parser.go

package gocookie_string_reader

import (
	"log"
	"net"
	"net/http"
	"strings"
	"time"

	"golang.org/x/net/http/httpguts"
)

/**
Parses Cookie format string to http Cookies
*/
func ParseToCookie(cookieString string) []*http.Cookie {

	cookies := []*http.Cookie{}

	parts := strings.Split(strings.TrimSpace(cookieString), ";")
	if len(parts) == 1 && parts[0] == "" {
		return cookies
	}

	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
		}
		val, ok := parseCookieValue(val, true)
		if !ok {
			continue
		}
		cookies = append(cookies, &http.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
}

// validCookieExpires returns whether v is a valid cookie expires-value.
func validCookieExpires(t time.Time) bool {
	// IETF RFC 6265 Section 5.1.1.5, the year must not be less than 1601
	return t.Year() >= 1601
}

// 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 strings.IndexByte(v, ' ') >= 0 || strings.IndexByte(v, ',') >= 0 {
		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
}

func isNotToken(r rune) bool {
	return !httpguts.IsTokenRune(r)
}