blob: e6cd0ced39283ebdf38d79bbde002dc6db70b534 [file] [log] [blame]
khenaidooac637102019-01-14 15:44:34 -05001// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// Package httpguts provides functions implementing various details
6// of the HTTP specification.
7//
8// This package is shared by the standard library (which vendors it)
9// and x/net/http2. It comes with no API stability promise.
10package httpguts
11
12import (
13 "net/textproto"
14 "strings"
15)
16
17// ValidTrailerHeader reports whether name is a valid header field name to appear
18// in trailers.
19// See RFC 7230, Section 4.1.2
20func ValidTrailerHeader(name string) bool {
21 name = textproto.CanonicalMIMEHeaderKey(name)
22 if strings.HasPrefix(name, "If-") || badTrailer[name] {
23 return false
24 }
25 return true
26}
27
28var badTrailer = map[string]bool{
29 "Authorization": true,
30 "Cache-Control": true,
31 "Connection": true,
32 "Content-Encoding": true,
33 "Content-Length": true,
34 "Content-Range": true,
35 "Content-Type": true,
36 "Expect": true,
37 "Host": true,
38 "Keep-Alive": true,
39 "Max-Forwards": true,
40 "Pragma": true,
41 "Proxy-Authenticate": true,
42 "Proxy-Authorization": true,
43 "Proxy-Connection": true,
44 "Range": true,
45 "Realm": true,
46 "Te": true,
47 "Trailer": true,
48 "Transfer-Encoding": true,
49 "Www-Authenticate": true,
50}