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== How to fix it in pyca
=== Code examples
include::../../common/fix/code-rationale.adoc[]
==== Noncompliant code example
[source,python,diff-id=2,diff-type=noncompliant]
----
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives import hashes
digest = PBKDF2HMAC(hashes.SHA256(), length=32, salt=b"F3MdWpeHeeSjlUxvKBnzzA", iterations=100000).derive(password)
----
==== Compliant solution
[source,python,diff-id=2,diff-type=compliant]
----
import secrets
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives import hashes
salt = secrets.token_bytes(32)
digest = PBKDF2HMAC(hashes.SHA256(), length=32, salt=salt, iterations=100000).derive(password)
----
=== How does this work?
include::../../common/fix/salt.adoc[]
Here, the compliant code example ensures the salt is random and has a sufficient
length by calling the `secrets.token_bytes` function. This one internally uses a
cryptographically secure pseudo random number generator.