Add bounds checking for Scrypt parameters. (#3130)
* Add bounds checking for Scrypt parameters.
* Pep8.
* More PEP8.
* Change wording.
diff --git a/docs/hazmat/primitives/key-derivation-functions.rst b/docs/hazmat/primitives/key-derivation-functions.rst
index 03260c0..511708d 100644
--- a/docs/hazmat/primitives/key-derivation-functions.rst
+++ b/docs/hazmat/primitives/key-derivation-functions.rst
@@ -805,6 +805,9 @@
:class:`~cryptography.hazmat.backends.interfaces.ScryptBackend`
:raises TypeError: This exception is raised if ``salt`` is not ``bytes``.
+ :raises ValueError: This exception is raised if ``n`` is less than 2, if
+ ``n`` is not a power of 2, if ``r`` is less than 1 or if ``p`` is less
+ than 1.
.. method:: derive(key_material)