Validate UUID for tankerkoenig (#32805)

* Validate UUIDs against custom validator

Instead of just validating against strings, use a custom validator,
so that the format can be checked.

* Add tests for custom UUID4 validator

homeassistant/components/tankerkoenig/__init__.py

@@ -1,6 +1,7 @@
 """Ask tankerkoenig.de for petrol price information."""
 from datetime import timedelta
 import logging
+from uuid import UUID
 
 import pytankerkoenig
 import voluptuous as vol
@@ -24,11 +25,26 @@ _LOGGER = logging.getLogger(__name__)
 DEFAULT_RADIUS = 2
 DEFAULT_SCAN_INTERVAL = timedelta(minutes=30)
 
+
+def uuid4_string(value):
+    """Validate a v4 UUID in string format."""
+    try:
+        result = UUID(value, version=4)
+    except (ValueError, AttributeError, TypeError) as error:
+        raise vol.Invalid("Invalid Version4 UUID", error_message=str(error))
+
+    if str(result) != value.lower():
+        # UUID() will create a uuid4 if input is invalid
+        raise vol.Invalid("Invalid Version4 UUID")
+
+    return str(result)
+
+
 CONFIG_SCHEMA = vol.Schema(
     {
         DOMAIN: vol.Schema(
             {
-                vol.Required(CONF_API_KEY): cv.string,
+                vol.Required(CONF_API_KEY): uuid4_string,
                 vol.Optional(
                     CONF_SCAN_INTERVAL, default=DEFAULT_SCAN_INTERVAL
                 ): cv.time_period,
@@ -49,7 +65,7 @@ CONFIG_SCHEMA = vol.Schema(
                     cv.positive_int, vol.Range(min=1)
                 ),
                 vol.Optional(CONF_STATIONS, default=[]): vol.All(
-                    cv.ensure_list, [cv.string]
+                    cv.ensure_list, [uuid4_string]
                 ),
             }
         )

requirements_test_all.txt

@@ -588,6 +588,9 @@ pysonos==0.0.24
 # homeassistant.components.spc
 pyspcwebgw==0.4.0
 
+# homeassistant.components.tankerkoenig
+pytankerkoenig==0.0.6
+
 # homeassistant.components.ecobee
 python-ecobee-api==0.2.2
 

tests/components/tankerkoenig/__init__.py

@@ -0,0 +1 @@
+"""Tests for the tankerkoenig integration."""

tests/components/tankerkoenig/test_tankerkoenig_validators.py

@@ -0,0 +1,32 @@
+"""The tests for the custom tankerkoenig validators."""
+import unittest
+import uuid
+
+import pytest
+import voluptuous as vol
+
+from homeassistant.components.tankerkoenig import uuid4_string
+
+
+class TestUUID4StringValidator(unittest.TestCase):
+    """Test the UUID4 string custom validator."""
+
+    def test_uuid4_string(caplog):
+        """Test string uuid validation."""
+        schema = vol.Schema(uuid4_string)
+
+        for value in ["Not a hex string", "0", 0]:
+            with pytest.raises(vol.Invalid):
+                schema(value)
+
+        with pytest.raises(vol.Invalid):
+            # the third block should start with 4
+            schema("a03d31b2-2eee-2acc-bb90-eec40be6ed23")
+
+        with pytest.raises(vol.Invalid):
+            # the fourth block should start with 8-a
+            schema("a03d31b2-2eee-4acc-1b90-eec40be6ed23")
+
+        _str = str(uuid.uuid4())
+        assert schema(_str) == _str
+        assert schema(_str.upper()) == _str