fix: tighten file perms and enforce Slack ACL checks (#186)

- write config and cron store with 0600 instead of 0644
- check allow list in Slack slash commands and app mentions
- pass workspace restrict flag to cron exec tool

Closes #179

cmd/picoclaw/main.go

@@ -562,7 +562,7 @@ func gatewayCmd() {
 		})
 
 	// Setup cron tool and service
-	cronService := setupCronTool(agentLoop, msgBus, cfg.WorkspacePath())
+	cronService := setupCronTool(agentLoop, msgBus, cfg.WorkspacePath(), cfg.Agents.Defaults.RestrictToWorkspace)
 
 	heartbeatService := heartbeat.NewHeartbeatService(
 		cfg.WorkspacePath(),
@@ -984,14 +984,14 @@ func getConfigPath() string {
 	return filepath.Join(home, ".picoclaw", "config.json")
 }
 
-func setupCronTool(agentLoop *agent.AgentLoop, msgBus *bus.MessageBus, workspace string) *cron.CronService {
+func setupCronTool(agentLoop *agent.AgentLoop, msgBus *bus.MessageBus, workspace string, restrict bool) *cron.CronService {
 	cronStorePath := filepath.Join(workspace, "cron", "jobs.json")
 
 	// Create cron service
 	cronService := cron.NewCronService(cronStorePath, nil)
 
 	// Create and register CronTool
-	cronTool := tools.NewCronTool(cronService, agentLoop, msgBus, workspace)
+	cronTool := tools.NewCronTool(cronService, agentLoop, msgBus, workspace, restrict)
 	agentLoop.RegisterTool(cronTool)
 
 	// Set the onJob handler

pkg/channels/slack.go

@@ -296,6 +296,13 @@ func (c *SlackChannel) handleAppMention(ev *slackevents.AppMentionEvent) {
 		return
 	}
 
+	if !c.IsAllowed(ev.User) {
+		logger.DebugCF("slack", "Mention rejected by allowlist", map[string]interface{}{
+			"user_id": ev.User,
+		})
+		return
+	}
+
 	senderID := ev.User
 	channelID := ev.Channel
 	threadTS := ev.ThreadTimeStamp
@@ -345,6 +352,13 @@ func (c *SlackChannel) handleSlashCommand(event socketmode.Event) {
 		c.socketClient.Ack(*event.Request)
 	}
 
+	if !c.IsAllowed(cmd.UserID) {
+		logger.DebugCF("slack", "Slash command rejected by allowlist", map[string]interface{}{
+			"user_id": cmd.UserID,
+		})
+		return
+	}
+
 	senderID := cmd.UserID
 	channelID := cmd.ChannelID
 	chatID := channelID

pkg/config/config.go

@@ -370,7 +370,7 @@ func SaveConfig(path string, cfg *Config) error {
 		return err
 	}
 
-	return os.WriteFile(path, data, 0644)
+	return os.WriteFile(path, data, 0600)
 }
 
 func (c *Config) WorkspacePath() string {

pkg/config/config_test.go

@@ -1,6 +1,9 @@
 package config
 
 import (
+	"os"
+	"path/filepath"
+	"runtime"
 	"testing"
 )
 
@@ -147,6 +150,30 @@ func TestDefaultConfig_WebTools(t *testing.T) {
 	}
 }
 
+func TestSaveConfig_FilePermissions(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("file permission bits are not enforced on Windows")
+	}
+
+	tmpDir := t.TempDir()
+	path := filepath.Join(tmpDir, "config.json")
+
+	cfg := DefaultConfig()
+	if err := SaveConfig(path, cfg); err != nil {
+		t.Fatalf("SaveConfig failed: %v", err)
+	}
+
+	info, err := os.Stat(path)
+	if err != nil {
+		t.Fatalf("Stat failed: %v", err)
+	}
+
+	perm := info.Mode().Perm()
+	if perm != 0600 {
+		t.Errorf("config file has permission %04o, want 0600", perm)
+	}
+}
+
 // TestConfig_Complete verifies all config fields are set
 func TestConfig_Complete(t *testing.T) {
 	cfg := DefaultConfig()

pkg/cron/service.go

@@ -340,7 +340,7 @@ func (cs *CronService) saveStoreUnsafe() error {
 		return err
 	}
 
-	return os.WriteFile(cs.storePath, data, 0644)
+	return os.WriteFile(cs.storePath, data, 0600)
 }
 
 func (cs *CronService) AddJob(name string, schedule CronSchedule, message string, deliver bool, channel, to string) (*CronJob, error) {

pkg/cron/service_test.go

@@ -0,0 +1,38 @@
+package cron
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func TestSaveStore_FilePermissions(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("file permission bits are not enforced on Windows")
+	}
+
+	tmpDir := t.TempDir()
+	storePath := filepath.Join(tmpDir, "cron", "jobs.json")
+
+	cs := NewCronService(storePath, nil)
+
+	_, err := cs.AddJob("test", CronSchedule{Kind: "every", EveryMS: int64Ptr(60000)}, "hello", false, "cli", "direct")
+	if err != nil {
+		t.Fatalf("AddJob failed: %v", err)
+	}
+
+	info, err := os.Stat(storePath)
+	if err != nil {
+		t.Fatalf("Stat failed: %v", err)
+	}
+
+	perm := info.Mode().Perm()
+	if perm != 0600 {
+		t.Errorf("cron store has permission %04o, want 0600", perm)
+	}
+}
+
+func int64Ptr(v int64) *int64 {
+	return &v
+}

pkg/tools/cron.go

@@ -28,12 +28,12 @@ type CronTool struct {
 }
 
 // NewCronTool creates a new CronTool
-func NewCronTool(cronService *cron.CronService, executor JobExecutor, msgBus *bus.MessageBus, workspace string) *CronTool {
+func NewCronTool(cronService *cron.CronService, executor JobExecutor, msgBus *bus.MessageBus, workspace string, restrict bool) *CronTool {
 	return &CronTool{
 		cronService: cronService,
 		executor:    executor,
 		msgBus:      msgBus,
-		execTool:    NewExecTool(workspace, false),
+		execTool:    NewExecTool(workspace, restrict),
 	}
 }