Use nfsAEAD & pfsAEAD for paddings; Refine comments

https://github.com/XTLS/Xray-core/pull/4952#issuecomment-3210125349

373558ed7a (r164355865)
This commit is contained in:
RPRX
2025-08-21 11:27:09 +00:00
committed by GitHub
parent 373558ed7a
commit 38cc306c95
4 changed files with 35 additions and 31 deletions

View File

@@ -41,7 +41,7 @@ type ServerConn struct {
baseKey []byte
ticket []byte
peerRandom []byte
peerAead cipher.AEAD
peerAEAD cipher.AEAD
peerNonce []byte
PeerCache []byte
aead cipher.AEAD
@@ -173,22 +173,23 @@ func (i *ServerInstance) Handshake(conn net.Conn) (*ServerConn, error) {
}
pfsKey, encapsulatedPfsKey := pfsEKey.Encapsulate()
c.baseKey = append(pfsKey, nfsKey...)
pfsAEAD := NewAEAD(c.cipher, c.baseKey, encapsulatedPfsKey, encapsulatedNfsKey)
c.ticket = append(i.hash11[:], pfsAEAD.Seal(nil, peerClientHello[:11+1], []byte("VLESS"), pfsEKeyBytes)...)
IncreaseNonce(peerClientHello[:11+1])
c.ticket = append(i.hash11[:], NewAEAD(c.cipher, c.baseKey, encapsulatedPfsKey, encapsulatedNfsKey).Seal(nil, peerClientHello[:12], []byte("VLESS"), pfsEKeyBytes)...)
paddingLen := crypto.RandBetween(100, 1000)
serverHello := make([]byte, 5+1088+21+5+paddingLen)
serverHello := make([]byte, 5+1088+21+crypto.RandBetween(100, 1000))
EncodeHeader(serverHello, 1, 1088+21)
copy(serverHello[5:], encapsulatedPfsKey)
copy(serverHello[5+1088:], c.ticket[11:])
EncodeHeader(serverHello[5+1088+21:], 23, int(paddingLen))
rand.Read(serverHello[5+1088+21+5:])
padding := serverHello[5+1088+21:]
rand.Read(padding) // important
EncodeHeader(padding, 23, len(padding)-5)
pfsAEAD.Seal(padding[:5], peerClientHello[:11+1], padding[5:len(padding)-16], padding[:5])
if _, err := c.Conn.Write(serverHello); err != nil {
return nil, err
}
// server can send more paddings / PFS AEAD messages if needed
// server can send more PFS AEAD paddings / messages if needed
if i.minutes > 0 {
i.Lock()
@@ -207,7 +208,7 @@ func (c *ServerConn) Read(b []byte) (int, error) {
if len(b) == 0 {
return 0, nil
}
if c.peerAead == nil {
if c.peerAEAD == nil {
if c.peerRandom == nil { // 1-RTT's 0-RTT
_, t, l, err := ReadAndDiscardPaddings(c.Conn) // allow paddings before ticket hello
if err != nil {
@@ -228,7 +229,7 @@ func (c *ServerConn) Read(b []byte) (int, error) {
}
c.peerRandom = peerTicketHello[32:]
}
c.peerAead = NewAEAD(c.cipher, c.baseKey, c.peerRandom, c.ticket)
c.peerAEAD = NewAEAD(c.cipher, c.baseKey, c.peerRandom, c.ticket)
c.peerNonce = make([]byte, 12)
}
if len(c.PeerCache) != 0 {
@@ -251,13 +252,13 @@ func (c *ServerConn) Read(b []byte) (int, error) {
if len(dst) <= len(b) {
dst = b[:len(dst)] // avoids another copy()
}
var peerAead cipher.AEAD
var peerAEAD cipher.AEAD
if bytes.Equal(c.peerNonce, MaxNonce) {
peerAead = NewAEAD(c.cipher, c.baseKey, peerData, h)
peerAEAD = NewAEAD(c.cipher, c.baseKey, peerData, h)
}
_, err = c.peerAead.Open(dst[:0], c.peerNonce, peerData, h)
if peerAead != nil {
c.peerAead = peerAead
_, err = c.peerAEAD.Open(dst[:0], c.peerNonce, peerData, h)
if peerAEAD != nil {
c.peerAEAD = peerAEAD
}
IncreaseNonce(c.peerNonce)
if err != nil {