http: add cookie support

R=rsc1, mattn, bradfitzwork, pascal, bradfitzgo
CC=golang-dev
https://golang.org/cl/4214042

5 files changed, 451 insertions, 0 deletions

diff --git a/src/pkg/http/Makefile b/src/pkg/http/Makefile
index 1167d8ef6b..389b042227 100644
--- a/src/pkg/http/Makefile
+++ b/src/pkg/http/Makefile
@@ -8,6 +8,7 @@ TARG=http
 GOFILES=\
 	chunked.go\
 	client.go\
+	cookie.go\
 	dump.go\
 	fs.go\
 	header.go\
diff --git a/src/pkg/http/cookie.go b/src/pkg/http/cookie.go
new file mode 100644
index 0000000000..ff75c47c92
--- /dev/null
+++ b/src/pkg/http/cookie.go
@@ -0,0 +1,336 @@
+// 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"
+	"io"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// A note on Version=0 vs. Version=1 cookies
+//
+// The difference between Set-Cookie and Set-Cookie2 is hard to discern from the
+// RFCs as it is not stated explicitly.  There seem to be three standards
+// lingering on the web: Netscape, RFC 2109 (aka Version=0) and RFC 2965 (aka
+// Version=1). It seems that Netscape and RFC 2109 are the same thing, hereafter
+// Version=0 cookies.
+//
+// In general, Set-Cookie2 is a superset of Set-Cookie. It has a few new
+// attributes like HttpOnly and Secure.  To be meticulous, if a server intends
+// to use these, it needs to send a Set-Cookie2.  However, it is most likely
+// most modern browsers will not complain seeing an HttpOnly attribute in a
+// Set-Cookie header.
+//
+// Both RFC 2109 and RFC 2965 use Cookie in the same way - two send cookie
+// values from clients to servers - and the allowable attributes seem to be the
+// same.
+// 
+// The Cookie2 header is used for a different purpose. If a client suspects that
+// the server speaks Version=1 (RFC 2965) then along with the Cookie header
+// lines, you can also send:
+//
+//   Cookie2: $Version="1"
+//
+// in order to suggest to the server that you understand Version=1 cookies. At
+// which point the server may continue responding with Set-Cookie2 headers.
+// When a client sends the (above) Cookie2 header line, it must be prepated to
+// understand incoming Set-Cookie2.
+//
+// This implementation of cookies supports neither Set-Cookie2 nor Cookie2
+// headers. However, it parses Version=1 Cookies (along with Version=0) as well
+// as Set-Cookie headers which utilize the full Set-Cookie2 syntax.
+
+// TODO(petar): Explicitly forbid parsing of Set-Cookie attributes
+// starting with '$', which have been used to hack into broken
+// servers using the eventual Request headers containing those
+// invalid attributes that may overwrite intended $Version, $Path, 
+// etc. attributes.
+// TODO(petar): Read 'Set-Cookie2' headers and prioritize them over equivalent
+// 'Set-Cookie' headers. 'Set-Cookie2' headers are still extremely rare.
+
+// A Cookie represents an RFC 2965 HTTP cookie as sent in
+// the Set-Cookie header of an HTTP response or the Cookie header
+// of an HTTP request.
+// The Set-Cookie2 and Cookie2 headers are unimplemented.
+type Cookie struct {
+	Name       string
+	Value      string
+	Path       string
+	Domain     string
+	Comment    string
+	Version    int
+	Expires    time.Time
+	RawExpires string
+	MaxAge     int // Max age in seconds
+	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, removes the successfully parsed values from the 
+// "Set-Cookie" key in h and returns the parsed Cookies.
+func readSetCookies(h Header) []*Cookie {
+	cookies := []*Cookie{}
+	var unparsedLines []string
+	for _, line := range h["Set-Cookie"] {
+		parts := strings.Split(strings.TrimSpace(line), ";", -1)
+		if len(parts) == 1 && parts[0] == "" {
+			continue
+		}
+		parts[0] = strings.TrimSpace(parts[0])
+		j := strings.Index(parts[0], "=")
+		if j < 0 {
+			unparsedLines = append(unparsedLines, line)
+			continue
+		}
+		name, value := parts[0][:j], parts[0][j+1:]
+		value, err := URLUnescape(value)
+		if err != nil {
+			unparsedLines = append(unparsedLines, line)
+			continue
+		}
+		c := &Cookie{
+			Name:   name,
+			Value:  value,
+			MaxAge: -1, // Not specified
+			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:]
+				val, err = URLUnescape(val)
+				if err != nil {
+					c.Unparsed = append(c.Unparsed, parts[i])
+					continue
+				}
+			}
+			switch strings.ToLower(attr) {
+			case "secure":
+				c.Secure = true
+				continue
+			case "httponly":
+				c.HttpOnly = true
+				continue
+			case "comment":
+				c.Comment = val
+				continue
+			case "domain":
+				c.Domain = val
+				// TODO: Add domain parsing
+				continue
+			case "max-age":
+				secs, err := strconv.Atoi(val)
+				if err != nil || secs < 0 {
+					break
+				}
+				c.MaxAge = secs
+				continue
+			case "expires":
+				c.RawExpires = val
+				exptime, err := time.Parse(time.RFC1123, val)
+				if err != nil {
+					c.Expires = time.Time{}
+					break
+				}
+				c.Expires = *exptime
+				continue
+			case "path":
+				c.Path = val
+				// TODO: Add path parsing
+				continue
+			case "version":
+				c.Version, err = strconv.Atoi(val)
+				if err != nil {
+					c.Version = 0
+					break
+				}
+				continue
+			}
+			c.Unparsed = append(c.Unparsed, parts[i])
+		}
+		cookies = append(cookies, c)
+	}
+	h["Set-Cookie"] = unparsedLines, unparsedLines != nil
+	return cookies
+}
+
+// writeSetCookies writes the wire representation of the set-cookies
+// to w. Each cookie is written on a separate "Set-Cookie: " line.
+// This choice is made because HTTP parsers tend to have a limit on
+// line-length, so it seems safer to place cookies on separate lines.
+func writeSetCookies(w io.Writer, kk []*Cookie) os.Error {
+	if kk == nil {
+		return nil
+	}
+	lines := make([]string, 0, len(kk))
+	var b bytes.Buffer
+	for _, c := range kk {
+		b.Reset()
+		// TODO(petar): c.Value (below) should be unquoted if it is recognized as quoted
+		fmt.Fprintf(&b, "%s=%s", CanonicalHeaderKey(c.Name), c.Value)
+		if c.Version > 0 {
+			fmt.Fprintf(&b, "Version=%d; ", c.Version)
+		}
+		if len(c.Path) > 0 {
+			fmt.Fprintf(&b, "; Path=%s", URLEscape(c.Path))
+		}
+		if len(c.Domain) > 0 {
+			fmt.Fprintf(&b, "; Domain=%s", URLEscape(c.Domain))
+		}
+		if len(c.Expires.Zone) > 0 {
+			fmt.Fprintf(&b, "; Expires=%s", c.Expires.Format(time.RFC1123))
+		}
+		if c.MaxAge >= 0 {
+			fmt.Fprintf(&b, "; Max-Age=%d", c.MaxAge)
+		}
+		if c.HttpOnly {
+			fmt.Fprintf(&b, "; HttpOnly")
+		}
+		if c.Secure {
+			fmt.Fprintf(&b, "; Secure")
+		}
+		if len(c.Comment) > 0 {
+			fmt.Fprintf(&b, "; Comment=%s", URLEscape(c.Comment))
+		}
+		lines = append(lines, "Set-Cookie: "+b.String()+"\r\n")
+	}
+	sort.SortStrings(lines)
+	for _, l := range lines {
+		if _, err := io.WriteString(w, l); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// readCookies parses all "Cookie" values from
+// the header h, removes the successfully parsed values from the 
+// "Cookie" key in h and returns the parsed Cookies.
+func readCookies(h Header) []*Cookie {
+	cookies := []*Cookie{}
+	lines, ok := h["Cookie"]
+	if !ok {
+		return cookies
+	}
+	unparsedLines := []string{}
+	for _, line := range lines {
+		parts := strings.Split(strings.TrimSpace(line), ";", -1)
+		if len(parts) == 1 && parts[0] == "" {
+			continue
+		}
+		// Per-line attributes
+		var lineCookies = make(map[string]string)
+		var version int
+		var path string
+		var domain string
+		var comment string
+		var httponly bool
+		for i := 0; i < len(parts); i++ {
+			parts[i] = strings.TrimSpace(parts[i])
+			if len(parts[i]) == 0 {
+				continue
+			}
+			attr, val := parts[i], ""
+			var err os.Error
+			if j := strings.Index(attr, "="); j >= 0 {
+				attr, val = attr[:j], attr[j+1:]
+				val, err = URLUnescape(val)
+				if err != nil {
+					continue
+				}
+			}
+			switch strings.ToLower(attr) {
+			case "$httponly":
+				httponly = true
+			case "$version":
+				version, err = strconv.Atoi(val)
+				if err != nil {
+					version = 0
+					continue
+				}
+			case "$domain":
+				domain = val
+				// TODO: Add domain parsing
+			case "$path":
+				path = val
+				// TODO: Add path parsing
+			case "$comment":
+				comment = val
+			default:
+				lineCookies[attr] = val
+			}
+		}
+		if len(lineCookies) == 0 {
+			unparsedLines = append(unparsedLines, line)
+		}
+		for n, v := range lineCookies {
+			cookies = append(cookies, &Cookie{
+				Name:     n,
+				Value:    v,
+				Path:     path,
+				Domain:   domain,
+				Comment:  comment,
+				Version:  version,
+				HttpOnly: httponly,
+				MaxAge:   -1,
+				Raw:      line,
+			})
+		}
+	}
+	h["Cookie"] = unparsedLines, len(unparsedLines) > 0
+	return cookies
+}
+
+// writeCookies writes the wire representation of the cookies
+// to w. Each cookie is written on a separate "Cookie: " line.
+// This choice is made because HTTP parsers tend to have a limit on
+// line-length, so it seems safer to place cookies on separate lines.
+func writeCookies(w io.Writer, kk []*Cookie) os.Error {
+	lines := make([]string, 0, len(kk))
+	var b bytes.Buffer
+	for _, c := range kk {
+		b.Reset()
+		n := c.Name
+		if c.Version > 0 {
+			fmt.Fprintf(&b, "$Version=%d; ", c.Version)
+		}
+		// TODO(petar): c.Value (below) should be unquoted if it is recognized as quoted
+		fmt.Fprintf(&b, "%s=%s", CanonicalHeaderKey(n), c.Value)
+		if len(c.Path) > 0 {
+			fmt.Fprintf(&b, "; $Path=%s", URLEscape(c.Path))
+		}
+		if len(c.Domain) > 0 {
+			fmt.Fprintf(&b, "; $Domain=%s", URLEscape(c.Domain))
+		}
+		if c.HttpOnly {
+			fmt.Fprintf(&b, "; $HttpOnly")
+		}
+		if len(c.Comment) > 0 {
+			fmt.Fprintf(&b, "; $Comment=%s", URLEscape(c.Comment))
+		}
+		lines = append(lines, "Cookie: "+b.String()+"\r\n")
+	}
+	sort.SortStrings(lines)
+	for _, l := range lines {
+		if _, err := io.WriteString(w, l); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/src/pkg/http/cookie_test.go b/src/pkg/http/cookie_test.go
new file mode 100644
index 0000000000..363c841bb0
--- /dev/null
+++ b/src/pkg/http/cookie_test.go
@@ -0,0 +1,96 @@
+// Copyright 2010 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"
+	"reflect"
+	"testing"
+)
+
+
+var writeSetCookiesTests = []struct {
+	Cookies []*Cookie
+	Raw     string
+}{
+	{
+		[]*Cookie{&Cookie{Name: "cookie-1", Value: "v$1", MaxAge: -1}},
+		"Set-Cookie: Cookie-1=v$1\r\n",
+	},
+}
+
+func TestWriteSetCookies(t *testing.T) {
+	for i, tt := range writeSetCookiesTests {
+		var w bytes.Buffer
+		writeSetCookies(&w, tt.Cookies)
+		seen := string(w.Bytes())
+		if seen != tt.Raw {
+			t.Errorf("Test %d, expecting:\n%s\nGot:\n%s\n", i, tt.Raw, seen)
+			continue
+		}
+	}
+}
+
+var writeCookiesTests = []struct {
+	Cookies []*Cookie
+	Raw     string
+}{
+	{
+		[]*Cookie{&Cookie{Name: "cookie-1", Value: "v$1", MaxAge: -1}},
+		"Cookie: Cookie-1=v$1\r\n",
+	},
+}
+
+func TestWriteCookies(t *testing.T) {
+	for i, tt := range writeCookiesTests {
+		var w bytes.Buffer
+		writeCookies(&w, tt.Cookies)
+		seen := string(w.Bytes())
+		if seen != tt.Raw {
+			t.Errorf("Test %d, expecting:\n%s\nGot:\n%s\n", i, tt.Raw, seen)
+			continue
+		}
+	}
+}
+
+var readSetCookiesTests = []struct {
+	Header  Header
+	Cookies []*Cookie
+}{
+	{
+		Header{"Set-Cookie": {"Cookie-1=v$1"}},
+		[]*Cookie{&Cookie{Name: "Cookie-1", Value: "v$1", MaxAge: -1, Raw: "Cookie-1=v$1"}},
+	},
+}
+
+func TestReadSetCookies(t *testing.T) {
+	for i, tt := range readSetCookiesTests {
+		c := readSetCookies(tt.Header)
+		if !reflect.DeepEqual(c, tt.Cookies) {
+			t.Errorf("#%d readSetCookies: have\n%#v\nwant\n%#v\n", i, c, tt.Cookies)
+			continue
+		}
+	}
+}
+
+var readCookiesTests = []struct {
+	Header  Header
+	Cookies []*Cookie
+}{
+	{
+		Header{"Cookie": {"Cookie-1=v$1"}},
+		[]*Cookie{&Cookie{Name: "Cookie-1", Value: "v$1", MaxAge: -1, Raw: "Cookie-1=v$1"}},
+	},
+}
+
+func TestReadCookies(t *testing.T) {
+	for i, tt := range readCookiesTests {
+		c := readCookies(tt.Header)
+		if !reflect.DeepEqual(c, tt.Cookies) {
+			t.Errorf("#%d readCookies: have\n%#v\nwant\n%#v\n", i, c, tt.Cookies)
+			continue
+		}
+	}
+}
diff --git a/src/pkg/http/request.go b/src/pkg/http/request.go
index 22b19959dd..2f6e33ae9b 100644
--- a/src/pkg/http/request.go
+++ b/src/pkg/http/request.go
@@ -92,6 +92,9 @@ type Request struct {
 	// following a hyphen uppercase and the rest lowercase.
 	Header Header
 
+	// Cookie records the HTTP cookies sent with the request.
+	Cookie []*Cookie
+
 	// The message body.
 	Body io.ReadCloser
 
@@ -249,6 +252,10 @@ func (req *Request) write(w io.Writer, usingProxy bool) os.Error {
 		return err
 	}
 
+	if err = writeCookies(w, req.Cookie); err != nil {
+		return err
+	}
+
 	io.WriteString(w, "\r\n")
 
 	// Write body and trailer
@@ -485,6 +492,8 @@ func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
 		return nil, err
 	}
 
+	req.Cookie = readCookies(req.Header)
+
 	return req, nil
 }
 
diff --git a/src/pkg/http/response.go b/src/pkg/http/response.go
index 3f919c86a3..4fd00ad61e 100644
--- a/src/pkg/http/response.go
+++ b/src/pkg/http/response.go
@@ -46,6 +46,9 @@ type Response struct {
 	// Keys in the map are canonicalized (see CanonicalHeaderKey).
 	Header Header
 
+	// SetCookie records the Set-Cookie requests sent with the response.
+	SetCookie []*Cookie
+
 	// Body represents the response body.
 	Body io.ReadCloser
 
@@ -124,6 +127,8 @@ func ReadResponse(r *bufio.Reader, requestMethod string) (resp *Response, err os
 		return nil, err
 	}
 
+	resp.SetCookie = readSetCookies(resp.Header)
+
 	return resp, nil
 }
 
@@ -193,6 +198,10 @@ func (resp *Response) Write(w io.Writer) os.Error {
 		return err
 	}
 
+	if err = writeSetCookies(w, resp.SetCookie); err != nil {
+		return err
+	}
+
 	// End-of-header
 	io.WriteString(w, "\r\n")