Merge pull request #782 from reaperhulk/enable-idea-cipher

Enable IDEA cipher

2 files changed, 21 insertions, 4 deletions

diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index b4625aae..bdbbffd6 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -28,7 +28,7 @@ from cryptography.hazmat.bindings.openssl.binding import Binding
 from cryptography.hazmat.primitives import interfaces, hashes
 from cryptography.hazmat.primitives.asymmetric import rsa
 from cryptography.hazmat.primitives.ciphers.algorithms import (
-    AES, Blowfish, Camellia, TripleDES, ARC4, CAST5
+    AES, Blowfish, Camellia, CAST5, TripleDES, ARC4, IDEA
 )
 from cryptography.hazmat.primitives.ciphers.modes import (
     CBC, CTR, ECB, OFB, CFB, GCM,
@@ -159,11 +159,14 @@ class Backend(object):
                 mode_cls,
                 GetCipherByName("bf-{mode.name}")
             )
-        for mode_cls in [CBC, CFB, OFB, ECB]:
+        for cipher_cls, mode_cls in itertools.product(
+            [CAST5, IDEA],
+            [CBC, OFB, CFB, ECB],
+        ):
             self.register_cipher_adapter(
-                CAST5,
+                cipher_cls,
                 mode_cls,
-                GetCipherByName("cast5-{mode.name}")
+                GetCipherByName("{cipher.name}-{mode.name}")
             )
         self.register_cipher_adapter(
             ARC4,
diff --git a/cryptography/hazmat/primitives/ciphers/algorithms.py b/cryptography/hazmat/primitives/ciphers/algorithms.py
index a5cfce92..2d37e0cf 100644
--- a/cryptography/hazmat/primitives/ciphers/algorithms.py
+++ b/cryptography/hazmat/primitives/ciphers/algorithms.py
@@ -116,3 +116,17 @@ class ARC4(object):
     @property
     def key_size(self):
         return len(self.key) * 8
+
+
+@utils.register_interface(interfaces.CipherAlgorithm)
+class IDEA(object):
+    name = "IDEA"
+    block_size = 64
+    key_sizes = frozenset([128])
+
+    def __init__(self, key):
+        self.key = _verify_key_size(self, key)
+
+    @property
+    def key_size(self):
+        return len(self.key) * 8