Fix partitioning bug

rpc/msg.go

@@ -33,30 +33,30 @@ func partitionMessage(msg []byte, headerMsgSize, otherMsgSize uint64) [][]byte {
 
 	numSzBytes := uint64(len(mSzBuf))
 	numMsgBytes := uint64(len(msg))
-	actualHeaderSize := headerMsgSize - numSzBytes
+	firstPartSize := headerMsgSize - numSzBytes
 	parts := make([][]byte, 1)
 
 	// Msg fits into header
-	if actualHeaderSize >= numMsgBytes {
+	if firstPartSize >= numMsgBytes {
 		copy(headerMsg[numSzBytes:], msg)
 		parts[0] = headerMsg
 		return parts
 	}
 
 	// Msg does not fit into header
-	copy(headerMsg[numSzBytes:], msg[:actualHeaderSize])
+	copy(headerMsg[numSzBytes:], msg[:firstPartSize])
 	parts[0] = headerMsg
-	msgBytesLeft := numMsgBytes - actualHeaderSize
+	msgBytesLeft := numMsgBytes - firstPartSize
 
 	// Add the rest of the parts
-	numParts := msgBytesLeft / otherMsgSize
-	offset := actualHeaderSize
-	for i := uint64(0); i < numParts; i++ {
+	numFullPartsLeft := msgBytesLeft / otherMsgSize
+	offset := firstPartSize
+	for i := uint64(0); i < numFullPartsLeft; i++ {
 		parts = append(parts, msg[offset:offset+otherMsgSize])
 		offset += otherMsgSize
 	}
 
-	// Partial part
+	// Last part (if necessary)
 	if (msgBytesLeft % otherMsgSize) != 0 {
 		p := make([]byte, otherMsgSize)
 		copy(p, msg[offset:])
@@ -82,9 +82,9 @@ func reconstructPartitions(parts [][]byte) ([]byte, error) {
 	}
 
 	// Do we have the whole message yet?
-	curSize := headerReader.Len()
-	if len(parts) != 1 {
-		curSize += len(parts[1]) * (len(parts) - 1)
+	curSize := 0
+	for i := 0; i < len(parts); i++ {
+		curSize += len(parts[i])
 	}
 	if mSz > uint64(curSize) {
 		jww.DEBUG.Printf("[RPC] still missing parts: %d > %d",
@@ -92,22 +92,16 @@ func reconstructPartitions(parts [][]byte) ([]byte, error) {
 		return nil, ErrMissingParts
 	}
 
-	msg := make([]byte, mSz)
+	msg := make([]byte, curSize)
 	offset, err := headerReader.Read(msg)
 	if err != nil {
 		return nil, err
 	}
 
 	for i := 1; i < len(parts); i++ {
-		if uint64(offset+len(parts[i])) <= mSz {
 		copy(msg[offset:], parts[i])
 		offset += len(parts[i])
-		} else {
-			stop := uint64(len(parts[i])) - (mSz - uint64(offset))
-			copy(msg[offset:], parts[i][:stop])
-			offset += len(parts[i])
-		}
 	}
 
-	return msg, nil
+	return msg[:mSz], nil
 }

rpc/msg_test.go

@@ -82,3 +82,16 @@ func TestMsgPartitions(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, msg, msgOut)
 }
+
+func TestActualMessage(t *testing.T) {
+	headerSize := (900 - handshakeCiphertextOverhead)
+	otherSize := (900 - channelCiphertextOverhead)
+	expected := []byte("{\"root\":\"0x2dba44d695326db3af5a8a25caf39330adeedfdd6a4738e30927f98bb1e4d9d9\",\"proof\":[{\"Left\":\"0x2793fc16cbd7b3340525b40bb46c1d7e4536ea6e1af9d96e13edd06052aaba63\"},{\"Right\":\"0x1f564825ad6f7c68443c9bc096295602c17339c2557e441b38dad0720ec5e9f1\"},{\"Left\":\"0x217c4c12af3b1b49c877960a5928899b060c2950a24bc92bb5a14af4524eb38\"},{\"Left\":\"0x2f309bf1cdd91b784dc4cbaec44881809750cac06ce2f4d3a411592c22ce7e40\"},{\"Left\":\"0x56d4471d170ba29faeacd33eb709150ae25daefe02bc8a515c84d389670cfd9\"},{\"Left\":\"0x22443ea99c74905cea7f0a4e7f537aec9c59d398e841d8d48a09859646ca965\"},{\"Left\":\"0xe4b4c5cdf28b5600fc26effa762c2996b3d6b8a92928803a95864a9fc2fd9e4\"},{\"Left\":\"0x2264260d21a5760b5dceec38507fce1c1ae6aa57ef352df147ae915b6eb2231f\"},{\"Left\":\"0x14f486de9e25f3e3e33b035d132b73cfd4d75e3285a6172d5534f85fd55a995a\"},{\"Left\":\"0x3219565149732ed57b90233f40df7e695127d5fb72ca5285f0b36166b2b9ce1\"},{\"Left\":\"0x19c489fbd3f07145fbbffb8fc8dd11e4e80f17963eb2f01aa7f76e3043137ba5\"},{\"Left\":\"0x12e5fbf330fe9950dc1f5fde62642e45cff737c569c13d07a8a93239a35c6a20\"},{\"Left\":\"0xc9bbaf5e960cfecf523868bcd0db2113df69e52d7f6c6f531c8358dcb984743\"},{\"Left\":\"0x16c7fb6a8aa40724b813d958dce15a8c3685354868267b6472eb24627754f915\"},{\"Left\":\"0x48c63ec390c6e641f1df2f8ab0063bc1e2c45a7682467ee260c52c81cc8ac15\"},{\"Left\":\"0xa5194a89cdd0f276e500e628ea7b10036dde1b89ef78be7421b8445f93a3c20\"},{\"Left\":\"0x2a7c7c9b6ce5880b9f6f228d72bf6a575a526f29c66ecceef8b753d38bba7323\"},{\"Left\":\"0x2e8186e558698ec1c67af9c14d463ffc470043c9c2988b954d75dd643f36b992\"},{\"Left\":\"0xf57c5571e9a4eab49e2c8cf050dae948aef6ead647392273546249d1c1ff10f\"},{\"Left\":\"0x1830ee67b5fb554ad5f63d4388800e1cfe78e310697d46e43c9ce36134f72cca\"},{\"Left\":\"0x2134e76ac5d21aab186c2be1dd8f84ee880a1e46eaf712f9d371b6df22191f3e\"},{\"Left\":\"0x19df90ec844ebc4ffeebd866f33859b0c051d8c958ee3aa88f8f8df3db91a5b1\"},{\"Left\":\"0x18cca2a66b5c0787981e69aefd84852d74af0e93ef4912b4648c05f722efe52b\"},{\"Left\":\"0x2388909415230d1b4d1304d2d54f473a628338f2efad83fadf05644549d2538d\"},{\"Left\":\"0x27171fb4a97b6cc0e9e8f543b5294de866a2af2c9c8d0b1d96e673e4529ed540\"},{\"Left\":\"0x2ff6650540f629fd5711a0bc74fc0d28dcb230b9392583e5f8d59696dde6ae21\"},{\"Left\":\"0x120c58f143d491e95902f7f5277778a2e0ad5168f6add75669932630ce611518\"},{\"Left\":\"0x1f21feb70d3f21b07bf853d5e5db03071ec495a0a565a21da2d665d279483795\"},{\"Left\":\"0x24be905fa71335e14c638cc0f66a8623a826e768068a9e968bb1a1dde18a72d2\"},{\"Left\":\"0xf8666b62ed17491c50ceadead57d4cd597ef3821d65c328744c74e553dac26d\"}]}")
+	msg := expected
+	parts := partitionMessage(msg, headerSize, otherSize)
+	require.Equal(t, 3, len(parts))
+	msgOut, err := reconstructPartitions(parts)
+	require.NoError(t, err)
+	require.Equal(t, expected, msgOut)
+
+}