test__UserFriendlyRNG.py 文件源码

def runTest(self):
        # Regression test for CVE-2013-1445.  We had a bug where, under the
        # right conditions, two processes might see the same random sequence.

        if sys.platform.startswith('win'):  # windows can't fork
            assert not hasattr(os, 'fork')    # ... right?
            return

        # Wait 150 ms so that we don't trigger the rate-limit prematurely.
        time.sleep(0.15)

        reseed_count_before = self._get_reseed_count()

        # One or both of these calls together should trigger a reseed right here.
        Crypto.Random._UserFriendlyRNG._get_singleton().reinit()
        Crypto.Random.get_random_bytes(1)

        reseed_count_after = self._get_reseed_count()
        self.assertNotEqual(reseed_count_before, reseed_count_after)  # sanity check: test should reseed parent before forking

        rfiles = []
        for i in range(10):
            rfd, wfd = os.pipe()
            if os.fork() == 0:
                # child
                os.close(rfd)
                f = os.fdopen(wfd, "wb")

                Crypto.Random.atfork()

                data = Crypto.Random.get_random_bytes(16)

                f.write(data)
                f.close()
                os._exit(0)
            # parent
            os.close(wfd)
            rfiles.append(os.fdopen(rfd, "rb"))

        results = []
        results_dict = {}
        for f in rfiles:
            data = binascii.hexlify(f.read())
            results.append(data)
            results_dict[data] = 1
            f.close()

        if len(results) != len(results_dict.keys()):
            raise AssertionError("RNG output duplicated across fork():\n%s" %
                                 (pprint.pformat(results)))


# For RNGMultiprocessingForkTest