C locking callback (#3226)

* Remove Python OpenSSL locking callback and replace it with one in C

The Python OpenSSL locking callback is unsafe; if GC is triggered
during the callback's invocation, it can result in the callback being
invoked reentrantly, which can lead to deadlocks. This patch replaces
it with one in C that gets built at compile time via cffi along with
the rest of the OpenSSL binding.

* fixes for some issues

* unused

* revert these changes

* these two for good measure

* missing param

* sigh, syntax

* delete tests that assumed an ability to mess with locks

* style fixes

* licensing stuff

* utf8

* Unicode. Huh. What it isn't good for, absolutely nothing.

1 files changed, 0 insertions, 65 deletions

diff --git a/tests/hazmat/bindings/test_openssl.py b/tests/hazmat/bindings/test_openssl.py
index 1c395c25..bbdd87ca 100644
--- a/tests/hazmat/bindings/test_openssl.py
+++ b/tests/hazmat/bindings/test_openssl.py
@@ -31,71 +31,6 @@ class TestOpenSSL(object):
         lock_cb = b.lib.CRYPTO_get_locking_callback()
         assert lock_cb != b.ffi.NULL
 
-    def _skip_if_not_fallback_lock(self, b):
-        # only run this test if we are using our locking cb
-        original_cb = b.lib.CRYPTO_get_locking_callback()
-        if original_cb != b._lock_cb_handle:
-            pytest.skip(
-                "Not using the fallback Python locking callback "
-                "implementation. Probably because import _ssl set one"
-            )
-
-    def test_fallback_crypto_lock_via_openssl_api(self):
-        b = Binding()
-        b.init_static_locks()
-
-        self._skip_if_not_fallback_lock(b)
-
-        # check that the lock state changes appropriately
-        lock = b._locks[b.lib.CRYPTO_LOCK_SSL]
-
-        # starts out unlocked
-        assert lock.acquire(False)
-        lock.release()
-
-        b.lib.CRYPTO_lock(
-            b.lib.CRYPTO_LOCK | b.lib.CRYPTO_READ,
-            b.lib.CRYPTO_LOCK_SSL, b.ffi.NULL, 0
-        )
-
-        # becomes locked
-        assert not lock.acquire(False)
-
-        b.lib.CRYPTO_lock(
-            b.lib.CRYPTO_UNLOCK | b.lib.CRYPTO_READ,
-            b.lib.CRYPTO_LOCK_SSL, b.ffi.NULL, 0
-        )
-
-        # then unlocked
-        assert lock.acquire(False)
-        lock.release()
-
-    def test_fallback_crypto_lock_via_binding_api(self):
-        b = Binding()
-        b.init_static_locks()
-
-        self._skip_if_not_fallback_lock(b)
-
-        lock = b._locks[b.lib.CRYPTO_LOCK_SSL]
-
-        with pytest.raises(RuntimeError):
-            b._lock_cb(0, b.lib.CRYPTO_LOCK_SSL, "<test>", 1)
-
-        # errors shouldn't cause locking
-        assert lock.acquire(False)
-        lock.release()
-
-        b._lock_cb(b.lib.CRYPTO_LOCK | b.lib.CRYPTO_READ,
-                   b.lib.CRYPTO_LOCK_SSL, "<test>", 1)
-        # locked
-        assert not lock.acquire(False)
-
-        b._lock_cb(b.lib.CRYPTO_UNLOCK | b.lib.CRYPTO_READ,
-                   b.lib.CRYPTO_LOCK_SSL, "<test>", 1)
-        # unlocked
-        assert lock.acquire(False)
-        lock.release()
-
     def test_add_engine_more_than_once(self):
         b = Binding()
         b._register_osrandom_engine()