Verify chunk id for snapshot chunks

integration_tests/resume_test.sh

@@ -8,7 +8,7 @@ fixture
 pushd ${TEST_REPO}
 ${DUPLICACY} init integration-tests $TEST_STORAGE -c  4 
 
-# Create 10 20 files
+# Create 10 small files
 add_file file1 20
 add_file file2 20
 add_file file3 20
@@ -25,6 +25,8 @@ env DUPLICACY_FAIL_CHUNK=10 ${DUPLICACY} backup
 
 # Try it again to test the multiple-resume case
 env DUPLICACY_FAIL_CHUNK=5 ${DUPLICACY} backup
+add_file file1 20
+add_file file2 20
 
 # Fail the backup before uploading the snapshot
 env DUPLICACY_FAIL_SNAPSHOT=true ${DUPLICACY} backup

src/duplicacy_chunk.go

@@ -154,6 +154,18 @@ func (chunk *Chunk) GetID() string {
     return chunk.id
 }
 
+func (chunk *Chunk) VerifyID() {
+    hasher := chunk.config.NewKeyedHasher(chunk.config.HashKey)
+    hasher.Write(chunk.buffer.Bytes())
+    hash := hasher.Sum(nil)
+    hasher = chunk.config.NewKeyedHasher(chunk.config.IDKey)
+    hasher.Write([]byte(hash))
+    chunkID := hex.EncodeToString(hasher.Sum(nil))
+    if chunkID != chunk.GetID() {
+        LOG_ERROR("CHUNK_ID", "The chunk id should be %s instead of %s, length: %d", chunkID, chunk.GetID(), len(chunk.buffer.Bytes()))
+    }
+}
+
 // Encrypt encrypts the plain data stored in the chunk buffer.  If derivationKey is not nil, the actual
 // encryption key will be HMAC-SHA256(encryptionKey, derivationKey).
 func (chunk *Chunk) Encrypt(encryptionKey []byte, derivationKey string) (err error) {

src/duplicacy_chunkuploader.go

@@ -92,6 +92,11 @@ func (uploader *ChunkUploader) Upload(threadIndex int, task ChunkUploadTask) boo
     chunkSize := chunk.GetLength()
     chunkID := chunk.GetID()
 
+    // For a snapshot chunk, verify that its chunk id is correct
+    if uploader.snapshotCache != nil {
+        chunk.VerifyID()
+    }
+
     if uploader.snapshotCache != nil && uploader.storage.IsCacheNeeded() {
         // Save a copy to the local snapshot.
         chunkPath, exist, _, err := uploader.snapshotCache.FindChunk(threadIndex, chunkID, false)