diff options
| -rw-r--r-- | cryptography/hazmat/backends/openssl/backend.py | 8 | ||||
| -rw-r--r-- | tests/hazmat/backends/test_openssl.py | 19 |
2 files changed, 25 insertions, 2 deletions
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index 021ce8c4..6bf3787a 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -293,7 +293,7 @@ class Backend(object): self._lib.OPENSSL_free(hex_cdata) return int(hex_str, 16) - def _int_to_bn(self, num): + def _int_to_bn(self, num, bn=None): """ Converts a python integer to a BIGNUM. The returned BIGNUM will not be garbage collected (to support adding them to structs that take @@ -301,11 +301,14 @@ class Backend(object): be discarded after use. """ + if bn is None: + bn = self._ffi.NULL + if six.PY3: # Python 3 has constant time to_bytes, so use that. binary = num.to_bytes(int(num.bit_length() / 8.0 + 1), "big") - bn_ptr = self._lib.BN_bin2bn(binary, len(binary), self._ffi.NULL) + bn_ptr = self._lib.BN_bin2bn(binary, len(binary), bn) assert bn_ptr != self._ffi.NULL return bn_ptr @@ -314,6 +317,7 @@ class Backend(object): hex_num = hex(num).rstrip("L").lstrip("0x").encode("ascii") or b"0" bn_ptr = self._ffi.new("BIGNUM **") + bn_ptr[0] = bn res = self._lib.BN_hex2bn(bn_ptr, hex_num) assert res != 0 assert bn_ptr[0] != self._ffi.NULL diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py index 4f682f66..43d28c33 100644 --- a/tests/hazmat/backends/test_openssl.py +++ b/tests/hazmat/backends/test_openssl.py @@ -233,6 +233,25 @@ class TestOpenSSLRandomEngine(object): e = backend._lib.ENGINE_get_default_RAND() assert e == backend._ffi.NULL + def test_int_to_bn(self): + value = (2 ** 4242) - 4242 + bn = backend._int_to_bn(value) + assert bn != backend._ffi.NULL + bn = backend._ffi.gc(bn, backend._lib.BN_free) + + assert bn + assert backend._bn_to_int(bn) == value + + def test_int_to_bn_inplace(self): + value = (2 ** 4242) - 4242 + bn_ptr = backend._lib.BN_new() + assert bn_ptr != backend._ffi.NULL + bn_ptr = backend._ffi.gc(bn_ptr, backend._lib.BN_free) + bn = backend._int_to_bn(value, bn_ptr) + + assert bn == bn_ptr + assert backend._bn_to_int(bn_ptr) == value + class TestOpenSSLRSA(object): @pytest.mark.skipif( |