http - HTTP 请求中是否允许多个 Cookie 标头？

Question

通常，浏览器将 cookie 分组到单个Cookie标头中，例如：

Cookie: a=1; b=2

标准是否允许将这些作为单独的标头发送，例如：

Cookie: a=1
Cookie: b=2

或者他们总是必须在同一条线上？

Answer 1

在查找有关该主题的详细信息时偶然发现了此页面。来自RFC 6265HTTP State Management Mechanism的引用应该让事情更清楚：

5.4. Cookie 标头

当用户代理生成一个 HTTP 请求时，用户代理不能附加多个 Cookie 头字段。

看起来使用多个Cookie标题实际上是被禁止的！

Answer 2

它现在在 HTTP/2 ( RFC 7540 ) 中被允许，它指定：

    8.1.2.5.  Compressing the Cookie Header Field

   The Cookie header field [COOKIE] uses a semi-colon (";") to delimit
   cookie-pairs (or "crumbs").  This header field doesn't follow the
   list construction rules in HTTP (see [RFC7230], Section 3.2.2), which
   prevents cookie-pairs from being separated into different name-value
   pairs.  This can significantly reduce compression efficiency as
   individual cookie-pairs are updated.

   To allow for better compression efficiency, the Cookie header field
   MAY be split into separate header fields, each with one or more
   cookie-pairs.  If there are multiple Cookie header fields after
   decompression, these MUST be concatenated into a single octet string
   using the two-octet delimiter of 0x3B, 0x20 (the ASCII string "; ")
   before being passed into a non-HTTP/2 context, such as an HTTP/1.1
   connection, or a generic HTTP server application.

   Therefore, the following two lists of Cookie header fields are
   semantically equivalent.

     cookie: a=b; c=d; e=f

     cookie: a=b
     cookie: c=d
     cookie: e=f