方法
set_cookie(name, value, domain=None, expires=None, path=’/’, expires_days=None)
参数说明
参数名 | 说明 |
---|---|
name | cookie名 |
value | cookie值 |
domain | 提交cookie时匹配的域名 |
path | 提交cookie时匹配的路径 |
expires | cookie的有效期,可以是时间戳整数、时间元组或者datetime类型,为UTC时间 |
expires_days | cookie的有效期,天数,优先级低于expires |
示例
<span class="hljs-keyword">import</span> time
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">IndexHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
self.set_cookie(<span class="hljs-string">"name"</span>, <span class="hljs-string">"lucky"</span>)
self.set_cookie(<span class="hljs-string">"age"</span>, <span class="hljs-string">"18"</span>, path=<span class="hljs-string">"/new"</span>, expires=time.strptime(<span class="hljs-string">"2020-03-04 23:59:59"</span>,<span class="hljs-string">"%Y-%m-%d %H:%M:%S"</span>))
self.set_cookie(<span class="hljs-string">"sex"</span>, <span class="hljs-string">"man"</span>, expires_days=<span class="hljs-number">20</span>)
<span class="hljs-comment"># 利用time.mktime将本地时间转换为UTC标准时间</span>
self.set_cookie(<span class="hljs-string">"info"</span>, <span class="hljs-string">"lucky_info"</span>, expires=time.mktime(time.strptime(<span class="hljs-string">"2020-03-04 23:59:59"</span>,<span class="hljs-string">"%Y-%m-%d %H:%M:%S"</span>)))
self.write(<span class="hljs-string">"OK"</span>)
结果
原理
设置cookie实际就是通过设置header的Set-Cookie来实现的
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">IndexHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
self.set_header(<span class="hljs-string">"Set-Cookie"</span>, <span class="hljs-string">"lucky=lucky_boy; expires=Wed, 04 Mar 2020 15:59:59 GMT; Path=/"</span>)
self.write(<span class="hljs-string">"OK"</span>)
方法
get_cookie(name, default=None) 获取名为name的cookie,可以设置默认值
示例
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">IndexHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
name = self.get_cookie(<span class="hljs-string">"name"</span>)
self.write(name)
方法
clear_cookie(name) 删除名为name的cookie
clear_all_cookies() 删除所有cookie
示例
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">ClearOneCookieHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
self.clear_cookie(<span class="hljs-string">"name"</span>)
self.write(<span class="hljs-string">"OK"</span>)
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">ClearAllCookieHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
self.clear_all_cookies()
self.write(<span class="hljs-string">"OK"</span>)
注意
执行清除cookie操作后,并不是立即删除了浏览器中的cookie,而是给cookie值置空,并改变其有效期使其失效。真正的删除cookie是由浏览器去清理的
说明
Cookie是存储在客户端浏览器中的,很容易被篡改。Tornado提供了一种对Cookie进行简易加密签名的方法来防止Cookie被恶意篡改
使用安全Cookie需要为应用配置一个用来给Cookie进行混淆的秘钥cookie_secret,将其传递给Application的构造函数。我们可以使用如下方法来生成一个随机字符串作为cookie_secret的值
示例
<span class="hljs-meta">>>> </span><span class="hljs-keyword">import</span> base64, uuid
<span class="hljs-meta">>>> </span>base64.b64encode(uuid.uuid4().bytes + uuid.uuid4().bytes)
<span class="hljs-string">'2hcicVu+TqShDpfsjMWQLZ0Mkq5NPEWSk9fi0zsSt3A='</span>
扩展
使用
将生成的cookie_secret传入Application构造函数
app = tornado.web.Application(
[(<span class="hljs-string">r"/"</span>, IndexHandler),],
cookie_secret = <span class="hljs-string">"2hcicVu+TqShDpfsjMWQLZ0Mkq5NPEWSk9fi0zsSt3A="</span>
)
方法
示例
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">IndexHandler</span><span class="hljs-params">(RequestHandler)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get</span><span class="hljs-params">(self)</span>:</span>
cookie = self.get_secure_cookie(<span class="hljs-string">"count"</span>)
count = int(cookie) + <span class="hljs-number">1</span> <span class="hljs-keyword">if</span> cookie <span class="hljs-keyword">else</span> <span class="hljs-number">1</span>
self.set_secure_cookie(<span class="hljs-string">"count"</span>, str(count))
self.write(
<span class="hljs-string">'<html><head><title>Cookie计数器</title></head>'</span>
<span class="hljs-string">'<body><h1>您已访问本页%d次。</h1>'</span> % count +
<span class="hljs-string">'</body></html>'</span>
)
我们看签名后的cookie值:
"2|1:0|10:1476412069|5:count|4:NQ==|cb5fc1d4434971de6abf87270ac33381c686e4ec8c6f7e62130a0f8cbe5b7609"
字段说明
注意
Tornado的安全cookie只是一定程度的安全,仅仅是增加了恶意修改的难度。Tornado的安全cookies仍然容易被窃听,而cookie值是签名不是加密,攻击者能够读取已存储的cookie值,并且可以传输他们的数据到任意服务器,或者通过发送没有修改的数据给应用伪造请求。因此,避免在浏览器cookie中存储敏感的用户数据是非常重要的
过程
将值进行base64加密 对除值以外的内容进行签名,哈希算法(无法逆向解析) 拼接 签名 + 加密值
读取 签名 + 加密值 对签名进行验证 base64解密,获取值内容