test_openssl.py

# 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 itertools
import typing

import pytest

from cryptography.exceptions import InternalError, _Reasons
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.backends.openssl.backend import backend
from cryptography.hazmat.bindings._rust import openssl as rust_openssl
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import padding

from ...doubles import (
    DummyAsymmetricPadding,
    DummyCipherAlgorithm,
    DummyHashAlgorithm,
    DummyMode,
)
from ...hazmat.primitives.test_rsa import rsa_key_2048
from ...utils import raises_unsupported_algorithm

# Make ruff happy since we're importing fixtures that pytest patches in as
# func args
__all__ = ["rsa_key_2048"]


class DummyMGF(padding.MGF):
    _salt_length = 0
    _algorithm = hashes.SHA1()

    def __eq__(self, other: typing.Any) -> bool:
        return isinstance(other, DummyMGF)


class TestOpenSSL:
    def test_backend_exists(self):
        assert backend

    def test_is_default_backend(self):
        assert backend is default_backend()

    def test_openssl_version_text(self):
        """
        This test checks the value of OPENSSL_VERSION_TEXT.

        Unfortunately, this define does not appear to have a
        formal content definition, so for now we'll test to see
        if it starts with OpenSSL or LibreSSL as that appears
        to be true for every OpenSSL-alike.
        """
        version = backend.openssl_version_text()
        assert version.startswith(
            ("OpenSSL", "LibreSSL", "BoringSSL", "AWS-LC")
        )

        # Verify the correspondence between these two. And do it in a way that
        # ensures coverage.
        if version.startswith("LibreSSL"):
            assert rust_openssl.CRYPTOGRAPHY_IS_LIBRESSL
        if rust_openssl.CRYPTOGRAPHY_IS_LIBRESSL:
            assert version.startswith("LibreSSL")

        if version.startswith("BoringSSL"):
            assert rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL
        if rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL:
            assert version.startswith("BoringSSL")

        if version.startswith("AWS-LC"):
            assert rust_openssl.CRYPTOGRAPHY_IS_AWSLC
        if rust_openssl.CRYPTOGRAPHY_IS_AWSLC:
            assert version.startswith("AWS-LC")

    def test_openssl_version_number(self):
        assert backend.openssl_version_number() > 0

    def test_supports_cipher(self):
        assert (
            backend.cipher_supported(DummyCipherAlgorithm(), DummyMode())
            is False
        )

    def test_openssl_assert(self):
        backend.openssl_assert(True)
        with pytest.raises(InternalError):
            backend.openssl_assert(False)

    def test_consume_errors(self):
        for i in range(10):
            backend._lib.ERR_put_error(
                backend._lib.ERR_LIB_EVP, 0, 0, b"test_openssl.py", -1
            )

        assert backend._lib.ERR_peek_error() != 0

        errors = backend._consume_errors()

        assert backend._lib.ERR_peek_error() == 0
        assert len(errors) == 10

    def test_ssl_ciphers_registered(self):
        meth = backend._lib.TLS_method()
        ctx = backend._lib.SSL_CTX_new(meth)
        assert ctx != backend._ffi.NULL
        backend._lib.SSL_CTX_free(ctx)

    def test_evp_ciphers_registered(self):
        cipher = backend._lib.EVP_get_cipherbyname(b"aes-256-cbc")
        assert cipher != backend._ffi.NULL


class TestOpenSSLRSA:
    def test_rsa_padding_unsupported_pss_mgf1_hash(self):
        assert (
            backend.rsa_padding_supported(
                padding.PSS(
                    mgf=padding.MGF1(DummyHashAlgorithm()), salt_length=0
                )
            )
            is False
        )

    def test_rsa_padding_unsupported(self):
        assert backend.rsa_padding_supported(DummyAsymmetricPadding()) is False

    def test_rsa_padding_supported_pkcs1v15(self):
        assert backend.rsa_padding_supported(padding.PKCS1v15()) is True

    def test_rsa_padding_supported_pss(self):
        assert (
            backend.rsa_padding_supported(
                padding.PSS(
                    mgf=padding.MGF1(hashes.SHA256()),
                    salt_length=padding.PSS.DIGEST_LENGTH,
                )
            )
            is True
        )

    def test_rsa_padding_supported_oaep(self):
        assert (
            backend.rsa_padding_supported(
                padding.OAEP(
                    mgf=padding.MGF1(algorithm=hashes.SHA256()),
                    algorithm=hashes.SHA256(),
                    label=None,
                ),
            )
            is True
        )

    def test_rsa_padding_supported_oaep_sha2_combinations(self):
        hashalgs = [
            hashes.SHA1(),
            hashes.SHA224(),
            hashes.SHA256(),
            hashes.SHA384(),
            hashes.SHA512(),
        ]
        for mgf1alg, oaepalg in itertools.product(hashalgs, hashalgs):
            if backend._fips_enabled and (
                isinstance(mgf1alg, hashes.SHA1)
                or isinstance(oaepalg, hashes.SHA1)
            ):
                continue

            assert (
                backend.rsa_padding_supported(
                    padding.OAEP(
                        mgf=padding.MGF1(algorithm=mgf1alg),
                        algorithm=oaepalg,
                        label=None,
                    ),
                )
                is True
            )

    def test_rsa_padding_unsupported_mgf(self):
        assert (
            backend.rsa_padding_supported(
                padding.OAEP(
                    mgf=DummyMGF(),
                    algorithm=hashes.SHA1(),
                    label=None,
                ),
            )
            is False
        )

        assert (
            backend.rsa_padding_supported(
                padding.PSS(mgf=DummyMGF(), salt_length=0)
            )
            is False
        )

    def test_dummy_mgf_eq(self):
        """This test just exists to fix code coverage for the dummy class."""
        assert DummyMGF() == DummyMGF()
        assert DummyMGF() != padding.MGF1(hashes.SHA256())

    def test_unsupported_mgf1_hash_algorithm_md5_decrypt(self, rsa_key_2048):
        with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_PADDING):
            rsa_key_2048.decrypt(
                b"0" * 256,
                padding.OAEP(
                    mgf=padding.MGF1(algorithm=hashes.MD5()),
                    algorithm=hashes.MD5(),
                    label=None,
                ),
            )


class TestRSAPEMSerialization:
    def test_password_length_limit(self, rsa_key_2048):
        password = b"x" * 1024
        with pytest.raises(ValueError):
            rsa_key_2048.private_bytes(
                serialization.Encoding.PEM,
                serialization.PrivateFormat.PKCS8,
                serialization.BestAvailableEncryption(password),
            )