add SEED docs, tests, small fixes

1 files changed, 11 insertions, 1 deletions

diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
index 9f8123eb..99ef043a 100644
--- a/tests/hazmat/primitives/test_ciphers.py
+++ b/tests/hazmat/primitives/test_ciphers.py
@@ -20,7 +20,7 @@ import pytest
 from cryptography.exceptions import _Reasons
 from cryptography.hazmat.primitives import ciphers
 from cryptography.hazmat.primitives.ciphers.algorithms import (
-    AES, ARC4, Blowfish, CAST5, Camellia, IDEA, TripleDES
+    AES, ARC4, Blowfish, CAST5, Camellia, IDEA, SEED, TripleDES
 )
 from cryptography.hazmat.primitives.ciphers.modes import ECB
 
@@ -127,6 +127,16 @@ class TestIDEA(object):
             IDEA(b"\x00" * 17)
 
 
+class TestSEED(object):
+    def test_key_size(self):
+        cipher = SEED(b"\x00" * 16)
+        assert cipher.key_size == 128
+
+    def test_invalid_key_size(self):
+        with pytest.raises(ValueError):
+            SEED(b"\x00" * 17)
+
+
 def test_invalid_backend():
     pretend_backend = object()