Fix SEC-09: hide admin nav links from non-admin users

- Add IsAdmin bool to PageData (embedded in all page view structs)
- Remove redundant IsAdmin from DashboardData
- Add isAdmin() helper to derive admin status from request claims
- Set IsAdmin in all page-level handlers that populate PageData
- Wrap admin-only nav links in base.html with {{if .IsAdmin}}
- Add tests: non-admin dashboard/profile hide admin links,
  admin dashboard shows them

Security: navigation links to /accounts, /audit, /policies,
and /pgcreds are now only rendered for admin users. Server-side
authorization (requireAdminRole middleware) was already in place;
this change removes the information leak of showing links that
return 403 to non-admin users.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/ui/handlers_accounts.go

@@ -39,7 +39,7 @@ func (u *UIServer) handleAccountsList(w http.ResponseWriter, r *http.Request) {
 	}
 
 	u.render(w, "accounts", AccountsData{
-		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Accounts: accounts,
 	})
 }
@@ -183,7 +183,7 @@ func (u *UIServer) handleAccountDetail(w http.ResponseWriter, r *http.Request) {
 	}
 
 	u.render(w, "account_detail", AccountDetailData{
-		PageData:          PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData:          PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Account:           acct,
 		Roles:             roles,
 		AllRoles:          knownRoles,
@@ -790,7 +790,7 @@ func (u *UIServer) handlePGCredsList(w http.ResponseWriter, r *http.Request) {
 	}
 
 	u.render(w, "pgcreds", PGCredsData{
-		PageData:               PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData:               PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Creds:                  creds,
 		UncredentialedAccounts: uncredentialed,
 		CredGrants:             credGrants,

internal/ui/handlers_audit.go

@@ -86,7 +86,7 @@ func (u *UIServer) handleAuditDetail(w http.ResponseWriter, r *http.Request) {
 	}
 
 	u.render(w, "audit_detail", AuditDetailData{
-		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Event:    event,
 	})
 }
@@ -116,7 +116,7 @@ func (u *UIServer) buildAuditData(r *http.Request, page int, csrfToken string) (
 	}
 
 	return AuditData{
-		PageData:   PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData:   PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Events:     events,
 		EventTypes: auditEventTypes,
 		FilterType: filterType,

internal/ui/handlers_auth.go

@@ -281,6 +281,7 @@ func (u *UIServer) handleProfilePage(w http.ResponseWriter, r *http.Request) {
 		PageData: PageData{
 			CSRFToken: csrfToken,
 			ActorName: u.actorName(r),
+			IsAdmin:   isAdmin(r),
 		},
 	})
 }
@@ -393,6 +394,7 @@ func (u *UIServer) handleSelfChangePassword(w http.ResponseWriter, r *http.Reque
 		PageData: PageData{
 			CSRFToken: csrfToken,
 			ActorName: u.actorName(r),
+			IsAdmin:   isAdmin(r),
 			Flash:     "Password updated successfully. Other active sessions have been revoked.",
 		},
 	})

internal/ui/handlers_dashboard.go

@@ -17,15 +17,13 @@ func (u *UIServer) handleDashboard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	claims := claimsFromContext(r.Context())
-	isAdmin := claims != nil && claims.HasRole("admin")
+	admin := isAdmin(r)
 
 	data := DashboardData{
-		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
-		IsAdmin:  isAdmin,
+		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: admin},
 	}
 
-	if isAdmin {
+	if admin {
 		accounts, err := u.db.ListAccounts()
 		if err != nil {
 			u.renderError(w, r, http.StatusInternalServerError, "failed to load accounts")

internal/ui/handlers_policy.go

@@ -61,7 +61,7 @@ func (u *UIServer) handlePoliciesPage(w http.ResponseWriter, r *http.Request) {
 	}
 
 	data := PoliciesData{
-		PageData:   PageData{CSRFToken: csrfToken, ActorName: u.actorName(r)},
+		PageData:   PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
 		Rules:      views,
 		AllActions: allActionStrings,
 	}

internal/ui/ui.go

@@ -569,6 +569,13 @@ func (u *UIServer) clientIP(r *http.Request) string {
 	return middleware.ClientIP(r, proxyIP)
 }
 
+// isAdmin reports whether the authenticated user holds the "admin" role.
+// Returns false if claims are absent.
+func isAdmin(r *http.Request) bool {
+	claims := claimsFromContext(r.Context())
+	return claims != nil && claims.HasRole("admin")
+}
+
 // actorName resolves the username of the currently authenticated user from the
 // request context.  Returns an empty string if claims are absent or the account
 // cannot be found; callers should treat an empty string as "not logged in".
@@ -594,6 +601,10 @@ type PageData struct {
 	// ActorName is the username of the currently logged-in user, populated by
 	// handlers so the base template can display it in the navigation bar.
 	ActorName string
+	// IsAdmin is true when the logged-in user holds the "admin" role.
+	// Used by the base template to conditionally render admin-only navigation
+	// links (SEC-09: non-admin users must not see links they cannot access).
+	IsAdmin bool
 }
 
 // LoginData is the view model for the login page.
@@ -609,7 +620,6 @@ type LoginData struct {
 // DashboardData is the view model for the dashboard page.
 type DashboardData struct {
 	PageData
-	IsAdmin        bool
 	RecentEvents   []*db.AuditEventView
 	TotalAccounts  int
 	ActiveAccounts int

internal/ui/ui_test.go

@@ -527,3 +527,121 @@ func TestAccountDetailShowsPGCredsSection(t *testing.T) {
 		t.Error("human account detail page must not include pgcreds-section")
 	}
 }
+
+// ---- SEC-09: admin nav link visibility tests ----
+
+// issueUserSession creates a human account with the "user" role (non-admin),
+// issues a JWT, tracks it, and returns the raw token string.
+func issueUserSession(t *testing.T, u *UIServer) string {
+	t.Helper()
+	acct, err := u.db.CreateAccount("regular-user", model.AccountTypeHuman, "")
+	if err != nil {
+		t.Fatalf("CreateAccount: %v", err)
+	}
+	if err := u.db.SetRoles(acct.ID, []string{"user"}, nil); err != nil {
+		t.Fatalf("SetRoles: %v", err)
+	}
+	tok, claims, err := token.IssueToken(u.privKey, testIssuer, acct.UUID, []string{"user"}, time.Hour)
+	if err != nil {
+		t.Fatalf("IssueToken: %v", err)
+	}
+	if err := u.db.TrackToken(claims.JTI, acct.ID, claims.IssuedAt, claims.ExpiresAt); err != nil {
+		t.Fatalf("TrackToken: %v", err)
+	}
+	return tok
+}
+
+// TestNonAdminDashboardHidesAdminNavLinks verifies that a non-admin user's
+// dashboard does not contain links to admin-only pages (SEC-09).
+func TestNonAdminDashboardHidesAdminNavLinks(t *testing.T) {
+	u := newTestUIServer(t)
+	mux := http.NewServeMux()
+	u.Register(mux)
+
+	userToken := issueUserSession(t, u)
+
+	req := authenticatedGET(t, userToken, "/dashboard")
+	rr := httptest.NewRecorder()
+	mux.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200; body: %s", rr.Code, rr.Body.String())
+	}
+
+	body := rr.Body.String()
+	for _, adminPath := range []string{
+		`href="/accounts"`,
+		`href="/audit"`,
+		`href="/policies"`,
+		`href="/pgcreds"`,
+	} {
+		if strings.Contains(body, adminPath) {
+			t.Errorf("non-admin dashboard contains admin link %s — SEC-09 violation", adminPath)
+		}
+	}
+
+	// Dashboard link should still be present.
+	if !strings.Contains(body, `href="/dashboard"`) {
+		t.Error("dashboard link missing from non-admin nav")
+	}
+}
+
+// TestAdminDashboardShowsAdminNavLinks verifies that an admin user's
+// dashboard contains all admin navigation links.
+func TestAdminDashboardShowsAdminNavLinks(t *testing.T) {
+	u := newTestUIServer(t)
+	mux := http.NewServeMux()
+	u.Register(mux)
+
+	adminToken, _, _ := issueAdminSession(t, u)
+
+	req := authenticatedGET(t, adminToken, "/dashboard")
+	rr := httptest.NewRecorder()
+	mux.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200; body: %s", rr.Code, rr.Body.String())
+	}
+
+	body := rr.Body.String()
+	for _, adminPath := range []string{
+		`href="/accounts"`,
+		`href="/audit"`,
+		`href="/policies"`,
+		`href="/pgcreds"`,
+	} {
+		if !strings.Contains(body, adminPath) {
+			t.Errorf("admin dashboard missing admin link %s", adminPath)
+		}
+	}
+}
+
+// TestNonAdminProfileHidesAdminNavLinks verifies that the profile page
+// also hides admin nav links for non-admin users (SEC-09).
+func TestNonAdminProfileHidesAdminNavLinks(t *testing.T) {
+	u := newTestUIServer(t)
+	mux := http.NewServeMux()
+	u.Register(mux)
+
+	userToken := issueUserSession(t, u)
+
+	req := authenticatedGET(t, userToken, "/profile")
+	rr := httptest.NewRecorder()
+	mux.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200; body: %s", rr.Code, rr.Body.String())
+	}
+
+	body := rr.Body.String()
+	for _, adminPath := range []string{
+		`href="/accounts"`,
+		`href="/audit"`,
+		`href="/policies"`,
+		`href="/pgcreds"`,
+	} {
+		if strings.Contains(body, adminPath) {
+			t.Errorf("non-admin profile page contains admin link %s — SEC-09 violation", adminPath)
+		}
+	}
+}

web/templates/base.html

@@ -12,10 +12,10 @@
     <span class="nav-brand">MCIAS</span>
     <ul class="nav-links">
       <li><a href="/dashboard">Dashboard</a></li>
-      <li><a href="/accounts">Accounts</a></li>
+      {{if .IsAdmin}}<li><a href="/accounts">Accounts</a></li>
       <li><a href="/audit">Audit</a></li>
       <li><a href="/policies">Policies</a></li>
-      <li><a href="/pgcreds">PG Creds</a></li>
+      <li><a href="/pgcreds">PG Creds</a></li>{{end}}
       {{if .ActorName}}<li><a href="/profile">{{.ActorName}}</a></li>{{end}}
       <li><form method="POST" action="/logout" style="margin:0"><button class="btn btn-sm btn-secondary" type="submit">Logout</button></form></li>
     </ul>