1 files changed, 503 insertions, 0 deletions
diff --git a/src/net/http/cookiejar/jar.go b/src/net/http/cookiejar/jar.go
new file mode 100644
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--- /dev/null
+++ b/src/net/http/cookiejar/jar.go
@@ -0,0 +1,503 @@
+// 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/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
+	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 implements "domain-match" of RFC 6265 section 5.1.3.
+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 !s[i].Creation.Equal(s[j].Creation) {
+			return s[i].Creation.Before(s[j].Creation)
+		}
+		return s[i].seqNum < s[j].seqNum
+	})
+	for _, e := range selected {
+		cookies = append(cookies, &http.Cookie{Name: e.Name, Value: e.Value})
+	}
+
+	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
+	host = strings.ToLower(host)
+	if hasPort(host) {
+		host, _, err = net.SplitHostPort(host)
+		if err != nil {
+			return "", err
+		}
+	}
+	if strings.HasSuffix(host, ".") {
+		// Strip trailing dot from fully qualified domain names.
+		host = host[:len(host)-1]
+	}
+	return toASCII(host)
+}
+
+// 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 {
+	return net.ParseIP(host) != nil
+}
+
+// defaultPath returns the directory part of an 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 a 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.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")
+	errNoHostname      = errors.New("cookiejar: no host name available (IP only)")
+)
+
+// 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) {
+		// According to RFC 6265 domain-matching includes not being
+		// an IP address.
+		// TODO: This might be relaxed as in common browsers.
+		return "", false, errNoHostname
+	}
+
+	// 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 = strings.ToLower(domain)
+
+	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
+}