func (handler *_CryptoClient) 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 handshake accept")
if message.Code != gorpc.CodeAccept {
handler.E("unexpect message(%s)", message.Code)
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "expect handshake(Accept) but got(%s)", message.Code)
}
handler.V("parse handshake accept")
val, ok := new(big.Int).SetString(string(message.Content), 0)
if !ok {
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "parse Accept#Content as big.Int error")
}
key := make([]byte, des.BlockSize)
keyval := handler.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.V("%s handshake -- success", context.Name())
context.FireActive()
for _, message := range handler.cached {
message, _ = handler.MessageSending(context, message)
context.Send(message)
}
handler.cached = nil
return nil, nil
}
if message.Code == gorpc.CodeHeartbeat {
return message, nil
}
blocksize := handler.block.BlockSize()
if len(message.Content)%blocksize != 0 {
context.Close()
return nil, gserrors.Newf(gorpc.ErrRPC, "%s invalid encrypt data", context)
}
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 *_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
}