Add OpenVPN, TrustTunnel, Sudoku, inbound managers. Fixes

transport/sudoku/handshake_kip.go

@@ -0,0 +1,67 @@
+package sudoku
+
+import (
+	"crypto/ecdh"
+	"crypto/rand"
+	"fmt"
+	"io"
+	"time"
+
+	"github.com/sagernet/sing-box/transport/sudoku/crypto"
+)
+
+const kipHandshakeSkew = 60 * time.Second
+
+func kipHandshakeClient(rc *crypto.RecordConn, seed string, userHash [kipHelloUserHashSize]byte, feats uint32, tableHint uint32, hasTableHint bool) (uint32, error) {
+	if rc == nil {
+		return 0, fmt.Errorf("nil conn")
+	}
+
+	curve := ecdh.X25519()
+	ephemeral, err := curve.GenerateKey(rand.Reader)
+	if err != nil {
+		return 0, fmt.Errorf("ecdh generate failed: %w", err)
+	}
+
+	var nonce [kipHelloNonceSize]byte
+	if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
+		return 0, fmt.Errorf("nonce generate failed: %w", err)
+	}
+
+	var clientPub [kipHelloPubSize]byte
+	copy(clientPub[:], ephemeral.PublicKey().Bytes())
+
+	ch := newKIPClientHello(userHash, nonce, clientPub, feats, tableHint, hasTableHint)
+	if err := WriteKIPMessage(rc, KIPTypeClientHello, ch.EncodePayload()); err != nil {
+		return 0, fmt.Errorf("write client hello failed: %w", err)
+	}
+
+	msg, err := ReadKIPMessage(rc)
+	if err != nil {
+		return 0, fmt.Errorf("read server hello failed: %w", err)
+	}
+	if msg.Type != KIPTypeServerHello {
+		return 0, fmt.Errorf("unexpected handshake message: %d", msg.Type)
+	}
+	sh, err := DecodeKIPServerHelloPayload(msg.Payload)
+	if err != nil {
+		return 0, fmt.Errorf("decode server hello failed: %w", err)
+	}
+	if sh.Nonce != nonce {
+		return 0, fmt.Errorf("handshake nonce mismatch")
+	}
+
+	shared, err := x25519SharedSecret(ephemeral, sh.ServerPub[:])
+	if err != nil {
+		return 0, fmt.Errorf("ecdh failed: %w", err)
+	}
+	sessC2S, sessS2C, err := deriveSessionDirectionalBases(seed, shared, nonce)
+	if err != nil {
+		return 0, fmt.Errorf("derive session keys failed: %w", err)
+	}
+	if err := rc.Rekey(sessC2S, sessS2C); err != nil {
+		return 0, fmt.Errorf("rekey failed: %w", err)
+	}
+
+	return sh.SelectedFeats, nil
+}