Switch from SWIG to a native Python module

The native Python module implements a narrower interface and is much
simpler than the SWIG-wrapped version (the Python sso module API stays
the same).

The native Python module supports Python 3.

configure.ac

@@ -84,13 +84,11 @@ if test "$build_pam_sso" != "no" ; then
 fi
 AM_CONDITIONAL(ENABLE_PAM_SSO, [ test "$build_pam_sso" != "no" ])
 
-dnl SWIG
-dnl AC_PROG_SWIG(1.3.17)
-AX_PKG_SWIG(1.3.17)
-AX_SWIG_ENABLE_CXX
-AX_SWIG_MULTI_MODULE_SUPPORT
-AX_SWIG_PYTHON
-AM_CONDITIONAL(SWIG, [ test -n "$SWIG" && $SWIG -version >/dev/null 2>&1 ])
+dnl Python-dev (actually only used for $PYTHON)
+AX_PYTHON_DEVEL
+
+dnl nosetests
+AC_PATH_PROG([NOSETESTS], [nosetests])
 
 dnl GoogleTest (use the embedded version)
 GTEST_LIBS="\$(top_builddir)/lib/gtest/libgtest.la"

m4/ax_pkg_swig.m4

-# ===========================================================================
-#        http://www.gnu.org/software/autoconf-archive/ax_pkg_swig.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_PKG_SWIG([major.minor.micro], [action-if-found], [action-if-not-found])
-#
-# DESCRIPTION
-#
-#   This macro searches for a SWIG installation on your system. If found,
-#   then SWIG is AC_SUBST'd; if not found, then $SWIG is empty.  If SWIG is
-#   found, then SWIG_LIB is set to the SWIG library path, and AC_SUBST'd.
-#
-#   You can use the optional first argument to check if the version of the
-#   available SWIG is greater than or equal to the value of the argument. It
-#   should have the format: N[.N[.N]] (N is a number between 0 and 999. Only
-#   the first N is mandatory.) If the version argument is given (e.g.
-#   1.3.17), AX_PKG_SWIG checks that the swig package is this version number
-#   or higher.
-#
-#   As usual, action-if-found is executed if SWIG is found, otherwise
-#   action-if-not-found is executed.
-#
-#   In configure.in, use as:
-#
-#     AX_PKG_SWIG(1.3.17, [], [ AC_MSG_ERROR([SWIG is required to build..]) ])
-#     AX_SWIG_ENABLE_CXX
-#     AX_SWIG_MULTI_MODULE_SUPPORT
-#     AX_SWIG_PYTHON
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
-#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
-#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
-#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
-#   Copyright (c) 2011 Murray Cumming <murrayc@openismus.com>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 2 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-
-#serial 8
-
-AC_DEFUN([AX_PKG_SWIG],[
-        # Ubuntu has swig 2.0 as /usr/bin/swig2.0
-        AC_PATH_PROGS([SWIG],[swig swig2.0])
-        if test -z "$SWIG" ; then
-                m4_ifval([$3],[$3],[:])
-        elif test -n "$1" ; then
-                AC_MSG_CHECKING([SWIG version])
-                [swig_version=`$SWIG -version 2>&1 | grep 'SWIG Version' | sed 's/.*\([0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\).*/\1/g'`]
-                AC_MSG_RESULT([$swig_version])
-                if test -n "$swig_version" ; then
-                        # Calculate the required version number components
-                        [required=$1]
-                        [required_major=`echo $required | sed 's/[^0-9].*//'`]
-                        if test -z "$required_major" ; then
-                                [required_major=0]
-                        fi
-                        [required=`echo $required | sed 's/[0-9]*[^0-9]//'`]
-                        [required_minor=`echo $required | sed 's/[^0-9].*//'`]
-                        if test -z "$required_minor" ; then
-                                [required_minor=0]
-                        fi
-                        [required=`echo $required | sed 's/[0-9]*[^0-9]//'`]
-                        [required_patch=`echo $required | sed 's/[^0-9].*//'`]
-                        if test -z "$required_patch" ; then
-                                [required_patch=0]
-                        fi
-                        # Calculate the available version number components
-                        [available=$swig_version]
-                        [available_major=`echo $available | sed 's/[^0-9].*//'`]
-                        if test -z "$available_major" ; then
-                                [available_major=0]
-                        fi
-                        [available=`echo $available | sed 's/[0-9]*[^0-9]//'`]
-                        [available_minor=`echo $available | sed 's/[^0-9].*//'`]
-                        if test -z "$available_minor" ; then
-                                [available_minor=0]
-                        fi
-                        [available=`echo $available | sed 's/[0-9]*[^0-9]//'`]
-                        [available_patch=`echo $available | sed 's/[^0-9].*//'`]
-                        if test -z "$available_patch" ; then
-                                [available_patch=0]
-                        fi
-                        # Convert the version tuple into a single number for easier comparison.
-                        # Using base 100 should be safe since SWIG internally uses BCD values
-                        # to encode its version number.
-                        required_swig_vernum=`expr $required_major \* 10000 \
-                            \+ $required_minor \* 100 \+ $required_patch`
-                        available_swig_vernum=`expr $available_major \* 10000 \
-                            \+ $available_minor \* 100 \+ $available_patch`
-
-                        if test $available_swig_vernum -lt $required_swig_vernum; then
-                                AC_MSG_WARN([SWIG version >= $1 is required.  You have $swig_version.])
-                                SWIG=''
-                                m4_ifval([$3],[$3],[])
-                        else
-                                AC_MSG_CHECKING([for SWIG library])
-                                SWIG_LIB=`$SWIG -swiglib`
-                                AC_MSG_RESULT([$SWIG_LIB])
-                                m4_ifval([$2],[$2],[])
-                        fi
-                else
-                        AC_MSG_WARN([cannot determine SWIG version])
-                        SWIG=''
-                        m4_ifval([$3],[$3],[])
-                fi
-        fi
-        AC_SUBST([SWIG_LIB])
-])

m4/ax_swig_enable_cxx.m4

-# ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_swig_enable_cxx.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_SWIG_ENABLE_CXX
-#
-# DESCRIPTION
-#
-#   Enable SWIG C++ support. This affects all invocations of $(SWIG).
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
-#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
-#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
-#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 2 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-
-#serial 6
-
-AU_ALIAS([SWIG_ENABLE_CXX], [AX_SWIG_ENABLE_CXX])
-AC_DEFUN([AX_SWIG_ENABLE_CXX],[
-        AC_REQUIRE([AX_PKG_SWIG])
-        AC_REQUIRE([AC_PROG_CXX])
-        SWIG="$SWIG -c++"
-])

m4/ax_swig_multi_module_support.m4

-# ================================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_swig_multi_module_support.html
-# ================================================================================
-#
-# SYNOPSIS
-#
-#   AX_SWIG_MULTI_MODULE_SUPPORT
-#
-# DESCRIPTION
-#
-#   Enable support for multiple modules. This effects all invocations of
-#   $(SWIG). You have to link all generated modules against the appropriate
-#   SWIG runtime library. If you want to build Python modules for example,
-#   use the AX_SWIG_PYTHON macro and link the modules against
-#   $(AX_SWIG_PYTHON_LIBS).
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
-#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
-#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
-#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 2 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-
-#serial 7
-
-AU_ALIAS([SWIG_MULTI_MODULE_SUPPORT], [AX_SWIG_MULTI_MODULE_SUPPORT])
-AC_DEFUN([AX_SWIG_MULTI_MODULE_SUPPORT],[
-        AC_REQUIRE([AX_PKG_SWIG])
-        SWIG="$SWIG -noruntime"
-])

m4/ax_swig_python.m4

-# ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_swig_python.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_SWIG_PYTHON([use-shadow-classes = {no, yes}])
-#
-# DESCRIPTION
-#
-#   Checks for Python and provides the $(AX_SWIG_PYTHON_CPPFLAGS), and
-#   $(AX_SWIG_PYTHON_OPT) output variables.
-#
-#   $(AX_SWIG_PYTHON_OPT) contains all necessary SWIG options to generate
-#   code for Python. Shadow classes are enabled unless the value of the
-#   optional first argument is exactly 'no'. If you need multi module
-#   support (provided by the AX_SWIG_MULTI_MODULE_SUPPORT macro) use
-#   $(AX_SWIG_PYTHON_LIBS) to link against the appropriate library. It
-#   contains the SWIG Python runtime library that is needed by the type
-#   check system for example.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
-#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
-#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
-#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 2 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-
-#serial 7
-
-AU_ALIAS([SWIG_PYTHON], [AX_SWIG_PYTHON])
-AC_DEFUN([AX_SWIG_PYTHON],[
-        AC_REQUIRE([AX_PKG_SWIG])
-        AC_REQUIRE([AX_PYTHON_DEVEL])
-        test "x$1" != "xno" || swig_shadow=" -noproxy"
-        AC_SUBST([AX_SWIG_PYTHON_OPT],[-python$swig_shadow])
-        AC_SUBST([AX_SWIG_PYTHON_CPPFLAGS],[$PYTHON_CPPFLAGS])
-])

src/Makefile.am

@@ -7,9 +7,7 @@ if ENABLE_PAM_SSO
 PAM_SSO_SUBDIR = pam_sso
 endif
 
-if SWIG
 PYTHON_SUBDIR = python sso_server
-endif
 
 SUBDIRS = \
 	sso \

src/python/Makefile.am

@@ -15,10 +15,10 @@ check-local:
 	env \
 	    LD_LIBRARY_PATH=$(top_builddir)/src/sso/.libs \
 	    DYLD_LIBRARY_PATH=$(top_builddir)/src/sso/.libs \
-	    nosetests -v
+	    $(NOSETESTS) -v
 
 clean-local:
-	-rm -f sso/sso_c.py sso/sso_wrap.cpp $(wildcard sso/_sso_c.*so)
+	-rm -f $(wildcard sso/_pysso*.so)
 	$(PYTHON_SETUP_PY) clean --all
 
 install-exec-local:

src/python/setup.py

@@ -10,7 +10,7 @@ top_srcdir = os.path.join(SRCDIR, '..')
 
 # If BUILD_MODULE is not defined, bundle libsso into the Python
 # extension so that this package is pip-installable directly.
-ext_sources = ['sso/sso.i']
+ext_sources = ['sso/sso_python.c']
 libraries = ['sso']
 if not os.getenv('BUILD_MODULE'):
     ext_sources.extend(os.path.join(top_srcdir, 'sso', x) for x in [
@@ -28,8 +28,8 @@ class build_py(_build_py):
 
 setup(name='sso',
       cmdclass={'build_py': build_py},
-      ext_modules=[Extension('sso._sso_c', ext_sources,
-                             swig_opts=['-modern', '-I' + top_srcdir, '-py3'],
+      ext_modules=[Extension('sso._pysso', ext_sources,
+                             #swig_opts=['-modern', '-I' + top_srcdir, '-py3'],
                              include_dirs=[top_srcdir],
                              libraries=libraries,
                              library_dirs=[SSO_LIB_DIR],

src/python/sso/.gitignore

-_sso_c.so
-sso_c.py
-sso_wrap.c
+*.so

src/python/sso/__init__.py

-# Python 3 compatibility for basestring check as used in isinstance() below.
-try:
-    basestring
-except NameError:
-    basestring = (str, bytes)
-
-from .sso_c import sso_generate_keys as generate_keys
-from .sso_c import sso_ticket_new, sso_ticket_free, \
-     sso_ticket_sign, sso_ticket_open, sso_strerror, \
-     sso_validate
-
-
-class Error(Exception):
-
-    def __init__(self, code):
-        self.code = code
-        Exception.__init__(self, sso_strerror(code))
+import time
+from ._pysso import generate_keys, create_and_sign_ticket, verify_ticket, error
 
+Error = error
 
+# Ticket is just a simple container for ticket attributes.
 class Ticket(object):
 
-    def __init__(self, tkt_or_user=None, service=None, domain=None,
-                 nonce=None, groups=None, ttl=3600):
-        # Fix old constructor behavior with positional args.
-        if isinstance(groups, int):
-            ttl = groups
-            groups = None
-        if tkt_or_user is None or isinstance(tkt_or_user, basestring):
-            self._tkt = sso_ticket_new(
-                tkt_or_user, service, domain, nonce, groups, ttl)
-        else:
-            self._tkt = tkt_or_user
-
-    def __del__(self):
-        if hasattr(self, '_tkt'):
-            sso_ticket_free(self._tkt)
+    def __init__(self, user, service, domain, nonce=None, groups=None, ttl=3600, expires=None):
+        self._user = user
+        self._service = service
+        self._domain = domain
+        self._nonce = nonce
+        self._groups = groups
+        # 'expires' has precedence over 'ttl'.
+        if expires is None:
+            expires = int(time.time()) + ttl
+        self._expires = expires
 
     def __eq__(self, t2):
         return (self.user() == t2.user() and
                 self.service() == t2.service() and
                 self.domain() == t2.domain() and
-                self.expires() == t2.expires())
+                self.nonce() == t2.nonce())
 
     def empty(self):
-        return (not self._tkt.user and not self._tkt.domain
-                and not self._tkt.service)
+        return (not self._user and not self._domain
+                and not self._service)
 
     def user(self):
-        return self._tkt.user
+        return self._user
 
     def domain(self):
-        return self._tkt.domain
+        return self._domain
 
     def service(self):
-        return self._tkt.service
+        return self._service
 
     def nonce(self):
-        return self._tkt.nonce
+        return self._nonce
 
     def groups(self):
-        return self._tkt.groups
+        return self._groups
 
     def expires(self):
-        return self._tkt.expires
+        return self._expires
+
+    def ttl(self):
+        return int(self._expires - time.time())
 
 
 class Signer(object):
@@ -70,10 +55,15 @@ class Signer(object):
         self._sk = sk
 
     def sign(self, t):
-        r, signed = sso_ticket_sign(t._tkt, self._sk)
-        if r != 0:
-            raise Error(r)
-        return signed
+        return create_and_sign_ticket(
+            self._sk,
+            t.user(),
+            t.service(),
+            t.domain(),
+            t.nonce(),
+            t.groups(),
+            t.ttl(),
+        )
 
 
 class Verifier(object):
@@ -85,10 +75,12 @@ class Verifier(object):
         self._ok_groups = ok_groups
 
     def verify(self, encoded_tkt, nonce=None):
-        r, tkt = sso_ticket_open(encoded_tkt, self._pk)
-        if r != 0:
-            raise Error(r)
-        r = sso_validate(tkt, self._service, self._domain, nonce, self._ok_groups)
-        if r != 0:
-            raise Error(r)
-        return Ticket(tkt)
+        result = verify_ticket(self._pk, encoded_tkt, self._service, self._domain, nonce, self._ok_groups)
+        return Ticket(
+            result['user'],
+            self._service,
+            self._domain,
+            nonce,
+            result['groups'],
+            result['expires'],
+        )

src/python/sso/py3compat.h

+/*
+   Unix SMB/CIFS implementation.
+   Python 3 compatibility macros
+   Copyright (C) Petr Viktorin <pviktori@redhat.com> 2015
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _SAMBA_PY3COMPAT_H_
+#define _SAMBA_PY3COMPAT_H_
+#include <Python.h>
+
+/* Quick docs:
+ *
+ * The IS_PY3 preprocessor constant is 1 on Python 3, and 0 on Python 2.
+ *
+ * "PyStr_*" works like PyUnicode_* on Python 3, but uses bytestrings (str)
+ * under Python 2.
+ *
+ * "PyBytes_*" work like in Python 3; on Python 2 they are aliased to their
+ * PyString_* names.
+ *
+ * "PyInt_*" works like PyLong_*
+ *
+ * Syntax for module initialization is as in Python 3, except the entrypoint
+ * function definition and declaration:
+ *     PyMODINIT_FUNC PyInit_modulename(void);
+ *     PyMODINIT_FUNC PyInit_modulename(void)
+ *     {
+ *         ...
+ *     }
+ * is replaced by:
+ *     MODULE_INIT_FUNC(modulename)
+ *     {
+ *         ...
+ *     }
+ *
+ * In the entrypoint, create a module using PyModule_Create and PyModuleDef,
+ * and return it. See Python 3 documentation for details.
+ * For Python 2 compatibility, always set PyModuleDef.m_size to -1.
+ *
+ */
+
+#if PY_MAJOR_VERSION >= 3
+
+/***** Python 3 *****/
+
+#define IS_PY3 1
+
+/* Strings */
+
+#define PyStr_Type PyUnicode_Type
+#define PyStr_Check PyUnicode_Check
+#define PyStr_CheckExact PyUnicode_CheckExact
+#define PyStr_FromString PyUnicode_FromString
+#define PyStr_FromStringAndSize PyUnicode_FromStringAndSize
+#define PyStr_FromFormat PyUnicode_FromFormat
+#define PyStr_FromFormatV PyUnicode_FromFormatV
+#define PyStr_AsString PyUnicode_AsUTF8
+#define PyStr_Concat PyUnicode_Concat
+#define PyStr_Format PyUnicode_Format
+#define PyStr_InternInPlace PyUnicode_InternInPlace
+#define PyStr_InternFromString PyUnicode_InternFromString
+#define PyStr_Decode PyUnicode_Decode
+
+#define PyStr_AsUTF8String PyUnicode_AsUTF8String // returns PyBytes
+#define PyStr_AsUTF8 PyUnicode_AsUTF8
+#define PyStr_AsUTF8AndSize PyUnicode_AsUTF8AndSize
+
+/* description of bytes and string objects */
+#define PY_DESC_PY3_BYTES "bytes"
+#define PY_DESC_PY3_STRING "string"
+
+/* Determine if object is really bytes, for code that runs
+ * in python2 & python3 (note: PyBytes_Check is replaced by
+ * PyString_Check in python2) so care needs to be taken when
+ * writing code that will check if incoming type is bytes that
+ * will work as expected in python2 & python3
+ */
+
+#define IsPy3Bytes PyBytes_Check
+
+#define IsPy3BytesOrString(pystr) \
+    (PyStr_Check(pystr) || PyBytes_Check(pystr))
+
+#else
+
+/***** Python 2 *****/
+
+#define IS_PY3 0
+
+/* Strings */
+
+#define PyStr_Type PyString_Type
+#define PyStr_Check PyString_Check
+#define PyStr_CheckExact PyString_CheckExact
+#define PyStr_FromString PyString_FromString
+#define PyStr_FromStringAndSize PyString_FromStringAndSize
+#define PyStr_FromFormat PyString_FromFormat
+#define PyStr_FromFormatV PyString_FromFormatV
+#define PyStr_AsString PyString_AsString
+#define PyStr_Format PyString_Format
+#define PyStr_InternInPlace PyString_InternInPlace
+#define PyStr_InternFromString PyString_InternFromString
+#define PyStr_Decode PyString_Decode
+
+#define PyStr_AsUTF8String(str) (Py_INCREF(str), (str))
+#define PyStr_AsUTF8 PyString_AsString
+#define PyStr_AsUTF8AndSize(pystr, sizeptr) \
+    ((*sizeptr=PyString_Size(pystr)), PyString_AsString(pystr))
+
+#define PyBytes_Type PyString_Type