_build_ffi.py

# -*- coding: utf-8 -*-
#
# build_ffi.py
#
# Copyright (C) 2006-2020 wolfSSL Inc.
#
# This file is part of wolfSSL. (formerly known as CyaSSL)
#
# wolfSSL 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.
#
# wolfSSL 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

# pylint: disable=missing-docstring, invalid-name

from distutils.util import get_platform
from cffi import FFI
from wolfssl._build_wolfssl import wolfssl_inc_path, wolfssl_lib_path
import wolfssl._openssl as openssl
import subprocess
import shlex
import os
from ctypes import cdll
from collections import namedtuple

def make_optional_func_list(libwolfssl_path, funcs):
    if libwolfssl_path.endswith(".so"):
        libwolfssl = cdll.LoadLibrary(libwolfssl_path)
        defined = []
        for func in funcs:
            try:
                getattr(libwolfssl, func.name)
                defined.append(func)
            except AttributeError as _:
                pass
    # Can't discover functions in a static library with ctypes. Need to fall
    # back to running nm, if available, as a subprocess.
    else:
        which_cmd = "which nm"
        result = subprocess.run(shlex.split(which_cmd))
        if result.returncode == 0:
            nm_cmd = "nm --defined-only {}".format(libwolfssl_path)
            result = subprocess.run(shlex.split(nm_cmd), capture_output=True)
            nm_stdout = result.stdout.decode()
            defined = [func for func in funcs if func.name in nm_stdout]
        else:
            print(("WARNING: Can't determine available libwolfssl functions."
                   " Assuming all optional functions are available."))
            defined = funcs

    return defined

libwolfssl_path = os.path.join(wolfssl_lib_path(), "libwolfssl.a")
if not os.path.exists(libwolfssl_path):
    libwolfssl_path = os.path.join(wolfssl_lib_path(), "libwolfssl.so")
    if not os.path.exists(libwolfssl_path):
        err = "Couldn't find libwolfssl under {}.".format(wolfssl_lib_path())
        raise Exception(err)

WolfFunction = namedtuple("WolfFunction", ["name", "native_sig", "ossl_sig"])
# Depending on how wolfSSL was configured, the functions below may or may not be
# defined.
optional_funcs = [
    WolfFunction("wolfSSL_Rehandshake",
                 "int wolfSSL_Rehandshake(WOLFSSL*)",
                 "int SSL_renegotiate(SSL*)"),
    WolfFunction("wolfSSL_ERR_func_error_string",
                 "const char* wolfSSL_ERR_func_error_string(unsigned long)",
                 "const char* ERR_func_error_string(unsigned long)"),
    WolfFunction("wolfSSL_ERR_lib_error_string",
                 "const char* wolfSSL_ERR_lib_error_string(unsigned long)",
                 "const char* ERR_lib_error_string(unsigned long)"),
    WolfFunction("wolfSSL_X509_EXTENSION_dup",
                 "WOLFSSL_X509_EXTENSION* wolfSSL_X509_EXTENSION_dup(WOLFSSL_X509_EXTENSION*)",
                 "X509_EXTENSION* X509_EXTENSION_dup(X509_EXTENSION*)")
]
optional_funcs = make_optional_func_list(libwolfssl_path, optional_funcs)

source = """
    #include <wolfssl/options.h>
    #include <wolfssl/ssl.h>
"""
ffi_source = source + openssl.source

ffi = FFI()

ffi.set_source(
    "wolfssl._ffi",
    ffi_source,
    include_dirs=[wolfssl_inc_path()],
    library_dirs=[wolfssl_lib_path()],
    libraries=["wolfssl"],
)

cdef = """
    /**
     * Constants
     */
    static const long SOCKET_PEER_CLOSED_E;

    /**
     * Types
     */
    typedef unsigned char byte;
    typedef unsigned int word32;
    
    typedef ... WOLFSSL_CTX;
    typedef ... WOLFSSL;
    typedef ... WOLFSSL_X509;
    typedef ... WOLFSSL_X509_EXTENSION;
    typedef ... WOLFSSL_X509_STORE_CTX;
    typedef ... WOLFSSL_X509_NAME;
    typedef ... WOLFSSL_X509_NAME_ENTRY;
    typedef ... WOLFSSL_ALERT_HISTORY;
    typedef ... WOLFSSL_METHOD;
    typedef ... WOLFSSL_ASN1_TIME;
    typedef ... WOLFSSL_ASN1_GENERALIZEDTIME;
    typedef ... WOLFSSL_ASN1_STRING;
    typedef ... WOLFSSL_ASN1_OBJECT;

    typedef int (*VerifyCallback)(int, WOLFSSL_X509_STORE_CTX*);
    typedef int pem_password_cb(char*, int, int, void*);
    typedef int (*CallbackSniRecv)(WOLFSSL*, int*, void*);

    /**
     * Memory
     */
    void  wolfSSL_Free(void*);
    void  wolfSSL_OPENSSL_free(void*);

    /**
     * Debugging
     */
    void wolfSSL_Debugging_ON();
    void wolfSSL_Debugging_OFF();

    /**
     * SSL/TLS Method functions
     */
    WOLFSSL_METHOD* wolfTLSv1_1_server_method(void);
    WOLFSSL_METHOD* wolfTLSv1_1_client_method(void);

    WOLFSSL_METHOD* wolfTLSv1_2_server_method(void);
    WOLFSSL_METHOD* wolfTLSv1_2_client_method(void);

    WOLFSSL_METHOD* wolfSSLv23_server_method(void);
    WOLFSSL_METHOD* wolfSSLv23_client_method(void);

    WOLFSSL_METHOD* wolfSSLv23_method(void);
    WOLFSSL_METHOD* wolfTLSv1_1_method(void);
    WOLFSSL_METHOD* wolfTLSv1_2_method(void);

    /**
     * SSL/TLS Context functions
     */
    WOLFSSL_CTX* wolfSSL_CTX_new(WOLFSSL_METHOD*);
    void         wolfSSL_CTX_free(WOLFSSL_CTX*);

    void wolfSSL_CTX_set_verify(WOLFSSL_CTX*, int, VerifyCallback);
    int  wolfSSL_CTX_set_cipher_list(WOLFSSL_CTX*, const char*);
    int  wolfSSL_CTX_use_PrivateKey_file(WOLFSSL_CTX*, const char*, int);
    int  wolfSSL_CTX_load_verify_locations(WOLFSSL_CTX*, const char*,
            const char*);
    int  wolfSSL_CTX_load_verify_buffer(WOLFSSL_CTX*, const unsigned char*,
            long,int);
    int  wolfSSL_CTX_use_certificate_chain_file(WOLFSSL_CTX*, const char *);
    int  wolfSSL_CTX_UseSNI(WOLFSSL_CTX*, unsigned char, const void*,
            unsigned short);
    long wolfSSL_CTX_get_options(WOLFSSL_CTX*);
    long wolfSSL_CTX_set_options(WOLFSSL_CTX*, long);
    void wolfSSL_CTX_set_default_passwd_cb(WOLFSSL_CTX*, pem_password_cb*);
    int  wolfSSL_CTX_set_tlsext_servername_callback(WOLFSSL_CTX*,
            CallbackSniRecv);
    long wolfSSL_CTX_set_mode(WOLFSSL_CTX*, long);

    /**
     * SSL/TLS Session functions
     */
    WOLFSSL* wolfSSL_new(WOLFSSL_CTX*);
    void  wolfSSL_free(WOLFSSL*);

    int           wolfSSL_set_fd(WOLFSSL*, int);
    int           wolfSSL_get_error(WOLFSSL*, int);
    char*         wolfSSL_ERR_error_string(int, char*);
    int           wolfSSL_negotiate(WOLFSSL*);
    int           wolfSSL_connect(WOLFSSL*);
    int           wolfSSL_accept(WOLFSSL*);
    int           wolfSSL_write(WOLFSSL*, const void*, int);
    int           wolfSSL_read(WOLFSSL*, void*, int);
    int           wolfSSL_pending(WOLFSSL*);
    int           wolfSSL_shutdown(WOLFSSL*);
    WOLFSSL_X509* wolfSSL_get_peer_certificate(WOLFSSL*);
    int           wolfSSL_UseSNI(WOLFSSL*, unsigned char, const void*,
                      unsigned short);
    int           wolfSSL_check_domain_name(WOLFSSL*, const char*);
    int           wolfSSL_get_alert_history(WOLFSSL*, WOLFSSL_ALERT_HISTORY*);
    const char*   wolfSSL_get_servername(WOLFSSL*, unsigned char);
    int           wolfSSL_set_tlsext_host_name(WOLFSSL*, const char*);
    long          wolfSSL_ctrl(WOLFSSL*, int, long, void*);
    void          wolfSSL_set_connect_state(WOLFSSL*);

    /**
     * WOLFSSL_X509 functions
     */
    char*                    wolfSSL_X509_get_subjectCN(void*);
    char*                    wolfSSL_X509_get_next_altname(void*);
    const unsigned char*     wolfSSL_X509_get_der(void*, int*);
    WOLFSSL_X509*            wolfSSL_X509_STORE_CTX_get_current_cert(
                                 WOLFSSL_X509_STORE_CTX*);
    int                      wolfSSL_X509_up_ref(WOLFSSL_X509*);
    void                     wolfSSL_X509_free(WOLFSSL_X509*);
    int                      wolfSSL_X509_STORE_CTX_get_error(
                                 WOLFSSL_X509_STORE_CTX*);
    int                      wolfSSL_X509_STORE_CTX_get_error_depth(
                                 WOLFSSL_X509_STORE_CTX*);
    int                      wolfSSL_get_ex_data_X509_STORE_CTX_idx(void);
    void*                    wolfSSL_X509_STORE_CTX_get_ex_data(
                                 WOLFSSL_X509_STORE_CTX*, int);
    void                     wolfSSL_X509_STORE_CTX_set_error(
                                 WOLFSSL_X509_STORE_CTX*, int);
    WOLFSSL_X509_NAME*       wolfSSL_X509_get_subject_name(WOLFSSL_X509*);
    char*                    wolfSSL_X509_NAME_oneline(WOLFSSL_X509_NAME*,
                                 char*, int);
    WOLFSSL_ASN1_TIME*       wolfSSL_X509_get_notBefore(const WOLFSSL_X509*);
    WOLFSSL_ASN1_TIME*       wolfSSL_X509_get_notAfter(const WOLFSSL_X509*);
    int                      wolfSSL_X509_NAME_entry_count(WOLFSSL_X509_NAME*);
    WOLFSSL_X509_NAME_ENTRY* wolfSSL_X509_NAME_get_entry(WOLFSSL_X509_NAME*, int);
    WOLFSSL_ASN1_OBJECT*     wolfSSL_X509_NAME_ENTRY_get_object(
                                 WOLFSSL_X509_NAME_ENTRY*);
    WOLFSSL_ASN1_STRING*     wolfSSL_X509_NAME_ENTRY_get_data(WOLFSSL_X509_NAME_ENTRY*);
    int                      wolfSSL_X509_NAME_get_index_by_NID(WOLFSSL_X509_NAME*, int,
                                 int);
    int                      wolfSSL_X509_NAME_cmp(const WOLFSSL_X509_NAME*,
                                 const WOLFSSL_X509_NAME*);
    int                      wolfSSL_X509_get_ext_count(const WOLFSSL_X509*);
    WOLFSSL_X509_EXTENSION*  wolfSSL_X509_get_ext(const WOLFSSL_X509*, int);
    void                     wolfSSL_X509_EXTENSION_free(
                                 WOLFSSL_X509_EXTENSION*);
    WOLFSSL_ASN1_OBJECT*     wolfSSL_X509_EXTENSION_get_object(
                                 WOLFSSL_X509_EXTENSION*);
    WOLFSSL_ASN1_STRING*     wolfSSL_X509_EXTENSION_get_data(
                                 WOLFSSL_X509_EXTENSION*);
    WOLFSSL_X509*            wolfSSL_X509_dup(WOLFSSL_X509*);

    /**
     * ASN.1
     */
    int                wolfSSL_ASN1_STRING_length(WOLFSSL_ASN1_STRING*);
    int                wolfSSL_ASN1_STRING_type(const WOLFSSL_ASN1_STRING*);
    unsigned char*     wolfSSL_ASN1_STRING_data(WOLFSSL_ASN1_STRING*);
    WOLFSSL_ASN1_TIME* wolfSSL_ASN1_TIME_to_generalizedtime(WOLFSSL_ASN1_TIME*,
                           WOLFSSL_ASN1_TIME**);
    void               wolfSSL_ASN1_GENERALIZEDTIME_free(
                           WOLFSSL_ASN1_GENERALIZEDTIME*);
    void               wolfSSL_ASN1_TIME_free(WOLFSSL_ASN1_TIME*);
    int                wolfSSL_ASN1_TIME_get_length(WOLFSSL_ASN1_TIME*);
    unsigned char*     wolfSSL_ASN1_TIME_get_data(WOLFSSL_ASN1_TIME*);
    int                wolfSSL_ASN1_STRING_to_UTF8(unsigned char **, 
                           WOLFSSL_ASN1_STRING*);

    /**
     * Misc.
     */
    int           wolfSSL_library_init(void);
    const char*   wolfSSL_alert_type_string_long(int);
    const char*   wolfSSL_alert_desc_string_long(int);
    unsigned long wolfSSL_ERR_get_error(void);
    const char*   wolfSSL_ERR_reason_error_string(unsigned long);
    int           wolfSSL_OBJ_obj2nid(const WOLFSSL_ASN1_OBJECT*);
    const char*   wolfSSL_OBJ_nid2sn(int n);
    int           wolfSSL_OBJ_txt2nid(const char*);
"""

for func in optional_funcs:
    cdef += "{};".format(func.native_sig)

ffi_cdef = cdef + openssl.construct_cdef(optional_funcs)
ffi.cdef(ffi_cdef)

if __name__ == "__main__":
    ffi.compile(verbose=True)