diff options
Diffstat (limited to 'cryptography/hazmat/backends/openssl/backend.py')
| -rw-r--r-- | cryptography/hazmat/backends/openssl/backend.py | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index 7e619a10..cb988ac9 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -16,6 +16,7 @@ from __future__ import absolute_import, division, print_function import collections import itertools import warnings +from contextlib import contextmanager import six @@ -1012,6 +1013,17 @@ class Backend(object): ) return curve_nid + @contextmanager + def _bn_ctx_manager(self): + bn_ctx = self._lib.BN_CTX_new() + assert bn_ctx != self._ffi.NULL + bn_ctx = self._ffi.gc(bn_ctx, self._lib.BN_CTX_free) + try: + self._lib.BN_CTX_start(bn_ctx) + yield bn_ctx + finally: + self._lib.BN_CTX_end(bn_ctx) + def _ec_key_set_public_key_affine_coordinates(self, ctx, x, y): """ This is a port of EC_KEY_set_public_key_affine_coordinates that was @@ -1029,10 +1041,6 @@ class Backend(object): nid_two_field = self._lib.OBJ_sn2nid(b"characteristic-two-field") assert nid_two_field != self._lib.NID_undef - bn_ctx = self._lib.BN_CTX_new() - assert bn_ctx != self._ffi.NULL - bn_ctx = self._ffi.gc(bn_ctx, self._lib.BN_CTX_free) - group = self._lib.EC_KEY_get0_group(ctx) assert group != self._ffi.NULL @@ -1046,9 +1054,6 @@ class Backend(object): nid = self._lib.EC_METHOD_get_field_type(method) assert nid != self._lib.NID_undef - check_x = self._lib.BN_CTX_get(bn_ctx) - check_y = self._lib.BN_CTX_get(bn_ctx) - if nid == nid_two_field and self._lib.Cryptography_HAS_EC2M: set_func = self._lib.EC_POINT_set_affine_coordinates_GF2m get_func = self._lib.EC_POINT_get_affine_coordinates_GF2m @@ -1058,16 +1063,20 @@ class Backend(object): assert set_func and get_func - res = set_func(group, point, bn_x, bn_y, bn_ctx) - assert res == 1 + with self._bn_ctx_manager() as bn_ctx: + check_x = self._lib.BN_CTX_get(bn_ctx) + check_y = self._lib.BN_CTX_get(bn_ctx) - res = get_func(group, point, check_x, check_y, bn_ctx) - assert res == 1 + res = set_func(group, point, bn_x, bn_y, bn_ctx) + assert res == 1 - assert ( - self._lib.BN_cmp(bn_x, check_x) == 0 and - self._lib.BN_cmp(bn_y, check_y) == 0 - ) + res = get_func(group, point, check_x, check_y, bn_ctx) + assert res == 1 + + assert ( + self._lib.BN_cmp(bn_x, check_x) == 0 and + self._lib.BN_cmp(bn_y, check_y) == 0 + ) res = self._lib.EC_KEY_set_public_key(ctx, point) assert res == 1 |