pylibscrypt 1.0.3

Scrypt for Python

There are a lot of different scrypt modules for Python, but none of them have everything that I’d like, so here’s One More1.

Features

• Uses system libscrypt2 as the first choice.

• If that isn’t available, tries the scrypt Python module3.

• Offers a pure Python scrypt implementation for when there’s no C scrypt.

• Not unusably slow, even in pure Python… at least with pypy4. (Around one fifth the C speed, anyway.)

Requirements

• Python 2.7 or 3.4 or so. Pypy 2.2 also works. Older versions may or may not.

• If you want speed: libscrypt 1.8+ (older may work) or py-scrypt 0.6+

Usage

from pylibscrypt import *
# Print a raw scrypt hash in hex
print(scrypt('Hello World', 'salt').encode('hex'))
# Generate an MCF hash with random salt
mcf = scrypt_mcf('Hello World')
# Test it
print(scrypt_mcf_check(mcf, 'Hello World'))
print(scrypt_mcf_check(mcf, 'HelloPyWorld'))

Versioning

The package has a version number that can be read from python like so:

print(pylibscrypt.__version__)

The version number is of the form X.Y.Z. The number X will only be incremented if an incompatible change is done, but this is not planned. The number Y will be incremented for new features or API for which a caller may wish to check. The last number will be incremented for bugfix-only releases.

Development

Development happens on GitHub2. If you find a bug, please open an issue there.

tests.py tests both implementations with some quick tests. Running either implementation directly will also compare to scrypt test vectors from the paper but this is slow for the Python version unless you have pypy. The best way to report a bug is to also provide a new test that fails, but that is not required.

The run_coverage.sh script calls coverage.py5 to report test coverage. If you would like to include a new feature, it should be adequately covered with tests.

TODO

• Embed C implementation for when there’s no system library?