Docs
diff --git a/docs/fernet.rst b/docs/fernet.rst
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+Fernet
+======
+
+.. currentmodule:: cryptography.fernet
+
+.. testsetup::
+
+ import binascii
+ key = binascii.unhexlify(b"0" * 32)
+
+
+`Fernet`_ is an implementation of symmetric (also known as "secret key")
+authenticated cryptography. Fernet provides guarntees that a message encrypted
+using it cannot be manipulated or read without the key.
+
+.. class:: Fernet(key)
+
+ This class provides both encryption and decryption facilities.
+
+ .. doctest::
+
+ >>> from cryptography.fernet import Fernet
+ >>> f = Fernet(key)
+ >>> ciphertext = f.encrypt(b"my deep dark secret")
+ >>> f.decrypt(ciphertext)
+ 'my deep dark secret'
+
+ :param bytes key: A 32-byte key. This **must** be kept secret. Anyone with
+ this key is able to create and read messages.
+
+
+ .. method:: encrypt(plaintext)
+
+ :param bytes plaintext: The message you would like to encrypt.
+ :returns bytes: A secure message which cannot be read or altered
+ without the key.
+
+ .. method:: decrypt(ciphertext, ttl=None)
+
+ :param bytes ciphertext: An encrypted message.
+ :param int ttl: Optionally, the number of seconds old a message may be
+ for it to be valid. If the message is older than
+ ``ttl`` seconds (from the time it was originally
+ created) an exception will be raised.
+ :returns bytes: The original plaintext.
+
+
+.. _`Fernet`: https://github.com/fernet/spec/
diff --git a/docs/index.rst b/docs/index.rst
index 4fd5d3b..b9c5b5f 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -30,6 +30,7 @@
.. toctree::
:maxdepth: 2
+ fernet
architecture
contributing
security