func (handler *_TransProxyHandler) forward(server Server, message *gorpc.Message) error {
handler.V("forward tunnel(%s) message", handler.device)
tunnel := gorpc.NewTunnel()
tunnel.ID = handler.device
tunnel.Message = message
var buff bytes.Buffer
err := gorpc.WriteTunnel(&buff, tunnel)
if err != nil {
return err
}
message.Code = gorpc.CodeTunnel
message.Content = buff.Bytes()
err = server.SendMessage(message)
if err == nil {
handler.V("forward tunnel(%s) message(%p) -- success", handler.device, message)
} else {
handler.E("forward tunnel(%s) message -- failed\n%s", handler.device, err)
}
return err
}
func (handler *_TunnelClient) SendMessage(device *gorpc.Device, message *gorpc.Message) error {
tunnel := gorpc.NewTunnel()
tunnel.ID = device
tunnel.Message = message
var buff bytes.Buffer
err := gorpc.WriteTunnel(&buff, tunnel)
if err != nil {
return err
}
message.Code = gorpc.CodeTunnel
message.Content = buff.Bytes()
handler.context.Send(message)
return nil
}
func (handler *_CryptoServer) MessageReceived(context gorpc.Context, message *gorpc.Message) (*gorpc.Message, error) {
if message.Code == gorpc.CodeHeartbeat {
return message, nil
}
if handler.block == nil {
handler.V("expect WhoAmI message")
// expect whoAmI message
if message.Code != gorpc.CodeWhoAmI {
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "expect WhoAmI message but got(%s)", message.Code)
}
handler.V("parse WhoAmI message")
whoAmI, err := gorpc.ReadWhoAmI(bytes.NewBuffer(message.Content))
if err != nil {
context.Close()
return nil, err
}
val, ok := new(big.Int).SetString(string(whoAmI.Context), 0)
if !ok {
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "parse WhoAmI#Context as big.Int error")
}
dhKey, err := handler.resovler.Resolve(whoAmI.ID)
if err != nil {
context.Close()
return nil, err
}
message.Code = gorpc.CodeAccept
message.Content = []byte(dhKey.Exchange().String())
context.Send(message)
key := make([]byte, des.BlockSize)
keyval := dhKey.Gen(val).Uint64()
binary.BigEndian.PutUint64(key[:8], keyval)
handler.V("shared key \n\t%d\n\t%v ", keyval, key)
block, err := des.NewCipher(key)
if err != nil {
context.Close()
return nil, gserrors.Newf(err, "create new des Cipher error")
}
handler.block = block
handler.device = whoAmI.ID
context.FireActive()
for _, message := range handler.cached {
message, _ = handler.MessageSending(context, message)
context.Send(message)
}
handler.cached = nil
handler.V("%s handshake -- success", context.Name())
return nil, nil
}
blocksize := handler.block.BlockSize()
if len(message.Content)%blocksize != 0 {
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "invalid encrypt data")
}
blocks := len(message.Content) / blocksize
for i := 0; i < blocks; i++ {
offset := i * blocksize
v := message.Content[offset : offset+blocksize]
handler.block.Decrypt(v, v)
}
message.Content = PKCS5UnPadding(message.Content)
return message, nil
}
func (handler *_TransProxyHandler) MessageReceived(context gorpc.Context, message *gorpc.Message) (*gorpc.Message, error) {
if message.Code == gorpc.CodeResponse {
if server, ok := handler.tunnel(message.Agent); ok {
err := handler.forward(server, message)
if err != nil {
context.Close()
}
return nil, err
}
return message, nil
}
if message.Code != gorpc.CodeRequest {
return message, nil
}
request, err := gorpc.ReadRequest(bytes.NewBuffer(message.Content))
if err != nil {
handler.E("[%s] unmarshal request error\n%s", handler.proxy.name, err)
return nil, err
}
service := request.Service
if transproxy, ok := handler.transproxy(service); ok {
handler.V("forward tunnel(%s) message", handler.device)
tunnel := gorpc.NewTunnel()
tunnel.ID = handler.device
tunnel.Message = message
var buff bytes.Buffer
err := gorpc.WriteTunnel(&buff, tunnel)
if err != nil {
return nil, err
}
message.Code = gorpc.CodeTunnel
message.Content = buff.Bytes()
err = transproxy.SendMessage(message)
if err != nil {
context.Close()
handler.V("forward tunnel(%s) message(%p) -- failed\n%s", handler.device, message, err)
return nil, err
}
handler.V("forward tunnel(%s) message(%p) -- success", handler.device, message)
return nil, err
}
return message, nil
}