Replace floating point arithmetic with integer arithmetic (#5181)

2 files changed, 2 insertions, 5 deletions

diff --git a/src/cryptography/hazmat/backends/openssl/rsa.py b/src/cryptography/hazmat/backends/openssl/rsa.py
index 3e4c2fd2..458071ca 100644
--- a/src/cryptography/hazmat/backends/openssl/rsa.py
+++ b/src/cryptography/hazmat/backends/openssl/rsa.py
@@ -4,8 +4,6 @@
 
 from __future__ import absolute_import, division, print_function
 
-import math
-
 from cryptography import utils
 from cryptography.exceptions import (
     InvalidSignature, UnsupportedAlgorithm, _Reasons
@@ -352,7 +350,7 @@ class _RSAPrivateKey(object):
         return _RSASignatureContext(self._backend, self, padding, algorithm)
 
     def decrypt(self, ciphertext, padding):
-        key_size_bytes = int(math.ceil(self.key_size / 8.0))
+        key_size_bytes = (self.key_size + 7) // 8
         if key_size_bytes != len(ciphertext):
             raise ValueError("Ciphertext length must be equal to key size.")
 
diff --git a/src/cryptography/hazmat/primitives/asymmetric/padding.py b/src/cryptography/hazmat/primitives/asymmetric/padding.py
index a37c3f90..828e03bc 100644
--- a/src/cryptography/hazmat/primitives/asymmetric/padding.py
+++ b/src/cryptography/hazmat/primitives/asymmetric/padding.py
@@ -5,7 +5,6 @@
 from __future__ import absolute_import, division, print_function
 
 import abc
-import math
 
 import six
 
@@ -73,7 +72,7 @@ def calculate_max_pss_salt_length(key, hash_algorithm):
     if not isinstance(key, (rsa.RSAPrivateKey, rsa.RSAPublicKey)):
         raise TypeError("key must be an RSA public or private key")
     # bit length - 1 per RFC 3447
-    emlen = int(math.ceil((key.key_size - 1) / 8.0))
+    emlen = (key.key_size + 6) // 8
     salt_length = emlen - hash_algorithm.digest_size - 2
     assert salt_length >= 0
     return salt_length