Xray-core/transport/internet/reality/reality.go

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package reality
import (
"bytes"
"context"
"crypto/aes"
"crypto/cipher"
"crypto/ed25519"
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
"crypto/sha512"
gotls "crypto/tls"
"crypto/x509"
"encoding/binary"
"fmt"
"io"
"math/big"
"net/http"
"reflect"
"regexp"
"strings"
"sync"
"time"
"unsafe"
utls "github.com/refraction-networking/utls"
"github.com/xtls/reality"
"github.com/xtls/xray-core/common/errors"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-core/core"
"github.com/xtls/xray-core/transport/internet/tls"
"golang.org/x/crypto/chacha20poly1305"
"golang.org/x/crypto/hkdf"
"golang.org/x/net/http2"
)
//go:generate go run github.com/xtls/xray-core/common/errors/errorgen
//go:linkname aesgcmPreferred github.com/refraction-networking/utls.aesgcmPreferred
func aesgcmPreferred(ciphers []uint16) bool
type Conn struct {
*reality.Conn
}
func (c *Conn) HandshakeAddress() net.Address {
if err := c.Handshake(); err != nil {
return nil
}
state := c.ConnectionState()
if state.ServerName == "" {
return nil
}
return net.ParseAddress(state.ServerName)
}
func Server(c net.Conn, config *reality.Config) (net.Conn, error) {
realityConn, err := reality.Server(context.Background(), c, config)
return &Conn{Conn: realityConn}, err
}
type UConn struct {
*utls.UConn
ServerName string
AuthKey []byte
Verified bool
}
func (c *UConn) HandshakeAddress() net.Address {
if err := c.Handshake(); err != nil {
return nil
}
state := c.ConnectionState()
if state.ServerName == "" {
return nil
}
return net.ParseAddress(state.ServerName)
}
func (c *UConn) VerifyPeerCertificate(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
p, _ := reflect.TypeOf(c.Conn).Elem().FieldByName("peerCertificates")
certs := *(*([]*x509.Certificate))(unsafe.Pointer(uintptr(unsafe.Pointer(c.Conn)) + p.Offset))
if pub, ok := certs[0].PublicKey.(ed25519.PublicKey); ok {
h := hmac.New(sha512.New, c.AuthKey)
h.Write(pub)
if bytes.Equal(h.Sum(nil), certs[0].Signature) {
c.Verified = true
return nil
}
}
opts := x509.VerifyOptions{
DNSName: c.ServerName,
Intermediates: x509.NewCertPool(),
}
for _, cert := range certs[1:] {
opts.Intermediates.AddCert(cert)
}
if _, err := certs[0].Verify(opts); err != nil {
return err
}
return nil
}
func UClient(c net.Conn, config *Config, ctx context.Context, dest net.Destination) (net.Conn, error) {
localAddr := c.LocalAddr().String()
uConn := &UConn{}
utlsConfig := &utls.Config{
VerifyPeerCertificate: uConn.VerifyPeerCertificate,
ServerName: config.ServerName,
InsecureSkipVerify: true,
SessionTicketsDisabled: true,
}
if utlsConfig.ServerName == "" {
utlsConfig.ServerName = dest.Address.String()
}
uConn.ServerName = utlsConfig.ServerName
fingerprint := tls.GetFingerprint(config.Fingerprint)
if fingerprint == nil {
return nil, newError("REALITY: failed to get fingerprint").AtError()
}
uConn.UConn = utls.UClient(c, utlsConfig, *fingerprint)
{
uConn.BuildHandshakeState()
hello := uConn.HandshakeState.Hello
hello.SessionId = make([]byte, 32)
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copy(hello.Raw[39:], hello.SessionId) // the fixed location of `Session ID`
hello.SessionId[0] = core.Version_x
hello.SessionId[1] = core.Version_y
hello.SessionId[2] = core.Version_z
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hello.SessionId[3] = 0 // reserved
binary.BigEndian.PutUint32(hello.SessionId[4:], uint32(time.Now().Unix()))
copy(hello.SessionId[8:], config.ShortId)
if config.Show {
fmt.Printf("REALITY localAddr: %v\thello.SessionId[:16]: %v\n", localAddr, hello.SessionId[:16])
}
uConn.AuthKey = uConn.HandshakeState.State13.EcdheParams.SharedKey(config.PublicKey)
if uConn.AuthKey == nil {
return nil, errors.New("REALITY: SharedKey == nil")
}
if _, err := hkdf.New(sha256.New, uConn.AuthKey, hello.Random[:20], []byte("REALITY")).Read(uConn.AuthKey); err != nil {
return nil, err
}
var aead cipher.AEAD
if aesgcmPreferred(hello.CipherSuites) {
block, _ := aes.NewCipher(uConn.AuthKey)
aead, _ = cipher.NewGCM(block)
} else {
aead, _ = chacha20poly1305.New(uConn.AuthKey)
}
if config.Show {
fmt.Printf("REALITY localAddr: %v\tuConn.AuthKey[:16]: %v\tAEAD: %T\n", localAddr, uConn.AuthKey[:16], aead)
}
aead.Seal(hello.SessionId[:0], hello.Random[20:], hello.SessionId[:16], hello.Raw)
copy(hello.Raw[39:], hello.SessionId)
}
if err := uConn.Handshake(); err != nil {
return nil, err
}
if config.Show {
fmt.Printf("REALITY localAddr: %v\tuConn.Verified: %v\n", localAddr, uConn.Verified)
}
if !uConn.Verified {
go func() {
client := &http.Client{
Transport: &http2.Transport{
DialTLSContext: func(ctx context.Context, network, addr string, cfg *gotls.Config) (net.Conn, error) {
fmt.Printf("REALITY localAddr: %v\tDialTLSContext\n", localAddr)
return uConn, nil
},
},
}
prefix := []byte("https://" + uConn.ServerName)
maps.Lock()
if maps.maps == nil {
maps.maps = make(map[string]map[string]bool)
}
paths := maps.maps[uConn.ServerName]
if paths == nil {
paths = make(map[string]bool)
paths[config.SpiderX] = true
maps.maps[uConn.ServerName] = paths
}
firstURL := string(prefix) + getPathLocked(paths)
maps.Unlock()
get := func(first bool) {
var (
req *http.Request
resp *http.Response
err error
body []byte
)
if first {
req, _ = http.NewRequest("GET", firstURL, nil)
} else {
maps.Lock()
req, _ = http.NewRequest("GET", string(prefix)+getPathLocked(paths), nil)
maps.Unlock()
}
req.Header.Set("User-Agent", fingerprint.Client) // TODO: User-Agent map
if first && config.Show {
fmt.Printf("REALITY localAddr: %v\treq.UserAgent(): %v\n", localAddr, req.UserAgent())
}
times := 1
if !first {
times = int(randBetween(config.SpiderY[4], config.SpiderY[5]))
}
for j := 0; j < times; j++ {
if !first && j == 0 {
req.Header.Set("Referer", firstURL)
}
req.AddCookie(&http.Cookie{Name: "padding", Value: strings.Repeat("0", int(randBetween(config.SpiderY[0], config.SpiderY[1])))})
if resp, err = client.Do(req); err != nil {
break
}
req.Header.Set("Referer", req.URL.String())
if body, err = io.ReadAll(resp.Body); err != nil {
break
}
maps.Lock()
for _, m := range href.FindAllSubmatch(body, -1) {
m[1] = bytes.TrimPrefix(m[1], prefix)
if !bytes.Contains(m[1], dot) {
paths[string(m[1])] = true
}
}
req.URL.Path = getPathLocked(paths)
if config.Show {
fmt.Printf("REALITY localAddr: %v\treq.Referer(): %v\n", localAddr, req.Referer())
fmt.Printf("REALITY localAddr: %v\tlen(body): %v\n", localAddr, len(body))
fmt.Printf("REALITY localAddr: %v\tlen(paths): %v\n", localAddr, len(paths))
}
maps.Unlock()
if !first {
time.Sleep(time.Duration(randBetween(config.SpiderY[6], config.SpiderY[7])) * time.Millisecond) // interval
}
}
}
get(true)
concurrency := int(randBetween(config.SpiderY[2], config.SpiderY[3]))
for i := 0; i < concurrency; i++ {
go get(false)
}
// Do not close the connection
}()
time.Sleep(time.Duration(randBetween(config.SpiderY[8], config.SpiderY[9])) * time.Millisecond) // return
return nil, errors.New("REALITY: processed invalid connection")
}
return uConn, nil
}
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var (
href = regexp.MustCompile(`href="([/h].*?)"`)
dot = []byte(".")
)
var maps struct {
sync.Mutex
maps map[string]map[string]bool
}
func getPathLocked(paths map[string]bool) string {
stopAt := int(randBetween(0, int64(len(paths)-1)))
i := 0
for s := range paths {
if i == stopAt {
return s
}
i++
}
return "/"
}
func randBetween(left int64, right int64) int64 {
if left == right {
return left
}
bigInt, _ := rand.Int(rand.Reader, big.NewInt(right-left))
return left + bigInt.Int64()
}