Ansible filter plugin to encrypt a string with yescrypt

yescrypt_ctypes.py

# Copyright (c) 2021 Matt Martz <matt@sivel.net>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import ctypes

from ansible.errors import AnsibleFilterError
from ansible.module_utils.common.text.converters import to_bytes, to_text
from ansible.utils.encrypt import random_salt

try:
    _libcrypt = ctypes.CDLL('libcrypt.so.1')
    HAS_LIBCRYPT = True
except OSError:
    HAS_LIBCRYPT = False
else:
    crypt_gensalt = _libcrypt.crypt_gensalt
    crypt_gensalt.argtypes = [ctypes.c_char_p, ctypes.c_long, ctypes.c_char_p, ctypes.c_int]
    crypt_gensalt.restype = ctypes.c_char_p
    crypt = _libcrypt.crypt
    crypt.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
    crypt.restype = ctypes.c_char_p


def yescrypt(word, salt=None, salt_length=20):
    if not HAS_LIBCRYPT:
        raise AnsibleFilterError('cannot locate libcrypt.so.1')
    if not salt:
        setting = crypt_gensalt(
            b'$y$',
            9,
            to_bytes(random_salt(salt_length)),
            salt_length
        )
    else:
        setting = b'$y$jDT$%s' % to_bytes(salt)
    try:
        return to_text(crypt(to_bytes(word), setting))
    except ctypes.ArgumentError as e:
        raise AnsibleFilterError('libcrypt likely missing yescrypt support: %s' % e)


class FilterModule(object):
    def filters(self):
        return {
            'yescrypt': yescrypt,
        }