# ===================================================================
#
# Copyright (c) 2019, Legrandin <helderijs@gmail.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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# ===================================================================
import sys
from Cryptodome.Cipher import _create_cipher
from Cryptodome.Util._raw_api import (load_pycryptodome_raw_lib,
VoidPointer, SmartPointer, c_size_t,
c_uint8_ptr, c_uint)
_raw_blowfish_lib = load_pycryptodome_raw_lib(
"Cryptodome.Cipher._raw_eksblowfish",
"""
int EKSBlowfish_start_operation(const uint8_t key[],
size_t key_len,
const uint8_t salt[16],
size_t salt_len,
unsigned cost,
unsigned invert,
void **pResult);
int EKSBlowfish_encrypt(const void *state,
const uint8_t *in,
uint8_t *out,
size_t data_len);
int EKSBlowfish_decrypt(const void *state,
const uint8_t *in,
uint8_t *out,
size_t data_len);
int EKSBlowfish_stop_operation(void *state);
"""
)
def _create_base_cipher(dict_parameters):
"""This method instantiates and returns a smart pointer to
a low-level base cipher. It will absorb named parameters in
the process."""
try:
key = dict_parameters.pop("key")
salt = dict_parameters.pop("salt")
cost = dict_parameters.pop("cost")
except KeyError as e:
raise TypeError("Missing EKSBlowfish parameter: " + str(e))
invert = dict_parameters.pop("invert", True)
if len(key) not in key_size:
raise ValueError("Incorrect EKSBlowfish key length (%d bytes)" % len(key))
start_operation = _raw_blowfish_lib.EKSBlowfish_start_operation
stop_operation = _raw_blowfish_lib.EKSBlowfish_stop_operation
void_p = VoidPointer()
result = start_operation(c_uint8_ptr(key),
c_size_t(len(key)),
c_uint8_ptr(salt),
c_size_t(len(salt)),
c_uint(cost),
c_uint(int(invert)),
void_p.address_of())
if result:
raise ValueError("Error %X while instantiating the EKSBlowfish cipher"
% result)
return SmartPointer(void_p.get(), stop_operation)
def new(key, mode, salt, cost, invert):
"""Create a new EKSBlowfish cipher
Args:
key (bytes, bytearray, memoryview):
The secret key to use in the symmetric cipher.
Its length can vary from 0 to 72 bytes.
mode (one of the supported ``MODE_*`` constants):
The chaining mode to use for encryption or decryption.
salt (bytes, bytearray, memoryview):
The salt that bcrypt uses to thwart rainbow table attacks
cost (integer):
The complexity factor in bcrypt
invert (bool):
If ``False``, in the inner loop use ``ExpandKey`` first over the salt
and then over the key, as defined in
the `original bcrypt specification <https://www.usenix.org/legacy/events/usenix99/provos/provos_html/node4.html>`_.
If ``True``, reverse the order, as in the first implementation of
`bcrypt` in OpenBSD.
:Return: an EKSBlowfish object
"""
kwargs = { 'salt':salt, 'cost':cost, 'invert':invert }
return _create_cipher(sys.modules[__name__], key, mode, **kwargs)
MODE_ECB = 1
# Size of a data block (in bytes)
block_size = 8
# Size of a key (in bytes)
key_size = range(0, 72 + 1)