled {
+		return nil
+	}
+
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	// Serialize details
+	detailsJSON := ""
+	if len(event.Details) > 0 {
+		if data, err := json.Marshal(event.Details); err == nil {
+			detailsJSON = string(data)
+		}
+	}
+
+	entry := SignedAuditEntry{
+		Sequence:  int64(len(a.entries) + 1),
+		Timestamp: event.Timestamp.Format(time.RFC3339Nano),
+		User:      event.User,
+		Action:    event.Action,
+		Resource:  event.Resource,
+		Result:    event.Result,
+		Details:   detailsJSON,
+		PrevHash:  a.prevHash,
+	}
+
+	// Calculate hash of entry (without signature)
+	entry.Hash = a.calculateEntryHash(entry)
+
+	// Sign if private key is available
+	if a.privateKey != nil {
+		hashBytes, _ := hex.DecodeString(entry.Hash)
+		signature := ed25519.Sign(a.privateKey, hashBytes)
+		entry.Signature = base64.StdEncoding.EncodeToString(signature)
+	}
+
+	// Update chain
+	a.prevHash = entry.Hash
+	a.entries = append(a.entries, entry)
+
+	// Also log to standard logger
+	a.logEvent(event)
+
+	return nil
+}
+
+// calculateEntryHash computes SHA-256 hash of an entry (without signature field)
+func (a *AuditLogger) calculateEntryHash(entry SignedAuditEntry) string {
+	// Create canonical representation for hashing
+	data := fmt.Sprintf("%d|%s|%s|%s|%s|%s|%s|%s",
+		entry.Sequence,
+		entry.Timestamp,
+		entry.User,
+		entry.Action,
+		entry.Resource,
+		entry.Result,
+		entry.Details,
+		entry.PrevHash,
+	)
+
+	hash := sha256.Sum256([]byte(data))
+	return hex.EncodeToString(hash[:])
+}
+
+// ExportSignedLog exports the signed audit log to a file
+func (a *AuditLogger) ExportSignedLog(path string) error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	data, err := json.MarshalIndent(a.entries, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal audit log: %w", err)
+	}
+
+	return os.WriteFile(path, data, 0644)
+}
+
+// VerifyAuditLog verifies the integrity of an exported audit log
+func VerifyAuditLog(logPath string, publicKeyPath string) (*AuditVerificationResult, error) {
+	// Load public key
+	publicKey, err := LoadPublicKey(publicKeyPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load public key: %w", err)
+	}
+
+	// Load audit log
+	data, err := os.ReadFile(logPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read audit log: %w", err)
+	}
+
+	var entries []SignedAuditEntry
+	if err := json.Unmarshal(data, &entries); err != nil {
+		return nil, fmt.Errorf("failed to parse audit log: %w", err)
+	}
+
+	result := &AuditVerificationResult{
+		TotalEntries: len(entries),
+		ValidEntries: 0,
+		Errors:       make([]string, 0),
+	}
+
+	prevHash := "genesis"
+
+	for i, entry := range entries {
+		// Verify hash chain
+		if entry.PrevHash != prevHash {
+			result.Errors = append(result.Errors,
+				fmt.Sprintf("Entry %d: hash chain broken (expected %s, got %s)",
+					i+1, prevHash[:16]+"...", entry.PrevHash[:min(16, len(entry.PrevHash))]+"..."))
+		}
+
+		// Recalculate hash
+		expectedHash := calculateVerifyHash(entry)
+		if entry.Hash != expectedHash {
+			result.Errors = append(result.Errors,
+				fmt.Sprintf("Entry %d: hash mismatch (entry may be tampered)", i+1))
+		}
+
+		// Verify signature
+		if entry.Signature != "" {
+			hashBytes, _ := hex.DecodeString(entry.Hash)
+			sigBytes, err := base64.StdEncoding.DecodeString(entry.Signature)
+			if err != nil {
+				result.Errors = append(result.Errors,
+					fmt.Sprintf("Entry %d: invalid signature encoding", i+1))
+			} else if !ed25519.Verify(publicKey, hashBytes, sigBytes) {
+				result.Errors = append(result.Errors,
+					fmt.Sprintf("Entry %d: signature verification failed", i+1))
+			} else {
+				result.ValidEntries++
+			}
+		} else {
+			result.Errors = append(result.Errors,
+				fmt.Sprintf("Entry %d: missing signature", i+1))
+		}
+
+		prevHash = entry.Hash
+	}
+
+	result.ChainValid = len(result.Errors) == 0 ||
+		!containsChainError(result.Errors)
+	result.AllSignaturesValid = result.ValidEntries == result.TotalEntries
+
+	return result, nil
+}
+
+// AuditVerificationResult contains the result of audit log verification
+type AuditVerificationResult struct {
+	TotalEntries       int
+	ValidEntries       int
+	ChainValid         bool
+	AllSignaturesValid bool
+	Errors             []string
+}
+
+// IsValid returns true if the audit log is completely valid
+func (r *AuditVerificationResult) IsValid() bool {
+	return r.ChainValid && r.AllSignaturesValid && len(r.Errors) == 0
+}
+
+// String returns a human-readable summary
+func (r *AuditVerificationResult) String() string {
+	if r.IsValid() {
+		return fmt.Sprintf("✅ Audit log verified: %d entries, chain intact, all signatures valid",
+			r.TotalEntries)
+	}
+
+	return fmt.Sprintf("❌ Audit log verification failed: %d/%d valid entries, %d errors",
+		r.ValidEntries, r.TotalEntries, len(r.Errors))
+}
+
+// calculateVerifyHash recalculates hash for verification
+func calculateVerifyHash(entry SignedAuditEntry) string {
+	data := fmt.Sprintf("%d|%s|%s|%s|%s|%s|%s|%s",
+		entry.Sequence,
+		entry.Timestamp,
+		entry.User,
+		entry.Action,
+		entry.Resource,
+		entry.Result,
+		entry.Details,
+		entry.PrevHash,
+	)
+
+	hash := sha256.Sum256([]byte(data))
+	return hex.EncodeToString(hash[:])
+}
+
+// containsChainError checks if errors include hash chain issues
+func containsChainError(errors []string) bool {
+	for _, err := range errors {
+		if len(err) > 0 && (err[0:min(20, len(err))] == "Entry" &&
+			(contains(err, "hash chain") || contains(err, "hash mismatch"))) {
+			return true
+		}
+	}
+	return false
+}
+
+// contains is a simple string contains helper
+func contains(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}
+
+// min returns the minimum of two ints
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

main.go

@@ -16,7 +16,7 @@ import (
 
 // Build information (set by ldflags)
 var (
-	version   = "5.8.7"
+	version   = "5.8.12"
 	buildTime = "unknown"
 	gitCommit = "unknown"
 )