Merge pull request #214 from reaperhulk/arc4-support

ARC4 Support

1 files changed, 21 insertions, 0 deletions

diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index 5542e832..28b143ba 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -157,6 +157,27 @@ Weak Ciphers
     :param bytes key: The secret key, 32-448 bits in length (in increments of
                       8).  This must be kept secret.
 
+.. class:: ARC4(key)
+
+    ARC4 (Alleged RC4) is a stream cipher with serious weaknesses in its
+    initial stream output. Its use is strongly discouraged. ARC4 does not use
+    mode constructions.
+
+    :param bytes key: The secret key, ``40``, ``56``, ``64``, ``80``, ``128``,
+                      ``192``, or ``256`` bits in length.  This must be kept
+                      secret.
+
+    .. doctest::
+
+        >>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+        >>> algorithm = algorithms.ARC4(key)
+        >>> cipher = Cipher(algorithm, mode=None)
+        >>> encryptor = cipher.encryptor()
+        >>> ct = encryptor.update(b"a secret message")
+        >>> decryptor = cipher.decryptor()
+        >>> decryptor.update(ct)
+        'a secret message'
+
 
 .. _symmetric-encryption-modes: