hopefully fixed block sync issue

docs/whitepaper.md

@@ -86,6 +86,12 @@ Blocks are stored indefinitely until the allocated space is filled, at which poi
 
 ## Block Timestamping
 
-Onionr can provide evidence when a block was inserted by requesting other users to sign a hash of the current time with the block data hash: sha3_256(time + sha3_256(block data)).
+Onionr can provide evidence of when a block was inserted by requesting other users to sign a hash of the current time with the block data hash: sha3_256(time + sha3_256(block data)).
 
 This can be done either by the creator of the block prior to generation, or by any node after insertion.
+
+In addition, randomness beacons such as the one operated by [NIST](https://beacon.nist.gov/home) or the hash of the latest blocks in a cryptocurrency network could be used to affirm that a block was at least not *created* before a given time.
+
+# Direct Connections
+
+We propose a system to 

onionr/api.py

@@ -474,7 +474,7 @@ class API:
             elif action == 'getData':
                 resp = ''
                 if self._utils.validateHash(data):
-                    if not os.path.exists('data/blocks/' + data + '.db'):
+                    if os.path.exists('data/blocks/' + data + '.dat'):
                         block = Block(hash=data.encode(), core=self._core)
                         resp = base64.b64encode(block.getRaw().encode()).decode()
                 if len(resp) == 0:

onionr/communicator2.py

@@ -216,6 +216,7 @@ class OnionrCommunicatorDaemon:
                             logger.warn('POW failed for block ' + blockHash)
                     else:
                         logger.warn('Metadata for ' + blockHash + ' is invalid.')
+                        self._core._blacklist.addToDB(blockHash)
                 else:
                     # if block didn't meet expected hash
                     tempHash = self._core._crypto.sha3Hash(content) # lazy hack, TODO use var