setup.py

#!/usr/bin/env python
from __future__ import print_function

import subprocess
import platform
import re
import sys
import os
import shutil
import shlex

# Enables the vendored distutils in setuptools over the stdlib one to avoid
# the deprecation warning. Must be done before importing setuptools,
# setuptools also must be imported before distutils.
# https://github.com/pypa/setuptools/blob/main/docs/deprecated/distutils-legacy.rst
os.environ['SETUPTOOLS_USE_DISTUTILS'] = 'local'

from setuptools import setup  # noqa: E402
from setuptools import Distribution  # noqa: E402
from setuptools.command.sdist import sdist  # noqa: E402
from setuptools.extension import Extension  # noqa: E402


SKIP_CYTHON_FILE = '__dont_use_cython__.txt'

if os.path.exists(SKIP_CYTHON_FILE):
    print("In distributed package, building from C files...", file=sys.stderr)
    SOURCE_EXT = 'c'
else:
    try:
        from Cython.Build import cythonize
        print("Building from Cython files...", file=sys.stderr)
        SOURCE_EXT = 'pyx'
    except ImportError:
        print("Cython not found, building from C files...",
              file=sys.stderr)
        SOURCE_EXT = 'c'


def get_output(*args, **kwargs):
    res = subprocess.check_output(*args, shell=True, **kwargs)
    decoded = res.decode('utf-8')
    return decoded.strip()


# get the compile and link args
kc = "krb5-config"
autodetect_kc = True
posix = os.name != 'nt'

# Per https://docs.python.org/3/library/platform.html#platform.architecture
# this is the preferred way of determining "64-bitness".
is64bit = sys.maxsize > 2**32

kc_env = 'GSSAPI_KRB5CONFIG'
if kc_env in os.environ:
    kc = os.environ[kc_env]
    autodetect_kc = False
    print(f"Using {kc} from env")

link_args, compile_args = [
    shlex.split(os.environ[e], posix=posix) if e in os.environ else None
    for e in ['GSSAPI_LINKER_ARGS', 'GSSAPI_COMPILER_ARGS']
]

osx_has_gss_framework = False
if sys.platform == 'darwin':
    mac_ver = [int(v) for v in platform.mac_ver()[0].split('.')]
    osx_has_gss_framework = (mac_ver >= [10, 7, 0])

winkrb_path = None
if os.name == 'nt':
    # Try to find location of MIT kerberos
    # First check program files of the appropriate architecture
    _pf_path = os.path.join(os.environ['ProgramFiles'], 'MIT', 'Kerberos')
    if os.path.exists(_pf_path):
        winkrb_path = _pf_path
    else:
        # Try to detect kinit in PATH
        _kinit_path = shutil.which('kinit')
        if _kinit_path is None:
            print("Failed find MIT kerberos!")
        else:
            winkrb_path = os.path.dirname(os.path.dirname(_kinit_path))

    # Monkey patch distutils if it throws errors getting msvcr.
    # For MinGW it won't need it.
    from distutils import cygwinccompiler
    try:
        cygwinccompiler.get_msvcr()
    except ValueError:
        cygwinccompiler.get_msvcr = lambda *a, **kw: []

if sys.platform.startswith("freebsd") and autodetect_kc:
    # FreeBSD does $PATH backward, for our purposes.  That is, the package
    # manager's version of the software is in /usr/local, which is in PATH
    # *after* the version in /usr.  We prefer the package manager's version
    # because the Heimdal in base is truly ancient, but this can be overridden
    # - either in the "normal" fashion by putting something in PATH in front
    # of it, or by removing /usr/local from PATH.

    bins = []
    for b in os.environ["PATH"].split(":"):
        p = f"{b}/krb5-config"
        if not os.path.exists(p):
            continue
        bins.append(p)

    if len(bins) > 1 and bins[0] == "/usr/bin/krb5-config" and \
       "/usr/local/bin/krb5-config" in bins:
        kc = "/usr/local/bin/krb5-config"
    print(f"Detected: {kc}")

if link_args is None:
    if osx_has_gss_framework:
        link_args = ['-framework', 'GSS']
    elif winkrb_path:
        _libs = os.path.join(
            winkrb_path, 'lib', 'amd64' if is64bit else 'i386'
        )
        link_args = (
            ['-L%s' % _libs]
            + ['-l%s' % os.path.splitext(lib)[0] for lib in os.listdir(_libs)]
        )
    elif os.environ.get('MINGW_PREFIX'):
        link_args = ['-lgss']
    else:
        link_args = shlex.split(get_output(f"{kc} --libs gssapi"))

if compile_args is None:
    if osx_has_gss_framework:
        compile_args = ['-DOSX_HAS_GSS_FRAMEWORK']
    elif winkrb_path:
        compile_args = [
            '-I%s' % os.path.join(winkrb_path, 'include'),
        ]
        if is64bit:
            compile_args.append('-DMS_WIN64')
    elif os.environ.get('MINGW_PREFIX'):
        compile_args = ['-fPIC']
    else:
        compile_args = shlex.split(get_output(f"{kc} --cflags gssapi"))

# add in the extra workarounds for different include structures
if winkrb_path:
    prefix = winkrb_path
else:
    try:
        prefix = get_output(f"{kc} gssapi --prefix")
    except Exception:
        print("WARNING: couldn't find krb5-config; assuming prefix of %s"
              % str(sys.prefix))
        prefix = sys.prefix
gssapi_ext_h = os.path.join(prefix, 'include/gssapi/gssapi_ext.h')
if os.path.exists(gssapi_ext_h):
    compile_args.append("-DHAS_GSSAPI_EXT_H")

# Create a define to detect msys in the headers
if sys.platform == 'msys':
    compile_args.append('-D__MSYS__')

# ensure that any specific directories are listed before any generic system
# directories inserted by setuptools
# Also separate out specified libraries as MSBuild requires different args
_link_args = link_args
library_dirs, libraries, link_args = [], [], []
for arg in _link_args:
    if arg.startswith('-L'):
        library_dirs.append(arg[2:])
    elif arg.startswith('-l'):
        libraries.append(arg[2:])
    else:
        link_args.append(arg)

ENABLE_SUPPORT_DETECTION = \
    (os.environ.get('GSSAPI_SUPPORT_DETECT', 'true').lower() == 'true')

if ENABLE_SUPPORT_DETECTION:
    import ctypes.util

    main_lib = os.environ.get('GSSAPI_MAIN_LIB', None)
    main_path = ""
    if main_lib is None and osx_has_gss_framework:
        main_lib = ctypes.util.find_library('GSS')
        if not main_lib:
            # https://github.com/pythongssapi/python-gssapi/issues/235
            # CPython has a bug on Big Sur where find_library will fail to
            # find the library path of shared frameworks.  This has been fixed
            # in newer versions but we have this fallback in case an older
            # version is still in use.  This fix is expected to be included in
            # 3.8.8 and 3.9.2.
            main_lib = '/System/Library/Frameworks/GSS.framework/GSS'
    elif os.environ.get('MINGW_PREFIX'):
        main_lib = os.environ.get('MINGW_PREFIX')+'/bin/libgss-3.dll'
    elif sys.platform == 'msys':
        # Plain msys, not running in MINGW_PREFIX. Try to get the lib from one
        _main_lib = f'/mingw{64 if is64bit else 32}/bin/libgss-3.dll'
        if os.path.exists(_main_lib):
            main_lib = _main_lib
            os.environ['PATH'] += os.pathsep + os.path.dirname(main_lib)
    elif main_lib is None:
        for opt in libraries:
            if opt.startswith('gssapi'):
                if os.name == 'nt':
                    main_lib = '%s.dll' % opt
                    if winkrb_path:
                        main_path = os.path.join(winkrb_path, 'bin')
                else:
                    main_lib = 'lib%s.so' % opt
        for opt in link_args:
            # To support Heimdal on Debian, read the linker path.
            if opt.startswith('-Wl,/'):
                main_path = opt[4:] + "/"
        if main_path == "":
            for d in library_dirs:
                if os.path.exists(os.path.join(d, main_lib)):
                    main_path = d
                    break

    if main_lib is None:
        raise Exception("Could not find main GSSAPI shared library.  Please "
                        "try setting GSSAPI_MAIN_LIB yourself or setting "
                        "GSSAPI_SUPPORT_DETECT to 'false'")

    GSSAPI_LIB = ctypes.CDLL(os.path.join(main_path, main_lib))


# add in the flag that causes us not to compile from Cython when
# installing from an sdist
class sdist_gssapi(sdist):
    def run(self):
        if not self.dry_run:
            with open(SKIP_CYTHON_FILE, 'w') as flag_file:
                flag_file.write('COMPILE_FROM_C_ONLY')

            sdist.run(self)

            os.remove(SKIP_CYTHON_FILE)


DONT_CYTHONIZE_FOR = ('clean',)


class GSSAPIDistribution(Distribution, object):
    def run_command(self, command):
        self._last_run_command = command
        Distribution.run_command(self, command)

    @property
    def ext_modules(self):
        if SOURCE_EXT != 'pyx':
            return getattr(self, '_ext_modules', None)

        if getattr(self, '_ext_modules', None) is None:
            return None

        if getattr(self, '_last_run_command', None) in DONT_CYTHONIZE_FOR:
            return self._ext_modules

        if getattr(self, '_cythonized_ext_modules', None) is None:
            self._cythonized_ext_modules = cythonize(
                self._ext_modules,
                language_level=2,
            )

        return self._cythonized_ext_modules

    @ext_modules.setter
    def ext_modules(self, mods):
        self._cythonized_ext_modules = None
        self._ext_modules = mods

    @ext_modules.deleter
    def ext_modules(self):
        del self._ext_modules
        del self._cythonized_ext_modules


def make_extension(name_fmt, module, **kwargs):
    """Helper method to remove the repetition in extension declarations."""
    source = name_fmt.replace('.', '/') % module + '.' + SOURCE_EXT
    if not os.path.exists(source):
        raise OSError(source)
    return Extension(
        name_fmt % module,
        extra_link_args=link_args,
        extra_compile_args=compile_args,
        library_dirs=library_dirs,
        libraries=libraries,
        sources=[source],
        **kwargs
    )


# detect support
def main_file(module):
    return make_extension('gssapi.raw.%s', module)


ENUM_EXTS = []


def extension_file(module, canary):
    if ENABLE_SUPPORT_DETECTION and not hasattr(GSSAPI_LIB, canary):
        print('Skipping the %s extension because it '
              'is not supported by your GSSAPI implementation...' % module)
        return

    try:
        ENUM_EXTS.append(
            make_extension('gssapi.raw._enum_extensions.ext_%s', module,
                           include_dirs=['gssapi/raw/'])
        )
    except OSError:
        pass

    return make_extension('gssapi.raw.ext_%s', module)


def gssapi_modules(lst):
    # filter out missing files
    res = [mod for mod in lst if mod is not None]

    # add in supported mech files
    res.extend(
        make_extension('gssapi.raw.mech_%s', mech)
        for mech in os.environ.get('GSSAPI_MECHS', 'krb5').split(',')
    )

    # add in any present enum extension files
    res.extend(ENUM_EXTS)

    return res


long_desc = re.sub(r'\.\. role:: \w+\(code\)\s*\n\s*.+', '',
                   re.sub(r':(python|bash|code):', '',
                          re.sub(r'\.\. code-block:: \w+', '::',
                                 open('README.txt').read())))

install_requires = [
    'decorator',
]

setup(
    name='gssapi',
    version='1.7.1rc1',
    author='The Python GSSAPI Team',
    author_email='jborean93@gmail.com',
    packages=['gssapi', 'gssapi.raw', 'gssapi.raw._enum_extensions',
              'gssapi.tests'],
    description='Python GSSAPI Wrapper',
    long_description=long_desc,
    license='LICENSE.txt',
    url="https://github.com/pythongssapi/python-gssapi",
    python_requires=">=3.6",
    classifiers=[
        'Development Status :: 5 - Production/Stable',
        'Programming Language :: Python',
        '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 :: 3.10',
        'Intended Audience :: Developers',
        'License :: OSI Approved :: ISC License (ISCL)',
        'Programming Language :: Python :: Implementation :: CPython',
        'Programming Language :: Cython',
        'Topic :: Security',
        'Topic :: Software Development :: Libraries :: Python Modules'
    ],
    distclass=GSSAPIDistribution,
    cmdclass={'sdist': sdist_gssapi},
    ext_modules=gssapi_modules([
        main_file('misc'),
        main_file('exceptions'),
        main_file('creds'),
        main_file('names'),
        main_file('sec_contexts'),
        main_file('types'),
        main_file('message'),
        main_file('oids'),
        main_file('cython_converters'),
        main_file('chan_bindings'),
        extension_file('s4u', 'gss_acquire_cred_impersonate_name'),
        extension_file('cred_store', 'gss_store_cred_into'),
        extension_file('rfc4178', 'gss_set_neg_mechs'),
        extension_file('rfc5587', 'gss_indicate_mechs_by_attrs'),
        extension_file('rfc5588', 'gss_store_cred'),
        extension_file('rfc5801', 'gss_inquire_saslname_for_mech'),
        extension_file('cred_imp_exp', 'gss_import_cred'),
        extension_file('dce',
                       '__ApplePrivate_gss_wrap_iov' if osx_has_gss_framework
                       else 'gss_wrap_iov'),
        extension_file('dce_aead', 'gss_wrap_aead'),
        extension_file('iov_mic', 'gss_get_mic_iov'),
        extension_file('ggf', 'gss_inquire_sec_context_by_oid'),
        extension_file('set_cred_opt', 'gss_set_cred_option'),

        # see ext_rfc6680_comp_oid for more information on this split
        extension_file('rfc6680', 'gss_display_name_ext'),
        extension_file('rfc6680_comp_oid', 'GSS_C_NT_COMPOSITE_EXPORT'),

        # see ext_password{,_add}.pyx for more information on this split
        extension_file('password', 'gss_acquire_cred_with_password'),
        extension_file('password_add', 'gss_add_cred_with_password'),

        extension_file('krb5', 'gss_krb5_ccache_name'),
    ]),
    keywords=['gssapi', 'security'],
    install_requires=install_requires
)