Check that public_exponent is odd

1 files changed, 6 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/asymmetric/rsa.py b/cryptography/hazmat/primitives/asymmetric/rsa.py
index 9124757a..1b33eaab 100644
--- a/cryptography/hazmat/primitives/asymmetric/rsa.py
+++ b/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -43,6 +43,9 @@ class RSAPublicKey(object):
         if public_exponent < 3 or public_exponent >= modulus:
             raise ValueError("public_exponent must be >= 3 and < modulus")
 
+        if public_exponent & 1 == 0:
+            raise ValueError("public_exponent must be odd")
+
         self._public_exponent = public_exponent
         self._modulus = modulus
 
@@ -94,6 +97,9 @@ class RSAPrivateKey(object):
         if public_exponent < 3 or public_exponent >= modulus:
             raise ValueError("public_exponent must be >= 3 and < modulus")
 
+        if public_exponent & 1 == 0:
+            raise ValueError("public_exponent must be odd")
+
         if p * q != modulus:
             raise ValueError("p*q must equal modulus")