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// Copyright 2012 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 cookiejar implements an in-memory RFC 6265-compliant http.CookieJar.
package cookiejar
import (
"errors"
"fmt"
"net"
"net/http"
"net/http/internal/ascii"
"net/url"
"sort"
"strings"
"sync"
"time"
)
// PublicSuffixList provides the public suffix of a domain. For example:
// - the public suffix of "example.com" is "com",
// - the public suffix of "foo1.foo2.foo3.co.uk" is "co.uk", and
// - the public suffix of "bar.pvt.k12.ma.us" is "pvt.k12.ma.us".
//
// Implementations of PublicSuffixList must be safe for concurrent use by
// multiple goroutines.
//
// An implementation that always returns "" is valid and may be useful for
// testing but it is not secure: it means that the HTTP server for foo.com can
// set a cookie for bar.com.
//
// A public suffix list implementation is in the package
// golang.org/x/net/publicsuffix.
type PublicSuffixList interface {
// PublicSuffix returns the public suffix of domain.
//
// TODO: specify which of the caller and callee is responsible for IP
// addresses, for leading and trailing dots, for case sensitivity, and
// for IDN/Punycode.
PublicSuffix(domain string) string
// String returns a description of the source of this public suffix
// list. The description will typically contain something like a time
// stamp or version number.
String() string
}
// Options are the options for creating a new Jar.
type Options struct {
// PublicSuffixList is the public suffix list that determines whether
// an HTTP server can set a cookie for a domain.
//
// A nil value is valid and may be useful for testing but it is not
// secure: it means that the HTTP server for foo.co.uk can set a cookie
// for bar.co.uk.
PublicSuffixList PublicSuffixList
}
// Jar implements the http.CookieJar interface from the net/http package.
type Jar struct {
psList PublicSuffixList
// mu locks the remaining fields.
mu sync.Mutex
// entries is a set of entries, keyed by their eTLD+1 and subkeyed by
// their name/domain/path.
entries map[string]map[string]entry
// nextSeqNum is the next sequence number assigned to a new cookie
// created SetCookies.
nextSeqNum uint64
}
// New returns a new cookie jar. A nil [*Options] is equivalent to a zero
// Options.
func New(o *Options) (*Jar, error) {
jar := &Jar{
entries: make(map[string]map[string]entry),
}
if o != nil {
jar.psList = o.PublicSuffixList
}
return jar, nil
}
// entry is the internal representation of a cookie.
//
// This struct type is not used outside of this package per se, but the exported
// fields are those of RFC 6265.
type entry struct {
Name string
Value string
Quoted bool
Domain string
Path string
SameSite string
Secure bool
HttpOnly bool
Persistent bool
HostOnly bool
Expires time.Time
Creation time.Time
LastAccess time.Time
// seqNum is a sequence number so that Cookies returns cookies in a
// deterministic order, even for cookies that have equal Path length and
// equal Creation time. This simplifies testing.
seqNum uint64
}
// id returns the domain;path;name triple of e as an id.
func (e *entry) id() string {
return fmt.Sprintf("%s;%s;%s", e.Domain, e.Path, e.Name)
}
// shouldSend determines whether e's cookie qualifies to be included in a
// request to host/path. It is the caller's responsibility to check if the
// cookie is expired.
func (e *entry) shouldSend(https bool, host, path string) bool {
return e.domainMatch(host) && e.pathMatch(path) && (https || !e.Secure)
}
// domainMatch checks whether e's Domain allows sending e back to host.
// It differs from "domain-match" of RFC 6265 section 5.1.3 because we treat
// a cookie with an IP address in the Domain always as a host cookie.
func (e *entry) domainMatch(host string) bool {
if e.Domain == host {
return true
}
return !e.HostOnly && hasDotSuffix(host, e.Domain)
}
// pathMatch implements "path-match" according to RFC 6265 section 5.1.4.
func (e *entry) pathMatch(requestPath string) bool {
if requestPath == e.Path {
return true
}
if strings.HasPrefix(requestPath, e.Path) {
if e.Path[len(e.Path)-1] == '/' {
return true // The "/any/" matches "/any/path" case.
} else if requestPath[len(e.Path)] == '/' {
return true // The "/any" matches "/any/path" case.
}
}
return false
}
// hasDotSuffix reports whether s ends in "."+suffix.
func hasDotSuffix(s, suffix string) bool {
return len(s) > len(suffix) && s[len(s)-len(suffix)-1] == '.' && s[len(s)-len(suffix):] == suffix
}
// Cookies implements the Cookies method of the [http.CookieJar] interface.
//
// It returns an empty slice if the URL's scheme is not HTTP or HTTPS.
func (j *Jar) Cookies(u *url.URL) (cookies []*http.Cookie) {
return j.cookies(u, time.Now())
}
// cookies is like Cookies but takes the current time as a parameter.
func (j *Jar) cookies(u *url.URL, now time.Time) (cookies []*http.Cookie) {
if u.Scheme != "http" && u.Scheme != "https" {
return cookies
}
host, err := canonicalHost(u.Host)
if err != nil {
return cookies
}
key := jarKey(host, j.psList)
j.mu.Lock()
defer j.mu.Unlock()
submap := j.entries[key]
if submap == nil {
return cookies
}
https := u.Scheme == "https"
path := u.Path
if path == "" {
path = "/"
}
modified := false
var selected []entry
for id, e := range submap {
if e.Persistent && !e.Expires.After(now) {
delete(submap, id)
modified = true
continue
}
if !e.shouldSend(https, host, path) {
continue
}
e.LastAccess = now
submap[id] = e
selected = append(selected, e)
modified = true
}
if modified {
if len(submap) == 0 {
delete(j.entries, key)
} else {
j.entries[key] = submap
}
}
// sort according to RFC 6265 section 5.4 point 2: by longest
// path and then by earliest creation time.
sort.Slice(selected, func(i, j int) bool {
s := selected
if len(s[i].Path) != len(s[j].Path) {
return len(s[i].Path) > len(s[j].Path)
}
if ret := s[i].Creation.Compare(s[j].Creation); ret != 0 {
return ret < 0
}
return s[i].seqNum < s[j].seqNum
})
for _, e := range selected {
cookies = append(cookies, &http.Cookie{Name: e.Name, Value: e.Value, Quoted: e.Quoted})
}
return cookies
}
// SetCookies implements the SetCookies method of the [http.CookieJar] interface.
//
// It does nothing if the URL's scheme is not HTTP or HTTPS.
func (j *Jar) SetCookies(u *url.URL, cookies []*http.Cookie) {
j.setCookies(u, cookies, time.Now())
}
// setCookies is like SetCookies but takes the current time as parameter.
func (j *Jar) setCookies(u *url.URL, cookies []*http.Cookie, now time.Time) {
if len(cookies) == 0 {
return
}
if u.Scheme != "http" && u.Scheme != "https" {
return
}
host, err := canonicalHost(u.Host)
if err != nil {
return
}
key := jarKey(host, j.psList)
defPath := defaultPath(u.Path)
j.mu.Lock()
defer j.mu.Unlock()
submap := j.entries[key]
modified := false
for _, cookie := range cookies {
e, remove, err := j.newEntry(cookie, now, defPath, host)
if err != nil {
continue
}
id := e.id()
if remove {
if submap != nil {
if _, ok := submap[id]; ok {
delete(submap, id)
modified = true
}
}
continue
}
if submap == nil {
submap = make(map[string]entry)
}
if old, ok := submap[id]; ok {
e.Creation = old.Creation
e.seqNum = old.seqNum
} else {
e.Creation = now
e.seqNum = j.nextSeqNum
j.nextSeqNum++
}
e.LastAccess = now
submap[id] = e
modified = true
}
if modified {
if len(submap) == 0 {
delete(j.entries, key)
} else {
j.entries[key] = submap
}
}
}
// canonicalHost strips port from host if present and returns the canonicalized
// host name.
func canonicalHost(host string) (string, error) {
var err error
if hasPort(host) {
host, _, err = net.SplitHostPort(host)
if err != nil {
return "", err
}
}
// Strip trailing dot from fully qualified domain names.
host = strings.TrimSuffix(host, ".")
encoded, err := toASCII(host)
if err != nil {
return "", err
}
// We know this is ascii, no need to check.
lower, _ := ascii.ToLower(encoded)
return lower, nil
}
// hasPort reports whether host contains a port number. host may be a host
// name, an IPv4 or an IPv6 address.
func hasPort(host string) bool {
colons := strings.Count(host, ":")
if colons == 0 {
return false
}
if colons == 1 {
return true
}
return host[0] == '[' && strings.Contains(host, "]:")
}
// jarKey returns the key to use for a jar.
func jarKey(host string, psl PublicSuffixList) string {
if isIP(host) {
return host
}
var i int
if psl == nil {
i = strings.LastIndex(host, ".")
if i <= 0 {
return host
}
} else {
suffix := psl.PublicSuffix(host)
if suffix == host {
return host
}
i = len(host) - len(suffix)
if i <= 0 || host[i-1] != '.' {
// The provided public suffix list psl is broken.
// Storing cookies under host is a safe stopgap.
return host
}
// Only len(suffix) is used to determine the jar key from
// here on, so it is okay if psl.PublicSuffix("www.buggy.psl")
// returns "com" as the jar key is generated from host.
}
prevDot := strings.LastIndex(host[:i-1], ".")
return host[prevDot+1:]
}
// isIP reports whether host is an IP address.
func isIP(host string) bool {
if strings.ContainsAny(host, ":%") {
// Probable IPv6 address.
// Hostnames can't contain : or %, so this is definitely not a valid host.
// Treating it as an IP is the more conservative option, and avoids the risk
// of interpeting ::1%.www.example.com as a subtomain of www.example.com.
return true
}
return net.ParseIP(host) != nil
}
// defaultPath returns the directory part of a URL's path according to
// RFC 6265 section 5.1.4.
func defaultPath(path string) string {
if len(path) == 0 || path[0] != '/' {
return "/" // Path is empty or malformed.
}
i := strings.LastIndex(path, "/") // Path starts with "/", so i != -1.
if i == 0 {
return "/" // Path has the form "/abc".
}
return path[:i] // Path is either of form "/abc/xyz" or "/abc/xyz/".
}
// newEntry creates an entry from an http.Cookie c. now is the current time and
// is compared to c.Expires to determine deletion of c. defPath and host are the
// default-path and the canonical host name of the URL c was received from.
//
// remove records whether the jar should delete this cookie, as it has already
// expired with respect to now. In this case, e may be incomplete, but it will
// be valid to call e.id (which depends on e's Name, Domain and Path).
//
// A malformed c.Domain will result in an error.
func (j *Jar) newEntry(c *http.Cookie, now time.Time, defPath, host string) (e entry, remove bool, err error) {
e.Name = c.Name
if c.Path == "" || c.Path[0] != '/' {
e.Path = defPath
} else {
e.Path = c.Path
}
e.Domain, e.HostOnly, err = j.domainAndType(host, c.Domain)
if err != nil {
return e, false, err
}
// MaxAge takes precedence over Expires.
if c.MaxAge < 0 {
return e, true, nil
} else if c.MaxAge > 0 {
e.Expires = now.Add(time.Duration(c.MaxAge) * time.Second)
e.Persistent = true
} else {
if c.Expires.IsZero() {
e.Expires = endOfTime
e.Persistent = false
} else {
if !c.Expires.After(now) {
return e, true, nil
}
e.Expires = c.Expires
e.Persistent = true
}
}
e.Value = c.Value
e.Quoted = c.Quoted
e.Secure = c.Secure
e.HttpOnly = c.HttpOnly
switch c.SameSite {
case http.SameSiteDefaultMode:
e.SameSite = "SameSite"
case http.SameSiteStrictMode:
e.SameSite = "SameSite=Strict"
case http.SameSiteLaxMode:
e.SameSite = "SameSite=Lax"
}
return e, false, nil
}
var (
errIllegalDomain = errors.New("cookiejar: illegal cookie domain attribute")
errMalformedDomain = errors.New("cookiejar: malformed cookie domain attribute")
)
// endOfTime is the time when session (non-persistent) cookies expire.
// This instant is representable in most date/time formats (not just
// Go's time.Time) and should be far enough in the future.
var endOfTime = time.Date(9999, 12, 31, 23, 59, 59, 0, time.UTC)
// domainAndType determines the cookie's domain and hostOnly attribute.
func (j *Jar) domainAndType(host, domain string) (string, bool, error) {
if domain == "" {
// No domain attribute in the SetCookie header indicates a
// host cookie.
return host, true, nil
}
if isIP(host) {
// RFC 6265 is not super clear here, a sensible interpretation
// is that cookies with an IP address in the domain-attribute
// are allowed.
// RFC 6265 section 5.2.3 mandates to strip an optional leading
// dot in the domain-attribute before processing the cookie.
//
// Most browsers don't do that for IP addresses, only curl
// (version 7.54) and IE (version 11) do not reject a
// Set-Cookie: a=1; domain=.127.0.0.1
// This leading dot is optional and serves only as hint for
// humans to indicate that a cookie with "domain=.bbc.co.uk"
// would be sent to every subdomain of bbc.co.uk.
// It just doesn't make sense on IP addresses.
// The other processing and validation steps in RFC 6265 just
// collapse to:
if host != domain {
return "", false, errIllegalDomain
}
// According to RFC 6265 such cookies should be treated as
// domain cookies.
// As there are no subdomains of an IP address the treatment
// according to RFC 6265 would be exactly the same as that of
// a host-only cookie. Contemporary browsers (and curl) do
// allows such cookies but treat them as host-only cookies.
// So do we as it just doesn't make sense to label them as
// domain cookies when there is no domain; the whole notion of
// domain cookies requires a domain name to be well defined.
return host, true, nil
}
// From here on: If the cookie is valid, it is a domain cookie (with
// the one exception of a public suffix below).
// See RFC 6265 section 5.2.3.
if domain[0] == '.' {
domain = domain[1:]
}
if len(domain) == 0 || domain[0] == '.' {
// Received either "Domain=." or "Domain=..some.thing",
// both are illegal.
return "", false, errMalformedDomain
}
domain, isASCII := ascii.ToLower(domain)
if !isASCII {
// Received non-ASCII domain, e.g. "perché.com" instead of "xn--perch-fsa.com"
return "", false, errMalformedDomain
}
if domain[len(domain)-1] == '.' {
// We received stuff like "Domain=www.example.com.".
// Browsers do handle such stuff (actually differently) but
// RFC 6265 seems to be clear here (e.g. section 4.1.2.3) in
// requiring a reject. 4.1.2.3 is not normative, but
// "Domain Matching" (5.1.3) and "Canonicalized Host Names"
// (5.1.2) are.
return "", false, errMalformedDomain
}
// See RFC 6265 section 5.3 #5.
if j.psList != nil {
if ps := j.psList.PublicSuffix(domain); ps != "" && !hasDotSuffix(domain, ps) {
if host == domain {
// This is the one exception in which a cookie
// with a domain attribute is a host cookie.
return host, true, nil
}
return "", false, errIllegalDomain
}
}
// The domain must domain-match host: www.mycompany.com cannot
// set cookies for .ourcompetitors.com.
if host != domain && !hasDotSuffix(host, domain) {
return "", false, errIllegalDomain
}
return domain, false, nil
}