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

proxy/vless/encryption/xor.go

@@ -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
+}