mirror of
https://github.com/XTLS/Xray-core.git
synced 2026-07-01 17:33:12 +00:00
VLESS protocol: Add lightweight, Post-Quantum ML-KEM-768-based PFS 1-RTT / anti-replay 0-RTT AEAD Encryption (#5067)
https://opensea.io/collection/vless
This commit is contained in:
RPRX
@@ -0,0 +1,202 @@
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package encryption
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import (
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"crypto/cipher"
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"crypto/ecdh"
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"crypto/mlkem"
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"crypto/rand"
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"io"
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"net"
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"sync"
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"time"
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"github.com/xtls/xray-core/common/crypto"
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"github.com/xtls/xray-core/common/errors"
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"lukechampine.com/blake3"
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)
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type ClientInstance struct {
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NfsPKeys []any
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NfsPKeysBytes [][]byte
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Hash32s [][32]byte
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RelaysLength int
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XorMode uint32
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Seconds uint32
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RWLock sync.RWMutex
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Expire time.Time
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PfsKey []byte
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Ticket []byte
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}
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func (i *ClientInstance) Init(nfsPKeysBytes [][]byte, xorMode, seconds uint32) (err error) {
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if i.NfsPKeys != nil {
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err = errors.New("already initialized")
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return
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}
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l := len(nfsPKeysBytes)
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if l == 0 {
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err = errors.New("empty nfsPKeysBytes")
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return
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}
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i.NfsPKeys = make([]any, l)
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i.NfsPKeysBytes = nfsPKeysBytes
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i.Hash32s = make([][32]byte, l)
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for j, k := range nfsPKeysBytes {
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if len(k) == 32 {
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if i.NfsPKeys[j], err = ecdh.X25519().NewPublicKey(k); err != nil {
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return
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}
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i.RelaysLength += 32 + 32
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} else {
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if i.NfsPKeys[j], err = mlkem.NewEncapsulationKey768(k); err != nil {
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return
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}
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i.RelaysLength += 1088 + 32
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}
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i.Hash32s[j] = blake3.Sum256(k)
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}
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i.RelaysLength -= 32
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i.XorMode = xorMode
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i.Seconds = seconds
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return
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}
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func (i *ClientInstance) Handshake(conn net.Conn) (*CommonConn, error) {
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if i.NfsPKeys == nil {
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return nil, errors.New("uninitialized")
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}
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c := NewCommonConn(conn)
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ivAndRealysLength := 16 + i.RelaysLength
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pfsKeyExchangeLength := 18 + 1184 + 32 + 16
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paddingLength := int(crypto.RandBetween(100, 1000))
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clientHello := make([]byte, ivAndRealysLength+pfsKeyExchangeLength+paddingLength)
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iv := clientHello[:16]
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rand.Read(iv)
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relays := clientHello[16:ivAndRealysLength]
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var nfsKey []byte
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var lastCTR cipher.Stream
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for j, k := range i.NfsPKeys {
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var index = 32
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if k, ok := k.(*ecdh.PublicKey); ok {
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privateKey, _ := ecdh.X25519().GenerateKey(rand.Reader)
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copy(relays, privateKey.PublicKey().Bytes())
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var err error
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nfsKey, err = privateKey.ECDH(k)
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if err != nil {
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return nil, err
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}
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}
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if k, ok := k.(*mlkem.EncapsulationKey768); ok {
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var ciphertext []byte
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nfsKey, ciphertext = k.Encapsulate()
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copy(relays, ciphertext)
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index = 1088
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}
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if i.XorMode > 0 { // this xor can (others can't) be recovered by client's config, revealing an X25519 public key / ML-KEM-768 ciphertext, that's why "native" values
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NewCTR(i.NfsPKeysBytes[j], iv).XORKeyStream(relays, relays[:index]) // make X25519 public key / ML-KEM-768 ciphertext distinguishable from random bytes
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}
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if lastCTR != nil {
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lastCTR.XORKeyStream(relays, relays[:32]) // make this relay irreplaceable
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}
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if j == len(i.NfsPKeys)-1 {
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break
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}
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lastCTR = NewCTR(nfsKey, iv)
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lastCTR.XORKeyStream(relays[index:], i.Hash32s[j+1][:])
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relays = relays[index+32:]
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}
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nfsGCM := NewGCM(iv, nfsKey)
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if i.Seconds > 0 {
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i.RWLock.RLock()
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if time.Now().Before(i.Expire) {
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c.Client = i
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c.UnitedKey = append(i.PfsKey, nfsKey...) // different unitedKey for each connection
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nfsGCM.Seal(clientHello[:ivAndRealysLength], nil, EncodeLength(32), nil)
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nfsGCM.Seal(clientHello[:ivAndRealysLength+18], nil, i.Ticket, nil)
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i.RWLock.RUnlock()
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c.PreWrite = clientHello[:ivAndRealysLength+18+32]
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c.GCM = NewGCM(clientHello[ivAndRealysLength+18:ivAndRealysLength+18+32], c.UnitedKey)
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if i.XorMode == 2 {
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c.Conn = NewXorConn(conn, NewCTR(c.UnitedKey, iv), nil, len(c.PreWrite), 16)
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}
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return c, nil
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}
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i.RWLock.RUnlock()
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}
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pfsKeyExchange := clientHello[ivAndRealysLength : ivAndRealysLength+pfsKeyExchangeLength]
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nfsGCM.Seal(pfsKeyExchange[:0], nil, EncodeLength(pfsKeyExchangeLength-18), nil)
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mlkem768DKey, _ := mlkem.GenerateKey768()
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x25519SKey, _ := ecdh.X25519().GenerateKey(rand.Reader)
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pfsPublicKey := append(mlkem768DKey.EncapsulationKey().Bytes(), x25519SKey.PublicKey().Bytes()...)
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nfsGCM.Seal(pfsKeyExchange[:18], nil, pfsPublicKey, nil)
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padding := clientHello[ivAndRealysLength+pfsKeyExchangeLength:]
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nfsGCM.Seal(padding[:0], nil, EncodeLength(paddingLength-18), nil)
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nfsGCM.Seal(padding[:18], nil, padding[18:paddingLength-16], nil)
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if _, err := conn.Write(clientHello); err != nil {
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return nil, err
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}
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// padding can be sent in a fragmented way, to create variable traffic pattern, before inner VLESS flow takes control
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encryptedPfsPublicKey := make([]byte, 1088+32+16)
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if _, err := io.ReadFull(conn, encryptedPfsPublicKey); err != nil {
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return nil, err
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}
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nfsGCM.Open(encryptedPfsPublicKey[:0], MaxNonce, encryptedPfsPublicKey, nil)
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mlkem768Key, err := mlkem768DKey.Decapsulate(encryptedPfsPublicKey[:1088])
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if err != nil {
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return nil, err
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}
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peerX25519PKey, err := ecdh.X25519().NewPublicKey(encryptedPfsPublicKey[1088 : 1088+32])
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if err != nil {
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return nil, err
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}
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x25519Key, err := x25519SKey.ECDH(peerX25519PKey)
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if err != nil {
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return nil, err
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}
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pfsKey := make([]byte, 32+32) // no more capacity
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copy(pfsKey, mlkem768Key)
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copy(pfsKey[32:], x25519Key)
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c.UnitedKey = append(pfsKey, nfsKey...)
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c.GCM = NewGCM(pfsPublicKey, c.UnitedKey)
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c.PeerGCM = NewGCM(encryptedPfsPublicKey[:1088+32], c.UnitedKey)
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encryptedTicket := make([]byte, 32)
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if _, err := io.ReadFull(conn, encryptedTicket); err != nil {
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return nil, err
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}
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if _, err := c.PeerGCM.Open(encryptedTicket[:0], nil, encryptedTicket, nil); err != nil {
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return nil, err
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}
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seconds := DecodeLength(encryptedTicket)
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if i.Seconds > 0 && seconds > 0 {
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i.RWLock.Lock()
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i.Expire = time.Now().Add(time.Duration(seconds) * time.Second)
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i.PfsKey = pfsKey
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i.Ticket = encryptedTicket[:16]
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i.RWLock.Unlock()
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}
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encryptedLength := make([]byte, 18)
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if _, err := io.ReadFull(conn, encryptedLength); err != nil {
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return nil, err
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}
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if _, err := c.PeerGCM.Open(encryptedLength[:0], nil, encryptedLength, nil); err != nil {
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return nil, err
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}
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length := DecodeLength(encryptedLength[:2])
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c.PeerPadding = make([]byte, length) // important: allows server sends padding slowly, eliminating 1-RTT's traffic pattern
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if i.XorMode == 2 {
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c.Conn = NewXorConn(conn, NewCTR(c.UnitedKey, iv), NewCTR(c.UnitedKey, encryptedTicket[:16]), 0, length)
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}
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return c, nil
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}
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@@ -0,0 +1,212 @@
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package encryption
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"fmt"
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"io"
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"net"
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"strings"
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"sync"
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"time"
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"github.com/xtls/xray-core/common/errors"
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"lukechampine.com/blake3"
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)
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var OutBytesPool = sync.Pool{
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New: func() any {
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return make([]byte, 5+8192+16)
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},
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}
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type CommonConn struct {
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net.Conn
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Client *ClientInstance
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UnitedKey []byte
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PreWrite []byte
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GCM *GCM
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PeerGCM *GCM
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PeerPadding []byte
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PeerInBytes []byte
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PeerCache []byte
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}
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func NewCommonConn(conn net.Conn) *CommonConn {
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return &CommonConn{
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Conn: conn,
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PeerInBytes: make([]byte, 5+17000), // no need to use sync.Pool, because we are always reading
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}
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}
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func (c *CommonConn) Write(b []byte) (int, error) {
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if len(b) == 0 {
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return 0, nil
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}
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outBytes := OutBytesPool.Get().([]byte)
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defer OutBytesPool.Put(outBytes)
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for n := 0; n < len(b); {
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b := b[n:]
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if len(b) > 8192 {
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b = b[:8192] // for avoiding another copy() in peer's Read()
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}
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n += len(b)
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headerAndData := outBytes[:5+len(b)+16]
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EncodeHeader(headerAndData, len(b)+16)
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max := false
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if bytes.Equal(c.GCM.Nonce[:], MaxNonce) {
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max = true
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}
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c.GCM.Seal(headerAndData[:5], nil, b, headerAndData[:5])
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if max {
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c.GCM = NewGCM(headerAndData, c.UnitedKey)
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}
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if c.PreWrite != nil {
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headerAndData = append(c.PreWrite, headerAndData...)
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c.PreWrite = nil
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}
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if _, err := c.Conn.Write(headerAndData); err != nil {
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return 0, err
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}
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}
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return len(b), nil
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}
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func (c *CommonConn) Read(b []byte) (int, error) {
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if len(b) == 0 {
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return 0, nil
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}
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if c.PeerGCM == nil { // client's 0-RTT
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serverRandom := make([]byte, 16)
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if _, err := io.ReadFull(c.Conn, serverRandom); err != nil {
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return 0, err
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}
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c.PeerGCM = NewGCM(serverRandom, c.UnitedKey)
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if xorConn, ok := c.Conn.(*XorConn); ok {
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xorConn.PeerCTR = NewCTR(c.UnitedKey, serverRandom)
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}
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}
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if c.PeerPadding != nil { // client's 1-RTT
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if _, err := io.ReadFull(c.Conn, c.PeerPadding); err != nil {
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return 0, err
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}
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if _, err := c.PeerGCM.Open(c.PeerPadding[:0], nil, c.PeerPadding, nil); err != nil {
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return 0, err
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}
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c.PeerPadding = nil
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}
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if len(c.PeerCache) > 0 {
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n := copy(b, c.PeerCache)
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c.PeerCache = c.PeerCache[n:]
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return n, nil
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}
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peerHeader := c.PeerInBytes[:5]
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if _, err := io.ReadFull(c.Conn, peerHeader); err != nil {
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return 0, err
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}
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l, err := DecodeHeader(c.PeerInBytes[:5]) // l: 17~17000
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if err != nil {
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if c.Client != nil && strings.Contains(err.Error(), "invalid header: ") { // client's 0-RTT
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c.Client.RWLock.Lock()
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if bytes.HasPrefix(c.UnitedKey, c.Client.PfsKey) {
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c.Client.Expire = time.Now() // expired
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}
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c.Client.RWLock.Unlock()
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return 0, errors.New("new handshake needed")
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}
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return 0, err
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}
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c.Client = nil
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peerData := c.PeerInBytes[5 : 5+l]
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if _, err := io.ReadFull(c.Conn, peerData); err != nil {
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return 0, err
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}
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dst := peerData[:l-16]
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if len(dst) <= len(b) {
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dst = b[:len(dst)] // avoids another copy()
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}
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var newGCM *GCM
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if bytes.Equal(c.PeerGCM.Nonce[:], MaxNonce) {
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newGCM = NewGCM(c.PeerInBytes[:5+l], c.UnitedKey)
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}
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_, err = c.PeerGCM.Open(dst[:0], nil, peerData, peerHeader)
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if newGCM != nil {
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c.PeerGCM = newGCM
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}
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if err != nil {
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return 0, err
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}
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if len(dst) > len(b) {
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c.PeerCache = dst[copy(b, dst):]
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dst = b // for len(dst)
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}
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return len(dst), nil
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}
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type GCM struct {
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cipher.AEAD
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Nonce [12]byte
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}
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func NewGCM(ctx, key []byte) *GCM {
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k := make([]byte, 32)
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blake3.DeriveKey(k, string(ctx), key)
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block, _ := aes.NewCipher(k)
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aead, _ := cipher.NewGCM(block)
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return &GCM{AEAD: aead}
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//chacha20poly1305.New()
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}
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func (a *GCM) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
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if nonce == nil {
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nonce = IncreaseNonce(a.Nonce[:])
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}
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return a.AEAD.Seal(dst, nonce, plaintext, additionalData)
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}
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func (a *GCM) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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if nonce == nil {
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nonce = IncreaseNonce(a.Nonce[:])
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}
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return a.AEAD.Open(dst, nonce, ciphertext, additionalData)
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}
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func IncreaseNonce(nonce []byte) []byte {
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for i := range 12 {
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nonce[11-i]++
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if nonce[11-i] != 0 {
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break
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}
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}
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return nonce
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}
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var MaxNonce = bytes.Repeat([]byte{255}, 12)
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func EncodeLength(l int) []byte {
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return []byte{byte(l >> 8), byte(l)}
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}
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func DecodeLength(b []byte) int {
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return int(b[0])<<8 | int(b[1])
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}
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func EncodeHeader(h []byte, l int) {
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h[0] = 23
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h[1] = 3
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h[2] = 3
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h[3] = byte(l >> 8)
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h[4] = byte(l)
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}
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func DecodeHeader(h []byte) (l int, err error) {
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l = int(h[3])<<8 | int(h[4])
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if h[0] != 23 || h[1] != 3 || h[2] != 3 {
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l = 0
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}
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if l < 17 || l > 17000 { // TODO: TLSv1.3 max length
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err = errors.New("invalid header: ", fmt.Sprintf("%v", h[:5])) // DO NOT CHANGE: relied by client's Read()
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}
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return
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}
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@@ -0,0 +1,282 @@
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package encryption
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import (
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"bytes"
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"crypto/cipher"
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"crypto/ecdh"
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"crypto/mlkem"
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"crypto/rand"
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"fmt"
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"io"
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"net"
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"sync"
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"time"
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"github.com/xtls/xray-core/common/crypto"
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"github.com/xtls/xray-core/common/errors"
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"lukechampine.com/blake3"
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)
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type ServerSession struct {
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Expire time.Time
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PfsKey []byte
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NfsKeys sync.Map
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}
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type ServerInstance struct {
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NfsSKeys []any
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NfsPKeysBytes [][]byte
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Hash32s [][32]byte
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RelaysLength int
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XorMode uint32
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Seconds uint32
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RWLock sync.RWMutex
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Sessions map[[16]byte]*ServerSession
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Closed bool
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}
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func (i *ServerInstance) Init(nfsSKeysBytes [][]byte, xorMode, seconds uint32) (err error) {
|
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if i.NfsSKeys != nil {
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err = errors.New("already initialized")
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return
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}
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l := len(nfsSKeysBytes)
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if l == 0 {
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err = errors.New("empty nfsSKeysBytes")
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return
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}
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i.NfsSKeys = make([]any, l)
|
||||
i.NfsPKeysBytes = make([][]byte, l)
|
||||
i.Hash32s = make([][32]byte, l)
|
||||
for j, k := range nfsSKeysBytes {
|
||||
if len(k) == 32 {
|
||||
if i.NfsSKeys[j], err = ecdh.X25519().NewPrivateKey(k); err != nil {
|
||||
return
|
||||
}
|
||||
i.NfsPKeysBytes[j] = i.NfsSKeys[j].(*ecdh.PrivateKey).PublicKey().Bytes()
|
||||
i.RelaysLength += 32 + 32
|
||||
} else {
|
||||
if i.NfsSKeys[j], err = mlkem.NewDecapsulationKey768(k); err != nil {
|
||||
return
|
||||
}
|
||||
i.NfsPKeysBytes[j] = i.NfsSKeys[j].(*mlkem.DecapsulationKey768).EncapsulationKey().Bytes()
|
||||
i.RelaysLength += 1088 + 32
|
||||
}
|
||||
i.Hash32s[j] = blake3.Sum256(i.NfsPKeysBytes[j])
|
||||
}
|
||||
i.RelaysLength -= 32
|
||||
i.XorMode = xorMode
|
||||
if seconds > 0 {
|
||||
i.Seconds = seconds
|
||||
i.Sessions = make(map[[16]byte]*ServerSession)
|
||||
go func() {
|
||||
for {
|
||||
time.Sleep(time.Minute)
|
||||
i.RWLock.Lock()
|
||||
if i.Closed {
|
||||
i.RWLock.Unlock()
|
||||
return
|
||||
}
|
||||
now := time.Now()
|
||||
for ticket, session := range i.Sessions {
|
||||
if now.After(session.Expire) {
|
||||
delete(i.Sessions, ticket)
|
||||
}
|
||||
}
|
||||
i.RWLock.Unlock()
|
||||
}
|
||||
}()
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
func (i *ServerInstance) Close() (err error) {
|
||||
i.RWLock.Lock()
|
||||
i.Closed = true
|
||||
i.RWLock.Unlock()
|
||||
return
|
||||
}
|
||||
|
||||
func (i *ServerInstance) Handshake(conn net.Conn) (*CommonConn, error) {
|
||||
if i.NfsSKeys == nil {
|
||||
return nil, errors.New("uninitialized")
|
||||
}
|
||||
c := NewCommonConn(conn)
|
||||
|
||||
ivAndRelays := make([]byte, 16+i.RelaysLength)
|
||||
if _, err := io.ReadFull(conn, ivAndRelays); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
iv := ivAndRelays[:16]
|
||||
relays := ivAndRelays[16:]
|
||||
var nfsKey []byte
|
||||
var lastCTR cipher.Stream
|
||||
for j, k := range i.NfsSKeys {
|
||||
if lastCTR != nil {
|
||||
lastCTR.XORKeyStream(relays, relays[:32]) // recover this relay
|
||||
}
|
||||
var index = 32
|
||||
if _, ok := k.(*mlkem.DecapsulationKey768); ok {
|
||||
index = 1088
|
||||
}
|
||||
if i.XorMode > 0 {
|
||||
NewCTR(i.NfsPKeysBytes[j], iv).XORKeyStream(relays, relays[:index]) // we don't use buggy elligator, because we have PSK :)
|
||||
}
|
||||
if k, ok := k.(*ecdh.PrivateKey); ok {
|
||||
publicKey, err := ecdh.X25519().NewPublicKey(relays[:index])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
nfsKey, err = k.ECDH(publicKey)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
if k, ok := k.(*mlkem.DecapsulationKey768); ok {
|
||||
var err error
|
||||
nfsKey, err = k.Decapsulate(relays[:index])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
if j == len(i.NfsSKeys)-1 {
|
||||
break
|
||||
}
|
||||
relays = relays[index:]
|
||||
lastCTR = NewCTR(nfsKey, iv)
|
||||
lastCTR.XORKeyStream(relays, relays[:32])
|
||||
if !bytes.Equal(relays[:32], i.Hash32s[j+1][:]) {
|
||||
return nil, errors.New("unexpected hash32: ", fmt.Sprintf("%v", relays[:32]))
|
||||
}
|
||||
relays = relays[32:]
|
||||
}
|
||||
nfsGCM := NewGCM(iv, nfsKey)
|
||||
|
||||
encryptedLength := make([]byte, 18)
|
||||
if _, err := io.ReadFull(conn, encryptedLength); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if _, err := nfsGCM.Open(encryptedLength[:0], nil, encryptedLength, nil); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
length := DecodeLength(encryptedLength[:2])
|
||||
|
||||
if length == 32 {
|
||||
if i.Seconds == 0 {
|
||||
return nil, errors.New("0-RTT is not allowed")
|
||||
}
|
||||
encryptedTicket := make([]byte, 32)
|
||||
if _, err := io.ReadFull(conn, encryptedTicket); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ticket, err := nfsGCM.Open(nil, nil, encryptedTicket, nil)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
i.RWLock.RLock()
|
||||
s := i.Sessions[[16]byte(ticket)]
|
||||
i.RWLock.RUnlock()
|
||||
if s == nil {
|
||||
noises := make([]byte, crypto.RandBetween(1268, 2268)) // matches 1-RTT's server hello length for "random", though it is not important, just for example
|
||||
var err error
|
||||
for err == nil {
|
||||
rand.Read(noises)
|
||||
_, err = DecodeHeader(noises)
|
||||
}
|
||||
conn.Write(noises) // make client do new handshake
|
||||
return nil, errors.New("expired ticket")
|
||||
}
|
||||
if _, loaded := s.NfsKeys.LoadOrStore([32]byte(nfsKey), true); loaded { // prevents bad client also
|
||||
return nil, errors.New("replay detected")
|
||||
}
|
||||
c.UnitedKey = append(s.PfsKey, nfsKey...) // the same nfsKey links the upload & download (prevents server -> client's another request)
|
||||
c.PreWrite = make([]byte, 16)
|
||||
rand.Read(c.PreWrite) // always trust yourself, not the client (also prevents being parsed as TLS thus causing false interruption for "native" and "xorpub")
|
||||
c.GCM = NewGCM(c.PreWrite, c.UnitedKey)
|
||||
c.PeerGCM = NewGCM(encryptedTicket, c.UnitedKey) // unchangeable ctx (prevents server -> server), and different ctx length for upload / download (prevents client -> client)
|
||||
if i.XorMode == 2 {
|
||||
c.Conn = NewXorConn(conn, NewCTR(c.UnitedKey, c.PreWrite), NewCTR(c.UnitedKey, iv), 16, 0) // it doesn't matter if the attacker sends client's iv back to the client
|
||||
}
|
||||
return c, nil
|
||||
}
|
||||
|
||||
if length < 1184+32+16 { // client may send more public keys in the future's version
|
||||
return nil, errors.New("too short length")
|
||||
}
|
||||
encryptedPfsPublicKey := make([]byte, length)
|
||||
if _, err := io.ReadFull(conn, encryptedPfsPublicKey); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if _, err := nfsGCM.Open(encryptedPfsPublicKey[:0], nil, encryptedPfsPublicKey, nil); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
mlkem768EKey, err := mlkem.NewEncapsulationKey768(encryptedPfsPublicKey[:1184])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
mlkem768Key, encapsulatedPfsKey := mlkem768EKey.Encapsulate()
|
||||
peerX25519PKey, err := ecdh.X25519().NewPublicKey(encryptedPfsPublicKey[1184 : 1184+32])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
x25519SKey, _ := ecdh.X25519().GenerateKey(rand.Reader)
|
||||
x25519Key, err := x25519SKey.ECDH(peerX25519PKey)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
pfsKey := make([]byte, 32+32) // no more capacity
|
||||
copy(pfsKey, mlkem768Key)
|
||||
copy(pfsKey[32:], x25519Key)
|
||||
pfsPublicKey := append(encapsulatedPfsKey, x25519SKey.PublicKey().Bytes()...)
|
||||
c.UnitedKey = append(pfsKey, nfsKey...)
|
||||
c.GCM = NewGCM(pfsPublicKey, c.UnitedKey)
|
||||
c.PeerGCM = NewGCM(encryptedPfsPublicKey[:1184+32], c.UnitedKey)
|
||||
ticket := make([]byte, 16)
|
||||
rand.Read(ticket)
|
||||
copy(ticket, EncodeLength(int(i.Seconds*4/5)))
|
||||
|
||||
pfsKeyExchangeLength := 1088 + 32 + 16
|
||||
encryptedTicketLength := 32
|
||||
paddingLength := int(crypto.RandBetween(100, 1000))
|
||||
serverHello := make([]byte, pfsKeyExchangeLength+encryptedTicketLength+paddingLength)
|
||||
nfsGCM.Seal(serverHello[:0], MaxNonce, pfsPublicKey, nil)
|
||||
c.GCM.Seal(serverHello[:pfsKeyExchangeLength], nil, ticket, nil)
|
||||
padding := serverHello[pfsKeyExchangeLength+encryptedTicketLength:]
|
||||
c.GCM.Seal(padding[:0], nil, EncodeLength(paddingLength-18), nil)
|
||||
c.GCM.Seal(padding[:18], nil, padding[18:paddingLength-16], nil)
|
||||
|
||||
if _, err := conn.Write(serverHello); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
// padding can be sent in a fragmented way, to create variable traffic pattern, before inner VLESS flow takes control
|
||||
|
||||
if i.Seconds > 0 {
|
||||
i.RWLock.Lock()
|
||||
i.Sessions[[16]byte(ticket)] = &ServerSession{
|
||||
Expire: time.Now().Add(time.Duration(i.Seconds) * time.Second),
|
||||
PfsKey: pfsKey,
|
||||
}
|
||||
i.RWLock.Unlock()
|
||||
}
|
||||
|
||||
// important: allows client sends padding slowly, eliminating 1-RTT's traffic pattern
|
||||
if _, err := io.ReadFull(conn, encryptedLength); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if _, err := nfsGCM.Open(encryptedLength[:0], nil, encryptedLength, nil); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
encryptedPadding := make([]byte, DecodeLength(encryptedLength[:2]))
|
||||
if _, err := io.ReadFull(conn, encryptedPadding); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if _, err := nfsGCM.Open(encryptedPadding[:0], nil, encryptedPadding, nil); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
if i.XorMode == 2 {
|
||||
c.Conn = NewXorConn(conn, NewCTR(c.UnitedKey, ticket), NewCTR(c.UnitedKey, iv), 0, 0)
|
||||
}
|
||||
return c, nil
|
||||
}
|
||||
@@ -0,0 +1,93 @@
|
||||
package encryption
|
||||
|
||||
import (
|
||||
"crypto/aes"
|
||||
"crypto/cipher"
|
||||
"net"
|
||||
|
||||
"lukechampine.com/blake3"
|
||||
)
|
||||
|
||||
func NewCTR(key, iv []byte) cipher.Stream {
|
||||
k := make([]byte, 32)
|
||||
blake3.DeriveKey(k, "VLESS", key) // avoids using key directly
|
||||
block, _ := aes.NewCipher(k)
|
||||
return cipher.NewCTR(block, iv)
|
||||
//chacha20.NewUnauthenticatedCipher()
|
||||
}
|
||||
|
||||
type XorConn struct {
|
||||
net.Conn
|
||||
CTR cipher.Stream
|
||||
PeerCTR cipher.Stream
|
||||
OutSkip int
|
||||
OutHeader []byte
|
||||
InSkip int
|
||||
InHeader []byte
|
||||
}
|
||||
|
||||
func NewXorConn(conn net.Conn, ctr, peerCTR cipher.Stream, outSkip, inSkip int) *XorConn {
|
||||
return &XorConn{
|
||||
Conn: conn,
|
||||
CTR: ctr,
|
||||
PeerCTR: peerCTR,
|
||||
OutSkip: outSkip,
|
||||
OutHeader: make([]byte, 0, 5), // important
|
||||
InSkip: inSkip,
|
||||
InHeader: make([]byte, 0, 5), // important
|
||||
}
|
||||
}
|
||||
|
||||
func (c *XorConn) Write(b []byte) (int, error) {
|
||||
if len(b) == 0 {
|
||||
return 0, nil
|
||||
}
|
||||
for p := b; ; {
|
||||
if len(p) <= c.OutSkip {
|
||||
c.OutSkip -= len(p)
|
||||
break
|
||||
}
|
||||
p = p[c.OutSkip:]
|
||||
c.OutSkip = 0
|
||||
need := 5 - len(c.OutHeader)
|
||||
if len(p) < need {
|
||||
c.OutHeader = append(c.OutHeader, p...)
|
||||
c.CTR.XORKeyStream(p, p)
|
||||
break
|
||||
}
|
||||
c.OutSkip, _ = DecodeHeader(append(c.OutHeader, p[:need]...))
|
||||
c.OutHeader = c.OutHeader[:0]
|
||||
c.CTR.XORKeyStream(p[:need], p[:need])
|
||||
p = p[need:]
|
||||
}
|
||||
if _, err := c.Conn.Write(b); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
return len(b), nil
|
||||
}
|
||||
|
||||
func (c *XorConn) Read(b []byte) (int, error) {
|
||||
if len(b) == 0 {
|
||||
return 0, nil
|
||||
}
|
||||
n, err := c.Conn.Read(b)
|
||||
for p := b[:n]; ; {
|
||||
if len(p) <= c.InSkip {
|
||||
c.InSkip -= len(p)
|
||||
break
|
||||
}
|
||||
p = p[c.InSkip:]
|
||||
c.InSkip = 0
|
||||
need := 5 - len(c.InHeader)
|
||||
if len(p) < need {
|
||||
c.PeerCTR.XORKeyStream(p, p)
|
||||
c.InHeader = append(c.InHeader, p...)
|
||||
break
|
||||
}
|
||||
c.PeerCTR.XORKeyStream(p[:need], p[:need])
|
||||
c.InSkip, _ = DecodeHeader(append(c.InHeader, p[:need]...))
|
||||
c.InHeader = c.InHeader[:0]
|
||||
p = p[need:]
|
||||
}
|
||||
return n, err
|
||||
}
|
||||
Reference in New Issue
Block a user