swarm/storage: Fix padding in hasherStore

There was a bug that data was not lengthened to padding
ethersphere · Mar 29, 2018 · 534217f · 534217f
1 parent 582c6e5
commit 534217f
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Showing 3 changed files with 26 additions and 10 deletions.
diff --git a/swarm/storage/dpa.go b/swarm/storage/dpa.go
@@ -90,7 +90,7 @@ func NewDPA(store ChunkStore, params *DPAParams) *DPA {
 // Chunk retrieval blocks on netStore requests with a timeout so reader will
 // report error if retrieval of chunks within requested range time out.
 func (self *DPA) Retrieve(key Key) LazySectionReader {
-	getter := NewHasherStore(self.ChunkStore, self.hashFunc, true)
+	getter := NewHasherStore(self.ChunkStore, self.hashFunc, len(key) > self.hashFunc().Size())
 	return TreeJoin(key, getter, 0)
 }
 

diff --git a/swarm/storage/dpa_test.go b/swarm/storage/dpa_test.go
@@ -86,6 +86,11 @@ func testDpaRandom(toEncrypt bool, t *testing.T) {
 }
 
 func TestDPA_capacity(t *testing.T) {
+	testDPA_capacity(false, t)
+	testDPA_capacity(true, t)
+}
+
+func testDPA_capacity(toEncrypt bool, t *testing.T) {
 	tdb, err := newTestDbStore(false)
 	if err != nil {
 		t.Fatalf("init dbStore failed: %v", err)
@@ -99,7 +104,7 @@ func TestDPA_capacity(t *testing.T) {
 	}
 	dpa := NewDPA(localStore, NewDPAParams())
 	reader, slice := generateRandomData(testDataSize)
-	key, wait, err := dpa.Store(reader, testDataSize, true)
+	key, wait, err := dpa.Store(reader, testDataSize, toEncrypt)
 	if err != nil {
 		t.Errorf("Store error: %v", err)
 	}

diff --git a/swarm/storage/hasherstore.go b/swarm/storage/hasherstore.go
@@ -42,7 +42,7 @@ type hasherStore struct {
 func newChunkEncryption() *chunkEncryption {
 	return &chunkEncryption{
 		spanEncryption: encryption.New(0, math.MaxUint32, sha3.NewKeccak256),
-		dataEncryption: encryption.New(4096, 0, sha3.NewKeccak256),
+		dataEncryption: encryption.New(int(DefaultChunkSize), 0, sha3.NewKeccak256),
 	}
 }
 
@@ -155,7 +155,6 @@ func (p *hasherStore) encryptChunkData(chunkData ChunkData) (ChunkData, encrypti
 		return nil, nil, err
 	}
 
-	c := make(ChunkData, len(chunkData))
 	encryptedSpan, err := p.chunkEncryption.spanEncryption.Encrypt(chunkData[:8], encryptionKey)
 	if err != nil {
 		return nil, nil, err
@@ -164,28 +163,40 @@ func (p *hasherStore) encryptChunkData(chunkData ChunkData) (ChunkData, encrypti
 	if err != nil {
 		return nil, nil, err
 	}
+	c := make(ChunkData, len(encryptedSpan)+len(encryptedData))
 	copy(c[:8], encryptedSpan)
 	copy(c[8:], encryptedData)
 	return c, encryptionKey, nil
 }
 
-func (p *hasherStore) decryptChunkData(chunkData ChunkData, encryptionKey encryption.Key) (ChunkData, error) {
+func (h *hasherStore) decryptChunkData(chunkData ChunkData, encryptionKey encryption.Key) (ChunkData, error) {
 	if len(chunkData) < 8 {
 		return nil, fmt.Errorf("Invalid ChunkData, min length 8 got %v", len(chunkData))
 	}
 
-	c := make(ChunkData, len(chunkData))
-	decryptedSpan, err := p.chunkEncryption.spanEncryption.Decrypt(chunkData[:8], encryptionKey)
+	decryptedSpan, err := h.chunkEncryption.spanEncryption.Decrypt(chunkData[:8], encryptionKey)
 	if err != nil {
 		return nil, err
 	}
-	decryptedData, err := p.chunkEncryption.dataEncryption.Decrypt(chunkData[8:], encryptionKey)
+
+	decryptedData, err := h.chunkEncryption.dataEncryption.Decrypt(chunkData[8:], encryptionKey)
 	if err != nil {
 		return nil, err
 	}
+
+	// removing extra bytes which were just added for padding
+	length := ChunkData(decryptedSpan).Size()
+	for length > DefaultChunkSize {
+		length = length + (DefaultChunkSize - 1)
+		length = length / DefaultChunkSize
+		length *= h.refSize
+	}
+
+	c := make(ChunkData, length+8)
 	copy(c[:8], decryptedSpan)
-	copy(c[8:], decryptedData)
-	return c, nil
+	copy(c[8:], decryptedData[:length])
+
+	return c[:length+8], nil
 }
 
 func (h *hasherStore) RefSize() int64 {