gostcrypto 1.1.0

GOST cryptographic functions

The package implements various cryptographic functions defined in the State standards of the Russian Federation. It includes the following modules:

• gosthash: The module implements functions for calculating hash amounts in accordance with GOST R 34.11-2012.

• gostcipher: The module implements block encryption functions in accordance with GOST R 34.12-2015 and their use modes in accordance with GOST R 34.13-2015.

• gostsignature: The module implements the functions of forming and verifying an electronic digital signature in accordance with GOST R 34.10-2012.

• gostrandom: The module implements functions for generating pseudo-random sequences in accordance with R 1323565.1.006-2017.

• gosthmac: The module implements the functions of calculating the HMAC message authentication code in accordance with R 50.1.113-2016.

• gostpbkdf: The module implements the password-based key derivation function in accordance with R 50.1.111-2016.

Installation

$ pip install gostcrypto

Usage ‘gosthash’ module

Getting a hash for a string

import gostcrypto

hash_string = u'Се ветри, Стрибожи внуци, веютъ с моря стрелами на храбрыя плъкы Игоревы'.encode('cp1251')
hash_obj = gostcrypto.gosthash.new('streebog256')
hash_obj.update(hash_string)
result = hash_obj.hexdigest()

Getting a hash for a file

In this case the buffer_size value must be a multiple of the block_size value.

import gostcrypto

file_path = 'd:/hash file.txt'
buffer_size = 128
hash_obj = gostcrypto.gosthash.new('streebog512')
with open(file_path, 'rb') as file:
    buffer = file.read(buffer_size)
    while len(buffer) > 0:
        hash_obj.update(buffer)
        buffer = file.read(buffer_size)
result = hash_obj.hexdigest()

Usage ‘gostcipher’ module

String encryption in ECB mode

import gostcrypto

key = bytearray([
    0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
    0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
])

plain_text = = bytearray([
    0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x00, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99, 0x88,
    0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xee, 0xff, 0x0a,
    0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xee, 0xff, 0x0a, 0x00,
    0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xee, 0xff, 0x0a, 0x00, 0x11,
])

cipher_obj = gostcrypto.gostcipher.new('kuznechik',
                                        key,
                                        gostcrypto.gostcipher.MODE_ECB,
                                        pad_mode=PAD_MODE_1)

cipher_text = cipher_obj.encrypt(plain_text)

File encryption in CTR mode

In this case the buffer_size value must be a multiple of the block_size value.

import gostcrypto

key = bytearray([
    0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
    0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
])

init_vect = bytearray([
    0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xce, 0xf0,
])

plain_file_path = 'd:/plain file.txt'
    cipher_file_path = 'd:/cipher file.txt'
cipher_obj = gostcrypto.gostcipher.new('kuznechik',
                                        key,
                                        gostcrypto.gostcipher.MODE_CTR,
                                        init_vect=init_vect)

buffer_size = 128
plain_file = open(plain_file_path, 'rb')
cipher_file = open(cipher_file_path', 'wb')
buffer = plain_file.read(buffer_size)
while len(buffer) > 0:
    cipher_data = cipher.decrypt(buffer)
    cipher_file.write(cipher_data)
    buffer = plain_file.read(buffer_size)

Calculating MAC of the file

In this case the buffer_size value must be a multiple of the block_size value.

import gostcrypto

key = bytearray([
    0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
    0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
])

file_path = 'd:/file.txt'
cipher = gostcrypto.gostcipher.new('kuznechik',
                                    key,
                                    gostcrypto.gostcipher.MODE_MAC)

    buffer_size = 128
    file = open(file_path, 'rb')
buffer = file.read(buffer_size)
while len(buffer) > 0:
    cipher.update(buffer)
    buffer = file.read(buffer_size)
mac_result = cipher.digest(8)

Usage ‘gostsignature’ module

Signing

import gostcrypto

private_key = bytearray.fromhex('7a929ade789bb9be10ed359dd39a72c11b60961f49397eee1d19ce9891ec3b28')
digest = bytearray.fromhex('2dfbc1b372d89a1188c09c52e0eec61fce52032ab1022e8e67ece6672b043ee5')

sign_obj = gostcrypto.gostsignature.new(gostcrypto.gostsignature.MODE_256,
                                        gostcrypto.gostsignature.CURVES_R_1323565_1_024_2019['id-tc26-gost-3410-2012-256-paramSetB'])

signature = sign_obj.sign(private_key, digest)

Verify

import gostcrypto

public_key = bytearray.fromhex('7f2b49e270db6d90d8595bec458b50c58585ba1d4e9b788f6689dbd8e56fd80b26f1b489d6701dd185c8413a977b3cbbaf64d1c593d26627dffb101a87ff77da')
digest = bytearray.fromhex('2dfbc1b372d89a1188c09c52e0eec61fce52032ab1022e8e67ece6672b043ee5')
signature = bytearray.fromhex('41aa28d2f1ab148280cd9ed56feda41974053554a42767b83ad043fd39dc049301456c64ba4642a1653c235a98a60249bcd6d3f746b631df928014f6c5bf9c40')

sign_obj = gostcrypto.gostsignature.new(gostcrypto.gostsignature.MODE_256,
                                        gostcrypto.gostsignature.CURVES_R_1323565_1_024_2019['id-tc26-gost-3410-2012-256-paramSetB'])

if sign_obj.verify(public_key, digest, signature):
    print('Signature is correct')
else:
    print('Signature is not correct')

Generating a public key

import gostcrypto

private_key = bytearray.fromhex('7a929ade789bb9be10ed359dd39a72c11b60961f49397eee1d19ce9891ec3b28')

sign_obj = gostcrypto.gostsignature.new(gostcrypto.gostsignature.MODE_256,
                                        gostcrypto.gostsignature.CURVES_R_1323565_1_024_2019['id-tc26-gost-3410-2012-256-paramSetB'])

public_key = sign_obj.public_key_generate(private_key)

Usage ‘gostrandom’ module

import gostcrypto

rand_k = bytearray([
    0xa8, 0xe2, 0xf9, 0x00, 0xdd, 0x4d, 0x7e, 0x24,
    0x5f, 0x09, 0x75, 0x3d, 0x01, 0xe8, 0x75, 0xfc,
    0x38, 0xf1, 0x4f, 0xf5, 0x25, 0x4c, 0x94, 0xea,
    0xdb, 0x45, 0x1e, 0x4a, 0xb6, 0x03, 0xb1, 0x47,
])

random_obj = gostcrypto.gostrandom.new(32,
                                       rand_k,
                                       gostcrypto.gostrandom.SIZE_S_320)
random_result = random_obj.random()
random_obj.clear()

Usage ‘gosthmac’ module

Getting a HMAC for a string

import gostcrypto

key = bytearray.fromhex('000102030405060708090a0b0c0d0e0f1011121315161718191a1b1c1d1e1f')
data = bytearray.fromhex('0126bdb87800af214341456563780100')

hmac_obj = gostcrypto.gosthmac.new('HMAC_GOSTR3411_2012_256', key)
hmac_obj.update(data)
result = hmac_obj.digest()

Getting a HMAC for a file

In this case the buffer_size value must be a multiple of the block_size value.

import gostcrypto

key = bytearray.fromhex('000102030405060708090a0b0c0d0e0f1011121315161718191a1b1c1d1e1f')
file_path = 'd:/file.txt'

buffer_size = 128
hmac_obj = gostcrypto.gosthmac.new('HMAC_GOSTR3411_2012_256', key)
with open(file_path, 'rb') as file:
    buffer = file.read(buffer_size)
    while len(buffer) > 0:
        hmac_obj.update(buffer)
        buffer = file.read(buffer_size)
result = hmac_obj.hexdigest()

Usage ‘gostpbkdf’ module

import gostcrypto

password = b'password'
salt = b'salt'

pbkdf_obj = new(password, salt, 4096)
pbkdf_result = pbkdf_obj.derive(32)

License

MIT Copyright (c) 2020 Evgeny Drobotun

Documentation

Documentation for using this package: https://gostcrypto.readthedocs.io/

Release History

1.1.0 (15.04.2020)

• Refactoring code gostcipher module (changed the class structure)

• Each module has its own exception class added

• In the new function of the gostcipher module for MAC mode, it is now possible to pass data for MAC calculation, followed by calling the digest method without first calling the update method

• In the new function of the gosthash module, it is now possible to pass data for hash calculation, followed by calling the digest method without first calling the update method

• Added new exceptions for various conflict situations

• Fixed some minor bugs

1.0.0 (08.04.2020)

• First release of ‘gostcrypto’