yess

client/modules/login.go

@@ -0,0 +1,164 @@
+package modules
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net"
+	"strconv"
+
+	"github.com/admin-else/strom/api"
+	"github.com/admin-else/strom/client"
+	"github.com/admin-else/strom/crypto"
+	"github.com/admin-else/strom/event"
+	"github.com/admin-else/strom/proto"
+	"github.com/admin-else/strom/proto_base"
+
+	"github.com/admin-else/strom/data"
+	"github.com/admin-else/strom/proto_generated/v1_21_8"
+)
+
+type LoginClient struct {
+	*proto.Conn
+	Account *api.Account
+
+	GivenAccount v1_21_8.LoginToClientPacketSuccess
+}
+
+func (s *LoginClient) Default(event any) (err error) {
+	err = fmt.Errorf("unexpected event: %#v", event)
+	return
+}
+
+func (s *LoginClient) OnCycle(_ event.OnLoopCycle) (err error) {
+	return
+}
+
+func (s *LoginClient) OnStart(_ event.OnStart) (err error) {
+	host, portStr, err := net.SplitHostPort(s.RemoteAddr().String())
+	if err != nil {
+		return
+	}
+	versionData, err := data.LookUpProtocolVersionByName(s.Version)
+	if err != nil {
+		return
+	}
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		return
+	}
+	err = s.Send(v1_21_8.HandshakingToServerPacketSetProtocol{
+		ProtocolVersion: proto_base.VarInt(versionData.Version),
+		ServerHost:      host,
+		ServerPort:      uint16(port),
+		NextState:       proto_base.VarInt(proto_base.Login),
+	})
+	if err != nil {
+		return
+	}
+	s.State = proto_base.Login
+	err = s.Send(v1_21_8.LoginToServerPacketLoginStart{Username: s.Account.Name, PlayerUUID: s.Account.Uuid})
+	return
+}
+
+func (s *LoginClient) OnCompress(compress v1_21_8.LoginToClientPacketCompress) (err error) {
+	s.CompressionThreshold = int32(compress.Threshold)
+	return
+}
+
+func (s *LoginClient) OnEncrypt(packet v1_21_8.LoginToClientPacketEncryptionBegin) (err error) {
+	sharedSecret := make([]byte, 16)
+	_, _ = rand.Read(sharedSecret) //never fails
+
+	if packet.ShouldAuthenticate {
+		if s.Account.Ygg == "" {
+			err = fmt.Errorf("the account has no token so we cant join online servers")
+			return
+		}
+		serverId := crypto.AuthDigest([]byte(packet.ServerId), sharedSecret, packet.PublicKey)
+		err = s.Account.JoinServer(serverId)
+		if err != nil {
+			return
+		}
+	}
+
+	pubAny, err := x509.ParsePKIXPublicKey(packet.PublicKey)
+	if err != nil {
+		return
+	}
+	pub, ok := pubAny.(*rsa.PublicKey)
+	if !ok {
+		err = fmt.Errorf("public key is not rsa")
+		return
+	}
+	verifyTokenEnc, err := rsa.EncryptPKCS1v15(rand.Reader, pub, packet.VerifyToken)
+	if err != nil {
+		return
+	}
+
+	sharedSecretEnc, err := rsa.EncryptPKCS1v15(rand.Reader, pub, sharedSecret)
+	if err != nil {
+		return
+	}
+	err = s.Send(v1_21_8.LoginToServerPacketEncryptionBegin{SharedSecret: sharedSecretEnc, VerifyToken: verifyTokenEnc})
+	if err != nil {
+		return
+	}
+
+	var b cipher.Block
+	b, err = aes.NewCipher(sharedSecret)
+	if err != nil {
+		return
+	}
+	s.R = cipher.StreamReader{
+		S: crypto.NewCFB8Decrypt(b, sharedSecret),
+		R: s.Conn,
+	}
+	s.W = cipher.StreamWriter{
+		S: crypto.NewCFB8Encrypt(b, sharedSecret),
+		W: s.Conn,
+	}
+	return
+
+}
+
+func (s *LoginClient) OnSuccess(success v1_21_8.LoginToClientPacketSuccess) (err error) {
+	s.GivenAccount = success
+	err = s.Send(v1_21_8.LoginToServerPacketLoginAcknowledged{})
+	if err != nil {
+		return
+	}
+	s.State = proto_base.Configuration
+	err = event.HandlerDone
+	return
+}
+
+func Login(c *proto.Conn, account *api.Account) (err error) {
+	err = c.Start(&LoginClient{
+		Conn:    c,
+		Account: account,
+	})
+	if err != nil {
+		err = errors.Join(err, errors.New("failed to login"))
+	}
+	return
+}
+
+func ConnectAndLogin(connectTo string, account *api.Account) (c *proto.Conn, err error) {
+	c, err = client.Connect(connectTo)
+	if err != nil {
+		return
+	}
+	err = c.Start(&LoginClient{
+		Conn:    c,
+		Account: account,
+	})
+	if err != nil {
+		err = errors.Join(err, errors.New("failed to login"))
+	}
+	return
+}