diff options
author | Niall Sheridan <nsheridan@gmail.com> | 2016-06-06 00:55:30 +0100 |
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committer | Niall Sheridan <nsheridan@gmail.com> | 2016-06-06 00:55:30 +0100 |
commit | a18a13fb09eac00cdacf1f74080524182b7243de (patch) | |
tree | bcf982d0054f0b86c01f93fe095633568aacfea8 /vendor/golang.org/x/net/lex | |
parent | b8af9fe60f27353bdd5933ed37508b30d4290046 (diff) |
update vendor
Diffstat (limited to 'vendor/golang.org/x/net/lex')
-rw-r--r-- | vendor/golang.org/x/net/lex/httplex/httplex.go | 312 |
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 new file mode 100644 index 0000000..bd0ec24 --- /dev/null +++ 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 +} |