Refactor add_appointment cli code

apps/cli/pisa_cli.py

@@ -9,8 +9,8 @@ from getopt import getopt, GetoptError
 from requests import ConnectTimeout, ConnectionError
 from uuid import uuid4
 
-from apps.cli.blob import Blob
 from apps.cli.help import help_add_appointment, help_get_appointment
+from apps.cli.blob import Blob
 from apps.cli import (
     DEFAULT_PISA_API_SERVER,
     DEFAULT_PISA_API_PORT,
@@ -22,9 +22,8 @@ from apps.cli import (
 
 from common.logger import Logger
 from common.appointment import Appointment
-from common.constants import LOCATOR_LEN_HEX
 from common.cryptographer import Cryptographer
-from common.tools import check_sha256_hex_format
+from common.tools import check_sha256_hex_format, compute_locator
 
 
 HTTP_OK = 200
@@ -46,11 +45,13 @@ def generate_dummy_appointment():
         "to_self_delay": 20,
     }
 
-    print("Generating dummy appointment data:" "\n\n" + json.dumps(dummy_appointment_data, indent=4, sort_keys=True))
+    logger.info(
+        "Generating dummy appointment data:" "\n\n" + json.dumps(dummy_appointment_data, indent=4, sort_keys=True)
+    )
 
     json.dump(dummy_appointment_data, open("dummy_appointment_data.json", "w"))
 
-    print("\nData stored in dummy_appointment_data.json")
+    logger.info("\nData stored in dummy_appointment_data.json")
 
 
 # Loads and returns Pisa keys from disk
@@ -61,11 +62,12 @@ def load_key_file_data(file_name):
         return key
 
     except FileNotFoundError:
-        raise FileNotFoundError("File not found.")
+        logger.error("Client's key file not found. Please check your settings.")
+        return False
 
-
+    except IOError as e:
-def compute_locator(tx_id):
+        logger.error("I/O error({}): {}".format(e.errno, e.strerror))
-    return tx_id[:LOCATOR_LEN_HEX]
+        return False
 
 
 # Makes sure that the folder APPOINTMENTS_FOLDER_NAME exists, then saves the appointment and signature in it.
@@ -85,12 +87,81 @@ def save_signed_appointment(appointment, signature):
 
 
 def add_appointment(args):
-    appointment_data = None
+    # Get appointment data from user.
+    appointment_data = parse_add_appointment_args(args)
+
+    if appointment_data is None:
+        logger.error("The provided appointment JSON is empty")
+        return False
+
+    valid_txid = check_sha256_hex_format(appointment_data.get("tx_id"))
+
+    if not valid_txid:
+        logger.error("The provided txid is not valid")
+        return False
+
+    tx_id = appointment_data.get("tx_id")
+    tx = appointment_data.get("tx")
+
+    if None not in [tx_id, tx]:
+        appointment_data["locator"] = compute_locator(tx_id)
+        appointment_data["encrypted_blob"] = Cryptographer.encrypt(Blob(tx), tx_id)
+
+    else:
+        logger.error("Appointment data is missing some fields.")
+        return False
+
+    appointment = Appointment.from_dict(appointment_data)
+
+    signature = get_appointment_signature(appointment)
+    hex_pk_der = get_pk()
+
+    if not (appointment and signature and hex_pk_der):
+        return False
+
+    data = {"appointment": appointment.to_dict(), "signature": signature, "public_key": hex_pk_der.decode("utf-8")}
+
+    appointment_json = json.dumps(data, sort_keys=True, separators=(",", ":"))
+
+    # Send appointment to the server.
+    add_appointment_endpoint = "http://{}:{}".format(pisa_api_server, pisa_api_port)
+    response_json = post_data_to_add_appointment_endpoint(add_appointment_endpoint, appointment_json)
+
+    if response_json is None:
+        return False
+
+    signature = response_json.get("signature")
+    # Check that the server signed the appointment as it should.
+    if signature is None:
+        logger.error("The response does not contain the signature of the appointment.")
+        return False
+
+    valid = check_signature(signature, appointment)
+
+    if not valid:
+        logger.error("The returned appointment's signature is invalid")
+        return False
+
+    logger.info("Appointment accepted and signed by Pisa")
+    # all good, store appointment and signature
+    try:
+        save_signed_appointment(appointment.to_dict(), signature)
+
+    except OSError as e:
+        logger.error("There was an error while saving the appointment", error=e)
+        return False
+
+    return True
+
+
+# Parse arguments passed to add_appointment and handle them accordingly.
+# Returns appointment data.
+def parse_add_appointment_args(args):
     use_help = "Use 'help add_appointment' for help of how to use the command"
 
     if not args:
         logger.error("No appointment data provided. " + use_help)
-        return False
+        return None
 
     arg_opt = args.pop(0)
 
@@ -102,7 +173,7 @@ def add_appointment(args):
             fin = args.pop(0)
             if not os.path.isfile(fin):
                 logger.error("Can't find file", filename=fin)
-                return False
+                return None
 
             try:
                 with open(fin) as f:
@@ -110,63 +181,19 @@ def add_appointment(args):
 
             except IOError as e:
                 logger.error("I/O error", errno=e.errno, error=e.strerror)
-                return False
+                return None
         else:
             appointment_data = json.loads(arg_opt)
 
     except json.JSONDecodeError:
         logger.error("Non-JSON encoded data provided as appointment. " + use_help)
-        return False
+        return None
 
-    if not appointment_data:
+    return appointment_data
-        logger.error("The provided JSON is empty")
-        return False
 
-    valid_locator = check_sha256_hex_format(appointment_data.get("tx_id"))
-
-    if not valid_locator:
-        logger.error("The provided locator is not valid")
-        return False
-
-    add_appointment_endpoint = "http://{}:{}".format(pisa_api_server, pisa_api_port)
-    appointment = Appointment.from_dict(appointment_data)
-
-    try:
-        sk_der = load_key_file_data(CLI_PRIVATE_KEY)
-        cli_sk = Cryptographer.load_private_key_der(sk_der)
-
-    except ValueError:
-        logger.error("Failed to deserialize the public key. It might be in an unsupported format")
-        return False
-
-    except FileNotFoundError:
-        logger.error("Client's private key file not found. Please check your settings")
-        return False
-
-    except IOError as e:
-        logger.error("I/O error", errno=e.errno, error=e.strerror)
-        return False
-
-    signature = Cryptographer.sign(appointment.serialize(), cli_sk)
-
-    try:
-        cli_pk_der = load_key_file_data(CLI_PUBLIC_KEY)
-        hex_pk_der = binascii.hexlify(cli_pk_der)
-
-    except FileNotFoundError:
-        logger.error("Client's public key file not found. Please check your settings")
-        return False
-
-    except IOError as e:
-        logger.error("I/O error", errno=e.errno, error=e.strerror)
-        return False
-
-    # FIXME: Exceptions for hexlify need to be covered
-
-    data = {"appointment": appointment, "signature": signature, "public_key": hex_pk_der.decode("utf-8")}
-
-    appointment_json = json.dumps(data, sort_keys=True, separators=(",", ":"))
 
+# Sends appointment data to add_appointment endpoint to be processed by the server.
+def post_data_to_add_appointment_endpoint(add_appointment_endpoint, appointment_json):
     logger.info("Sending appointment to PISA")
 
     try:
@@ -176,15 +203,15 @@ def add_appointment(args):
 
     except json.JSONDecodeError:
         logger.error("The response was not valid JSON")
-        return False
+        return None
 
     except ConnectTimeout:
         logger.error("Can't connect to pisa API. Connection timeout")
-        return False
+        return None
 
     except ConnectionError:
         logger.error("Can't connect to pisa API. Server cannot be reached")
-        return False
+        return None
 
     if r.status_code != HTTP_OK:
         if "error" not in response_json:
@@ -196,14 +223,17 @@ def add_appointment(args):
                 status_code=r.status_code,
                 description=error,
             )
-        return False
+        return None
 
     if "signature" not in response_json:
         logger.error("The response does not contain the signature of the appointment")
-        return False
+        return None
 
-    signature = response_json["signature"]
+    return response_json
-    # verify that the returned signature is valid
+
+
+# Verify that the signature returned from the watchtower is valid.
+def check_signature(signature, appointment):
     try:
         pisa_pk_der = load_key_file_data(PISA_PUBLIC_KEY)
         pisa_pk = Cryptographer.load_public_key_der(pisa_pk_der)
@@ -212,7 +242,7 @@ def add_appointment(args):
             logger.error("Failed to deserialize the public key. It might be in an unsupported format")
             return False
 
-        is_sig_valid = Cryptographer.verify(appointment.serialize(), signature, pisa_pk)
+        return Cryptographer.verify(appointment.serialize(), signature, pisa_pk)
 
     except FileNotFoundError:
         logger.error("Pisa's public key file not found. Please check your settings")
@@ -222,21 +252,6 @@ def add_appointment(args):
         logger.error("I/O error", errno=e.errno, error=e.strerror)
         return False
 
-    if not is_sig_valid:
-        logger.error("The returned appointment's signature is invalid")
-        return False
-
-    logger.info("Appointment accepted and signed by Pisa")
-    # all good, store appointment and signature
-    try:
-        save_signed_appointment(appointment, signature)
-
-    except OSError as e:
-        logger.error("There was an error while saving the appointment", error=e)
-        return False
-
-    return True
-
 
 def get_appointment(args):
     if not args:
@@ -260,8 +275,9 @@ def get_appointment(args):
 
     try:
         r = requests.get(url=get_appointment_endpoint + parameters, timeout=5)
+        logger.info("Appointment response returned from server: " + str(r))
+        return True
 
-        print(json.dumps(r.json(), indent=4, sort_keys=True))
     except ConnectTimeout:
         logger.error("Can't connect to pisa API. Connection timeout")
         return False
@@ -270,7 +286,47 @@ def get_appointment(args):
         logger.error("Can't connect to pisa API. Server cannot be reached")
         return False
 
-    return True
+
+def get_appointment_signature(appointment):
+    try:
+        sk_der = load_key_file_data(CLI_PRIVATE_KEY)
+        cli_sk = Cryptographer.load_private_key_der(sk_der)
+
+        signature = Cryptographer.sign(appointment.serialize(), cli_sk)
+
+        return signature
+
+    except ValueError:
+        logger.error("Failed to deserialize the public key. It might be in an unsupported format")
+        return False
+
+    except FileNotFoundError:
+        logger.error("Client's private key file not found. Please check your settings")
+        return False
+
+    except IOError as e:
+        logger.error("I/O error", errno=e.errno, error=e.strerror)
+        return False
+
+
+def get_pk():
+    try:
+        cli_pk_der = load_key_file_data(CLI_PUBLIC_KEY)
+        hex_pk_der = binascii.hexlify(cli_pk_der)
+
+        return hex_pk_der
+
+    except FileNotFoundError:
+        logger.error("Client's public key file not found. Please check your settings")
+        return False
+
+    except IOError as e:
+        logger.error("I/O error", errno=e.errno, error=e.strerror)
+        return False
+
+    except binascii.Error as e:
+        logger.error("Could not successfully encode public key as hex: ", e)
+        return False
 
 
 def show_usage():

common/tools.py

@@ -1,4 +1,5 @@
 import re
+from common.constants import LOCATOR_LEN_HEX
 
 
 def check_sha256_hex_format(value):
@@ -12,3 +13,15 @@ def check_sha256_hex_format(value):
         :mod:`bool`: Whether or not the value matches the format.
     """
     return isinstance(value, str) and re.match(r"^[0-9A-Fa-f]{64}$", value) is not None
+
+
+def compute_locator(tx_id):
+    """
+    Computes an appointment locator given a transaction id.
+    Args:
+        tx_id (:obj:`str`): the transaction id used to compute the locator.
+    Returns:
+       (:obj:`str`): The computed locator.
+    """
+
+    return tx_id[:LOCATOR_LEN_HEX]

pisa/watcher.py

@@ -3,7 +3,7 @@ from queue import Queue
 from threading import Thread
 
 from common.cryptographer import Cryptographer
-from common.constants import LOCATOR_LEN_HEX
+from common.tools import compute_locator
 
 from common.logger import Logger
 from pisa.cleaner import Cleaner
@@ -71,20 +71,6 @@ class Watcher:
         if not isinstance(responder, Responder):
             self.responder = Responder(db_manager)
 
-    @staticmethod
-    def compute_locator(tx_id):
-        """
-        Computes an appointment locator given a transaction id.
-
-        Args:
-            tx_id (:obj:`str`): the transaction id used to compute the locator.
-
-        Returns:
-           (:obj:`str`): The computed locator.
-        """
-
-        return tx_id[:LOCATOR_LEN_HEX]
-
     def add_appointment(self, appointment):
         """
         Adds a new appointment to the ``appointments`` dictionary if ``max_appointments`` has not been reached.
@@ -238,7 +224,7 @@ class Watcher:
             found.
         """
 
-        potential_locators = {Watcher.compute_locator(txid): txid for txid in txids}
+        potential_locators = {compute_locator(txid): txid for txid in txids}
 
         # Check is any of the tx_ids in the received block is an actual match
         intersection = set(self.locator_uuid_map.keys()).intersection(potential_locators.keys())

test/pisa/unit/conftest.py

@@ -16,6 +16,7 @@ from pisa.watcher import Watcher
 from pisa.tools import bitcoin_cli
 from pisa.db_manager import DBManager
 from common.appointment import Appointment
+from common.tools import compute_locator
 
 from bitcoind_mock.utils import sha256d
 from bitcoind_mock.transaction import TX
@@ -103,7 +104,7 @@ def generate_dummy_appointment_data(real_height=True, start_time_offset=5, end_t
         encoding=serialization.Encoding.DER, format=serialization.PublicFormat.SubjectPublicKeyInfo
     )
 
-    locator = Watcher.compute_locator(dispute_txid)
+    locator = compute_locator(dispute_txid)
     blob = Blob(dummy_appointment_data.get("tx"))
 
     encrypted_blob = Cryptographer.encrypt(blob, dummy_appointment_data.get("tx_id"))

test/pisa/unit/test_watcher.py

@@ -16,7 +16,7 @@ from test.pisa.unit.conftest import (
 )
 from pisa.conf import EXPIRY_DELTA, MAX_APPOINTMENTS
 
-from common.tools import check_sha256_hex_format
+from common.tools import check_sha256_hex_format, compute_locator
 from common.cryptographer import Cryptographer
 
 
@@ -46,7 +46,7 @@ def txids():
 
 @pytest.fixture(scope="module")
 def locator_uuid_map(txids):
-    return {Watcher.compute_locator(txid): uuid4().hex for txid in txids}
+    return {compute_locator(txid): uuid4().hex for txid in txids}
 
 
 def create_appointments(n):
@@ -219,7 +219,7 @@ def test_filter_valid_breaches(watcher):
 
     dummy_appointment, _ = generate_dummy_appointment()
     dummy_appointment.encrypted_blob.data = encrypted_blob
-    dummy_appointment.locator = Watcher.compute_locator(dispute_txid)
+    dummy_appointment.locator = compute_locator(dispute_txid)
     uuid = uuid4().hex
 
     appointments = {uuid: dummy_appointment}