5 files changed, 83 insertions, 3 deletions
diff --git a/cryptography/hazmat/backends/commoncrypto/backend.py b/cryptography/hazmat/backends/commoncrypto/backend.py
index e5d4ee00..523aac82 100644
--- a/cryptography/hazmat/backends/commoncrypto/backend.py
+++ b/cryptography/hazmat/backends/commoncrypto/backend.py
@@ -25,7 +25,7 @@ from cryptography.hazmat.backends.interfaces import (
 from cryptography.hazmat.bindings.commoncrypto.binding import Binding
 from cryptography.hazmat.primitives import interfaces, constant_time
 from cryptography.hazmat.primitives.ciphers.algorithms import (
-    AES, Blowfish, TripleDES, ARC4
+    AES, Blowfish, TripleDES, ARC4, CAST5
 )
 from cryptography.hazmat.primitives.ciphers.modes import (
     CBC, CTR, ECB, OFB, CFB, GCM
@@ -199,6 +199,12 @@ class Backend(object):
                 mode_const
             )
         self._register_cipher_adapter(
+            CAST5,
+            self._lib.kCCAlgorithmCAST,
+            ECB,
+            self._lib.kCCModeECB
+        )
+        self._register_cipher_adapter(
             ARC4,
             self._lib.kCCAlgorithmRC4,
             type(None),
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index fc3c3bda..0e5e92a5 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -26,7 +26,7 @@ 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,
+    AES, Blowfish, Camellia, TripleDES, ARC4, CAST5
 )
 from cryptography.hazmat.primitives.ciphers.modes import (
     CBC, CTR, ECB, OFB, CFB, GCM,
@@ -154,6 +154,11 @@ class Backend(object):
                 GetCipherByName("bf-{mode.name}")
             )
         self.register_cipher_adapter(
+            CAST5,
+            ECB,
+            GetCipherByName("cast5-{mode.name}")
+        )
+        self.register_cipher_adapter(
             ARC4,
             type(None),
             GetCipherByName("rc4")
diff --git a/cryptography/hazmat/primitives/ciphers/algorithms.py b/cryptography/hazmat/primitives/ciphers/algorithms.py
index 19cf1920..a5cfce92 100644
--- a/cryptography/hazmat/primitives/ciphers/algorithms.py
+++ b/cryptography/hazmat/primitives/ciphers/algorithms.py
@@ -90,6 +90,21 @@ class Blowfish(object):
         return len(self.key) * 8
 
 
+@utils.register_interface(interfaces.BlockCipherAlgorithm)
+@utils.register_interface(interfaces.CipherAlgorithm)
+class CAST5(object):
+    name = "CAST5"
+    block_size = 64
+    key_sizes = frozenset(range(40, 129, 8))
+
+    def __init__(self, key):
+        self.key = _verify_key_size(self, key)
+
+    @property
+    def key_size(self):
+        return len(self.key) * 8
+
+
 @utils.register_interface(interfaces.CipherAlgorithm)
 class ARC4(object):
     name = "RC4"
diff --git a/tests/hazmat/primitives/test_cast5.py b/tests/hazmat/primitives/test_cast5.py
new file mode 100644
index 00000000..d65a86b2
--- /dev/null
+++ b/tests/hazmat/primitives/test_cast5.py
@@ -0,0 +1,41 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import, division, print_function
+
+import binascii
+import os
+
+import pytest
+
+from cryptography.hazmat.primitives.ciphers import algorithms, modes
+
+from .utils import generate_encrypt_test
+from ...utils import load_nist_vectors
+
+
+@pytest.mark.supported(
+    only_if=lambda backend: backend.cipher_supported(
+        algorithms.CAST5("\x00" * 16), modes.ECB()
+    ),
+    skip_message="Does not support CAST5 ECB",
+)
+@pytest.mark.cipher
+class TestCAST5(object):
+    test_ECB = generate_encrypt_test(
+        load_nist_vectors,
+        os.path.join("ciphers", "CAST5"),
+        ["cast5-ecb.txt"],
+        lambda key, **kwargs: algorithms.CAST5(binascii.unhexlify((key))),
+        lambda **kwargs: modes.ECB(),
+    )
diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
index 6a7b2f93..50cadf64 100644
--- a/tests/hazmat/primitives/test_ciphers.py
+++ b/tests/hazmat/primitives/test_ciphers.py
@@ -18,7 +18,7 @@ import binascii
 import pytest
 
 from cryptography.hazmat.primitives.ciphers.algorithms import (
-    AES, Camellia, TripleDES, Blowfish, ARC4
+    AES, Camellia, TripleDES, Blowfish, ARC4, CAST5
 )
 
 
@@ -80,6 +80,19 @@ class TestBlowfish(object):
             Blowfish(binascii.unhexlify(b"0" * 6))
 
 
+class TestCAST5(object):
+    @pytest.mark.parametrize(("key", "keysize"), [
+        (b"0" * (keysize // 4), keysize) for keysize in range(40, 129, 8)
+    ])
+    def test_key_size(self, key, keysize):
+        cipher = CAST5(binascii.unhexlify(key))
+        assert cipher.key_size == keysize
+
+    def test_invalid_key_size(self):
+        with pytest.raises(ValueError):
+            CAST5(binascii.unhexlify(b"0" * 34))
+
+
 class TestARC4(object):
     @pytest.mark.parametrize(("key", "keysize"), [
         (b"0" * 10, 40),