Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/test/test_randbytes.py

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+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Test cases for L{twisted.python.randbytes}.
+"""
+
+from __future__ import division, absolute_import
+
+from twisted.trial import unittest
+from twisted.python import randbytes
+
+
+
+class SecureRandomTestCaseBase(object):
+    """
+    Base class for secureRandom test cases.
+    """
+
+    def _check(self, source):
+        """
+        The given random bytes source should return the number of bytes
+        requested each time it is called and should probably not return the
+        same bytes on two consecutive calls (although this is a perfectly
+        legitimate occurrence and rejecting it may generate a spurious failure
+        -- maybe we'll get lucky and the heat death with come first).
+        """
+        for nbytes in range(17, 25):
+            s = source(nbytes)
+            self.assertEqual(len(s), nbytes)
+            s2 = source(nbytes)
+            self.assertEqual(len(s2), nbytes)
+            # This is crude but hey
+            self.assertNotEqual(s2, s)
+
+
+
+class SecureRandomTests(SecureRandomTestCaseBase, unittest.TestCase):
+    """
+    Test secureRandom under normal conditions.
+    """
+
+    def test_normal(self):
+        """
+        L{randbytes.secureRandom} should return a string of the requested
+        length and make some effort to make its result otherwise unpredictable.
+        """
+        self._check(randbytes.secureRandom)
+
+
+
+class ConditionalSecureRandomTests(SecureRandomTestCaseBase,
+                                   unittest.SynchronousTestCase):
+    """
+    Test random sources one by one, then remove it to.
+    """
+
+    def setUp(self):
+        """
+        Create a L{randbytes.RandomFactory} to use in the tests.
+        """
+        self.factory = randbytes.RandomFactory()
+
+
+    def errorFactory(self, nbytes):
+        """
+        A factory raising an error when a source is not available.
+        """
+        raise randbytes.SourceNotAvailable()
+
+
+    def test_osUrandom(self):
+        """
+        L{RandomFactory._osUrandom} should work as a random source whenever
+        L{os.urandom} is available.
+        """
+        self._check(self.factory._osUrandom)
+
+
+    def test_withoutAnything(self):
+        """
+        Remove all secure sources and assert it raises a failure. Then try the
+        fallback parameter.
+        """
+        self.factory._osUrandom = self.errorFactory
+        self.assertRaises(randbytes.SecureRandomNotAvailable,
+                          self.factory.secureRandom, 18)
+        def wrapper():
+            return self.factory.secureRandom(18, fallback=True)
+        s = self.assertWarns(
+            RuntimeWarning,
+            "urandom unavailable - "
+            "proceeding with non-cryptographically secure random source",
+            __file__,
+            wrapper)
+        self.assertEqual(len(s), 18)
+
+
+
+class RandomBaseTests(SecureRandomTestCaseBase, unittest.SynchronousTestCase):
+    """
+    'Normal' random test cases.
+    """
+
+    def test_normal(self):
+        """
+        Test basic case.
+        """
+        self._check(randbytes.insecureRandom)
+
+
+    def test_withoutGetrandbits(self):
+        """
+        Test C{insecureRandom} without C{random.getrandbits}.
+        """
+        factory = randbytes.RandomFactory()
+        factory.getrandbits = None
+        self._check(factory.insecureRandom)
+