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-rw-r--r--vendor/golang.org/x/net/lex/httplex/httplex.go312
1 files changed, 312 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/lex/httplex/httplex.go b/vendor/golang.org/x/net/lex/httplex/httplex.go
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+++ b/vendor/golang.org/x/net/lex/httplex/httplex.go
@@ -0,0 +1,312 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package httplex contains rules around lexical matters of various
+// HTTP-related specifications.
+//
+// This package is shared by the standard library (which vendors it)
+// and x/net/http2. It comes with no API stability promise.
+package httplex
+
+import (
+ "strings"
+ "unicode/utf8"
+)
+
+var isTokenTable = [127]bool{
+ '!': true,
+ '#': true,
+ '$': true,
+ '%': true,
+ '&': true,
+ '\'': true,
+ '*': true,
+ '+': true,
+ '-': true,
+ '.': true,
+ '0': true,
+ '1': true,
+ '2': true,
+ '3': true,
+ '4': true,
+ '5': true,
+ '6': true,
+ '7': true,
+ '8': true,
+ '9': true,
+ 'A': true,
+ 'B': true,
+ 'C': true,
+ 'D': true,
+ 'E': true,
+ 'F': true,
+ 'G': true,
+ 'H': true,
+ 'I': true,
+ 'J': true,
+ 'K': true,
+ 'L': true,
+ 'M': true,
+ 'N': true,
+ 'O': true,
+ 'P': true,
+ 'Q': true,
+ 'R': true,
+ 'S': true,
+ 'T': true,
+ 'U': true,
+ 'W': true,
+ 'V': true,
+ 'X': true,
+ 'Y': true,
+ 'Z': true,
+ '^': true,
+ '_': true,
+ '`': true,
+ 'a': true,
+ 'b': true,
+ 'c': true,
+ 'd': true,
+ 'e': true,
+ 'f': true,
+ 'g': true,
+ 'h': true,
+ 'i': true,
+ 'j': true,
+ 'k': true,
+ 'l': true,
+ 'm': true,
+ 'n': true,
+ 'o': true,
+ 'p': true,
+ 'q': true,
+ 'r': true,
+ 's': true,
+ 't': true,
+ 'u': true,
+ 'v': true,
+ 'w': true,
+ 'x': true,
+ 'y': true,
+ 'z': true,
+ '|': true,
+ '~': true,
+}
+
+func IsTokenRune(r rune) bool {
+ i := int(r)
+ return i < len(isTokenTable) && isTokenTable[i]
+}
+
+func isNotToken(r rune) bool {
+ return !IsTokenRune(r)
+}
+
+// HeaderValuesContainsToken reports whether any string in values
+// contains the provided token, ASCII case-insensitively.
+func HeaderValuesContainsToken(values []string, token string) bool {
+ for _, v := range values {
+ if headerValueContainsToken(v, token) {
+ return true
+ }
+ }
+ return false
+}
+
+// isOWS reports whether b is an optional whitespace byte, as defined
+// by RFC 7230 section 3.2.3.
+func isOWS(b byte) bool { return b == ' ' || b == '\t' }
+
+// trimOWS returns x with all optional whitespace removes from the
+// beginning and end.
+func trimOWS(x string) string {
+ // TODO: consider using strings.Trim(x, " \t") instead,
+ // if and when it's fast enough. See issue 10292.
+ // But this ASCII-only code will probably always beat UTF-8
+ // aware code.
+ for len(x) > 0 && isOWS(x[0]) {
+ x = x[1:]
+ }
+ for len(x) > 0 && isOWS(x[len(x)-1]) {
+ x = x[:len(x)-1]
+ }
+ return x
+}
+
+// headerValueContainsToken reports whether v (assumed to be a
+// 0#element, in the ABNF extension described in RFC 7230 section 7)
+// contains token amongst its comma-separated tokens, ASCII
+// case-insensitively.
+func headerValueContainsToken(v string, token string) bool {
+ v = trimOWS(v)
+ if comma := strings.IndexByte(v, ','); comma != -1 {
+ return tokenEqual(trimOWS(v[:comma]), token) || headerValueContainsToken(v[comma+1:], token)
+ }
+ return tokenEqual(v, token)
+}
+
+// lowerASCII returns the ASCII lowercase version of b.
+func lowerASCII(b byte) byte {
+ if 'A' <= b && b <= 'Z' {
+ return b + ('a' - 'A')
+ }
+ return b
+}
+
+// tokenEqual reports whether t1 and t2 are equal, ASCII case-insensitively.
+func tokenEqual(t1, t2 string) bool {
+ if len(t1) != len(t2) {
+ return false
+ }
+ for i, b := range t1 {
+ if b >= utf8.RuneSelf {
+ // No UTF-8 or non-ASCII allowed in tokens.
+ return false
+ }
+ if lowerASCII(byte(b)) != lowerASCII(t2[i]) {
+ return false
+ }
+ }
+ return true
+}
+
+// isLWS reports whether b is linear white space, according
+// to http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2
+// LWS = [CRLF] 1*( SP | HT )
+func isLWS(b byte) bool { return b == ' ' || b == '\t' }
+
+// isCTL reports whether b is a control byte, according
+// to http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2
+// CTL = <any US-ASCII control character
+// (octets 0 - 31) and DEL (127)>
+func isCTL(b byte) bool {
+ const del = 0x7f // a CTL
+ return b < ' ' || b == del
+}
+
+// ValidHeaderFieldName reports whether v is a valid HTTP/1.x header name.
+// HTTP/2 imposes the additional restriction that uppercase ASCII
+// letters are not allowed.
+//
+// RFC 7230 says:
+// header-field = field-name ":" OWS field-value OWS
+// field-name = token
+// token = 1*tchar
+// tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." /
+// "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
+func ValidHeaderFieldName(v string) bool {
+ if len(v) == 0 {
+ return false
+ }
+ for _, r := range v {
+ if !IsTokenRune(r) {
+ return false
+ }
+ }
+ return true
+}
+
+// ValidHostHeader reports whether h is a valid host header.
+func ValidHostHeader(h string) bool {
+ // The latest spec is actually this:
+ //
+ // http://tools.ietf.org/html/rfc7230#section-5.4
+ // Host = uri-host [ ":" port ]
+ //
+ // Where uri-host is:
+ // http://tools.ietf.org/html/rfc3986#section-3.2.2
+ //
+ // But we're going to be much more lenient for now and just
+ // search for any byte that's not a valid byte in any of those
+ // expressions.
+ for i := 0; i < len(h); i++ {
+ if !validHostByte[h[i]] {
+ return false
+ }
+ }
+ return true
+}
+
+// See the validHostHeader comment.
+var validHostByte = [256]bool{
+ '0': true, '1': true, '2': true, '3': true, '4': true, '5': true, '6': true, '7': true,
+ '8': true, '9': true,
+
+ 'a': true, 'b': true, 'c': true, 'd': true, 'e': true, 'f': true, 'g': true, 'h': true,
+ 'i': true, 'j': true, 'k': true, 'l': true, 'm': true, 'n': true, 'o': true, 'p': true,
+ 'q': true, 'r': true, 's': true, 't': true, 'u': true, 'v': true, 'w': true, 'x': true,
+ 'y': true, 'z': true,
+
+ 'A': true, 'B': true, 'C': true, 'D': true, 'E': true, 'F': true, 'G': true, 'H': true,
+ 'I': true, 'J': true, 'K': true, 'L': true, 'M': true, 'N': true, 'O': true, 'P': true,
+ 'Q': true, 'R': true, 'S': true, 'T': true, 'U': true, 'V': true, 'W': true, 'X': true,
+ 'Y': true, 'Z': true,
+
+ '!': true, // sub-delims
+ '$': true, // sub-delims
+ '%': true, // pct-encoded (and used in IPv6 zones)
+ '&': true, // sub-delims
+ '(': true, // sub-delims
+ ')': true, // sub-delims
+ '*': true, // sub-delims
+ '+': true, // sub-delims
+ ',': true, // sub-delims
+ '-': true, // unreserved
+ '.': true, // unreserved
+ ':': true, // IPv6address + Host expression's optional port
+ ';': true, // sub-delims
+ '=': true, // sub-delims
+ '[': true,
+ '\'': true, // sub-delims
+ ']': true,
+ '_': true, // unreserved
+ '~': true, // unreserved
+}
+
+// ValidHeaderFieldValue reports whether v is a valid "field-value" according to
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2 :
+//
+// message-header = field-name ":" [ field-value ]
+// field-value = *( field-content | LWS )
+// field-content = <the OCTETs making up the field-value
+// and consisting of either *TEXT or combinations
+// of token, separators, and quoted-string>
+//
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2 :
+//
+// TEXT = <any OCTET except CTLs,
+// but including LWS>
+// LWS = [CRLF] 1*( SP | HT )
+// CTL = <any US-ASCII control character
+// (octets 0 - 31) and DEL (127)>
+//
+// RFC 7230 says:
+// field-value = *( field-content / obs-fold )
+// obj-fold = N/A to http2, and deprecated
+// field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+// field-vchar = VCHAR / obs-text
+// obs-text = %x80-FF
+// VCHAR = "any visible [USASCII] character"
+//
+// http2 further says: "Similarly, HTTP/2 allows header field values
+// that are not valid. While most of the values that can be encoded
+// will not alter header field parsing, carriage return (CR, ASCII
+// 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII
+// 0x0) might be exploited by an attacker if they are translated
+// verbatim. Any request or response that contains a character not
+// permitted in a header field value MUST be treated as malformed
+// (Section 8.1.2.6). Valid characters are defined by the
+// field-content ABNF rule in Section 3.2 of [RFC7230]."
+//
+// This function does not (yet?) properly handle the rejection of
+// strings that begin or end with SP or HTAB.
+func ValidHeaderFieldValue(v string) bool {
+ for i := 0; i < len(v); i++ {
+ b := v[i]
+ if isCTL(b) && !isLWS(b) {
+ return false
+ }
+ }
+ return true
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 13:45:28 +0000