tests/test_load_save_keys.py

#  Copyright 2011 Sybren A. Stüvel <sybren@stuvel.eu>
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

"""Unittest for saving and loading keys."""

import base64
import os.path
import pickle
import unittest
import warnings
from unittest import mock

import rsa.key

B64PRIV_DER = b'MC4CAQACBQDeKYlRAgMBAAECBQDHn4npAgMA/icCAwDfxwIDANcXAgInbwIDAMZt'
PRIVATE_DER = base64.standard_b64decode(B64PRIV_DER)

B64PUB_DER = b'MAwCBQDeKYlRAgMBAAE='
PUBLIC_DER = base64.standard_b64decode(B64PUB_DER)

PRIVATE_PEM = b'''\
-----BEGIN CONFUSING STUFF-----
Cruft before the key

-----BEGIN RSA PRIVATE KEY-----
Comment: something blah

''' + B64PRIV_DER + b'''
-----END RSA PRIVATE KEY-----

Stuff after the key
-----END CONFUSING STUFF-----
'''

CLEAN_PRIVATE_PEM = b'''\
-----BEGIN RSA PRIVATE KEY-----
''' + B64PRIV_DER + b'''
-----END RSA PRIVATE KEY-----
'''

PUBLIC_PEM = b'''\
-----BEGIN CONFUSING STUFF-----
Cruft before the key

-----BEGIN RSA PUBLIC KEY-----
Comment: something blah

''' + B64PUB_DER + b'''
-----END RSA PUBLIC KEY-----

Stuff after the key
-----END CONFUSING STUFF-----
'''

CLEAN_PUBLIC_PEM = b'''\
-----BEGIN RSA PUBLIC KEY-----
''' + B64PUB_DER + b'''
-----END RSA PUBLIC KEY-----
'''


class DerTest(unittest.TestCase):
    """Test saving and loading DER keys."""

    def test_load_private_key(self):
        """Test loading private DER keys."""

        key = rsa.key.PrivateKey.load_pkcs1(PRIVATE_DER, 'DER')
        expected = rsa.key.PrivateKey(3727264081, 65537, 3349121513, 65063, 57287)

        self.assertEqual(expected, key)
        self.assertEqual(key.exp1, 55063)
        self.assertEqual(key.exp2, 10095)
        self.assertEqual(key.coef, 50797)

    @mock.patch('pyasn1.codec.der.decoder.decode')
    def test_load_malformed_private_key(self, der_decode):
        """Test loading malformed private DER keys."""

        # Decode returns an invalid exp2 value.
        der_decode.return_value = (
            [0, 3727264081, 65537, 3349121513, 65063, 57287, 55063, 0, 50797],
            0,
        )

        with warnings.catch_warnings(record=True) as w:
            # Always print warnings
            warnings.simplefilter('always')

            # Load 3 keys
            for _ in range(3):
                key = rsa.key.PrivateKey.load_pkcs1(PRIVATE_DER, 'DER')

            # Check that 3 warnings were generated.
            self.assertEqual(3, len(w))

            for warning in w:
                self.assertTrue(issubclass(warning.category, UserWarning))
                self.assertIn('malformed', str(warning.message))

        # Check that we are creating the key with correct values
        self.assertEqual(key.exp1, 55063)
        self.assertEqual(key.exp2, 10095)
        self.assertEqual(key.coef, 50797)

    def test_save_private_key(self):
        """Test saving private DER keys."""

        key = rsa.key.PrivateKey(3727264081, 65537, 3349121513, 65063, 57287)
        der = key.save_pkcs1('DER')

        self.assertIsInstance(der, bytes)
        self.assertEqual(PRIVATE_DER, der)

    def test_load_public_key(self):
        """Test loading public DER keys."""

        key = rsa.key.PublicKey.load_pkcs1(PUBLIC_DER, 'DER')
        expected = rsa.key.PublicKey(3727264081, 65537)

        self.assertEqual(expected, key)

    def test_save_public_key(self):
        """Test saving public DER keys."""

        key = rsa.key.PublicKey(3727264081, 65537)
        der = key.save_pkcs1('DER')

        self.assertIsInstance(der, bytes)
        self.assertEqual(PUBLIC_DER, der)


class PemTest(unittest.TestCase):
    """Test saving and loading PEM keys."""

    def test_load_private_key(self):
        """Test loading private PEM files."""

        key = rsa.key.PrivateKey.load_pkcs1(PRIVATE_PEM, 'PEM')
        expected = rsa.key.PrivateKey(3727264081, 65537, 3349121513, 65063, 57287)

        self.assertEqual(expected, key)
        self.assertEqual(key.exp1, 55063)
        self.assertEqual(key.exp2, 10095)
        self.assertEqual(key.coef, 50797)

    def test_save_private_key(self):
        """Test saving private PEM files."""

        key = rsa.key.PrivateKey(3727264081, 65537, 3349121513, 65063, 57287)
        pem = key.save_pkcs1('PEM')

        self.assertIsInstance(pem, bytes)
        self.assertEqual(CLEAN_PRIVATE_PEM, pem)

    def test_load_public_key(self):
        """Test loading public PEM files."""

        key = rsa.key.PublicKey.load_pkcs1(PUBLIC_PEM, 'PEM')
        expected = rsa.key.PublicKey(3727264081, 65537)

        self.assertEqual(expected, key)

    def test_save_public_key(self):
        """Test saving public PEM files."""

        key = rsa.key.PublicKey(3727264081, 65537)
        pem = key.save_pkcs1('PEM')

        self.assertIsInstance(pem, bytes)
        self.assertEqual(CLEAN_PUBLIC_PEM, pem)

    def test_load_from_disk(self):
        """Test loading a PEM file from disk."""

        fname = os.path.join(os.path.dirname(__file__), 'private.pem')
        with open(fname, mode='rb') as privatefile:
            keydata = privatefile.read()
        privkey = rsa.key.PrivateKey.load_pkcs1(keydata)

        self.assertEqual(15945948582725241569, privkey.p)
        self.assertEqual(14617195220284816877, privkey.q)


class PickleTest(unittest.TestCase):
    """Test saving and loading keys by pickling."""

    def test_private_key(self):
        pk = rsa.key.PrivateKey(3727264081, 65537, 3349121513, 65063, 57287)

        pickled = pickle.dumps(pk)
        unpickled = pickle.loads(pickled)
        self.assertEqual(pk, unpickled)

        for attr in rsa.key.AbstractKey.__slots__:
            self.assertTrue(hasattr(unpickled, attr))

    def test_public_key(self):
        pk = rsa.key.PublicKey(3727264081, 65537)

        pickled = pickle.dumps(pk)
        unpickled = pickle.loads(pickled)

        self.assertEqual(pk, unpickled)
        for attr in rsa.key.AbstractKey.__slots__:
            self.assertTrue(hasattr(unpickled, attr))