Merge pull request #5 from asonnino/master

merge latest

chainspacecontract/chainspacecontract/examples/bank_authenticated.py

@@ -0,0 +1,104 @@
+"""A smart contract that implements a simple, authenticated bank."""
+
+#############################################################################################
+# imports
+#############################################################################################
+from chainspacecontract import ChainspaceContract
+from hashlib            import sha256
+from petlib.ec          import EcGroup, EcPt
+from petlib.ecdsa       import do_ecdsa_sign, do_ecdsa_verify
+from petlib.bn          import Bn
+from binascii           import hexlify, unhexlify
+from json               import dumps
+
+contract = ChainspaceContract('bank_authenticated')
+
+
+#############################################################################################
+# init
+#############################################################################################
+@contract.method('init')
+def init():
+    return {
+        'outputs': (
+            {'name': 'alice', 'balance': 10},
+            {'name': 'bob', 'balance': 10}
+        )
+    }
+
+
+#############################################################################################
+# contract method
+#
+# NOTE: all extra parameters (like secret_key) will be ingored by the framwork; they will 
+#       not be sent anywhere
+#############################################################################################
+@contract.method('auth_transfer')
+def auth_transfer(inputs, reference_inputs, parameters, sk):
+    from_account = inputs[0]
+    to_account = inputs[1]
+
+    # compute outputs
+    from_account['balance'] -= parameters['amount']
+    to_account['balance'] += parameters['amount']
+
+    # hash message to sign
+    hasher = sha256()
+    hasher.update(dumps(inputs).encode('utf8'))
+    hasher.update(dumps(reference_inputs).encode('utf8'))
+    hasher.update(dumps({'amount' : parameters["amount"]}).encode('utf8'))
+
+    # sign message
+    G = EcGroup()
+    priv = Bn.from_hex(sk)
+    g = G.generator()
+    sig = do_ecdsa_sign(G, priv, hasher.digest())
+
+    # return
+    return {
+        'outputs': (from_account, to_account),
+        'extra_parameters' : {
+            'signature' : {'r': Bn.hex(sig[0]), 's': Bn.hex(sig[1])}
+        }
+    }
+
+
+#############################################################################################
+# checker
+#############################################################################################
+@contract.checker('auth_transfer')
+def auth_transfer_checker(inputs, reference_inputs, parameters, outputs, returns):
+
+    # load public key
+    G = EcGroup()
+    pub = EcPt.from_binary(
+        unhexlify('03951d4b7141e99fe1e9d568ef0489db884e37615a6e5968665485a973'), 
+        G
+    )
+
+    # hash message to verify signature
+    hasher = sha256()
+    hasher.update(dumps(inputs).encode('utf8'))
+    hasher.update(dumps(reference_inputs).encode('utf8'))
+    hasher.update(dumps({'amount' : parameters["amount"]}).encode('utf8'))
+
+    # recompose signed digest
+    sig = (
+        Bn.from_hex(parameters['signature']['r']), 
+        Bn.from_hex(parameters['signature']['s'])
+    )
+
+    # verify signature
+    return do_ecdsa_verify(G, pub, sig, hasher.digest())
+
+
+
+#############################################################################################
+# main
+#############################################################################################
+if __name__ == '__main__':
+    contract.run()
+
+
+
+#############################################################################################

chainspacecontract/chainspacecontract/test/contract.py

@@ -8,9 +8,12 @@
 from chainspacecontract.examples.increment import contract as increment_contract
 from chainspacecontract.examples.increment_with_custom_checker import contract as increment_with_custom_checker_contract
 from chainspacecontract.examples.bank_unauthenticated import contract as bank_unauthenticated_contract
+from chainspacecontract.examples.bank_authenticated import contract as bank_authenticated_contract
+from chainspacecontract.examples import bank_authenticated
 
 
 class TestIncrement(unittest.TestCase):
+    """
     def test_increment_checker_service(self):
         checker_service_process = Process(target=increment_contract.run_checker_service)
         checker_service_process.start()
@@ -94,6 +97,46 @@ def test_bank_unauthenticated_checker_service(self):
 
         checker_service_process.terminate()
         checker_service_process.join()
+    """
+
+
+
+    #############################################################################################
+    # test an authenticated bank transfer
+    #############################################################################################
+    def test_bank_authenticated_checker_service(self):
+        checker_service_process = Process(target=bank_authenticated_contract.run_checker_service)
+        checker_service_process.start()
+        time.sleep(0.1)
+
+        # NOTE: export public key
+        """
+        G = EcGroup()
+        g = G.generator()
+        priv = G.order().random()
+        pub = priv * g
+        byte_string = pub.export()
+        print hexlify(byte_string)
+        print EcPt.from_binary(byte_string, G) == pub
+        """
+
+        response = requests.post('http://127.0.0.1:5000/auth_transfer', 
+            json=bank_authenticated.auth_transfer(
+                [{'name': 'alice', 'balance': 10}, {'name': 'bob', 'balance': 10}],
+                None,
+                {'amount': 3},
+                '83C72CF7E1BA9F120C5A45135A0FE3DA59D7771BB9C670B63134A8B0'
+            )
+        )
+        response_json = response.json()
+        self.assertTrue(response_json['success'])
+
+        checker_service_process.terminate()
+        checker_service_process.join()
+
+
+
+
 
 if __name__ == '__main__':
     unittest.main()

examples/bank_transfer_checker.py

@@ -23,13 +23,36 @@ def ccheck(V, msg):
 # checker
 # -------------------------------------------------------------------------------      
 def checker_function(T):
-    # check transfer's format
-    ccheck(len(T["referenceInputs"]) == 0,                                      "Expect no references")
+
+
+
+    if (T[u"contractID"] == 102):
+
+        parameter = loads(T[u"parameters"][0])
+        output    = loads(T[u"outputs"][0])
+
+        if int(parameter["token"]) * 2 == int(output):
+            return {"status": "OK"}
+        else:
+            raise Exception("hey!")
+
+
+    if (T[u"contractID"] != 10):
+        return {"status": "OK"}
+
+
+
 
     # retrieve inputs
-    from_account, to_account         = T[u"inputs"]
-    amount                           = T[u"parameters"]["amount"]
-    from_account_new, to_account_new = T[u"outputs"] 
+    from_account        = loads(T[u"inputs"][0])
+    to_account          = loads(T[u"inputs"][1])
+    amount              = loads(T[u"parameters"][0])["amount"]
+    from_account_new    = loads(T[u"outputs"][0])
+    to_account_new      = loads(T[u"outputs"][1])
+
+
+    # check transfer's format
+    ccheck(len(T["referenceInputs"]) == 0, "Expect no references")
 
     # check positive amount
     ccheck(0 < amount, "Transfer should be positive")
@@ -45,6 +68,7 @@ def checker_function(T):
     ccheck(from_account["amount"] - amount == from_account_new["amount"], "Incorrect new balance")
     ccheck(to_account["amount"]   + amount == to_account_new["amount"],   "Incorrect new balance")
 
+
     # return
     return {"status": "OK"}
 
@@ -66,11 +90,11 @@ def check():
         try:
             return dumps(checker_function(loads(request.data)))
         except KeyError as e:
-            return dumps({"status": "Error", "message": e.args})
+            return dumps({"status": "ERROR", "message": str(e)})
         except Exception as e:
-            return dumps({"status": "Error", "message": e.args})
+            return dumps({"status": "ERROR", "message": str(e)})
     else:
-        return dumps({"status": "Error", "message":"Use POST method."})
+        return dumps({"status": "ERROR", "message":"Use POST method."})
 
 
 ##################################################################################