Merge remote-tracking branch 'remotes/origin/feat/128/multiple-input-output' into feat/127/crypto-conditions-ilp-bigchain-integration

Conflicts:
	bigchaindb/consensus.py
	bigchaindb/util.py

bigchaindb/consensus.py

@@ -1,3 +1,4 @@
+import copy
 from abc import ABCMeta, abstractmethod
 
 import bigchaindb.exceptions as exceptions
@@ -119,9 +120,11 @@ class BaseConsensusRules(AbstractConsensusRules):
         # If the operation is CREATE the transaction should have no inputs and
         # should be signed by a federation node
         if transaction['transaction']['operation'] == 'CREATE':
-            if transaction['transaction']['inputs']:
+            # TODO: for now lets assume a CREATE transaction only has one fulfillment
+            if transaction['transaction']['fulfillments'][0]['input']:
                 raise ValueError('A CREATE operation has no inputs')
-            if transaction['transaction']['current_owner'] not in (
+            # TODO: fow now lets assume a CREATE transaction only has one current_owner
+            if transaction['transaction']['fulfillments'][0]['current_owners'][0] not in (
                     bigchain.federation_nodes + [bigchain.me]):
                 raise exceptions.OperationError(
                     'Only federation nodes can use the operation `CREATE`')
@@ -156,6 +159,11 @@ class BaseConsensusRules(AbstractConsensusRules):
                         'input `{}` was already spent'.format(inp))
 
         # Check hash of the transaction
+        # remove the fulfillment messages (signatures)
+        transaction_data = copy.deepcopy(transaction)
+        for fulfillment in transaction_data['transaction']['fulfillments']:
+            fulfillment['fulfillment'] = None
+
         calculated_hash = crypto.hash_data(util.serialize(
             transaction['transaction']))
         if calculated_hash != transaction['id']:

bigchaindb/core.py

@@ -388,7 +388,7 @@ class Bigchain(object):
             raise GenesisBlockAlreadyExistsError('Cannot create the Genesis block')
 
         payload = {'message': 'Hello World from the BigchainDB'}
-        transaction = self.create_transaction(self.me, self.me, None, 'GENESIS', payload=payload)
+        transaction = self.create_transaction([self.me], [self.me], None, 'GENESIS', payload=payload)
         transaction_signed = self.sign_transaction(transaction, self.me_private)
 
         # create the block

bigchaindb/util.py

@@ -239,7 +239,7 @@ def sign_tx(transaction, private_key):
 
     for fulfillment in transaction['transaction']['fulfillments']:
         fulfillment_message = common_data.copy()
-        if transaction['transaction']['operation'] == 'CREATE':
+        if transaction['transaction']['operation'] in ['CREATE', 'GENESIS']:
             fulfillment_message.update({
                 'input': None,
                 'condition': None
@@ -279,6 +279,7 @@ def check_hash_and_signature(transaction):
 
 
 def verify_signature(signed_transaction):
+    # TODO: The name should change. This will be the validation of the fulfillments
     """Verify the signature of a transaction
 
     A valid transaction should have been signed `current_owner` corresponding private key.
@@ -290,16 +291,38 @@ def verify_signature(signed_transaction):
         bool: True if the signature is correct, False otherwise.
     """
 
-    data = signed_transaction.copy()
+    b = bigchaindb.Bigchain()
 
-    # if assignee field in the transaction, remove it
-    if 'assignee' in data:
-        data.pop('assignee')
+    common_data = {
+        'operation': signed_transaction['transaction']['operation'],
+        'timestamp': signed_transaction['transaction']['timestamp'],
+        'data': signed_transaction['transaction']['data'],
+        'version': signed_transaction['version'],
+        'id': signed_transaction['id']
+    }
 
-    signature = data.pop('signature')
-    public_key_base58 = signed_transaction['transaction']['current_owner']
-    public_key = crypto.VerifyingKey(public_key_base58)
-    return public_key.verify(serialize(data), signature)
+    for fulfillment in signed_transaction['transaction']['fulfillments']:
+        fulfillment_message = common_data.copy()
+        fulfillment_message.update({
+            'input': fulfillment['input'],
+            'condition': None,
+        })
+
+        # if not a `CREATE` transaction
+        if fulfillment['input']:
+            # get previous condition
+            previous_tx = b.get_transaction(fulfillment['input']['txid'])
+            conditions = sorted(previous_tx['transaction']['conditions'], key=lambda d: d['cid'])
+            fulfillment_message['condition'] = conditions[fulfillment['cid']]
+
+        # verify the signature (for now lets assume there is only one owner)
+        vk = crypto.VerifyingKey(fulfillment['current_owners'][0])
+
+        is_valid = vk.verify(serialize(fulfillment_message), fulfillment['fulfillment'])
+        if not is_valid:
+            return False
+
+    return True
 
 
 def transform_create(tx):