rspec/rules/S3329/python/rule.adoc

== Why is this an issue?

include::../description.adoc[]

=== Noncompliant code example

For https://github.com/Legrandin/pycryptodome[PyCryptodome] module:

[source,python]
----
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
from Crypto.Util.Padding import pad, unpad

static_vector = b'x' * AES.block_size
cipher = AES.new(key, AES.MODE_CBC, static_vector)
cipher.encrypt(pad(data, AES.block_size))  # Noncompliant
----

For https://github.com/pyca/cryptography[cryptography] module:

[source,python]
----
from os import urandom
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes

static_vector = b'x' * 16
cipher = Cipher(algorithms.AES(key), modes.CBC(static_vector))
cipher.encryptor()  # Noncompliant
----

=== Compliant solution

For https://github.com/Legrandin/pycryptodome[PyCryptodome] module:

[source,python]
----
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
from Crypto.Util.Padding import pad, unpad

random_vector = get_random_bytes(AES.block_size)
cipher = AES.new(key, AES.MODE_CBC, random_vector)
cipher.encrypt(pad(data, AES.block_size))
----

For https://github.com/pyca/cryptography[cryptography] module:

[source,python]
----
from os import urandom
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes

random_vector = urandom(16)
cipher = Cipher(algorithms.AES(key), modes.CBC(random_vector))
cipher.encryptor()
----

include::../see.adoc[]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

include::../message.adoc[]

'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]
endif::env-github,rspecator-view[]