1# This file is dual licensed under the terms of the Apache License, Version 2# 2.0, and the BSD License. See the LICENSE file in the root of this repository 3# for complete details. 4 5from __future__ import absolute_import, division, print_function 6 7import binascii 8 9import pytest 10 11from cryptography.exceptions import InvalidTag 12from cryptography.hazmat.backends.interfaces import CipherBackend 13from cryptography.hazmat.primitives.ciphers.aead import ChaCha20Poly1305 14 15from ..hazmat.primitives.test_aead import _aead_supported 16 17 18@pytest.mark.skipif( 19 not _aead_supported(ChaCha20Poly1305), 20 reason="Requires OpenSSL with ChaCha20Poly1305 support" 21) 22@pytest.mark.requires_backend_interface(interface=CipherBackend) 23@pytest.mark.wycheproof_tests("chacha20_poly1305_test.json") 24def test_chacha2poly1305(wycheproof): 25 key = binascii.unhexlify(wycheproof.testcase["key"]) 26 iv = binascii.unhexlify(wycheproof.testcase["iv"]) 27 aad = binascii.unhexlify(wycheproof.testcase["aad"]) 28 msg = binascii.unhexlify(wycheproof.testcase["msg"]) 29 ct = binascii.unhexlify(wycheproof.testcase["ct"]) 30 tag = binascii.unhexlify(wycheproof.testcase["tag"]) 31 32 if wycheproof.valid: 33 chacha = ChaCha20Poly1305(key) 34 computed_ct = chacha.encrypt(iv, msg, aad) 35 assert computed_ct == ct + tag 36 computed_msg = chacha.decrypt(iv, ct + tag, aad) 37 assert computed_msg == msg 38 elif len(iv) != 12: 39 chacha = ChaCha20Poly1305(key) 40 with pytest.raises(ValueError): 41 chacha.encrypt(iv, msg, aad) 42 with pytest.raises(ValueError): 43 chacha.decrypt(iv, ct + tag, aad) 44 else: 45 chacha = ChaCha20Poly1305(key) 46 with pytest.raises(InvalidTag): 47 chacha.decrypt(iv, msg + tag, aad) 48