Django之中间件，csrf跨站伪造请求，auth认证模块
Django请求生命周期
django的中间件
django的中间件相当于保安，请求的时候要经过django的中间件才能连接django的后端
能用来干什么：能够做网站的全局身份认证，访问频率，权限认证，只要是全局的校验都可以用中间件来完成。
django的默认七个中间件
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', 'django.middleware.clickjacking.XFrameOptionsMiddleware', ]
class SecurityMiddleware(MiddlewareMixin): def __init__(self, get_response=None): self.sts_seconds = settings.SECURE_HSTS_SECONDS self.sts_include_subdomains = settings.SECURE_HSTS_INCLUDE_SUBDOMAINS self.sts_preload = settings.SECURE_HSTS_PRELOAD self.content_type_nosniff = settings.SECURE_CONTENT_TYPE_NOSNIFF self.xss_filter = settings.SECURE_BROWSER_XSS_FILTER self.redirect = settings.SECURE_SSL_REDIRECT self.redirect_host = settings.SECURE_SSL_HOST self.redirect_exempt = [re.compile(r) for r in settings.SECURE_REDIRECT_EXEMPT] self.get_response = get_response def process_request(self, request): path = request.path.lstrip("/") if (self.redirect and not request.is_secure() and not any(pattern.search(path) for pattern in self.redirect_exempt)): host = self.redirect_host or request.get_host() return HttpResponsePermanentRedirect( "https://%s%s" % (host, request.get_full_path()) ) def process_response(self, request, response): if (self.sts_seconds and request.is_secure() and 'strict-transport-security' not in response): sts_header = "max-age=%s" % self.sts_seconds if self.sts_include_subdomains: sts_header = sts_header + "; includeSubDomains" if self.sts_preload: sts_header = sts_header + "; preload" response["strict-transport-security"] = sts_header if self.content_type_nosniff and 'x-content-type-options' not in response: response["x-content-type-options"] = "nosniff" if self.xss_filter and 'x-xss-protection' not in response: response["x-xss-protection"] = "1; mode=block" return response class CsrfViewMiddleware(MiddlewareMixin): if settings.CSRF_USE_SESSIONS: request.session[CSRF_SESSION_KEY] = request.META['CSRF_COOKIE'] else: response.set_cookie( settings.CSRF_COOKIE_NAME, request.META['CSRF_COOKIE'], max_age=settings.CSRF_COOKIE_AGE, domain=settings.CSRF_COOKIE_DOMAIN, path=settings.CSRF_COOKIE_PATH, secure=settings.CSRF_COOKIE_SECURE, httponly=settings.CSRF_COOKIE_HTTPONLY, ) # Set the Vary header since content varies with the CSRF cookie. patch_vary_headers(response, ('Cookie',)) def process_request(self, request): csrf_token = self._get_token(request) if csrf_token is not None: # Use same token next time. request.META['CSRF_COOKIE'] = csrf_token def process_view(self, request, callback, callback_args, callback_kwargs): if getattr(request, 'csrf_processing_done', False): return None # Wait until request.META["CSRF_COOKIE"] has been manipulated before # bailing out, so that get_token still works if getattr(callback, 'csrf_exempt', False): return None # Assume that anything not defined as 'safe' by RFC7231 needs protection if request.method not in ('GET', 'HEAD', 'OPTIONS', 'TRACE'): if getattr(request, '_dont_enforce_csrf_checks', False): # Mechanism to turn off CSRF checks for test suite. # It comes after the creation of CSRF cookies, so that # everything else continues to work exactly the same # (e.g. cookies are sent, etc.), but before any # branches that call reject(). return self._accept(request) if request.is_secure(): # Suppose user visits http://example.com/ # An active network attacker (man-in-the-middle, MITM) sends a # POST form that targets https://example.com/detonate-bomb/ and # submits it via JavaScript. # # The attacker will need to provide a CSRF cookie and token, but # that's no problem for a MITM and the session-independent # secret we're using. So the MITM can circumvent the CSRF # protection. This is true for any HTTP connection, but anyone # using HTTPS expects better! For this reason, for # https://example.com/ we need additional protection that treats # http://example.com/ as completely untrusted. Under HTTPS, # Barth et al. found that the Referer header is missing for # same-domain requests in only about 0.2% of cases or less, so # we can use strict Referer checking. referer = force_text( request.META.get('HTTP_REFERER'), strings_only=True, errors='replace' ) if referer is None: return self._reject(request, REASON_NO_REFERER) referer = urlparse(referer) # Make sure we have a valid URL for Referer. if '' in (referer.scheme, referer.netloc): return self._reject(request, REASON_MALFORMED_REFERER) # Ensure that our Referer is also secure. if referer.scheme != 'https': return self._reject(request, REASON_INSECURE_REFERER) # If there isn't a CSRF_COOKIE_DOMAIN, require an exact match # match on host:port. If not, obey the cookie rules (or those # for the session cookie, if CSRF_USE_SESSIONS). good_referer = ( settings.SESSION_COOKIE_DOMAIN if settings.CSRF_USE_SESSIONS else settings.CSRF_COOKIE_DOMAIN ) if good_referer is not None: server_port = request.get_port() if server_port not in ('443', '80'): good_referer = '%s:%s' % (good_referer, server_port) else: # request.get_host() includes the port. good_referer = request.get_host() # Here we generate a list of all acceptable HTTP referers, # including the current host since that has been validated # upstream. good_hosts = list(settings.CSRF_TRUSTED_ORIGINS) good_hosts.append(good_referer) if not any(is_same_domain(referer.netloc, host) for host in good_hosts): reason = REASON_BAD_REFERER % referer.geturl() return self._reject(request, reason) csrf_token = request.META.get('CSRF_COOKIE') if csrf_token is None: # No CSRF cookie. For POST requests, we insist on a CSRF cookie, # and in this way we can avoid all CSRF attacks, including login # CSRF. return self._reject(request, REASON_NO_CSRF_COOKIE) # Check non-cookie token for match. request_csrf_token = "" if request.method == "POST": try: request_csrf_token = request.POST.get('csrfmiddlewaretoken', '') except IOError: # Handle a broken connection before we've completed reading # the POST data. process_view shouldn't raise any # exceptions, so we'll ignore and serve the user a 403 # (assuming they're still listening, which they probably # aren't because of the error). pass if request_csrf_token == "": # Fall back to X-CSRFToken, to make things easier for AJAX, # and possible for PUT/DELETE. request_csrf_token = request.META.get(settings.CSRF_HEADER_NAME, '') request_csrf_token = _sanitize_token(request_csrf_token) if not _compare_salted_tokens(request_csrf_token, csrf_token): return self._reject(request, REASON_BAD_TOKEN) return self._accept(request) def process_response(self, request, response): if not getattr(request, 'csrf_cookie_needs_reset', False): if getattr(response, 'csrf_cookie_set', False): return response if not request.META.get("CSRF_COOKIE_USED", False): return response # Set the CSRF cookie even if it's already set, so we renew # the expiry timer. self._set_token(request, response) response.csrf_cookie_set = True return response class AuthenticationMiddleware(MiddlewareMixin): def process_request(self, request): assert hasattr(request, 'session'), ( "The Django authentication middleware requires session middleware " "to be installed. Edit your MIDDLEWARE%s setting to insert " "'django.contrib.sessions.middleware.SessionMiddleware' before " "'django.contrib.auth.middleware.AuthenticationMiddleware'." ) % ("_CLASSES" if settings.MIDDLEWARE is None else "") request.user = SimpleLazyObject(lambda: get_user(request))
django中间件可以自定义有五种方法
掌握：
1.process_request()方法
规律:
请求来的时候，会从上往下依次执行每个中间件里面的process_request方法，如果没有就跳过。
但需要注意的是，如果在某个中间件的process_request方法中返回了一个HttpResponse对象的话，那么就不会在走下面的中间件了，会在同级别从下往上依次执行每个中间件的process_response方法
2.process_response()方法
响应走的时候，会从下至上依次执行每个中间件的process_response方法。
不过要注意的是，最后要返回一个response，这个形参就是返回给浏览器的数据，只要是参数有response的，最后都要返回一下，因为返回的response就是代表要返回给浏览器的数据，如果没有就是代表你想截获它
了解
3.process_view
这个方法是在路由匹配成功，进入视图层前执行的一个方法，但要注意的是如果我某一个中间件的process_view()方法里面返回了一个HttpResponse对象，则会掉头，从最底下，从下往上依次执行每个中间件的process_respnse方法
4.process_exception
这个方法要报错的时候才会执行，顺序从下往上
5.process_template_response()
是返回的对象含有render这个方法的时候执行，顺序是从下往上 def index(request): print('我是index视图函数') def render(): return HttpResponse('什么鬼玩意') obj = HttpResponse('index') obj.render = render return obj
注意：如果要想让你写的中间件有效，那么写的类一定要继承自MiddlemareMixin
在seetings中注册自定义的中间件的时候，一定要注意路径不要写错
Csrf跨站请求伪造(钓鱼网站)
钓鱼网站
就是制作一个正儿八经的网站，欺骗用户转账
你比如中国银行转账，交易请求确确实实发送给了中国银行，也的确完成了交易，但是就是交易方不对。
内部原理：
就是在用户输入转账用户的那个input框做手脚
给这个input框不设置name属性，而是将这个设置下隐藏在下面的input框内，value值就是钓鱼网站受益人账号。
防止钓鱼网站的思路:
给每个返回给用户输入的form表单页面偷偷塞入一个特殊的随机字符串。
请求来的时候，会先比较是否与我保存的一致，不一致就不通过报个(403)
该随机字符串有以下特点:
1.同一个浏览器每一次访问都不一样
2.不同浏览器绝对不会重复
form表单来的时候就是固定一句话
{% csrf_token %}
ajax来的时候有3种避免csrf校验的
1.现在页面上写{% csrf_token %},利用标签查找 获取到该input键值信息
{'username':'jason','csrfmiddlewaretoken':$('[name=csrfmiddlewaretoken]').val()}
$('[name=csrfmiddlewaretoken]').val()
2.直接书写'{{ csrf_token }}'
{'username':'jason','csrfmiddlewaretoken':'{{ csrf_token }}'}
{{ csrf_token }}
3.你可以将该获取随机键值对的方法 写到一个js文件中,之后只需要导入该文件即可
新建一个js文件 存放以下代码 之后导入即可
function getCookie(name) {
var cookieValue = null;
if (document.cookie && document.cookie !== '') {
var cookies = document.cookie.split(';');
for (var i = 0; i < cookies.length; i++) {
var cookie = jQuery.trim(cookies[i]);
// Does this cookie string begin with the name we want?
if (cookie.substring(0, name.length + 1) === (name + '=')) {
cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
break;
}
}
}
return cookieValue;
}
var csrftoken = getCookie('csrftoken');
function csrfSafeMethod(method) {
// these HTTP methods do not require CSRF protection
return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));
}
$.ajaxSetup({
beforeSend: function (xhr, settings) {
if (!csrfSafeMethod(settings.type) && !this.crossDomain) {
xhr.setRequestHeader("X-CSRFToken", csrftoken);
}
}
});
接下来的2中需求
1.全部都要校验，但有几个不想让其校验
2.全部都不检验，但有几个想要其校验
from django.utils.decorators import method_decorator from django.views.decorators.csrf import csrf_exempt,csrf_protect # 这两个装饰器在给CBV装饰的时候 有一定的区别 如果是csrf_protect 那么有三种方式 # 第一种方式 # @method_decorator(csrf_protect,name='post') # 有效的 class MyView(View): # 第三种方式 # @method_decorator(csrf_protect) def dispatch(self, request, *args, **kwargs): res = super().dispatch(request, *args, **kwargs) return res def get(self,request): return HttpResponse('get') # 第二种方式 # @method_decorator(csrf_protect) # 有效的 def post(self,request): return HttpResponse('post') 如果是csrf_exempt 只有两种(只能给dispatch装) 特例 @method_decorator(csrf_exempt,name='dispatch') # 第二种可以不校验的方式 class MyView(View): # @method_decorator(csrf_exempt) # 第一种可以不校验的方式 def dispatch(self, request, *args, **kwargs): res = super().dispatch(request, *args, **kwargs) return res def get(self,request): return HttpResponse('get') def post(self,request): return HttpResponse('post') 总结 装饰器中只有csrf_exempt是特例,其他的装饰器在给CBV装饰的时候 都可以有三种方式
Auth用户登录认证模块
auth模块 如果你想用auth模块 那么你就用全套 跟用户相关的功能模块 用户的注册 登陆 验证 修改密码 ... 执行数据库迁移命令之后 会生成很多表 其中的auth_user是一张用户相关的表格 添加数据 createsuperuser 创建超级用户 这个超级用户就可以拥有登陆django admin后台管理的权限 auth模块的功能 查询用户 from django.contrib import auth user_obj = auth.authenticate(username=username,password=password) # 必须要用 因为数据库中的密码字段是密文的 而你获取的用户输入的是明文 记录用户状态 auth.login(request,user_obj) # 将用户状态记录到session中 判断用户是否登录 print(request.user.is_authenticated) # 判断用户是否登录 如果是你们用户会返回False 用户登录之后 获取用户对象 print(request.user) # 如果没有执行auth.login那么拿到的是匿名用户 校验用户是否登录 from django.contrib.auth.decorators import login_required @login_required(login_url='/xxx/') # 局部配置 def index(request): pass # 全局配置 settings文件中 LOGIN_URL = '/xxx/' 验证密码是否正确 request.user.check_password(old_password) 修改密码 request.user.set_password(new_password) request.user.save() # 修改密码的时候 一定要save保存 否则无法生效 退出登陆 auth.logout(request) # request.session.flush() 注册用户 # User.objects.create(username =username,password=password) # 创建用户名的时候 千万不要再使用create 了 # User.objects.create_user(username =username,password=password) # 创建普通用户 User.objects.create_superuser(username =username,password=password,email='123@qq.com') # 创建超级用户 邮箱必填 自定义auth_user表 from django.contrib.auth.models import AbstractUser # Create your models here. # 第一种 使用一对一关系 不考虑 # 第二种方式 使用类的继承 class Userinfo(AbstractUser): # 千万不要跟原来表中的字段重复 只能创新 phone = models.BigIntegerField() avatar = models.CharField(max_length=32) # 一定要在配置文件中 告诉django # 告诉django orm不再使用auth默认的表 而是使用你自定义的表 AUTH_USER_MODEL = 'app01.Userinfo' # '应用名.类名' 1.执行数据库迁移命令 所有的auth模块功能 全部都基于你创建的表 而不再使用auth_user
