guts.go

     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  	"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
    20  func 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  
    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
View as plain text