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每天40分玩转Django：Django安全专题

article 2025/1/5 9:04:40

Django安全专题

一、学习内容概述表

类别	具体内容	重要性
XSS攻击	HTML转义、JavaScript注入防护	非常重要
XSS防护方案	Django模板转义、clean方法	非常重要
点击劫持	Clickjacking防护、X-Frame-Options	重要
安全中间件	SecurityMiddleware配置与使用	重要

二、跨站脚本攻击(XSS)详解

2.1 XSS攻击原理

XSS(Cross-Site Scripting)是一种网站应用程序的安全漏洞攻击，是代码注入的一种。它允许恶意用户将代码注入到网页上，其他用户在观看网页时就会受到影响。

2.2 Django防护机制

让我们通过一个具体的例子来了解Django如何防护XSS攻击：

# models.py
from django.db import models
from django.utils.html import escape

class Comment(models.Model):
    content = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)
    
    def clean_content(self):
        """清理评论内容，防止XSS攻击"""
        return escape(self.content)

# views.py
from django.shortcuts import render
from django.views.generic import CreateView
from .models import Comment
from django.utils.html import escape
from django.core.exceptions import ValidationError

class CommentCreateView(CreateView):
    model = Comment
    fields = ['content']
    template_name = 'comments/create.html'
    
    def form_valid(self, form):
        # 在保存之前进行内容清理
        comment = form.save(commit=False)
        cleaned_content = escape(comment.content)
        
        # 检查是否包含可疑的JavaScript代码
        if '<script>' in comment.content.lower():
            raise ValidationError("评论内容包含不允许的脚本标签")
            
        comment.content = cleaned_content
        return super().form_valid(form)

def comment_list(request):
    comments = Comment.objects.all()
    return render(request, 'comments/list.html', {'comments': comments})

<!-- templates/comments/list.html -->
{% extends 'base.html' %}

{% block content %}
<div class="comments-container">
    {% for comment in comments %}
        <div class="comment">
            <!-- Django模板系统默认会转义HTML -->
            <p>{{ comment.content }}</p>
            <small>{{ comment.created_at|date:"Y-m-d H:i" }}</small>
        </div>
    {% endfor %}
</div>
{% endblock %}

2.3 防护措施配置

# settings.py

# 开启XSS防护
SECURE_BROWSER_XSS_FILTER = True

# 开启CSRF防护
CSRF_COOKIE_SECURE = True

# 设置安全的Content Type
SECURE_CONTENT_TYPE_NOSNIFF = True

三、点击劫持(Clickjacking)防护

3.1 点击劫持原理

点击劫持是一种视觉欺骗攻击，攻击者使用透明的iframe覆盖在网页上，诱导用户点击。

3.2 Django防护实现

# middleware.py
from django.http import HttpResponseForbidden

class ClickjackingMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        response = self.get_response(request)
        
        # 添加X-Frame-Options头
        response['X-Frame-Options'] = 'SAMEORIGIN'
        
        return response

# settings.py

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    # 添加自定义中间件
    'myapp.middleware.ClickjackingMiddleware',
]

# 设置X-Frame-Options
X_FRAME_OPTIONS = 'SAMEORIGIN'

3.3 装饰器方式实现点击劫持防护

# decorators.py
from functools import wraps
from django.http import HttpResponseForbidden

def prevent_clickjacking(view_func):
    @wraps(view_func)
    def wrapper(request, *args, **kwargs):
        response = view_func(request, *args, **kwargs)
        response['X-Frame-Options'] = 'DENY'
        return response
    return wrapper

# views.py使用示例
from .decorators import prevent_clickjacking

@prevent_clickjacking
def sensitive_view(request):
    return render(request, 'sensitive_template.html')

四、安全测试实例

4.1 XSS测试用例

# tests.py
from django.test import TestCase, Client
from django.urls import reverse
from .models import Comment

class SecurityTests(TestCase):
    def setUp(self):
        self.client = Client()
        
    def test_xss_protection(self):
        # 创建包含潜在XSS攻击的评论
        malicious_content = '<script>alert("XSS")</script>'
        response = self.client.post(
            reverse('comment_create'),
            {'content': malicious_content}
        )
        
        # 验证评论是否被正确转义
        comment = Comment.objects.first()
        self.assertNotIn('<script>', comment.content)
        self.assertIn('&lt;script&gt;', comment.content)

    def test_clickjacking_protection(self):
        response = self.client.get(reverse('home'))
        self.assertEqual(
            response['X-Frame-Options'],
            'SAMEORIGIN'
        )

五、完整的安全防护实现示例

让我们创建一个更完整的安全防护系统：

# security.py
import re
from django.core.exceptions import ValidationError
from django.utils.html import strip_tags

class SecurityCleaner:
    @staticmethod
    def clean_html(content):
        """清理HTML内容"""
        # 移除所有HTML标签
        cleaned = strip_tags(content)
        # 移除可能的JavaScript代码
        cleaned = re.sub(r'javascript:', '', cleaned, flags=re.IGNORECASE)
        return cleaned
    
    @staticmethod
    def validate_content(content):
        """验证内容是否安全"""
        dangerous_patterns = [
            r'<script',
            r'javascript:',
            r'οnerrοr=',
            r'οnlοad=',
            r'οnclick=',
        ]
        
        for pattern in dangerous_patterns:
            if re.search(pattern, content, re.IGNORECASE):
                raise ValidationError(
                    f"内容包含不安全的模式: {pattern}"
                )

# forms.py
from django import forms
from .security import SecurityCleaner

class SecureCommentForm(forms.ModelForm):
    class Meta:
        model = Comment
        fields = ['content']
        
    def clean_content(self):
        content = self.cleaned_data['content']
        # 验证内容安全性
        SecurityCleaner.validate_content(content)
        # 清理内容
        return SecurityCleaner.clean_html(content)