src/net/http/cookie.go - go - Git at Google

 // Copyright 2009 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 http

 import (
 	"bytes"
 	"fmt"
 	"log"
 	"net"
 	"strconv"
 	"strings"
 	"time"
 )

 // A Cookie represents an HTTP cookie as sent in the Set-Cookie header of an
 // HTTP response or the Cookie header of an HTTP request.
 //
 // See http://tools.ietf.org/html/rfc6265 for details.
 type Cookie struct {
 	Name  string
 	Value string

 	Path       string    // optional
 	Domain     string    // optional
 	Expires    time.Time // optional
 	RawExpires string    // for reading cookies only

 	// MaxAge=0 means no 'Max-Age' attribute specified.
 	// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
 	// MaxAge>0 means Max-Age attribute present and given in seconds
 	MaxAge   int
 	Secure   bool
 	HttpOnly bool
 	Raw      string
 	Unparsed []string // Raw text of unparsed attribute-value pairs
 }

 // readSetCookies parses all "Set-Cookie" values from
 // the header h and returns the successfully parsed Cookies.
 func readSetCookies(h Header) []*Cookie {
 	cookies := []*Cookie{}
 	for _, line := range h["Set-Cookie"] {
 		parts := strings.Split(strings.TrimSpace(line), ";")
 		if len(parts) == 1 && parts[0] == "" {
 			continue
 		}
 		parts[0] = strings.TrimSpace(parts[0])
 		j := strings.Index(parts[0], "=")
 		if j < 0 {
 			continue
 		}
 		name, value := parts[0][:j], parts[0][j+1:]
 		if !isCookieNameValid(name) {
 			continue
 		}
 		value, success := parseCookieValue(value, true)
 		if !success {
 			continue
 		}
 		c := &Cookie{
 			Name:  name,
 			Value: value,
 			Raw:   line,
 		}
 		for i := 1; i < len(parts); i++ {
 			parts[i] = strings.TrimSpace(parts[i])
 			if len(parts[i]) == 0 {
 				continue
 			}

 			attr, val := parts[i], ""
 			if j := strings.Index(attr, "="); j >= 0 {
 				attr, val = attr[:j], attr[j+1:]
 			}
 			lowerAttr := strings.ToLower(attr)
 			val, success = parseCookieValue(val, false)
 			if !success {
 				c.Unparsed = append(c.Unparsed, parts[i])
 				continue
 			}
 			switch lowerAttr {
 			case "secure":
 				c.Secure = true
 				continue
 			case "httponly":
 				c.HttpOnly = true
 				continue
 			case "domain":
 				c.Domain = val
 				continue
 			case "max-age":
 				secs, err := strconv.Atoi(val)
 				if err != nil || secs != 0 && val[0] == '0' {
 					break
 				}
 				if secs <= 0 {
 					c.MaxAge = -1
 				} else {
 					c.MaxAge = secs
 				}
 				continue
 			case "expires":
 				c.RawExpires = val
 				exptime, err := time.Parse(time.RFC1123, val)
 				if err != nil {
 					exptime, err = time.Parse("Mon, 02-Jan-2006 15:04:05 MST", val)
 					if err != nil {
 						c.Expires = time.Time{}
 						break
 					}
 				}
 				c.Expires = exptime.UTC()
 				continue
 			case "path":
 				c.Path = val
 				continue
 			}
 			c.Unparsed = append(c.Unparsed, parts[i])
 		}
 		cookies = append(cookies, c)
 	}
 	return cookies
 }

 // SetCookie adds a Set-Cookie header to the provided ResponseWriter's headers.
 // The provided cookie must have a valid Name. Invalid cookies may be
 // silently dropped.
 func SetCookie(w ResponseWriter, cookie *Cookie) {
 	if v := cookie.String(); v != "" {
 		w.Header().Add("Set-Cookie", v)
 	}
 }

 // String returns the serialization of the cookie for use in a Cookie
 // header (if only Name and Value are set) or a Set-Cookie response
 // header (if other fields are set).
 // If c is nil or c.Name is invalid, the empty string is returned.
 func (c *Cookie) String() string {
 	if c == nil || !isCookieNameValid(c.Name) {
 		return ""
 	}
 	var b bytes.Buffer
 	fmt.Fprintf(&b, "%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
 	if len(c.Path) > 0 {
 		fmt.Fprintf(&b, "; Path=%s", sanitizeCookiePath(c.Path))
 	}
 	if len(c.Domain) > 0 {
 		if validCookieDomain(c.Domain) {
 			// A c.Domain containing illegal characters is not
 			// sanitized but simply dropped which turns the cookie
 			// into a host-only cookie. A leading dot is okay
 			// but won't be sent.
 			d := c.Domain
 			if d[0] == '.' {
 				d = d[1:]
 			}
 			fmt.Fprintf(&b, "; Domain=%s", d)
 		} else {
 			log.Printf("net/http: invalid Cookie.Domain %q; dropping domain attribute",
 				c.Domain)
 		}
 	}
 	if c.Expires.Unix() > 0 {
 		fmt.Fprintf(&b, "; Expires=%s", c.Expires.UTC().Format(TimeFormat))
 	}
 	if c.MaxAge > 0 {
 		fmt.Fprintf(&b, "; Max-Age=%d", c.MaxAge)
 	} else if c.MaxAge < 0 {
 		fmt.Fprintf(&b, "; Max-Age=0")
 	}
 	if c.HttpOnly {
 		fmt.Fprintf(&b, "; HttpOnly")
 	}
 	if c.Secure {
 		fmt.Fprintf(&b, "; Secure")
 	}
 	return b.String()
 }

 // readCookies parses all "Cookie" values from the header h and
 // returns the successfully parsed Cookies.
 //
 // if filter isn't empty, only cookies of that name are returned
 func readCookies(h Header, filter string) []*Cookie {
 	cookies := []*Cookie{}
 	lines, ok := h["Cookie"]
 	if !ok {
 		return cookies
 	}

 	for _, line := range lines {
 		parts := strings.Split(strings.TrimSpace(line), ";")
 		if len(parts) == 1 && parts[0] == "" {
 			continue
 		}
 		// Per-line attributes
 		parsedPairs := 0
 		for i := 0; i < len(parts); i++ {
 			parts[i] = strings.TrimSpace(parts[i])
 			if len(parts[i]) == 0 {
 				continue
 			}
 			name, val := parts[i], ""
 			if j := strings.Index(name, "="); j >= 0 {
 				name, val = name[:j], name[j+1:]
 			}
 			if !isCookieNameValid(name) {
 				continue
 			}
 			if filter != "" && filter != name {
 				continue
 			}
 			val, success := parseCookieValue(val, true)
 			if !success {
 				continue
 			}
 			cookies = append(cookies, &Cookie{Name: name, Value: val})
 			parsedPairs++
 		}
 	}
 	return cookies
 }

 // validCookieDomain returns whether v is a valid cookie domain-value.
 func validCookieDomain(v string) bool {
 	if isCookieDomainName(v) {
 		return true
 	}
 	if net.ParseIP(v) != nil && !strings.Contains(v, ":") {
 		return true
 	}
 	return false
 }

 // isCookieDomainName returns whether s is a valid domain name or a valid
 // domain name with a leading dot '.'.  It is almost a direct copy of
 // package net's isDomainName.
 func isCookieDomainName(s string) bool {
 	if len(s) == 0 {
 		return false
 	}
 	if len(s) > 255 {
 		return false
 	}

 	if s[0] == '.' {
 		// A cookie a domain attribute may start with a leading dot.
 		s = s[1:]
 	}
 	last := byte('.')
 	ok := false // Ok once we've seen a letter.
 	partlen := 0
 	for i := 0; i < len(s); i++ {
 		c := s[i]
 		switch {
 		default:
 			return false
 		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
 			// No '_' allowed here (in contrast to package net).
 			ok = true
 			partlen++
 		case '0' <= c && c <= '9':
 			// fine
 			partlen++
 		case c == '-':
 			// Byte before dash cannot be dot.
 			if last == '.' {
 				return false
 			}
 			partlen++
 		case c == '.':
 			// Byte before dot cannot be dot, dash.
 			if last == '.' || last == '-' {
 				return false
 			}
 			if partlen > 63 || partlen == 0 {
 				return false
 			}
 			partlen = 0
 		}
 		last = c
 	}
 	if last == '-' || partlen > 63 {
 		return false
 	}

 	return ok
 }

 var cookieNameSanitizer = strings.NewReplacer("\n", "-", "\r", "-")

 func sanitizeCookieName(n string) string {
 	return cookieNameSanitizer.Replace(n)
 }

 // http://tools.ietf.org/html/rfc6265#section-4.1.1
 // cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
 // cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
 //           ; US-ASCII characters excluding CTLs,
 //           ; whitespace DQUOTE, comma, semicolon,
 //           ; and backslash
 // We loosen this as spaces and commas are common in cookie values
 // but we produce a quoted cookie-value in when value starts or ends
 // with a comma or space.
 // See https://golang.org/issue/7243 for the discussion.
 func sanitizeCookieValue(v string) string {
 	v = sanitizeOrWarn("Cookie.Value", validCookieValueByte, v)
 	if len(v) == 0 {
 		return v
 	}
 	if v[0] == ' ' || v[0] == ',' || v[len(v)-1] == ' ' || v[len(v)-1] == ',' {
 		return `"` + v + `"`
 	}
 	return v
 }

 func validCookieValueByte(b byte) bool {
 	return 0x20 <= b && b < 0x7f && b != '"' && b != ';' && b != '\\'
 }

 // path-av           = "Path=" path-value
 // path-value        = <any CHAR except CTLs or ";">
 func sanitizeCookiePath(v string) string {
 	return sanitizeOrWarn("Cookie.Path", validCookiePathByte, v)
 }

 func validCookiePathByte(b byte) bool {
 	return 0x20 <= b && b < 0x7f && b != ';'
 }

 func sanitizeOrWarn(fieldName string, valid func(byte) bool, v string) string {
 	ok := true
 	for i := 0; i < len(v); i++ {
 		if valid(v[i]) {
 			continue
 		}
 		log.Printf("net/http: invalid byte %q in %s; dropping invalid bytes", v[i], fieldName)
 		ok = false
 		break
 	}
 	if ok {
 		return v
 	}
 	buf := make([]byte, 0, len(v))
 	for i := 0; i < len(v); i++ {
 		if b := v[i]; valid(b) {
 			buf = append(buf, b)
 		}
 	}
 	return string(buf)
 }

 func parseCookieValue(raw string, allowDoubleQuote bool) (string, bool) {
 	// Strip the quotes, if present.
 	if allowDoubleQuote && len(raw) > 1 && raw[0] == '"' && raw[len(raw)-1] == '"' {
 		raw = raw[1 : len(raw)-1]
 	}
 	for i := 0; i < len(raw); i++ {
 		if !validCookieValueByte(raw[i]) {
 			return "", false
 		}
 	}
 	return raw, true
 }

 func isCookieNameValid(raw string) bool {
 	if raw == "" {
 		return false
 	}
 	return strings.IndexFunc(raw, isNotToken) < 0
 }
	// Copyright 2009 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 http

	import (
	"bytes"
	"fmt"
	"log"
	"net"
	"strconv"
	"strings"
	"time"
	)

	// A Cookie represents an HTTP cookie as sent in the Set-Cookie header of an
	// HTTP response or the Cookie header of an HTTP request.
	//
	// See http://tools.ietf.org/html/rfc6265 for details.
	type Cookie struct {
	Name string
	Value string

	Path string // optional
	Domain string // optional
	Expires time.Time // optional
	RawExpires string // for reading cookies only

	// MaxAge=0 means no 'Max-Age' attribute specified.
	// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
	// MaxAge>0 means Max-Age attribute present and given in seconds
	MaxAge int
	Secure bool
	HttpOnly bool
	Raw string
	Unparsed []string // Raw text of unparsed attribute-value pairs
	}

	// readSetCookies parses all "Set-Cookie" values from
	// the header h and returns the successfully parsed Cookies.
	func readSetCookies(h Header) []*Cookie {
	cookies := []*Cookie{}
	for _, line := range h["Set-Cookie"] {
	parts := strings.Split(strings.TrimSpace(line), ";")
	if len(parts) == 1 && parts[0] == "" {
	continue
	}
	parts[0] = strings.TrimSpace(parts[0])
	j := strings.Index(parts[0], "=")
	if j < 0 {
	continue
	}
	name, value := parts[0][:j], parts[0][j+1:]
	if !isCookieNameValid(name) {
	continue
	}
	value, success := parseCookieValue(value, true)
	if !success {
	continue
	}
	c := &Cookie{
	Name: name,
	Value: value,
	Raw: line,
	}
	for i := 1; i < len(parts); i++ {
	parts[i] = strings.TrimSpace(parts[i])
	if len(parts[i]) == 0 {
	continue
	}

	attr, val := parts[i], ""
	if j := strings.Index(attr, "="); j >= 0 {
	attr, val = attr[:j], attr[j+1:]
	}
	lowerAttr := strings.ToLower(attr)
	val, success = parseCookieValue(val, false)
	if !success {
	c.Unparsed = append(c.Unparsed, parts[i])
	continue
	}
	switch lowerAttr {
	case "secure":
	c.Secure = true
	continue
	case "httponly":
	c.HttpOnly = true
	continue
	case "domain":
	c.Domain = val
	continue
	case "max-age":
	secs, err := strconv.Atoi(val)
	if err != nil \|\| secs != 0 && val[0] == '0' {
	break
	}
	if secs <= 0 {
	c.MaxAge = -1
	} else {
	c.MaxAge = secs
	}
	continue
	case "expires":
	c.RawExpires = val
	exptime, err := time.Parse(time.RFC1123, val)
	if err != nil {
	exptime, err = time.Parse("Mon, 02-Jan-2006 15:04:05 MST", val)
	if err != nil {
	c.Expires = time.Time{}
	break
	}
	}
	c.Expires = exptime.UTC()
	continue
	case "path":
	c.Path = val
	continue
	}
	c.Unparsed = append(c.Unparsed, parts[i])
	}
	cookies = append(cookies, c)
	}
	return cookies
	}

	// SetCookie adds a Set-Cookie header to the provided ResponseWriter's headers.
	// The provided cookie must have a valid Name. Invalid cookies may be
	// silently dropped.
	func SetCookie(w ResponseWriter, cookie *Cookie) {
	if v := cookie.String(); v != "" {
	w.Header().Add("Set-Cookie", v)
	}
	}

	// String returns the serialization of the cookie for use in a Cookie
	// header (if only Name and Value are set) or a Set-Cookie response
	// header (if other fields are set).
	// If c is nil or c.Name is invalid, the empty string is returned.
	func (c *Cookie) String() string {
	if c == nil \|\| !isCookieNameValid(c.Name) {
	return ""
	}
	var b bytes.Buffer
	fmt.Fprintf(&b, "%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
	if len(c.Path) > 0 {
	fmt.Fprintf(&b, "; Path=%s", sanitizeCookiePath(c.Path))
	}
	if len(c.Domain) > 0 {
	if validCookieDomain(c.Domain) {
	// A c.Domain containing illegal characters is not
	// sanitized but simply dropped which turns the cookie
	// into a host-only cookie. A leading dot is okay
	// but won't be sent.
	d := c.Domain
	if d[0] == '.' {
	d = d[1:]
	}
	fmt.Fprintf(&b, "; Domain=%s", d)
	} else {
	log.Printf("net/http: invalid Cookie.Domain %q; dropping domain attribute",
	c.Domain)
	}
	}
	if c.Expires.Unix() > 0 {
	fmt.Fprintf(&b, "; Expires=%s", c.Expires.UTC().Format(TimeFormat))
	}
	if c.MaxAge > 0 {
	fmt.Fprintf(&b, "; Max-Age=%d", c.MaxAge)
	} else if c.MaxAge < 0 {
	fmt.Fprintf(&b, "; Max-Age=0")
	}
	if c.HttpOnly {
	fmt.Fprintf(&b, "; HttpOnly")
	}
	if c.Secure {
	fmt.Fprintf(&b, "; Secure")
	}
	return b.String()
	}

	// readCookies parses all "Cookie" values from the header h and
	// returns the successfully parsed Cookies.
	//
	// if filter isn't empty, only cookies of that name are returned
	func readCookies(h Header, filter string) []*Cookie {
	cookies := []*Cookie{}
	lines, ok := h["Cookie"]
	if !ok {
	return cookies
	}

	for _, line := range lines {
	parts := strings.Split(strings.TrimSpace(line), ";")
	if len(parts) == 1 && parts[0] == "" {
	continue
	}
	// Per-line attributes
	parsedPairs := 0
	for i := 0; i < len(parts); i++ {
	parts[i] = strings.TrimSpace(parts[i])
	if len(parts[i]) == 0 {
	continue
	}
	name, val := parts[i], ""
	if j := strings.Index(name, "="); j >= 0 {
	name, val = name[:j], name[j+1:]
	}
	if !isCookieNameValid(name) {
	continue
	}
	if filter != "" && filter != name {
	continue
	}
	val, success := parseCookieValue(val, true)
	if !success {
	continue
	}
	cookies = append(cookies, &Cookie{Name: name, Value: val})
	parsedPairs++
	}
	}
	return cookies
	}

	// validCookieDomain returns whether v is a valid cookie domain-value.
	func validCookieDomain(v string) bool {
	if isCookieDomainName(v) {
	return true
	}
	if net.ParseIP(v) != nil && !strings.Contains(v, ":") {
	return true
	}
	return false
	}

	// isCookieDomainName returns whether s is a valid domain name or a valid
	// domain name with a leading dot '.'. It is almost a direct copy of
	// package net's isDomainName.
	func isCookieDomainName(s string) bool {
	if len(s) == 0 {
	return false
	}
	if len(s) > 255 {
	return false
	}

	if s[0] == '.' {
	// A cookie a domain attribute may start with a leading dot.
	s = s[1:]
	}
	last := byte('.')
	ok := false // Ok once we've seen a letter.
	partlen := 0
	for i := 0; i < len(s); i++ {
	c := s[i]
	switch {
	default:
	return false
	case 'a' <= c && c <= 'z' \|\| 'A' <= c && c <= 'Z':
	// No '_' allowed here (in contrast to package net).
	ok = true
	partlen++
	case '0' <= c && c <= '9':
	// fine
	partlen++
	case c == '-':
	// Byte before dash cannot be dot.
	if last == '.' {
	return false
	}
	partlen++
	case c == '.':
	// Byte before dot cannot be dot, dash.
	if last == '.' \|\| last == '-' {
	return false
	}
	if partlen > 63 \|\| partlen == 0 {
	return false
	}
	partlen = 0
	}
	last = c
	}
	if last == '-' \|\| partlen > 63 {
	return false
	}

	return ok
	}

	var cookieNameSanitizer = strings.NewReplacer("\n", "-", "\r", "-")

	func sanitizeCookieName(n string) string {
	return cookieNameSanitizer.Replace(n)
	}

	// http://tools.ietf.org/html/rfc6265#section-4.1.1
	// cookie-value = cookie-octet / ( DQUOTE cookie-octet DQUOTE )
	// cookie-octet = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
	// ; US-ASCII characters excluding CTLs,
	// ; whitespace DQUOTE, comma, semicolon,
	// ; and backslash
	// We loosen this as spaces and commas are common in cookie values
	// but we produce a quoted cookie-value in when value starts or ends
	// with a comma or space.
	// See https://golang.org/issue/7243 for the discussion.
	func sanitizeCookieValue(v string) string {
	v = sanitizeOrWarn("Cookie.Value", validCookieValueByte, v)
	if len(v) == 0 {
	return v
	}
	if v[0] == ' ' \|\| v[0] == ',' \|\| v[len(v)-1] == ' ' \|\| v[len(v)-1] == ',' {
	return `"` + v + `"`
	}
	return v
	}

	func validCookieValueByte(b byte) bool {
	return 0x20 <= b && b < 0x7f && b != '"' && b != ';' && b != '\\'
	}

	// path-av = "Path=" path-value
	// path-value = <any CHAR except CTLs or ";">
	func sanitizeCookiePath(v string) string {
	return sanitizeOrWarn("Cookie.Path", validCookiePathByte, v)
	}

	func validCookiePathByte(b byte) bool {
	return 0x20 <= b && b < 0x7f && b != ';'
	}

	func sanitizeOrWarn(fieldName string, valid func(byte) bool, v string) string {
	ok := true
	for i := 0; i < len(v); i++ {
	if valid(v[i]) {
	continue
	}
	log.Printf("net/http: invalid byte %q in %s; dropping invalid bytes", v[i], fieldName)
	ok = false
	break
	}
	if ok {
	return v
	}
	buf := make([]byte, 0, len(v))
	for i := 0; i < len(v); i++ {
	if b := v[i]; valid(b) {
	buf = append(buf, b)
	}
	}
	return string(buf)
	}

	func parseCookieValue(raw string, allowDoubleQuote bool) (string, bool) {
	// Strip the quotes, if present.
	if allowDoubleQuote && len(raw) > 1 && raw[0] == '"' && raw[len(raw)-1] == '"' {
	raw = raw[1 : len(raw)-1]
	}
	for i := 0; i < len(raw); i++ {
	if !validCookieValueByte(raw[i]) {
	return "", false
	}
	}
	return raw, true
	}

	func isCookieNameValid(raw string) bool {
	if raw == "" {
	return false
	}
	return strings.IndexFunc(raw, isNotToken) < 0
	}