From 17b4aa4290cb1098bbd8021bd74de92b1dac5d71 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 24 Sep 2014 12:18:09 -0500 Subject: put BN_CTX_end in a finally to ensure it is invoked --- cryptography/hazmat/backends/openssl/backend.py | 30 +++++++++++++------------ 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index 7da0ae25..959f6559 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -1033,8 +1033,6 @@ class Backend(object): assert bn_ctx != self._ffi.NULL bn_ctx = self._ffi.gc(bn_ctx, self._lib.BN_CTX_free) - self._lib.BN_CTX_start(bn_ctx) - group = self._lib.EC_KEY_get0_group(ctx) assert group != self._ffi.NULL @@ -1048,9 +1046,6 @@ 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 @@ -1060,18 +1055,25 @@ class Backend(object): assert set_func and get_func - res = set_func(group, point, bn_x, bn_y, bn_ctx) - assert res == 1 + try: + self._lib.BN_CTX_start(bn_ctx) - res = get_func(group, point, check_x, check_y, bn_ctx) - assert res == 1 + check_x = self._lib.BN_CTX_get(bn_ctx) + check_y = self._lib.BN_CTX_get(bn_ctx) - assert ( - self._lib.BN_cmp(bn_x, check_x) == 0 and - self._lib.BN_cmp(bn_y, check_y) == 0 - ) - self._lib.BN_CTX_end(bn_ctx) + res = set_func(group, point, bn_x, bn_y, bn_ctx) + assert res == 1 + + 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 + ) + finally: + self._lib.BN_CTX_end(bn_ctx) res = self._lib.EC_KEY_set_public_key(ctx, point) assert res == 1 -- cgit v1.2.3