From 02fd2e51494ad77dfeb1c6725469d76e81003c28 Mon Sep 17 00:00:00 2001
From: Sergi Delgado Segura <sergi.delgado.s@gmail.com>
Date: Fri, 27 Mar 2020 17:27:30 +0100
Subject: [PATCH] Adds gatekeeper unit tests

---
 test/teos/unit/test_gatekeeper.py | 141 ++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 test/teos/unit/test_gatekeeper.py

diff --git a/test/teos/unit/test_gatekeeper.py b/test/teos/unit/test_gatekeeper.py
new file mode 100644
index 0000000..eccc8c8
--- /dev/null
+++ b/test/teos/unit/test_gatekeeper.py
@@ -0,0 +1,141 @@
+import pytest
+
+from teos.gatekeeper import Gatekeeper, IdentificationFailure, NotEnoughSlots
+
+from common.cryptographer import Cryptographer
+
+from test.teos.unit.conftest import get_random_value_hex, generate_keypair
+
+DEFAULT_SLOTS = 42
+gatekeeper = Gatekeeper(DEFAULT_SLOTS)
+
+
+def test_init():
+    assert isinstance(gatekeeper.default_slots, int) and gatekeeper.default_slots == DEFAULT_SLOTS
+    assert isinstance(gatekeeper.registered_users, dict) and len(gatekeeper.registered_users) == 0
+
+
+def test_check_user_pk():
+    # check_user_pk must only accept values that is not a 33-byte hex string
+    for _ in range(100):
+        assert gatekeeper.check_user_pk(get_random_value_hex(33))
+
+
+def test_check_wrong_user_pk():
+    wrong_values = [None, 3, 15.23, "", {}, (), object, str, get_random_value_hex(32), get_random_value_hex(34)]
+
+    # check_user_pk must only accept values that is not a 33-byte hex string
+    for value in wrong_values:
+        assert not gatekeeper.check_user_pk(value)
+
+
+def test_add_update_user():
+    # add_update_user adds DEFAULT_SLOTS to a given user as long as the identifier is a 33-byte hex str
+    user_pk = get_random_value_hex(33)
+
+    for _ in range(10):
+        current_slots = gatekeeper.registered_users.get(user_pk)
+        current_slots = current_slots if current_slots is not None else 0
+
+        gatekeeper.add_update_user(user_pk)
+
+        assert gatekeeper.registered_users.get(user_pk) == current_slots + DEFAULT_SLOTS
+
+    # The same can be checked for multiple users
+    for _ in range(10):
+        # The user identifier is changed every call
+        user_pk = get_random_value_hex(33)
+
+        gatekeeper.add_update_user(user_pk)
+        assert gatekeeper.registered_users.get(user_pk) == DEFAULT_SLOTS
+
+
+def test_add_update_user_wrong_pk():
+    # Passing a wrong pk defaults to the errors in check_user_pk. We can try with one.
+    wrong_pk = get_random_value_hex(32)
+
+    with pytest.raises(ValueError):
+        gatekeeper.add_update_user(wrong_pk)
+
+
+def test_identify_user():
+    # Identify user should return a user_pk for registered users. It raises
+    # IdentificationFailure for invalid parameters or non-registered users.
+
+    # Let's first register a user
+    sk, pk = generate_keypair()
+    compressed_pk = Cryptographer.get_compressed_pk(pk)
+    gatekeeper.add_update_user(compressed_pk)
+
+    message = "Hey, it's me"
+    signature = Cryptographer.sign(message.encode(), sk)
+
+    assert gatekeeper.identify_user(message.encode(), signature) == compressed_pk
+
+
+def test_identify_user_non_registered():
+    # Non-registered user won't be identified
+    sk, pk = generate_keypair()
+
+    message = "Hey, it's me"
+    signature = Cryptographer.sign(message.encode(), sk)
+
+    with pytest.raises(IdentificationFailure):
+        gatekeeper.identify_user(message.encode(), signature)
+
+
+def test_identify_user_invalid_signature():
+    # If the signature does not match the message given a public key, the user won't be identified
+    message = "Hey, it's me"
+    signature = get_random_value_hex(72)
+
+    with pytest.raises(IdentificationFailure):
+        gatekeeper.identify_user(message.encode(), signature)
+
+
+def test_identify_user_wrong():
+    # Wrong parameters shouldn't verify either
+    sk, pk = generate_keypair()
+
+    message = "Hey, it's me"
+    signature = Cryptographer.sign(message.encode(), sk)
+
+    # Non-byte message and str sig
+    with pytest.raises(IdentificationFailure):
+        gatekeeper.identify_user(message, signature)
+
+    # byte message and non-str sig
+    with pytest.raises(IdentificationFailure):
+        gatekeeper.identify_user(message.encode(), signature.encode())
+
+    # non-byte message and non-str sig
+    with pytest.raises(IdentificationFailure):
+        gatekeeper.identify_user(message, signature.encode())
+
+
+def test_fill_slots():
+    # Free slots will decrease the slot count of a user as long as he has enough slots, otherwise raise NotEnoughSlots
+    user_pk = get_random_value_hex(33)
+    gatekeeper.add_update_user(user_pk)
+
+    gatekeeper.fill_slots(user_pk, DEFAULT_SLOTS - 1)
+    assert gatekeeper.registered_users.get(user_pk) == 1
+
+    with pytest.raises(NotEnoughSlots):
+        gatekeeper.fill_slots(user_pk, 2)
+
+    # NotEnoughSlots is also raised if the user does not exist
+    with pytest.raises(NotEnoughSlots):
+        gatekeeper.fill_slots(get_random_value_hex(33), 2)
+
+
+def test_free_slots():
+    # Free slots simply adds slots to the user as long as it exists.
+    user_pk = get_random_value_hex(33)
+    gatekeeper.add_update_user(user_pk)
+    gatekeeper.free_slots(user_pk, 33)
+
+    assert gatekeeper.registered_users.get(user_pk) == DEFAULT_SLOTS + 33
+
+    # Just making sure it does not crash for non-registered user
+    assert gatekeeper.free_slots(get_random_value_hex(33), 10) is None