guts.mx raw

   1  // 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.
  10  package httpguts
  11  
  12  import (
  13  	"net/textproto"
  14  	"bytes"
  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
  20  func ValidTrailerHeader(name []byte) bool {
  21  	name = textproto.CanonicalMIMEHeaderKey(name)
  22  	if bytes.HasPrefix(name, "If-") || badTrailer[name] {
  23  		return false
  24  	}
  25  	return true
  26  }
  27  
  28  var 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  }
  51