sbft: check signature count on blocks

Change-Id: I66113390aa1b0993359c16187c689f3f9389da23
Signed-off-by: Simon Schubert <[email protected]>

Author: corecode

orderer/sbft/simplebft/batch.go

@@ -41,7 +41,7 @@ func (s *SBFT) makeBatch(seq uint64, prevHash []byte, data [][]byte) *Batch {
 	}
 }
 
-func (s *SBFT) checkBatch(b *Batch, checkData bool) (*BatchHeader, error) {
+func (s *SBFT) checkBatch(b *Batch, checkData bool, needSigs bool) (*BatchHeader, error) {
 	batchheader := &BatchHeader{}
 	err := proto.Unmarshal(b.Header, batchheader)
 	if err != nil {
@@ -55,6 +55,14 @@ func (s *SBFT) checkBatch(b *Batch, checkData bool) (*BatchHeader, error) {
 		}
 	}
 
+	if batchheader.PrevHash == nil {
+		// TODO check against root hash, which should be part of constructor
+	} else if needSigs {
+		if len(b.Signatures) < s.oneCorrectQuorum() {
+			return nil, fmt.Errorf("insufficient number of signatures on batch: need %d, got %d", s.oneCorrectQuorum(), len(b.Signatures))
+		}
+	}
+
 	bh := b.Hash()
 	for r, sig := range b.Signatures {
 		err = s.sys.CheckSig(bh, r, sig)

orderer/sbft/simplebft/connection.go

@@ -39,7 +39,7 @@ func (s *SBFT) Connection(replica uint64) {
 	// commit, checkpoint so that the reconnecting replica can
 	// catch up on the in-flight batch.
 
-	batchheader, err := s.checkBatch(&batch, false)
+	batchheader, err := s.checkBatch(&batch, false, true)
 	if err != nil {
 		panic(err)
 	}
@@ -60,7 +60,7 @@ func (s *SBFT) Connection(replica uint64) {
 }
 
 func (s *SBFT) handleHello(h *Hello, src uint64) {
-	bh, err := s.checkBatch(h.Batch, false)
+	bh, err := s.checkBatch(h.Batch, false, true)
 	if err != nil {
 		log.Warningf("invalid hello batch from %d: %s", src, err)
 		return

orderer/sbft/simplebft/newview.go

@@ -128,7 +128,7 @@ func (s *SBFT) handleNewView(nv *NewView, src uint64) {
 		return
 	}
 
-	_, err = s.checkBatch(nv.Batch, true)
+	_, err = s.checkBatch(nv.Batch, true, false)
 	if err != nil {
 		log.Warningf("invalid new view from %d: invalid batch, %s",
 			src, err)

orderer/sbft/simplebft/preprepare.go

@@ -59,9 +59,9 @@ func (s *SBFT) handlePreprepare(pp *Preprepare, src uint64) {
 		return
 	}
 
-	batchheader, err := s.checkBatch(pp.Batch, true)
+	batchheader, err := s.checkBatch(pp.Batch, true, false)
 	if err != nil || batchheader.Seq != pp.Seq.Seq {
-		log.Infof("preprepare %v batch head inconsistent from %d", pp.Seq, src)
+		log.Infof("preprepare %v batch head inconsistent from %d: %s", pp.Seq, src, err)
 		return
 	}
 

orderer/sbft/simplebft/testsys_test.go

@@ -170,7 +170,7 @@ func (t *testSystemAdapter) Restore(key string, out proto.Message) bool {
 
 func (t *testSystemAdapter) LastBatch() *Batch {
 	if len(t.batches) == 0 {
-		return t.receiver.(*SBFT).makeBatch(0, []byte("ROOTHASH"), nil)
+		return t.receiver.(*SBFT).makeBatch(0, nil, nil)
 	} else {
 		return t.batches[len(t.batches)-1]
 	}