#!/usr/bin/env python

"""
<Program Name>
  test_gpg.py

<Author>
  Santiago Torres-Arias <santiago@nyu.edu>
  Lukas Puehringer <lukas.puehringer@nyu.edu>

<Started>
  Nov 15, 2017

<Copyright>
  See LICENSE for licensing information.

<Purpose>
  Test gpg/pgp-related functions.

"""

import os
import shutil
import tempfile
import unittest

# pylint: disable=wrong-import-position
from collections import OrderedDict
from copy import deepcopy
from unittest.mock import patch

import cryptography.hazmat.primitives.hashes as hashing
from cryptography.hazmat import backends
from cryptography.hazmat.primitives import serialization

from securesystemslib import exceptions, process
from securesystemslib.formats import ANY_PUBKEY_DICT_SCHEMA, GPG_PUBKEY_SCHEMA
from securesystemslib.gpg.common import (
    _assign_certified_key_info,
    _get_verified_subkeys,
    get_pubkey_bundle,
    parse_pubkey_bundle,
    parse_pubkey_payload,
    parse_signature_packet,
)
from securesystemslib.gpg.constants import (
    PACKET_TYPE_PRIMARY_KEY,
    PACKET_TYPE_SUB_KEY,
    PACKET_TYPE_USER_ATTR,
    PACKET_TYPE_USER_ID,
    SHA1,
    SHA256,
    SHA512,
    gpg_export_pubkey_command,
    have_gpg,
)
from securesystemslib.gpg.dsa import create_pubkey as dsa_create_pubkey
from securesystemslib.gpg.eddsa import ED25519_SIG_LENGTH
from securesystemslib.gpg.exceptions import (
    CommandError,
    KeyExpirationError,
    KeyNotFoundError,
    PacketParsingError,
    PacketVersionNotSupportedError,
    SignatureAlgorithmNotSupportedError,
)
from securesystemslib.gpg.functions import (
    create_signature,
    export_pubkey,
    export_pubkeys,
    verify_signature,
)
from securesystemslib.gpg.rsa import create_pubkey as rsa_create_pubkey
from securesystemslib.gpg.util import (
    Version,
    get_hashing_class,
    get_version,
    is_version_fully_supported,
    parse_packet_header,
    parse_subpacket_header,
)

# pylint: enable=wrong-import-position


class GPGTestUtils:
    """GPG Test utility class"""

    @staticmethod
    def ignore_not_found_error(
        function, path, exc_info
    ):  # pylint: disable=unused-argument,unused-argument
        """Callback that ignores FileNotFoundError"""
        _, error, _ = exc_info
        if not isinstance(error, FileNotFoundError):
            raise error


@unittest.skipIf(not have_gpg(), "gpg not found")
class TestUtil(unittest.TestCase):
    """Test util functions."""

    def test_version_utils_return_types(self):
        """Run dummy tests for coverage."""
        self.assertTrue(isinstance(get_version(), Version))
        self.assertTrue(isinstance(is_version_fully_supported(), bool))

    def test_version_utils_error(self):
        """Run dummy tests for coverage."""
        with patch(
            "securesystemslib.gpg.constants.have_gpg", return_value=False
        ):
            with self.assertRaises(exceptions.UnsupportedLibraryError):
                get_version()

    def test_get_hashing_class(self):
        # Assert return expected hashing class
        expected_hashing_class = [hashing.SHA1, hashing.SHA256, hashing.SHA512]
        for idx, hashing_id in enumerate([SHA1, SHA256, SHA512]):
            result = get_hashing_class(hashing_id)
            self.assertEqual(result, expected_hashing_class[idx])

        # Assert raises ValueError with non-supported hashing id
        with self.assertRaises(ValueError):
            get_hashing_class("bogus_hashing_id")

    def test_parse_packet_header(self):
        """Test parse_packet_header with manually crafted data."""
        data_list = [
            ## New format packet length with mock packet type 100001
            # one-octet length, header len: 2, body len: 0 to 191
            [0b01100001, 0],
            [0b01100001, 191],
            # two-octet length, header len: 3, body len: 192 to 8383
            [0b01100001, 192, 0],
            [0b01100001, 223, 255],
            # five-octet length, header len: 6, body len: 0 to 4,294,967,295
            [0b01100001, 255, 0, 0, 0, 0],
            [0b01100001, 255, 255, 255, 255, 255],
            ## Old format packet lengths with mock packet type 1001
            # one-octet length, header len: 2, body len: 0 to 255
            [0b00100100, 0],
            [0b00100100, 255],
            # two-octet length, header len: 3, body len: 0 to 65,535
            [0b00100101, 0, 0],
            [0b00100101, 255, 255],
            # four-octet length, header len: 5, body len: 0 to 4,294,967,295
            [0b00100110, 0, 0, 0, 0, 0],
            [0b00100110, 255, 255, 255, 255, 255],
        ]

        # packet_type | header_len | body_len | packet_len
        expected = [
            (33, 2, 0, 2),
            (33, 2, 191, 193),
            (33, 3, 192, 195),
            (33, 3, 8383, 8386),
            (33, 6, 0, 6),
            (33, 6, 4294967295, 4294967301),
            (9, 2, 0, 2),
            (9, 2, 255, 257),
            (9, 3, 0, 3),
            (9, 3, 65535, 65538),
            (9, 5, 0, 5),
            (9, 5, 4294967295, 4294967300),
        ]

        for idx, data in enumerate(data_list):
            result = parse_packet_header(bytearray(data))
            self.assertEqual(result, expected[idx])

        # New Format Packet Lengths with Partial Body Lengths range
        for second_octet in [224, 254]:
            with self.assertRaises(PacketParsingError):
                parse_packet_header(bytearray([0b01100001, second_octet]))

        # Old Format Packet Lengths with indeterminate length (length type 3)
        with self.assertRaises(PacketParsingError):
            parse_packet_header(bytearray([0b00100111]))

        # Get expected type
        parse_packet_header(bytearray([0b01100001, 0]), expected_type=33)

        # Raise with unexpected type
        with self.assertRaises(PacketParsingError):
            parse_packet_header(bytearray([0b01100001, 0]), expected_type=34)

    def test_parse_subpacket_header(self):
        """Test parse_subpacket_header with manually crafted data."""
        # All items until last item encode the length of the subpacket,
        # the last item encodes the mock subpacket type.
        data_list = [
            # length of length 1, subpacket length 0 to 191
            [0, 33],  # NOTE: Nonsense 0-length
            [191, 33],
            # # length of length 2, subpacket length 192 to 16,319
            [192, 0, 33],
            [254, 255, 33],
            # # length of length 5, subpacket length 0 to 4,294,967,295
            [255, 0, 0, 0, 0, 33],  # NOTE: Nonsense 0-length
            [255, 255, 255, 255, 255, 33],
        ]
        # packet_type | header_len | body_len | packet_len
        expected = [
            (33, 2, -1, 1),  # NOTE: Nonsense negative payload
            (33, 2, 190, 192),
            (33, 3, 191, 194),
            (33, 3, 16318, 16321),
            (33, 6, -1, 5),  # NOTE: Nonsense negative payload
            (33, 6, 4294967294, 4294967300),
        ]

        for idx, data in enumerate(data_list):
            result = parse_subpacket_header(bytearray(data))
            self.assertEqual(result, expected[idx])


@unittest.skipIf(not have_gpg(), "gpg not found")
class TestCommon(unittest.TestCase):
    """Test common functions of the securesystemslib.gpg module."""

    @classmethod
    def setUpClass(self):  # pylint: disable=bad-classmethod-argument
        gpg_keyring_path = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), "gpg_keyrings", "rsa"
        )
        homearg = (
            "--homedir {}".format(  # pylint: disable=consider-using-f-string
                gpg_keyring_path
            ).replace("\\", "/")
        )

        # Load test raw public key bundle from rsa keyring, used to construct
        # erroneous gpg data in tests below.
        keyid = "F557D0FF451DEF45372591429EA70BD13D883381"
        cmd = gpg_export_pubkey_command(keyid=keyid, homearg=homearg)
        proc = process.run(cmd, stdout=process.PIPE, stderr=process.PIPE)
        self.raw_key_data = proc.stdout
        self.raw_key_bundle = parse_pubkey_bundle(self.raw_key_data)

        # Export pubkey bundle with expired key for key expiration tests
        keyid = "E8AC80C924116DABB51D4B987CB07D6D2C199C7C"
        cmd = gpg_export_pubkey_command(keyid=keyid, homearg=homearg)
        proc = process.run(cmd, stdout=process.PIPE, stderr=process.PIPE)
        self.raw_expired_key_bundle = parse_pubkey_bundle(proc.stdout)

    def test_parse_pubkey_payload_errors(self):
        """Test parse_pubkey_payload errors with manually crafted data."""
        # passed data | expected error | expected error message
        test_data = [
            (None, ValueError, "empty pubkey"),
            (
                bytearray([0x03]),
                PacketVersionNotSupportedError,
                "packet version '3' not supported",
            ),
            (
                bytearray([0x04, 0, 0, 0, 0, 255]),
                SignatureAlgorithmNotSupportedError,
                "Signature algorithm '255' not supported",
            ),
        ]

        for data, error, error_str in test_data:
            with self.assertRaises(error) as ctx:
                parse_pubkey_payload(data)
            self.assertTrue(error_str in str(ctx.exception))

    def test_parse_pubkey_bundle_errors(self):
        """Test parse_pubkey_bundle errors with manually crafted data partially
        based on real gpg key data (see self.raw_key_bundle)."""
        # Extract sample (legitimate) user ID packet and pass as first packet to
        # raise first packet must be primary key error
        user_id_packet = list(self.raw_key_bundle[PACKET_TYPE_USER_ID].keys())[
            0
        ]
        # Extract sample (legitimate) primary key packet and pass as first two
        # packets to raise unexpected second primary key error
        primary_key_packet = self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY][
            "packet"
        ]
        # Create incomplete packet to re-raise header parsing IndexError as
        # PacketParsingError
        incomplete_packet = bytearray([0b01111111])

        # passed data | expected error message
        test_data = [
            (None, "empty gpg data"),
            (user_id_packet, "must be a primary key"),
            (primary_key_packet + primary_key_packet, "Unexpected primary key"),
            (incomplete_packet, "index out of range"),
        ]
        for data, error_str in test_data:
            with self.assertRaises(PacketParsingError) as ctx:
                parse_pubkey_bundle(data)
            self.assertTrue(error_str in str(ctx.exception))

        # Create empty packet of unsupported type 66 (bit 0-5) and length 0 and
        # pass as second packet to provoke skipping of unsupported packet
        unsupported_packet = bytearray([0b01111111, 0])
        with patch("securesystemslib.gpg.common.log") as mock_log:
            parse_pubkey_bundle(primary_key_packet + unsupported_packet)
            self.assertTrue(
                "Ignoring gpg key packet '63'" in mock_log.info.call_args[0][0]
            )

    def test_parse_pubkey_bundle(self):
        """Assert presence of packets expected returned from `parse_pubkey_bundle`
    for specific test key). See
    ```
    gpg --homedir tests/gpg_keyrings/rsa/ --export 9EA70BD13D883381 | \
        gpg --list-packets
    ```
    """
        # Expect parsed primary key matching GPG_PUBKEY_SCHEMA
        self.assertTrue(
            GPG_PUBKEY_SCHEMA.matches(
                self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY]["key"]
            )
        )

        # Parse corresponding raw packet for comparison
        _, header_len, _, _ = parse_packet_header(
            self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY]["packet"]
        )

        # pylint: disable=unsubscriptable-object
        parsed_raw_packet = parse_pubkey_payload(
            bytearray(
                self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY]["packet"][
                    header_len:
                ]
            )
        )

        # And compare
        self.assertDictEqual(
            self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY]["key"],
            parsed_raw_packet,
        )

        # Expect one primary key signature (revocation signature)
        self.assertEqual(
            len(self.raw_key_bundle[PACKET_TYPE_PRIMARY_KEY]["signatures"]), 1
        )

        # Expect one User ID packet, one User Attribute packet and one Subkey,
        # each with correct data
        for _type in [
            PACKET_TYPE_USER_ID,
            PACKET_TYPE_USER_ATTR,
            PACKET_TYPE_SUB_KEY,
        ]:
            # Of each type there is only one packet
            self.assertTrue(len(self.raw_key_bundle[_type]) == 1)
            # The raw packet is stored as key in the per-packet type collection
            raw_packet = next(iter(self.raw_key_bundle[_type]))
            # Its values are the raw packets header and body length
            self.assertEqual(
                len(raw_packet),
                self.raw_key_bundle[_type][raw_packet]["header_len"]
                + self.raw_key_bundle[_type][raw_packet]["body_len"],
            )
            # and one self-signature
            self.assertEqual(
                len(self.raw_key_bundle[_type][raw_packet]["signatures"]), 1
            )

    def test_assign_certified_key_info_errors(self):
        """Test _assign_certified_key_info errors with manually crafted data
        based on real gpg key data (see self.raw_key_bundle)."""

        # Replace legitimate user certifacte with a bogus packet
        wrong_cert_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = wrong_cert_bundle[PACKET_TYPE_USER_ID].popitem()
        packet_data["signatures"] = [bytearray([0b01111111, 0])]
        wrong_cert_bundle[PACKET_TYPE_USER_ID][packet] = packet_data

        # Replace primary key id with a non-associated keyid
        wrong_keyid_bundle = deepcopy(self.raw_key_bundle)
        wrong_keyid_bundle[PACKET_TYPE_PRIMARY_KEY]["key"][
            "keyid"
        ] = "8465A1E2E0FB2B40ADB2478E18FB3F537E0C8A17"

        # Remove a byte in user id packet to make signature verification fail
        invalid_cert_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = invalid_cert_bundle[PACKET_TYPE_USER_ID].popitem()
        packet = packet[:-1]
        invalid_cert_bundle[PACKET_TYPE_USER_ID][packet] = packet_data

        test_data = [
            # Skip and log parse_signature_packet error
            (wrong_cert_bundle, "Expected packet 2, but got 63 instead"),
            # Skip and log signature packet that doesn't match primary key id
            (wrong_keyid_bundle, "Ignoring User ID certificate issued by"),
            # Skip and log invalid signature
            (invalid_cert_bundle, "Ignoring invalid User ID self-certificate"),
        ]

        for bundle, expected_msg in test_data:
            with patch("securesystemslib.gpg.common.log") as mock_log:
                _assign_certified_key_info(bundle)
                msg = str(mock_log.info.call_args[0][0])
                self.assertTrue(
                    expected_msg in msg,
                    "'{}' not in '{}'".format(  # pylint: disable=consider-using-f-string
                        expected_msg, msg
                    ),
                )

    def test_assign_certified_key_info_expiration(self):
        """Test assignment of key expiration date in
        gpg.common._assign_certified_key_info using real gpg data (with ambiguity
        resolution / prioritization).

        # FIXME: Below tests are missing proper assertions for which User ID
        self-certificate is considered for the expiration date. Reasons are:
        - gpg does not let you (easily) modify individual expiration dates of User
          IDs (changing one changes all), hence we cannot assert the chosen packet
          by the particular date
        -  _assign_certified_key_info first verifies all self-certificates and then
           only considers successfully verified ones, hence we cannot modify the
           certificate data, before passing it to _assign_certified_key_info

        IMO the best solution is a better separation of concerns, e.g. separate
        self-certificate verification and packet prioritization.

        """
        # Test ambiguity resolution scheme with 3 User IDs
        #   :user ID packet: "Test Expiration I <test@expir.one>"
        #   :user ID packet: "Test Expiration II <test@expir.two>"
        #   :user ID packet: "Test Expiration III <test@expir.three>"
        # User ID packets are ordered by their creation time in ascending order.
        # "Test Expiration II" has the primary user ID flag set and therefor has
        # the highest priority.
        key = _assign_certified_key_info(self.raw_expired_key_bundle)
        self.assertTrue(key["validity_period"] == 87901)  # ~ 1 day

        # Test ambiguity resolution scheme with 2 User IDs
        #   :user ID packet: "Test Expiration III <test@expir.three>"
        #   :user ID packet: "Test Expiration I <test@expir.one>"
        # User ID packets are ordered by their creation time in descending order.
        # Neither packet has the primary user ID flag set.
        # "Test Expiration III" has the highest priority.
        raw_key_bundle = deepcopy(self.raw_expired_key_bundle)
        user_id_items = list(
            reversed(raw_key_bundle[PACKET_TYPE_USER_ID].items())
        )
        del user_id_items[1]
        raw_key_bundle[PACKET_TYPE_USER_ID] = OrderedDict(user_id_items)
        key = _assign_certified_key_info(raw_key_bundle)
        self.assertTrue(key["validity_period"] == 87901)  # ~ 1 day

    def test_get_verified_subkeys_errors(self):
        """Test _get_verified_subkeys errors with manually crafted data based on
        real gpg key data (see self.raw_key_bundle)."""

        # Tamper with subkey (change version number) to trigger key parsing error
        bad_subkey_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = bad_subkey_bundle[PACKET_TYPE_SUB_KEY].popitem()
        packet = bytes(
            packet[: packet_data["header_len"]]
            + bytearray([0x03])
            + packet[packet_data["header_len"] + 1 :]
        )
        bad_subkey_bundle[PACKET_TYPE_SUB_KEY][packet] = packet_data

        # Add bogus sig to trigger sig parsing error
        wrong_sig_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = wrong_sig_bundle[PACKET_TYPE_SUB_KEY].popitem()
        # NOTE: We can't only pass the bogus sig, because that would also trigger
        # the not enough sigs error (see not_enough_sigs_bundle) and mock only
        # lets us assert for the most recent log statement
        packet_data["signatures"].append(bytearray([0b01111111, 0]))
        wrong_sig_bundle[PACKET_TYPE_SUB_KEY][packet] = packet_data

        # Remove sigs to trigger not enough sigs error
        not_enough_sigs_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = not_enough_sigs_bundle[
            PACKET_TYPE_SUB_KEY
        ].popitem()
        packet_data["signatures"] = []
        not_enough_sigs_bundle[PACKET_TYPE_SUB_KEY][packet] = packet_data

        # Duplicate sig to trigger wrong amount signatures
        too_many_sigs_bundle = deepcopy(self.raw_key_bundle)
        packet, packet_data = too_many_sigs_bundle[
            PACKET_TYPE_SUB_KEY
        ].popitem()
        packet_data["signatures"] = packet_data["signatures"] * 2
        too_many_sigs_bundle[PACKET_TYPE_SUB_KEY][packet] = packet_data

        # Tamper with primary key to trigger signature verification error
        invalid_sig_bundle = deepcopy(self.raw_key_bundle)
        invalid_sig_bundle[PACKET_TYPE_PRIMARY_KEY][
            "packet"
        ] = invalid_sig_bundle[PACKET_TYPE_PRIMARY_KEY]["packet"][:-1]

        test_data = [
            (bad_subkey_bundle, "Pubkey packet version '3' not supported"),
            (wrong_sig_bundle, "Expected packet 2, but got 63 instead"),
            (
                not_enough_sigs_bundle,
                "wrong amount of key binding signatures (0)",
            ),
            (
                too_many_sigs_bundle,
                "wrong amount of key binding signatures (2)",
            ),
            (invalid_sig_bundle, "invalid key binding signature"),
        ]

        for bundle, expected_msg in test_data:
            with patch("securesystemslib.gpg.common.log") as mock_log:
                _get_verified_subkeys(bundle)
                msg = str(mock_log.info.call_args[0][0])
                self.assertTrue(
                    expected_msg in msg,
                    "'{}' not in '{}'".format(  # pylint: disable=consider-using-f-string
                        expected_msg, msg
                    ),
                )

    def test_get_verified_subkeys(self):
        """Test correct assignment of subkey expiration date in
        gpg.common._get_verified_subkeys using real gpg data."""
        subkeys = _get_verified_subkeys(self.raw_expired_key_bundle)
        # Test subkey with validity period 175451, i.e. ~ 2 days
        self.assertTrue(
            subkeys["0ce427fa3f0f50bc83a4a760ed95e1581691db4d"].get(
                "validity_period"
            )
            == 175451
        )

        # Test subkey  without validity period, i.e. it does not expire
        self.assertTrue(
            subkeys[  # pylint: disable=singleton-comparison
                "70cfabf1e2f1dc60ac5c7bca10cd20d3d5bcb6ef"
            ].get("validity_period")
            == None
        )

    def test_get_pubkey_bundle_errors(self):
        """Test correct error raising in get_pubkey_bundle."""
        # Call without key data
        with self.assertRaises(KeyNotFoundError):
            get_pubkey_bundle(None, "deadbeef")

        # Pass wrong keyid with valid gpg data to trigger KeyNotFoundError.
        not_associated_keyid = "8465A1E2E0FB2B40ADB2478E18FB3F537E0C8A17"
        with self.assertRaises(KeyNotFoundError):
            get_pubkey_bundle(self.raw_key_data, not_associated_keyid)

    def test_parse_signature_packet_errors(self):
        """Test parse_signature_packet errors with manually crafted data."""

        # passed data | expected error message
        test_data = [
            (
                bytearray([0b01000010, 1, 255]),
                "Signature version '255' not supported",
            ),
            (
                bytearray([0b01000010, 2, 4, 255]),
                "Signature type '255' not supported",
            ),
            (
                bytearray([0b01000010, 3, 4, 0, 255]),
                "Signature algorithm '255' not supported",
            ),
            (
                bytearray([0b01000010, 4, 4, 0, 1, 255]),
                "Hash algorithm '255' not supported",
            ),
        ]
        for data, expected_error_str in test_data:
            with self.assertRaises(ValueError) as ctx:
                parse_signature_packet(data)
            self.assertTrue(
                expected_error_str in str(ctx.exception),
                "'{}' not in '{}'".format(  # pylint: disable=consider-using-f-string
                    expected_error_str, str(ctx.exception)
                ),
            )


@unittest.skipIf(not have_gpg(), "gpg not found")
class TestGPGRSA(unittest.TestCase):
    """Test signature creation, verification and key export from the gpg
    module"""

    default_keyid = "8465A1E2E0FB2B40ADB2478E18FB3F537E0C8A17"
    signing_subkey_keyid = "C5A0ABE6EC19D0D65F85E2C39BE9DF5131D924E9"
    encryption_subkey_keyid = "6A112FD3390B2E53AFC2E57F8FC8E12099AECEEA"
    unsupported_subkey_keyid = "611A9B648E16F54E8A7FAD5DA51E8CDF3B06524F"
    expired_key_keyid = "E8AC80C924116DABB51D4B987CB07D6D2C199C7C"

    keyid_768C43 = "7B3ABB26B97B655AB9296BD15B0BD02E1C768C43"  # pylint: disable=invalid-name

    @classmethod
    def setUpClass(self):  # pylint: disable=bad-classmethod-argument
        # Create directory to run the tests without having everything blow up
        self.working_dir = os.getcwd()

        # Find demo files
        gpg_keyring_path = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), "gpg_keyrings", "rsa"
        )

        self.test_dir = os.path.realpath(tempfile.mkdtemp())
        self.gnupg_home = os.path.join(self.test_dir, "rsa")
        shutil.copytree(gpg_keyring_path, self.gnupg_home)
        os.chdir(self.test_dir)

    @classmethod
    def tearDownClass(self):  # pylint: disable=bad-classmethod-argument
        """Change back to initial working dir and remove temp test directory."""
        os.chdir(self.working_dir)
        shutil.rmtree(
            self.test_dir, onerror=GPGTestUtils.ignore_not_found_error
        )

    def test_export_pubkey_error(self):
        """Test correct error is raised if function called incorrectly."""
        with self.assertRaises(ValueError):
            export_pubkey("not-a-key-id")

    def test_export_pubkey(self):
        """export a public key and make sure the parameters are the right ones:

        since there's very little we can do to check rsa key parameters are right
        we pre-exported the public key to an ssh key, which we can load with
        cryptography for the sake of comparison"""

        # export our gpg key, using our functions
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)
        our_exported_key = rsa_create_pubkey(key_data)

        # load the equivalent ssh key, and make sure that we get the same RSA key
        # parameters
        ssh_key_basename = (
            "{}.ssh".format(  # pylint: disable=consider-using-f-string
                self.default_keyid
            )
        )
        ssh_key_path = os.path.join(self.gnupg_home, ssh_key_basename)
        with open(ssh_key_path, "rb") as fp:
            keydata = fp.read()

        ssh_key = serialization.load_ssh_public_key(
            keydata, backends.default_backend()
        )

        self.assertEqual(
            ssh_key.public_numbers().n, our_exported_key.public_numbers().n
        )
        self.assertEqual(
            ssh_key.public_numbers().e, our_exported_key.public_numbers().e
        )

        subkey_keyids = list(key_data["subkeys"].keys())
        # We export the whole master key bundle which must contain the subkeys
        self.assertTrue(self.signing_subkey_keyid.lower() in subkey_keyids)
        # Currently we do not exclude encryption subkeys
        self.assertTrue(self.encryption_subkey_keyid.lower() in subkey_keyids)
        # However we do exclude subkeys, whose algorithm we do not support
        self.assertFalse(self.unsupported_subkey_keyid.lower() in subkey_keyids)

        # When passing the subkey keyid we also export the whole keybundle
        key_data2 = export_pubkey(
            self.signing_subkey_keyid, homedir=self.gnupg_home
        )
        self.assertDictEqual(key_data, key_data2)

    def test_export_pubkeys(self):
        """Test export multiple pubkeys at once."""
        key_dict = export_pubkeys(
            [self.default_keyid, self.keyid_768C43], homedir=self.gnupg_home
        )

        ANY_PUBKEY_DICT_SCHEMA.check_match(key_dict)
        self.assertListEqual(
            sorted([self.default_keyid.lower(), self.keyid_768C43.lower()]),
            sorted(key_dict.keys()),
        )

    def test_gpg_sign_and_verify_object_with_default_key(self):
        """Create a signature using the default key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(test_data, homedir=self.gnupg_home)
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)

        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))

    def test_gpg_sign_and_verify_object(self):
        """Create a signature using a specific key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(
            test_data, keyid=self.default_keyid, homedir=self.gnupg_home
        )
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)
        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))

    def test_gpg_sign_and_verify_object_default_keyring(self):
        """Sign/verify using keyring from envvar."""

        test_data = b"test_data"

        gnupg_home_backup = os.environ.get("GNUPGHOME")
        os.environ["GNUPGHOME"] = self.gnupg_home

        signature = create_signature(test_data, keyid=self.default_keyid)
        key_data = export_pubkey(self.default_keyid)
        self.assertTrue(verify_signature(signature, key_data, test_data))

        # Reset GNUPGHOME
        if gnupg_home_backup:
            os.environ["GNUPGHOME"] = gnupg_home_backup
        else:
            del os.environ["GNUPGHOME"]

    def test_create_signature_with_expired_key(self):
        """Test signing with expired key raises gpg CommandError."""
        with self.assertRaises(CommandError) as ctx:
            create_signature(
                b"livestock",
                keyid=self.expired_key_keyid,
                homedir=self.gnupg_home,
            )

        expected = "returned non-zero exit status '2'"
        self.assertTrue(
            expected in str(ctx.exception),
            "{} not in {}".format(  # pylint: disable=consider-using-f-string
                expected, ctx.exception
            ),
        )

    def test_verify_signature_with_expired_key(self):
        """Test sig verification with expired key raises KeyExpirationError."""
        signature = {
            "keyid": self.expired_key_keyid,
            "other_headers": "deadbeef",
            "signature": "deadbeef",
        }
        content = b"livestock"
        key = export_pubkey(self.expired_key_keyid, homedir=self.gnupg_home)

        with self.assertRaises(KeyExpirationError) as ctx:
            verify_signature(signature, key, content)

        expected = (
            "GPG key 'e8ac80c924116dabb51d4b987cb07d6d2c199c7c' "
            "created on '2019-03-25 12:46 UTC' with validity period '1 day, "
            "0:25:01' expired on '2019-03-26 13:11 UTC'."
        )
        self.assertTrue(
            expected == str(ctx.exception),
            "\nexpected: {}"  # pylint: disable=consider-using-f-string
            "\ngot:      {}".format(  # pylint: disable=consider-using-f-string
                expected, ctx.exception
            ),
        )


@unittest.skipIf(not have_gpg(), "gpg not found")
class TestGPGDSA(unittest.TestCase):
    """Test signature creation, verification and key export from the gpg
    module"""

    default_keyid = "C242A830DAAF1C2BEF604A9EF033A3A3E267B3B1"

    @classmethod
    def setUpClass(self):  # pylint: disable=bad-classmethod-argument
        # Create directory to run the tests without having everything blow up
        self.working_dir = os.getcwd()
        self.test_dir = os.path.realpath(tempfile.mkdtemp())
        self.gnupg_home = os.path.join(self.test_dir, "dsa")

        # Find keyrings
        keyrings = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), "gpg_keyrings", "dsa"
        )

        shutil.copytree(keyrings, self.gnupg_home)
        os.chdir(self.test_dir)

    @classmethod
    def tearDownClass(self):  # pylint: disable=bad-classmethod-argument
        """Change back to initial working dir and remove temp test directory."""
        os.chdir(self.working_dir)
        shutil.rmtree(
            self.test_dir, onerror=GPGTestUtils.ignore_not_found_error
        )

    def test_export_pubkey(self):
        """export a public key and make sure the parameters are the right ones:

        since there's very little we can do to check key parameters are right
        we pre-exported the public key to an x.509 SubjectPublicKeyInfo key,
        which we can load with cryptography for the sake of comparison"""

        # export our gpg key, using our functions
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)
        our_exported_key = dsa_create_pubkey(key_data)

        # load same key, pre-exported with 3rd-party tooling
        pem_key_basename = (
            "{}.pem".format(  # pylint: disable=consider-using-f-string
                self.default_keyid
            )
        )
        pem_key_path = os.path.join(self.gnupg_home, pem_key_basename)
        with open(pem_key_path, "rb") as fp:
            keydata = fp.read()

        pem_key = serialization.load_pem_public_key(
            keydata, backends.default_backend()
        )

        # make sure keys match
        self.assertEqual(
            pem_key.public_numbers().y, our_exported_key.public_numbers().y
        )
        self.assertEqual(
            pem_key.public_numbers().parameter_numbers.g,
            our_exported_key.public_numbers().parameter_numbers.g,
        )
        self.assertEqual(
            pem_key.public_numbers().parameter_numbers.q,
            our_exported_key.public_numbers().parameter_numbers.q,
        )
        self.assertEqual(
            pem_key.public_numbers().parameter_numbers.p,
            our_exported_key.public_numbers().parameter_numbers.p,
        )

    def test_gpg_sign_and_verify_object_with_default_key(self):
        """Create a signature using the default key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(test_data, homedir=self.gnupg_home)
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)

        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))

    def test_gpg_sign_and_verify_object(self):
        """Create a signature using a specific key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(
            test_data, keyid=self.default_keyid, homedir=self.gnupg_home
        )
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)

        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))


@unittest.skipIf(not have_gpg(), "gpg not found")
class TestGPGEdDSA(unittest.TestCase):
    """Test signature creation, verification and key export from the gpg
    module"""

    default_keyid = "4E630F84838BF6F7447B830B22692F5FEA9E2DD2"

    @classmethod
    def setUpClass(self):  # pylint: disable=bad-classmethod-argument
        # Create directory to run the tests without having everything blow up
        self.working_dir = os.getcwd()
        self.test_dir = os.path.realpath(tempfile.mkdtemp())
        self.gnupg_home = os.path.join(self.test_dir, "dsa")

        # Find keyrings
        keyrings = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), "gpg_keyrings", "eddsa"
        )

        shutil.copytree(keyrings, self.gnupg_home)
        os.chdir(self.test_dir)

    @classmethod
    def tearDownClass(self):  # pylint: disable=bad-classmethod-argument
        """Change back to initial working dir and remove temp test directory."""
        os.chdir(self.working_dir)
        shutil.rmtree(
            self.test_dir, onerror=GPGTestUtils.ignore_not_found_error
        )

    def test_gpg_sign_and_verify_object_with_default_key(self):
        """Create a signature using the default key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(test_data, homedir=self.gnupg_home)
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)

        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))

    def test_gpg_sign_and_verify_object_with_specific_key(self):
        """Create a signature using a specific key on the keyring"""

        test_data = b"test_data"
        wrong_data = b"something malicious"

        signature = create_signature(
            test_data, keyid=self.default_keyid, homedir=self.gnupg_home
        )
        key_data = export_pubkey(self.default_keyid, homedir=self.gnupg_home)

        self.assertTrue(verify_signature(signature, key_data, test_data))
        self.assertFalse(verify_signature(signature, key_data, wrong_data))

    def test_verify_short_signature(self):
        """Correctly verify a special-crafted short signature."""

        test_data = b"hello"
        signature_path = os.path.join(self.gnupg_home, "short.sig")

        # Read special-crafted raw gpg signature that is one byte too short
        with open(signature_path, "rb") as f:
            signature_data = f.read()

        # Check that the signature is padded upon parsing
        # NOTE: The returned signature is a hex string and thus twice as long
        signature = parse_signature_packet(signature_data)
        self.assertTrue(len(signature["signature"]) == (ED25519_SIG_LENGTH * 2))

        # Check that the signature can be successfully verified
        key = export_pubkey(self.default_keyid, homedir=self.gnupg_home)
        self.assertTrue(verify_signature(signature, key, test_data))


class TestVersion(unittest.TestCase):
    """Tests for the Version utility class."""

    def test_version_roundtrip_string(self):
        """Version parses and formats strings correctly."""
        for value, expected in [
            ("1.3.0", Version(1, 3, 0)),
            ("1.3.1", Version(1, 3, 1)),
            ("1.3.22", Version(1, 3, 22)),
        ]:
            self.assertEqual(Version.from_string(value), expected)
            self.assertEqual(str(expected), value)

    def test_version_from_string_invalid(self):
        """Version.from_string rejects invalid inputs."""
        for value in [
            "1.3",
            "1.33.0",
            "1.3.-1",
            "1.3.1a",
        ]:
            with self.assertRaises(
                ValueError, msg=f"expected error for input '{value}'"
            ):
                Version.from_string(value)


if __name__ == "__main__":
    unittest.main()