well-goknown/vendor/github.com/gobwas/httphead/cookie.go

201 lines
4.6 KiB
Go

package httphead
import (
"bytes"
)
// ScanCookie scans cookie pairs from data using DefaultCookieScanner.Scan()
// method.
func ScanCookie(data []byte, it func(key, value []byte) bool) bool {
return DefaultCookieScanner.Scan(data, it)
}
// DefaultCookieScanner is a CookieScanner which is used by ScanCookie().
// Note that it is intended to have the same behavior as http.Request.Cookies()
// has.
var DefaultCookieScanner = CookieScanner{}
// CookieScanner contains options for scanning cookie pairs.
// See https://tools.ietf.org/html/rfc6265#section-4.1.1
type CookieScanner struct {
// DisableNameValidation disables name validation of a cookie. If false,
// only RFC2616 "tokens" are accepted.
DisableNameValidation bool
// DisableValueValidation disables value validation of a cookie. If false,
// only RFC6265 "cookie-octet" characters are accepted.
//
// Note that Strict option also affects validation of a value.
//
// If Strict is false, then scanner begins to allow space and comma
// characters inside the value for better compatibility with non standard
// cookies implementations.
DisableValueValidation bool
// BreakOnPairError sets scanner to immediately return after first pair syntax
// validation error.
// If false, scanner will try to skip invalid pair bytes and go ahead.
BreakOnPairError bool
// Strict enables strict RFC6265 mode scanning. It affects name and value
// validation, as also some other rules.
// If false, it is intended to bring the same behavior as
// http.Request.Cookies().
Strict bool
}
// Scan maps data to name and value pairs. Usually data represents value of the
// Cookie header.
func (c CookieScanner) Scan(data []byte, it func(name, value []byte) bool) bool {
lexer := &Scanner{data: data}
const (
statePair = iota
stateBefore
)
state := statePair
for lexer.Buffered() > 0 {
switch state {
case stateBefore:
// Pairs separated by ";" and space, according to the RFC6265:
// cookie-pair *( ";" SP cookie-pair )
//
// Cookie pairs MUST be separated by (";" SP). So our only option
// here is to fail as syntax error.
a, b := lexer.Peek2()
if a != ';' {
return false
}
state = statePair
advance := 1
if b == ' ' {
advance++
} else if c.Strict {
return false
}
lexer.Advance(advance)
case statePair:
if !lexer.FetchUntil(';') {
return false
}
var value []byte
name := lexer.Bytes()
if i := bytes.IndexByte(name, '='); i != -1 {
value = name[i+1:]
name = name[:i]
} else if c.Strict {
if !c.BreakOnPairError {
goto nextPair
}
return false
}
if !c.Strict {
trimLeft(name)
}
if !c.DisableNameValidation && !ValidCookieName(name) {
if !c.BreakOnPairError {
goto nextPair
}
return false
}
if !c.Strict {
value = trimRight(value)
}
value = stripQuotes(value)
if !c.DisableValueValidation && !ValidCookieValue(value, c.Strict) {
if !c.BreakOnPairError {
goto nextPair
}
return false
}
if !it(name, value) {
return true
}
nextPair:
state = stateBefore
}
}
return true
}
// ValidCookieValue reports whether given value is a valid RFC6265
// "cookie-octet" bytes.
//
// cookie-octet = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
// ; US-ASCII characters excluding CTLs,
// ; whitespace DQUOTE, comma, semicolon,
// ; and backslash
//
// Note that the false strict parameter disables errors on space 0x20 and comma
// 0x2c. This could be useful to bring some compatibility with non-compliant
// clients/servers in the real world.
// It acts the same as standard library cookie parser if strict is false.
func ValidCookieValue(value []byte, strict bool) bool {
if len(value) == 0 {
return true
}
for _, c := range value {
switch c {
case '"', ';', '\\':
return false
case ',', ' ':
if strict {
return false
}
default:
if c <= 0x20 {
return false
}
if c >= 0x7f {
return false
}
}
}
return true
}
// ValidCookieName reports wheter given bytes is a valid RFC2616 "token" bytes.
func ValidCookieName(name []byte) bool {
for _, c := range name {
if !OctetTypes[c].IsToken() {
return false
}
}
return true
}
func stripQuotes(bts []byte) []byte {
if last := len(bts) - 1; last > 0 && bts[0] == '"' && bts[last] == '"' {
return bts[1:last]
}
return bts
}
func trimLeft(p []byte) []byte {
var i int
for i < len(p) && OctetTypes[p[i]].IsSpace() {
i++
}
return p[i:]
}
func trimRight(p []byte) []byte {
j := len(p)
for j > 0 && OctetTypes[p[j-1]].IsSpace() {
j--
}
return p[:j]
}