# This file is dual licensed under the terms of the Apache License, Version # 2.0, and the BSD License. See the LICENSE file in the root of this repository # for complete details. import base64 import calendar import json import os import time import iso8601 import pretend import pytest from cryptography.fernet import Fernet, InvalidToken, MultiFernet from cryptography.hazmat.primitives.ciphers import algorithms, modes import cryptography_vectors def json_parametrize(keys, filename): vector_file = cryptography_vectors.open_vector_file( os.path.join("fernet", filename), "r" ) with vector_file: data = json.load(vector_file) return pytest.mark.parametrize( keys, [tuple([entry[k] for k in keys]) for entry in data], ids=[f"{filename}[{i}]" for i in range(len(data))], ) @pytest.mark.supported( only_if=lambda backend: backend.cipher_supported( algorithms.AES(b"\x00" * 32), modes.CBC(b"\x00" * 16) ), skip_message="Does not support AES CBC", ) class TestFernet: @json_parametrize( ("secret", "now", "iv", "src", "token"), "generate.json", ) def test_generate(self, secret, now, iv, src, token, backend): f = Fernet(secret.encode("ascii"), backend=backend) actual_token = f._encrypt_from_parts( src.encode("ascii"), calendar.timegm(iso8601.parse_date(now).utctimetuple()), bytes(iv), ) assert actual_token == token.encode("ascii") @json_parametrize( ("secret", "now", "src", "ttl_sec", "token"), "verify.json", ) def test_verify( self, secret, now, src, ttl_sec, token, backend, monkeypatch ): # secret & token are both str f = Fernet(secret.encode("ascii"), backend=backend) current_time = calendar.timegm(iso8601.parse_date(now).utctimetuple()) payload = f.decrypt_at_time( token, # str ttl=ttl_sec, current_time=current_time, ) assert payload == src.encode("ascii") payload = f.decrypt_at_time( token.encode("ascii"), # bytes ttl=ttl_sec, current_time=current_time, ) assert payload == src.encode("ascii") monkeypatch.setattr(time, "time", lambda: current_time) payload = f.decrypt(token, ttl=ttl_sec) # str assert payload == src.encode("ascii") payload = f.decrypt(token.encode("ascii"), ttl=ttl_sec) # bytes assert payload == src.encode("ascii") @json_parametrize(("secret", "token", "now", "ttl_sec"), "invalid.json") def test_invalid(self, secret, token, now, ttl_sec, backend, monkeypatch): f = Fernet(secret.encode("ascii"), backend=backend) current_time = calendar.timegm(iso8601.parse_date(now).utctimetuple()) with pytest.raises(InvalidToken): f.decrypt_at_time( token.encode("ascii"), ttl=ttl_sec, current_time=current_time, ) monkeypatch.setattr(time, "time", lambda: current_time) with pytest.raises(InvalidToken): f.decrypt(token.encode("ascii"), ttl=ttl_sec) def test_invalid_start_byte(self, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) with pytest.raises(InvalidToken): f.decrypt(base64.urlsafe_b64encode(b"\x81")) def test_timestamp_too_short(self, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) with pytest.raises(InvalidToken): f.decrypt(base64.urlsafe_b64encode(b"\x80abc")) def test_non_base64_token(self, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) with pytest.raises(InvalidToken): f.decrypt(b"\x00") with pytest.raises(InvalidToken): f.decrypt("nonsensetoken") def test_invalid_types(self, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) with pytest.raises(TypeError): f.encrypt("") # type: ignore[arg-type] with pytest.raises(TypeError): f.decrypt(12345) # type: ignore[arg-type] def test_timestamp_ignored_no_ttl(self, monkeypatch, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) pt = b"encrypt me" token = f.encrypt(pt) monkeypatch.setattr(time, "time", pretend.raiser(ValueError)) assert f.decrypt(token, ttl=None) == pt def test_ttl_required_in_decrypt_at_time(self, monkeypatch, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) pt = b"encrypt me" token = f.encrypt(pt) with pytest.raises(ValueError): f.decrypt_at_time( token, ttl=None, # type: ignore[arg-type] current_time=int(time.time()), ) @pytest.mark.parametrize("message", [b"", b"Abc!", b"\x00\xFF\x00\x80"]) def test_roundtrips(self, message, backend): f = Fernet(Fernet.generate_key(), backend=backend) assert f.decrypt(f.encrypt(message)) == message @pytest.mark.parametrize("key", [base64.urlsafe_b64encode(b"abc"), b"abc"]) def test_bad_key(self, backend, key): with pytest.raises(ValueError): Fernet(key, backend=backend) def test_extract_timestamp(self, monkeypatch, backend): f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) current_time = 1526138327 token = f.encrypt_at_time(b"encrypt me", current_time) assert f.extract_timestamp(token) == current_time assert f.extract_timestamp(token.decode("ascii")) == current_time with pytest.raises(InvalidToken): f.extract_timestamp(b"nonsensetoken") @pytest.mark.supported( only_if=lambda backend: backend.cipher_supported( algorithms.AES(b"\x00" * 32), modes.CBC(b"\x00" * 16) ), skip_message="Does not support AES CBC", ) class TestMultiFernet: def test_encrypt(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) f = MultiFernet([f1, f2]) assert f1.decrypt(f.encrypt(b"abc")) == b"abc" def test_decrypt(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) f = MultiFernet([f1, f2]) # token as bytes assert f.decrypt(f1.encrypt(b"abc")) == b"abc" assert f.decrypt(f2.encrypt(b"abc")) == b"abc" # token as str assert f.decrypt(f1.encrypt(b"abc").decode("ascii")) == b"abc" assert f.decrypt(f2.encrypt(b"abc").decode("ascii")) == b"abc" with pytest.raises(InvalidToken): f.decrypt(b"\x00" * 16) def test_decrypt_at_time(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f = MultiFernet([f1]) pt = b"encrypt me" token = f.encrypt_at_time(pt, current_time=100) assert f.decrypt_at_time(token, ttl=1, current_time=100) == pt with pytest.raises(InvalidToken): f.decrypt_at_time(token, ttl=1, current_time=102) with pytest.raises(ValueError): f.decrypt_at_time( token, ttl=None, current_time=100 # type: ignore[arg-type] ) def test_no_fernets(self, backend): with pytest.raises(ValueError): MultiFernet([]) def test_non_iterable_argument(self, backend): with pytest.raises(TypeError): MultiFernet(None) # type: ignore[arg-type] def test_rotate_bytes(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) mf1 = MultiFernet([f1]) mf2 = MultiFernet([f2, f1]) plaintext = b"abc" mf1_ciphertext = mf1.encrypt(plaintext) assert mf2.decrypt(mf1_ciphertext) == plaintext rotated = mf2.rotate(mf1_ciphertext) assert rotated != mf1_ciphertext assert mf2.decrypt(rotated) == plaintext with pytest.raises(InvalidToken): mf1.decrypt(rotated) def test_rotate_str(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) mf1 = MultiFernet([f1]) mf2 = MultiFernet([f2, f1]) plaintext = b"abc" mf1_ciphertext = mf1.encrypt(plaintext).decode("ascii") assert mf2.decrypt(mf1_ciphertext) == plaintext rotated = mf2.rotate(mf1_ciphertext).decode("ascii") assert rotated != mf1_ciphertext assert mf2.decrypt(rotated) == plaintext with pytest.raises(InvalidToken): mf1.decrypt(rotated) def test_rotate_preserves_timestamp(self, backend, monkeypatch): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) mf1 = MultiFernet([f1]) mf2 = MultiFernet([f2, f1]) plaintext = b"abc" original_time = int(time.time()) - 5 * 60 mf1_ciphertext = mf1.encrypt_at_time(plaintext, original_time) rotated_time, _ = Fernet._get_unverified_token_data( mf2.rotate(mf1_ciphertext) ) assert int(time.time()) != rotated_time assert original_time == rotated_time def test_rotate_decrypt_no_shared_keys(self, backend): f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend) f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend) mf1 = MultiFernet([f1]) mf2 = MultiFernet([f2]) with pytest.raises(InvalidToken): mf2.rotate(mf1.encrypt(b"abc"))