[#1093] Mailserver compatible with sync AND async keys (#1096)

mailserver/mailserver.go

@@ -83,10 +83,11 @@ type dbImpl interface {
 
 // WMailServer whisper mailserver.
 type WMailServer struct {
-	db     dbImpl
-	w      *whisper.Whisper
-	pow    float64
-	filter *whisper.Filter
+	db         dbImpl
+	w          *whisper.Whisper
+	pow        float64
+	symFilter  *whisper.Filter
+	asymFilter *whisper.Filter
 
 	muLimiter sync.RWMutex
 	limiter   *limiter
@@ -154,7 +155,8 @@ func (s *WMailServer) setupLimiter(limit time.Duration) {
 // setupRequestMessageDecryptor setup a Whisper filter to decrypt
 // incoming Whisper requests.
 func (s *WMailServer) setupRequestMessageDecryptor(config *params.WhisperConfig) error {
-	var filter whisper.Filter
+	s.symFilter = nil
+	s.asymFilter = nil
 
 	if config.MailServerPassword != "" {
 		keyID, err := s.w.AddSymKeyFromPassword(config.MailServerPassword)
@@ -167,12 +169,12 @@ func (s *WMailServer) setupRequestMessageDecryptor(config *params.WhisperConfig)
 			return fmt.Errorf("save symmetric key: %v", err)
 		}
 
-		filter = whisper.Filter{KeySym: symKey}
-	} else if config.MailServerAsymKey != nil {
-		filter = whisper.Filter{KeyAsym: config.MailServerAsymKey}
+		s.symFilter = &whisper.Filter{KeySym: symKey}
 	}
 
-	s.filter = &filter
+	if config.MailServerAsymKey != nil {
+		s.asymFilter = &whisper.Filter{KeyAsym: config.MailServerAsymKey}
+	}
 
 	return nil
 }
@@ -357,13 +359,29 @@ func (s *WMailServer) sendHistoricMessageResponse(peer *whisper.Peer, request *w
 	return s.w.SendHistoricMessageResponse(peer, payload)
 }
 
+// openEnvelope tries to decrypt an envelope, first based on asymetric key (if
+// provided) and second on the symetric key (if provided)
+func (s *WMailServer) openEnvelope(request *whisper.Envelope) *whisper.ReceivedMessage {
+	if s.asymFilter != nil {
+		if d := request.Open(s.asymFilter); d != nil {
+			return d
+		}
+	}
+	if s.symFilter != nil {
+		if d := request.Open(s.symFilter); d != nil {
+			return d
+		}
+	}
+	return nil
+}
+
 // validateRequest runs different validations on the current request.
 func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope) (bool, uint32, uint32, []byte, uint32, cursorType) {
 	if s.pow > 0.0 && request.PoW() < s.pow {
 		return false, 0, 0, nil, 0, nil
 	}
 
-	decrypted := request.Open(s.filter)
+	decrypted := s.openEnvelope(request)
 	if decrypted == nil {
 		log.Warn("Failed to decrypt p2p request")
 		return false, 0, 0, nil, 0, nil

mailserver/mailserver_test.go

@@ -39,6 +39,7 @@ const powRequirement = 0.00001
 
 var keyID string
 var seed = time.Now().Unix()
+var testPayload = []byte("test payload")
 
 type ServerTestParams struct {
 	topic whisper.TopicType
@@ -191,25 +192,66 @@ func (s *MailserverSuite) TestSetupRequestMessageDecryptor() {
 	config = *s.config
 	s.NoError(config.ReadMailServerPasswordFile())
 	s.NoError(s.server.Init(s.shh, &config))
-	s.NotNil(s.server.filter.KeySym)
-	s.Nil(s.server.filter.KeyAsym)
+	s.Require().NotNil(s.server.symFilter)
+	s.NotNil(s.server.symFilter.KeySym)
+	s.Nil(s.server.asymFilter)
 	s.server.Close()
 
 	// AsymKey can also be used
 	config = *s.config
 	s.NoError(config.ReadMailServerAsymKeyFile())
 	s.NoError(s.server.Init(s.shh, &config))
-	s.Nil(s.server.filter.KeySym) // important: symmetric key should be nil
-	s.Equal(config.MailServerAsymKey, s.server.filter.KeyAsym)
+	s.Nil(s.server.symFilter) // important: symmetric filter should be nil
+	s.Require().NotNil(s.server.asymFilter)
+	s.Equal(config.MailServerAsymKey, s.server.asymFilter.KeyAsym)
 	s.server.Close()
 
-	// when both Password and AsymKey are set, Password has a preference
+	// when Password and AsymKey are set, both are supported
 	config = *s.config
 	s.NoError(config.ReadMailServerPasswordFile())
 	s.NoError(config.ReadMailServerAsymKeyFile())
 	s.NoError(s.server.Init(s.shh, &config))
-	s.NotNil(s.server.filter.KeySym)
-	s.Nil(s.server.filter.KeyAsym)
+	s.Require().NotNil(s.server.symFilter)
+	s.NotNil(s.server.symFilter.KeySym)
+	s.NotNil(s.server.asymFilter.KeyAsym)
+	s.server.Close()
+}
+
+func (s *MailserverSuite) TestOpenEnvelopeWithSymKey() {
+	// Setup the server with a sym key
+	config := *s.config
+	s.NoError(config.ReadMailServerPasswordFile())
+	s.NoError(s.server.Init(s.shh, &config))
+
+	// Prepare a valid envelope
+	s.Require().NotNil(s.server.symFilter)
+	symKey := s.server.symFilter.KeySym
+	env, err := generateEnvelopeWithKeys(time.Now(), symKey, nil)
+	s.Require().NoError(err)
+
+	// Test openEnvelope with a valid envelope
+	d := s.server.openEnvelope(env)
+	s.NotNil(d)
+	s.Equal(testPayload, d.Payload)
+	s.server.Close()
+}
+
+func (s *MailserverSuite) TestOpenEnvelopeWithAsymKey() {
+	// Setup the server with an asymetric key
+	config := *s.config
+	s.NoError(config.ReadMailServerAsymKeyFile())
+	s.NoError(s.server.Init(s.shh, &config))
+
+	// Prepare a valid envelope
+	s.Require().NotNil(s.server.asymFilter)
+	pubKey := s.server.asymFilter.KeyAsym.PublicKey
+	env, err := generateEnvelopeWithKeys(time.Now(), nil, &pubKey)
+	s.Require().NoError(err)
+
+	// Test openEnvelope with a valid asymetric key
+	d := s.server.openEnvelope(env)
+	s.NotNil(d)
+	s.Equal(testPayload, d.Payload)
 	s.server.Close()
 }
 
@@ -538,16 +580,20 @@ func (s *MailserverSuite) createRequest(p *ServerTestParams) *whisper.Envelope {
 	return env
 }
 
-func generateEnvelope(sentTime time.Time) (*whisper.Envelope, error) {
-	h := crypto.Keccak256Hash([]byte("test sample data"))
+func generateEnvelopeWithKeys(sentTime time.Time, keySym []byte, keyAsym *ecdsa.PublicKey) (*whisper.Envelope, error) {
 	params := &whisper.MessageParams{
-		KeySym:   h[:],
 		Topic:    whisper.TopicType{0x1F, 0x7E, 0xA1, 0x7F},
-		Payload:  []byte("test payload"),
+		Payload:  testPayload,
 		PoW:      powRequirement,
 		WorkTime: 2,
 	}
 
+	if len(keySym) > 0 {
+		params.KeySym = keySym
+	} else if keyAsym != nil {
+		params.Dst = keyAsym
+	}
+
 	msg, err := whisper.NewSentMessage(params)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create new message with seed %d: %s", seed, err)
@@ -559,3 +605,8 @@ func generateEnvelope(sentTime time.Time) (*whisper.Envelope, error) {
 
 	return env, nil
 }
+
+func generateEnvelope(sentTime time.Time) (*whisper.Envelope, error) {
+	h := crypto.Keccak256Hash([]byte("test sample data"))
+	return generateEnvelopeWithKeys(sentTime, h[:], nil)
+}