diff --git a/setup.py b/setup.py
index 5b29d32..4ebbc1b 100644
--- a/setup.py
+++ b/setup.py
@@ -8,27 +8,11 @@
 
 import os
 import platform
-import subprocess
 import sys
-from distutils.command.build import build
 
-import pkg_resources
-
-import setuptools
 from setuptools import find_packages, setup
-from setuptools.command.install import install
-from setuptools.command.test import test
 
 
-if (
-    pkg_resources.parse_version(setuptools.__version__) <
-    pkg_resources.parse_version("18.5")
-):
-    raise RuntimeError(
-        "cryptography requires setuptools 18.5 or newer, please upgrade to a "
-        "newer version of setuptools"
-    )
-
 base_dir = os.path.dirname(__file__)
 src_dir = os.path.join(base_dir, "src")
 
@@ -38,13 +22,11 @@
 
 about = {}
 with open(os.path.join(src_dir, "cryptography", "__about__.py")) as f:
-    exec(f.read(), about)
+    exec (f.read(), about)
 
 
-VECTORS_DEPENDENCY = "cryptography_vectors=={0}".format(about['__version__'])
-
 # `setup_requirements` must be kept in sync with `pyproject.toml`
-setup_requirements = ["cffi>=1.8,!=1.11.3"]
+setup_requirements = ["cffi>=1.12"]
 
 if platform.python_implementation() == "PyPy":
     if sys.pypy_version_info < (5, 4):
@@ -53,273 +35,112 @@
             "PyPy to use this library."
         )
 
-test_requirements = [
-    "pytest>=3.6.0,!=3.9.0,!=3.9.1,!=3.9.2",
-    "pretend",
-    "iso8601",
-    "pytz",
-    "hypothesis>=1.11.4,!=3.79.2",
-]
-
-
-# If there's no vectors locally that probably means we are in a tarball and
-# need to go and get the matching vectors package from PyPi
-if not os.path.exists(os.path.join(base_dir, "vectors/setup.py")):
-    test_requirements.append(VECTORS_DEPENDENCY)
-
-
-class PyTest(test):
-    def finalize_options(self):
-        test.finalize_options(self)
-        self.test_args = []
-        self.test_suite = True
-
-        # This means there's a vectors/ folder with the package in here.
-        # cd into it, install the vectors package and then refresh sys.path
-        if VECTORS_DEPENDENCY not in test_requirements:
-            subprocess.check_call(
-                [sys.executable, "setup.py", "install"], cwd="vectors"
-            )
-            pkg_resources.get_distribution("cryptography_vectors").activate()
-
-    def run_tests(self):
-        # Import here because in module scope the eggs are not loaded.
-        import pytest
-        test_args = [os.path.join(base_dir, "tests")]
-        errno = pytest.main(test_args)
-        sys.exit(errno)
-
-
-def keywords_with_side_effects(argv):
-    """
-    Get a dictionary with setup keywords that (can) have side effects.
-
-    :param argv: A list of strings with command line arguments.
-    :returns: A dictionary with keyword arguments for the ``setup()`` function.
-
-    This setup.py script uses the setuptools 'setup_requires' feature because
-    this is required by the cffi package to compile extension modules. The
-    purpose of ``keywords_with_side_effects()`` is to avoid triggering the cffi
-    build process as a result of setup.py invocations that don't need the cffi
-    module to be built (setup.py serves the dual purpose of exposing package
-    metadata).
-
-    All of the options listed by ``python setup.py --help`` that print
-    information should be recognized here. The commands ``clean``,
-    ``egg_info``, ``register``, ``sdist`` and ``upload`` are also recognized.
-    Any combination of these options and commands is also supported.
-
-    This function was originally based on the `setup.py script`_ of SciPy (see
-    also the discussion in `pip issue #25`_).
-
-    .. _pip issue #25: https://github.com/pypa/pip/issues/25
-    .. _setup.py script: https://github.com/scipy/scipy/blob/master/setup.py
-    """
-    no_setup_requires_arguments = (
-        '-h', '--help',
-        '-n', '--dry-run',
-        '-q', '--quiet',
-        '-v', '--verbose',
-        '-V', '--version',
-        '--author',
-        '--author-email',
-        '--classifiers',
-        '--contact',
-        '--contact-email',
-        '--description',
-        '--egg-base',
-        '--fullname',
-        '--help-commands',
-        '--keywords',
-        '--licence',
-        '--license',
-        '--long-description',
-        '--maintainer',
-        '--maintainer-email',
-        '--name',
-        '--no-user-cfg',
-        '--obsoletes',
-        '--platforms',
-        '--provides',
-        '--requires',
-        '--url',
-        'clean',
-        'egg_info',
-        'register',
-        'sdist',
-        'upload',
-    )
-
-    def is_short_option(argument):
-        """Check whether a command line argument is a short option."""
-        return len(argument) >= 2 and argument[0] == '-' and argument[1] != '-'
-
-    def expand_short_options(argument):
-        """Expand combined short options into canonical short options."""
-        return ('-' + char for char in argument[1:])
-
-    def argument_without_setup_requirements(argv, i):
-        """Check whether a command line argument needs setup requirements."""
-        if argv[i] in no_setup_requires_arguments:
-            # Simple case: An argument which is either an option or a command
-            # which doesn't need setup requirements.
-            return True
-        elif (is_short_option(argv[i]) and
-              all(option in no_setup_requires_arguments
-                  for option in expand_short_options(argv[i]))):
-            # Not so simple case: Combined short options none of which need
-            # setup requirements.
-            return True
-        elif argv[i - 1:i] == ['--egg-base']:
-            # Tricky case: --egg-info takes an argument which should not make
-            # us use setup_requires (defeating the purpose of this code).
-            return True
-        else:
-            return False
-
-    if all(argument_without_setup_requirements(argv, i)
-           for i in range(1, len(argv))):
-        return {
-            "cmdclass": {
-                "build": DummyBuild,
-                "install": DummyInstall,
-                "test": DummyPyTest,
-            }
-        }
-    else:
-        cffi_modules = [
-            "src/_cffi_src/build_openssl.py:ffi",
-            "src/_cffi_src/build_constant_time.py:ffi",
-            "src/_cffi_src/build_padding.py:ffi",
-        ]
-
-        return {
-            "setup_requires": setup_requirements,
-            "cmdclass": {
-                "test": PyTest,
-            },
-            "cffi_modules": cffi_modules
-        }
-
-
-setup_requires_error = ("Requested setup command that needs 'setup_requires' "
-                        "while command line arguments implied a side effect "
-                        "free command or option.")
-
-
-class DummyBuild(build):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py build`` as
-    one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
-
-class DummyInstall(install):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py install``
-    as one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
-
-class DummyPyTest(test):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py test`` as
-    one of the 'side effect free' commands or options.
-    """
-
-    def run_tests(self):
-        raise RuntimeError(setup_requires_error)
-
 
 with open(os.path.join(base_dir, "README.rst")) as f:
     long_description = f.read()
 
 
-setup(
-    name=about["__title__"],
-    version=about["__version__"],
-
-    description=about["__summary__"],
-    long_description=long_description,
-    license=about["__license__"],
-    url=about["__uri__"],
-
-    author=about["__author__"],
-    author_email=about["__email__"],
-
-    classifiers=[
-        "Development Status :: 5 - Production/Stable",
-        "Intended Audience :: Developers",
-        "License :: OSI Approved :: Apache Software License",
-        "License :: OSI Approved :: BSD License",
-        "Natural Language :: English",
-        "Operating System :: MacOS :: MacOS X",
-        "Operating System :: POSIX",
-        "Operating System :: POSIX :: BSD",
-        "Operating System :: POSIX :: Linux",
-        "Operating System :: Microsoft :: Windows",
-        "Programming Language :: Python",
-        "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.7",
-        "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.4",
-        "Programming Language :: Python :: 3.5",
-        "Programming Language :: Python :: 3.6",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: Implementation :: CPython",
-        "Programming Language :: Python :: Implementation :: PyPy",
-        "Topic :: Security :: Cryptography",
-    ],
-
-    package_dir={"": "src"},
-    packages=find_packages(where="src", exclude=["_cffi_src", "_cffi_src.*"]),
-    include_package_data=True,
-
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*',
-
-    install_requires=[
-        "asn1crypto >= 0.21.0",
-        "six >= 1.4.1",
-    ] + setup_requirements,
-    tests_require=test_requirements,
-    extras_require={
-        ":python_version < '3'": ["enum34", "ipaddress"],
-
-        "test": test_requirements,
-        "docs": [
-            "sphinx >= 1.6.5,!=1.8.0",
-            "sphinx_rtd_theme",
+try:
+    setup(
+        name=about["__title__"],
+        version=about["__version__"],
+        description=about["__summary__"],
+        long_description=long_description,
+        long_description_content_type="text/x-rst",
+        license=about["__license__"],
+        url=about["__uri__"],
+        author=about["__author__"],
+        author_email=about["__email__"],
+        classifiers=[
+            "Development Status :: 5 - Production/Stable",
+            "Intended Audience :: Developers",
+            "License :: OSI Approved :: Apache Software License",
+            "License :: OSI Approved :: BSD License",
+            "Natural Language :: English",
+            "Operating System :: MacOS :: MacOS X",
+            "Operating System :: POSIX",
+            "Operating System :: POSIX :: BSD",
+            "Operating System :: POSIX :: Linux",
+            "Operating System :: Microsoft :: Windows",
+            "Programming Language :: Python",
+            "Programming Language :: Python :: 2",
+            "Programming Language :: Python :: 2.7",
+            "Programming Language :: Python :: 3",
+            "Programming Language :: Python :: 3.6",
+            "Programming Language :: Python :: 3.7",
+            "Programming Language :: Python :: 3.8",
+            "Programming Language :: Python :: 3.9",
+            "Programming Language :: Python :: Implementation :: CPython",
+            "Programming Language :: Python :: Implementation :: PyPy",
+            "Topic :: Security :: Cryptography",
         ],
-        "docstest": [
-            "doc8",
-            "pyenchant >= 1.6.11",
-            "twine >= 1.12.0",
-            "sphinxcontrib-spelling >= 4.0.1",
+        package_dir={"": "src"},
+        packages=find_packages(
+            where="src", exclude=["_cffi_src", "_cffi_src.*"]
+        ),
+        include_package_data=True,
+        python_requires=(
+            ">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*"
+        ),
+        install_requires=["six >= 1.4.1"] + setup_requirements,
+        setup_requires=setup_requirements,
+        extras_require={
+            ":python_version < '3'": ["enum34", "ipaddress"],
+            "test": [
+                "pytest>=3.6.0,!=3.9.0,!=3.9.1,!=3.9.2",
+                "pretend",
+                "iso8601",
+                "pytz",
+                "hypothesis>=1.11.4,!=3.79.2",
+            ],
+            "docs": [
+                "sphinx >= 1.6.5,!=1.8.0,!=3.1.0,!=3.1.1",
+                "sphinx_rtd_theme",
+            ],
+            "docstest": [
+                "doc8",
+                "pyenchant >= 1.6.11",
+                "twine >= 1.12.0",
+                "sphinxcontrib-spelling >= 4.0.1",
+            ],
+            "pep8test": [
+                "black",
+                "flake8",
+                "flake8-import-order",
+                "pep8-naming",
+            ],
+            # This extra is for OpenSSH private keys that use bcrypt KDF
+            # Versions: v3.1.3 - ignore_few_rounds, v3.1.5 - abi3
+            "ssh": ["bcrypt >= 3.1.5"],
+        },
+        # for cffi
+        zip_safe=False,
+        ext_package="cryptography.hazmat.bindings",
+        cffi_modules=[
+            "src/_cffi_src/build_openssl.py:ffi",
+            "src/_cffi_src/build_padding.py:ffi",
         ],
-        "pep8test": [
-            "flake8",
-            "flake8-import-order",
-            "pep8-naming",
-        ],
-        # This extra is for the U-label support that was deprecated in
-        # cryptography 2.1. If you need this deprecated path install with
-        # pip install cryptography[idna]
-        "idna": [
-            "idna >= 2.1",
-        ]
-    },
-
-    # for cffi
-    zip_safe=False,
-    ext_package="cryptography.hazmat.bindings",
-    **keywords_with_side_effects(sys.argv)
-)
+    )
+except:  # noqa: E722
+    # Note: This is a bare exception that re-raises so that we don't interfere
+    # with anything the installation machinery might want to do. Because we
+    # print this for any exception this msg can appear (e.g. in verbose logs)
+    # even if there's no failure. For example, SetupRequirementsError is raised
+    # during PEP517 building and prints this text. setuptools raises SystemExit
+    # when compilation fails right now, but it's possible this isn't stable
+    # or a public API commitment so we'll remain ultra conservative.
+    print(
+        """
+    =============================DEBUG ASSISTANCE=============================
+    If you are seeing a compilation error please try the following steps to
+    successfully install cryptography:
+    1) Upgrade to the latest pip and try again. This will fix errors for most
+       users. See: https://pip.pypa.io/en/stable/installing/#upgrading-pip
+    2) Read https://cryptography.io/en/latest/installation.html for specific
+       instructions for your platform.
+    3) Check our frequently asked questions for more information:
+       https://cryptography.io/en/latest/faq.html
+    =============================DEBUG ASSISTANCE=============================
+    """
+    )
+    raise