由于奇怪的域/子域cookie问题，我得到了，我想知道浏览器如何处理cookie。如果他们用不同的方式做这件事，知道其中的区别也会很好。
换句话说，当浏览器接收到一个cookie时，该cookie可能有一个域和一个路径附加到它。或者不是，在这种情况下，浏览器可能会用一些默认值代替它们。问题1:它们是什么?
稍后，当浏览器准备发出请求时，它会检查它的cookie并过滤掉应该为该请求发送的cookie。它通过将它们与请求路径和域进行匹配来做到这一点。问题2:匹配规则是什么?
补充道:
我问这个问题是因为我对一些边缘情况感兴趣。如:
用于。example.com的cookie可以用于www.example.com吗?
example.com的cookie是否可用于example.com?
example.com的cookie可以用于www.example.com吗?
example.com的cookie是否可用于anotherexample.com?
www.example.com可以为example.com设置cookie吗?
www.example.com是否可以为www2.example.com设置cookie ?
www.example.com是否可以为。com设置cookie ?
等。
补充2:
还有，谁能建议一下我应该如何设置cookie，以便:
可以通过www.example.com或example.com设置;
它可以通过www.example.com和example.com访问。
要获得广泛的覆盖，请查看RFC2965的内容。当然，这并不意味着所有浏览器的行为都完全相同。
但是，通常情况下，如果cookie中没有指定默认路径，则默认路径是Set-Cookie报头到达的URL中的路径。类似地，Domain的默认值是来自Set-Cookie的URL中的完整主机名。
Matching rules for the domain require the cookie Domain to match the host to which the request is being made. The cookie can specify a wider domain match by include *. in the domain attribute of Set-Cookie (this one area that browsers may vary). Matching the path (assuming the domain matches) is a simple matter that the requested path must be inside the path specified on the cookie. Typically session cookies are set with path=/ or path=/applicationName/ so the cookie is available to all requests into the application.
__Response to Added:__
Will a cookie for .example.com be available for www.example.com? Yes
Will a cookie for .example.com be available for example.com? Don't Know
Will a cookie for example.com be available for www.example.com? Shouldn't but... *
Will a cookie for example.com be available for anotherexample.com? No
Will www.example.com be able to set cookie for example.com? Yes
Will www.example.com be able to set cookie for www2.example.com? No (Except via .example.com)
Will www.example.com be able to set cookie for .com? No (Can't set a cookie this high up the namespace nor can you set one for something like .co.uk).
*我现在无法测试这个，但我有一个暗示，至少IE7/6会把路径example.com视为。example.com。
2019年，我在最新的Chrome、Firefox和Safari中测试了所有的保护套。
回复新增:
Will a cookie for .example.com be available for www.example.com? YES
Will a cookie for .example.com be available for example.com? YES
Will a cookie for example.com be available for www.example.com? NO, Domain without wildcard only matches itself.
Will a cookie for example.com be available for anotherexample.com? NO
Will www.example.com be able to set cookie for example.com? NO, it will be able to set cookie for '.example.com', but not 'example.com'.
Will www.example.com be able to set cookie for www2.example.com? NO. But it can set cookie for .example.com, which www2.example.com can access.
Will www.example.com be able to set cookie for .com? NO
之前的答案有点过时了。
基于当时的浏览器共识，RFC 6265于2011年发布。
从那时起，公共后缀域名就出现了一些复杂情况。我已经写了一篇文章解释目前的情况- http://bayou.io/draft/cookie.domain.html
综上所述，cookie域的规则如下:
The origin domain of a cookie is the domain of the originating request.
If the origin domain is an IP, the cookie's domain attribute must not be set.
If a cookie's domain attribute is not set, the cookie is only applicable to its origin domain.
If a cookie's domain attribute is set,
the cookie is applicable to that domain and all its subdomains;
the cookie's domain must be the same as, or a parent of, the origin domain
the cookie's domain must not be a TLD, a public suffix, or a parent of a public suffix.
可以推导出cookie总是适用于它的原始域。
cookie域不应该有一个前导点，就像。foo.com -简单地使用foo.com
举个例子，
X.y.z.com可以为自己或父母设置cookie域- X.y.z.com, y.z.com, z.com。但不是com，它是一个公共后缀。
域名=y.z.com的cookie适用于y.z.com、x.y.z.com、a.x.y.z.com等。
公共后缀的例子- com, edu, uk, co.uk, blogspot.com, compute.amazonaws.com
要获得广泛的覆盖，请查看RFC2965的内容。当然，这并不意味着所有浏览器的行为都完全相同。
但是，通常情况下，如果cookie中没有指定默认路径，则默认路径是Set-Cookie报头到达的URL中的路径。类似地，Domain的默认值是来自Set-Cookie的URL中的完整主机名。
Matching rules for the domain require the cookie Domain to match the host to which the request is being made. The cookie can specify a wider domain match by include *. in the domain attribute of Set-Cookie (this one area that browsers may vary). Matching the path (assuming the domain matches) is a simple matter that the requested path must be inside the path specified on the cookie. Typically session cookies are set with path=/ or path=/applicationName/ so the cookie is available to all requests into the application.
__Response to Added:__
Will a cookie for .example.com be available for www.example.com? Yes
Will a cookie for .example.com be available for example.com? Don't Know
Will a cookie for example.com be available for www.example.com? Shouldn't but... *
Will a cookie for example.com be available for anotherexample.com? No
Will www.example.com be able to set cookie for example.com? Yes
Will www.example.com be able to set cookie for www2.example.com? No (Except via .example.com)
Will www.example.com be able to set cookie for .com? No (Can't set a cookie this high up the namespace nor can you set one for something like .co.uk).
*我现在无法测试这个，但我有一个暗示，至少IE7/6会把路径example.com视为。example.com。
