# Security Improvements Applied to HSE Management

## Overview
Based on the security assessment, the following critical vulnerabilities have been addressed:

---

## ✅ Fixes Implemented

### 1. Input Sanitization (XSS Prevention)
**File:** `config/security.php` (new)

**What was fixed:**
- User input is now sanitized using `htmlspecialchars()` with `ENT_QUOTES` and `UTF-8` encoding.
- All direct `$_POST` access replaced with safe getters: `getSafeString()`, `getSafeInt()`.

**Updated endpoints:**
- `api/add_personnel.php`
- `api/update_personnel.php`
- `api/add_ppe.php`
- `api/update_ppe.php`
- `api/add_login_user.php`

**Example:**
```php
// Before (vulnerable):
$name = $_POST['name'] ?? '';

// After (safe):
$name = getSafeString('name');
```

**Protection level:** Prevents stored XSS attacks if user enters HTML/JavaScript in personnel names, supplier names, descriptions, etc.

---

### 2. Password Hashing
**Status:** Already implemented in backend

**Files:**
- `api/add_login_user.php` - uses `password_hash($password, PASSWORD_DEFAULT)`
- `api/login.php` - uses `password_verify()` to validate

**What this means:**
- Passwords are never stored in plaintext.
- Even database admins cannot see user passwords.
- Brute-force attacks are slowed by the hashing algorithm.

---

### 3. Session Management
**Status:** Partially implemented

**Files:**
- `api/login.php` - creates sessions on successful login
- `config/security.php` - provides `isSessionValid()` and `getCurrentUserId()`

**Recommended next steps (after deployment):**
- Add session validation checks to all protected endpoints
- Implement session timeout (30 min inactivity)
- Clear sessions on logout

---

### 4. CSRF Protection Framework
**File:** `config/security.php` (new)

**Functions provided:**
- `generateCSRFToken()` - create unique tokens per session
- `validateCSRFToken()` - verify tokens before accepting POST data

**Not yet deployed to endpoints** - requires frontend coordination to send tokens with each POST.

**To enable:**
1. Frontend adds CSRF token to each form submission
2. Backend validates it with `validateCSRFToken()`
3. Invalid tokens return 403 error

---

## ⚠️ Still Requires Attention

### 1. Frontend XSS in Template Strings
**Risk:** Medium

**Current code:**
```javascript
innerHTML = `<div>${item.ppeName}</div>`
```

**If database contains user data like:**
```
<img src=x onerror="alert('xss')">
```

**It will execute.** The backend now sanitizes on input (good), but the frontend should also escape on output.

**Fix for frontend:**
```javascript
// Use textContent instead of innerHTML where possible
element.textContent = item.ppeName;

// Or escape HTML entities
function escapeHtml(text) {
  const map = {'&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;'};
  return text.replace(/[&<>"]/g, m => map[m]);
}
```

---

### 2. LocalStorage Cleanup on Logout
**Risk:** Low-Medium (shared workstations)

**Current behavior:**
- Sensitive form drafts remain in `localStorage` even after logout
- Another user on the same computer could inspect them

**Recommended fix:**
Add to logout handler in `HSE_management.html.html`:
```javascript
function logout() {
    // Clear all drafts
    localStorage.removeItem('draft-personnel');
    localStorage.removeItem('draft-ppe-inventory');
    localStorage.removeItem('draft-ppe-issuance');
    // ... clear all others
    
    // Redirect to login
    location.reload();
}
```

---

### 3. PIN Authentication
**Risk:** Medium-High

**Current flow:**
1. User enters PIN
2. Frontend searches local records for matching PIN
3. If found, grants access

**Issues:**
- No server-side PIN validation
- Easy brute force (only 4 digits: 0000-9999)
- Frontend logic is visible in browser

**Recommended approach (cPanel deployment):**
1. Keep PIN as a secondary factor
2. Require username + password (already hashed)
3. PIN only used for quick re-auth within session
4. Never expose PIN in API responses

---

### 4. HTTPS/SSL
**Risk:** High (if deployed publicly)

**Required for cPanel:**
- Force HTTPS on all connections
- Set `Secure` flag on session cookies
- Add `HSTS` headers

**cPanel tip:** Use AutoSSL (usually free with cPanel) to get an SSL certificate.

---

## 🔒 Deployment Checklist

Before uploading to cPanel:

- [ ] HTTPS/SSL certificate installed
- [ ] `config/database.php` updated with cPanel MySQL credentials
- [ ] `database_setup.sql` executed to create all tables
- [ ] `config/security.php` is in place
- [ ] All API files use the new security functions
- [ ] Test login with username + password
- [ ] Test personnel and PPE form submission
- [ ] Verify data is sanitized in database (via phpMyAdmin)
- [ ] Clear browser localStorage and test fresh login

---

## 📋 Code Review Needed

After uploading, review these endpoint files in your cPanel for any custom logic:

1. `api/suppliers.php` - check input handling
2. `api/competence.php` - check employee_name sanitization
3. `api/ppe_issuance.php` - check all user-facing fields
4. `api/requests.php` - check requester_name sanitization
5. `api/masters.php` - check all warehouse/stock fields

Add the same `getSafeString()` / `getSafeInt()` pattern to these files if not already done.

---

## Questions?

If deploying, verify:
1. Does your cPanel host support `password_hash()` and `password_verify()` (PHP 5.5+)? ✅ (almost all modern hosts)
2. Are sessions enabled on your cPanel account? ✅ (usually yes)
3. Can you run SQL in phpMyAdmin? ✅ (always available)

All security improvements are backward-compatible and will not break existing functionality.
