Always show where a baackend comes form in the docs
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index 2f39017..ef6f087 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -12,9 +12,6 @@
key = binascii.unhexlify(b"0" * 32)
iv = binascii.unhexlify(b"0" * 32)
- from cryptography.hazmat.bindings import default_backend
- backend = default_backend()
-
Symmetric encryption is a way to encrypt (hide the plaintext value) material
where the sender and receiver both use the same key. Note that symmetric
@@ -37,6 +34,8 @@
.. doctest::
>>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+ >>> from cryptography.hazmat.bindings import default_backend
+ >>> backend = default_backend()
>>> cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
>>> encryptor = cipher.encryptor()
>>> ct = encryptor.update(b"a secret message") + encryptor.finalize()
@@ -230,8 +229,9 @@
.. doctest::
>>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+ >>> from cryptography.hazmat.bindings import default_backend
>>> algorithm = algorithms.ARC4(key)
- >>> cipher = Cipher(algorithm, mode=None, backend=backend)
+ >>> cipher = Cipher(algorithm, mode=None, backend=default_backend())
>>> encryptor = cipher.encryptor()
>>> ct = encryptor.update(b"a secret message")
>>> decryptor = cipher.decryptor()
@@ -356,7 +356,8 @@
.. doctest::
>>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
- >>> cipher = Cipher(algorithms.AES(key), modes.GCM(iv), backend)
+ >>> from cryptography.hazmat.bindings import default_backend
+ >>> cipher = Cipher(algorithms.AES(key), modes.GCM(iv), backend=default_backend())
>>> encryptor = cipher.encryptor()
>>> encryptor.authenticate_additional_data(b"authenticated but not encrypted payload")
>>> ct = encryptor.update(b"a secret message") + encryptor.finalize()