From 1de5375962306b1ce04c553eb38ad5237839959f Mon Sep 17 00:00:00 2001
From: kansi <kansi13@gmail.com>
Date: Tue, 31 Oct 2017 15:16:59 +0530
Subject: [PATCH] Validate asset data keys

---
 bigchaindb/common/utils.py     | 19 ++++++++++++++++++-
 bigchaindb/models.py           |  4 +++-
 tests/web/test_transactions.py | 28 ++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/bigchaindb/common/utils.py b/bigchaindb/common/utils.py
index f6f671db..fd9386e1 100644
--- a/bigchaindb/common/utils.py
+++ b/bigchaindb/common/utils.py
@@ -1,7 +1,10 @@
 import time
-
+import re
 import rapidjson
 
+import bigchaindb
+from bigchaindb.common.exceptions import ValidationError
+
 
 def gen_timestamp():
     """The Unix time, rounded to the nearest second.
@@ -46,3 +49,17 @@ def deserialize(data):
             string.
     """
     return rapidjson.loads(data)
+
+
+def validate_asset_data_keys(tx_body):
+    backend = bigchaindb.config['database']['backend']
+
+    if backend == 'mongodb':
+        data = tx_body['asset'].get('data', {})
+        keys = data.keys() if data else []
+        for key in keys:
+            if re.search(r'^[$]|\.', key):
+                error_str = ('Invalid key name "{}" in asset object. The '
+                             'key name cannot contain characters '
+                             '"." and "$"').format(key)
+                raise ValidationError(error_str) from ValueError()
diff --git a/bigchaindb/models.py b/bigchaindb/models.py
index c8ad9dd3..9704372d 100644
--- a/bigchaindb/models.py
+++ b/bigchaindb/models.py
@@ -8,7 +8,8 @@ from bigchaindb.common.exceptions import (InvalidHash, InvalidSignature,
                                           SybilError,
                                           DuplicateTransaction)
 from bigchaindb.common.transaction import Transaction
-from bigchaindb.common.utils import gen_timestamp, serialize
+from bigchaindb.common.utils import (gen_timestamp, serialize,
+                                     validate_asset_data_keys)
 from bigchaindb.common.schema import validate_transaction_schema
 
 
@@ -84,6 +85,7 @@ class Transaction(Transaction):
     @classmethod
     def from_dict(cls, tx_body):
         validate_transaction_schema(tx_body)
+        validate_asset_data_keys(tx_body)
         return super().from_dict(tx_body)
 
     @classmethod
diff --git a/tests/web/test_transactions.py b/tests/web/test_transactions.py
index acea8c2c..4c2a6ed9 100644
--- a/tests/web/test_transactions.py
+++ b/tests/web/test_transactions.py
@@ -47,6 +47,34 @@ def test_post_create_transaction_endpoint(b, client):
     assert res.json['outputs'][0]['public_keys'][0] == user_pub
 
 
+@pytest.mark.parametrize("key,expected_status_code", [
+    ('bad.key', 400),
+    ('$bad.key', 400),
+    ('$badkey', 400),
+    ('good_key', 202)
+])
+@pytest.mark.assetkey
+@pytest.mark.bdb
+def test_post_create_transaction_with_invalid_asset_key(b, client, key, expected_status_code):
+    from bigchaindb.models import Transaction
+    from bigchaindb.backend.mongodb.connection import MongoDBConnection
+    user_priv, user_pub = crypto.generate_key_pair()
+
+    if isinstance(b.connection, MongoDBConnection):
+        tx = Transaction.create([user_pub], [([user_pub], 1)],
+                                asset={key: 'random_value'})
+        tx = tx.sign([user_priv])
+        res = client.post(TX_ENDPOINT, data=json.dumps(tx.to_dict()))
+
+        assert res.status_code == expected_status_code
+        if res.status_code == 400:
+            expected_error_message = (
+                'Invalid transaction (ValidationError): Invalid key name "{}" '
+                'in asset object. The key name cannot contain characters '
+                '"." and "$"').format(key)
+            assert res.json['message'] == expected_error_message
+
+
 @patch('bigchaindb.web.views.base.logger')
 def test_post_create_transaction_with_invalid_id(mock_logger, b, client):
     from bigchaindb.common.exceptions import InvalidHash