http - 处理 http header 中的空格

Question

是否应该在 HTTP 请求/响应中忽略前导或尾随空格？

例如，如果一个 HTTP/1.1 兼容的客户端解释这个:

Connection  :   close      \r\n

像这样:

Connection: close\r\n

Answer 1

根据 RFC2616 的第 4.2 段(HTTP/1.1)，字段值前面可能有空格，但不是字段名:

Each header field consistsof a name followed by a colon (":") and the field value. Field namesare case-insensitive. The field value may be preceded by any amountof LWS (linear white space), though a single SP is preferred. Header fields can be extended over multiple lines by preceding each extra line with at least one SP or HT. Applications ought to follow "common form", whereone is known or indicated, when generating HTTP constructs, sincethere might exist some implementations that fail to accept anything.