eth: SEC-29 eth wire protocol decoding invalid message data crashes client

- add validate method to types.Block
- validate after Decode -> error
- add tests for NewBlockMsg

core/types/block.go

@@ -148,6 +148,26 @@ func NewBlockWithHeader(header *Header) *Block {
 	return &Block{header: header}
 }
 
+func (self *Block) Validate() error {
+	if self.header == nil {
+		return fmt.Errorf("header is nil")
+	}
+	// check *big.Int fields
+	if self.header.Difficulty == nil {
+		return fmt.Errorf("Difficulty undefined")
+	}
+	if self.header.GasLimit == nil {
+		return fmt.Errorf("GasLimit undefined")
+	}
+	if self.header.GasUsed == nil {
+		return fmt.Errorf("GasUsed undefined")
+	}
+	if self.header.Number == nil {
+		return fmt.Errorf("Number undefined")
+	}
+	return nil
+}
+
 func (self *Block) DecodeRLP(s *rlp.Stream) error {
 	var eb extblock
 	if err := s.Decode(&eb); err != nil {

eth/protocol.go

@@ -105,7 +105,7 @@ type getBlockHashesMsgData struct {
 type statusMsgData struct {
 	ProtocolVersion uint32
 	NetworkId       uint32
-	TD              *big.Int
+	TD              big.Int
 	CurrentBlock    common.Hash
 	GenesisBlock    common.Hash
 }
@@ -276,6 +276,9 @@ func (self *ethProtocol) handle() error {
 		if err := msg.Decode(&request); err != nil {
 			return self.protoError(ErrDecode, "%v: %v", msg, err)
 		}
+		if err := request.Block.Validate(); err != nil {
+			return self.protoError(ErrDecode, "block validation %v: %v", msg, err)
+		}
 		hash := request.Block.Hash()
 		_, chainHead, _ := self.chainManager.Status()
 
@@ -335,7 +338,7 @@ func (self *ethProtocol) handleStatus() error {
 		return self.protoError(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, self.protocolVersion)
 	}
 
-	_, suspended := self.blockPool.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
+	_, suspended := self.blockPool.AddPeer(&status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
 	if suspended {
 		return self.protoError(ErrSuspendedPeer, "")
 	}
@@ -366,7 +369,7 @@ func (self *ethProtocol) sendStatus() error {
 	return p2p.Send(self.rw, StatusMsg, &statusMsgData{
 		ProtocolVersion: uint32(self.protocolVersion),
 		NetworkId:       uint32(self.networkId),
-		TD:              td,
+		TD:              *td,
 		CurrentBlock:    currentBlock,
 		GenesisBlock:    genesisBlock,
 	})

eth/protocol_test.go

@@ -1,6 +1,7 @@
 package eth
 
 import (
+	"fmt"
 	"log"
 	"math/big"
 	"os"
@@ -63,6 +64,10 @@ func (self *testChainManager) GetBlockHashesFromHash(hash common.Hash, amount ui
 func (self *testChainManager) Status() (td *big.Int, currentBlock common.Hash, genesisBlock common.Hash) {
 	if self.status != nil {
 		td, currentBlock, genesisBlock = self.status()
+	} else {
+		td = common.Big1
+		currentBlock = common.Hash{1}
+		genesisBlock = common.Hash{2}
 	}
 	return
 }
@@ -163,14 +168,29 @@ func (self *ethProtocolTester) run() {
 	self.quit <- err
 }
 
+func (self *ethProtocolTester) handshake(t *testing.T, mock bool) {
+	td, currentBlock, genesis := self.chainManager.Status()
+	// first outgoing msg should be StatusMsg.
+	err := p2p.ExpectMsg(self, StatusMsg, &statusMsgData{
+		ProtocolVersion: ProtocolVersion,
+		NetworkId:       NetworkId,
+		TD:              *td,
+		CurrentBlock:    currentBlock,
+		GenesisBlock:    genesis,
+	})
+	if err != nil {
+		t.Fatalf("incorrect outgoing status: %v", err)
+	}
+	if mock {
+		go p2p.Send(self, StatusMsg, &statusMsgData{ProtocolVersion, NetworkId, *td, currentBlock, genesis})
+	}
+}
+
 func TestStatusMsgErrors(t *testing.T) {
 	logInit()
 	eth := newEth(t)
-	td := common.Big1
-	currentBlock := common.Hash{1}
-	genesis := common.Hash{2}
-	eth.chainManager.status = func() (*big.Int, common.Hash, common.Hash) { return td, currentBlock, genesis }
 	go eth.run()
+	td, currentBlock, genesis := eth.chainManager.Status()
 
 	tests := []struct {
 		code          uint64
@@ -182,31 +202,20 @@ func TestStatusMsgErrors(t *testing.T) {
 			wantErrorCode: ErrNoStatusMsg,
 		},
 		{
-			code: StatusMsg, data: statusMsgData{10, NetworkId, td, currentBlock, genesis},
+			code: StatusMsg, data: statusMsgData{10, NetworkId, *td, currentBlock, genesis},
 			wantErrorCode: ErrProtocolVersionMismatch,
 		},
 		{
-			code: StatusMsg, data: statusMsgData{ProtocolVersion, 999, td, currentBlock, genesis},
+			code: StatusMsg, data: statusMsgData{ProtocolVersion, 999, *td, currentBlock, genesis},
 			wantErrorCode: ErrNetworkIdMismatch,
 		},
 		{
-			code: StatusMsg, data: statusMsgData{ProtocolVersion, NetworkId, td, currentBlock, common.Hash{3}},
+			code: StatusMsg, data: statusMsgData{ProtocolVersion, NetworkId, *td, currentBlock, common.Hash{3}},
 			wantErrorCode: ErrGenesisBlockMismatch,
 		},
 	}
 	for _, test := range tests {
-		// first outgoing msg should be StatusMsg.
+		eth.handshake(t, false)
-		err := p2p.ExpectMsg(eth, StatusMsg, &statusMsgData{
-			ProtocolVersion: ProtocolVersion,
-			NetworkId:       NetworkId,
-			TD:              td,
-			CurrentBlock:    currentBlock,
-			GenesisBlock:    genesis,
-		})
-		if err != nil {
-			t.Fatalf("incorrect outgoing status: %v", err)
-		}
-
 		// the send call might hang until reset because
 		// the protocol might not read the payload.
 		go p2p.Send(eth, test.code, test.data)
@@ -216,3 +225,73 @@ func TestStatusMsgErrors(t *testing.T) {
 		go eth.run()
 	}
 }
+
+func TestNewBlockMsg(t *testing.T) {
+	logInit()
+	eth := newEth(t)
+	eth.blockPool.addBlock = func(block *types.Block, peerId string) (err error) {
+		fmt.Printf("Add Block: %v\n", block)
+		return
+	}
+
+	var disconnected bool
+	eth.blockPool.removePeer = func(peerId string) {
+		fmt.Printf("peer <%s> is disconnected\n", peerId)
+		disconnected = true
+	}
+
+	go eth.run()
+
+	eth.handshake(t, true)
+	err := p2p.ExpectMsg(eth, TxMsg, []interface{}{})
+	if err != nil {
+		t.Errorf("transactions expected, got %v", err)
+	}
+
+	var tds = make(chan *big.Int)
+	eth.blockPool.addPeer = func(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool) {
+		tds <- td
+		return
+	}
+
+	var delay = 1 * time.Second
+	// eth.reset()
+	block := types.NewBlock(common.Hash{1}, common.Address{1}, common.Hash{1}, common.Big1, 1, "extra")
+
+	go p2p.Send(eth, NewBlockMsg, &newBlockMsgData{Block: block})
+	timer := time.After(delay)
+
+	select {
+	case td := <-tds:
+		if td.Cmp(common.Big0) != 0 {
+			t.Errorf("incorrect td %v, expected %v", td, common.Big0)
+		}
+	case <-timer:
+		t.Errorf("no td recorded after %v", delay)
+		return
+	case err := <-eth.quit:
+		t.Errorf("no error expected, got %v", err)
+		return
+	}
+
+	go p2p.Send(eth, NewBlockMsg, &newBlockMsgData{block, common.Big2})
+	timer = time.After(delay)
+
+	select {
+	case td := <-tds:
+		if td.Cmp(common.Big2) != 0 {
+			t.Errorf("incorrect td %v, expected %v", td, common.Big2)
+		}
+	case <-timer:
+		t.Errorf("no td recorded after %v", delay)
+		return
+	case err := <-eth.quit:
+		t.Errorf("no error expected, got %v", err)
+		return
+	}
+
+	go p2p.Send(eth, NewBlockMsg, []interface{}{})
+	// Block.DecodeRLP: validation failed: header is nil
+	eth.checkError(ErrDecode, delay)
+
+}