devices/linux/Files/main.py

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#!/usr/bin/env python3
"""
 * **************************************************************************
 * Contributions to this work were made on behalf of the GÉANT project,
 * a project that has received funding from the European Union’s Framework
 * Programme 7 under Grant Agreements No. 238875 (GN3)
 * and No. 605243 (GN3plus), Horizon 2020 research and innovation programme
 * under Grant Agreements No. 691567 (GN4-1) and No. 731122 (GN4-2).
 * On behalf of the aforementioned projects, GEANT Association is
 * the sole owner of the copyright in all material which was developed
 * by a member of the GÉANT project.
 * GÉANT Vereniging (Association) is registered with the Chamber of
 * Commerce in Amsterdam with registration number 40535155 and operates
 * in the UK as a branch of GÉANT Vereniging.
 *
 * Registered office: Hoekenrode 3, 1102BR Amsterdam, The Netherlands.
 * UK branch address: City House, 126-130 Hills Road, Cambridge CB2 1PQ, UK
 *
 * License: see the web/copyright.inc.php file in the file structure or
 *          <base_url>/copyright.php after deploying the software

Authors:
    Tomasz Wolniewicz <twoln@umk.pl>
    Michał Gasewicz <genn@umk.pl> (Network Manager support)

Contributors:
    Steffen Klemer https://github.com/sklemer1
    ikreb7 https://github.com/ikreb7
    Dimitri Papadopoulos Orfanos https://github.com/DimitriPapadopoulos
    sdasda7777 https://github.com/sdasda7777
Many thanks for multiple code fixes, feature ideas, styling remarks
much of the code provided by them in the form of pull requests
has been incorporated into the final form of this script.

This script is the main body of the CAT Linux installer.
In the generation process configuration settings are added
as well as messages which are getting translated into the language
selected by the user.

The script runs under python3.

"""
import argparse
import base64
import getpass
import os
import platform
import re
import subprocess
import sys
import uuid
from shutil import copyfile
from typing import List, Type, Union

NM_AVAILABLE = True
CRYPTO_AVAILABLE = True
DEBUG_ON = False

parser = argparse.ArgumentParser(description='eduroam linux installer.')
parser.add_argument('--debug', '-d', action='store_true', dest='debug',
                    default=False, help='set debug flag')
parser.add_argument('--username', '-u', action='store', dest='username',
                    help='set username')
parser.add_argument('--password', '-p', action='store', dest='password',
                    help='set text_mode flag')
parser.add_argument('--silent', '-s', action='store_true', dest='silent',
                    help='set silent flag')
parser.add_argument('--pfxfile', action='store', dest='pfx_file',
                    help='set path to user certificate file')
parser.add_argument("--wpa_conf", action='store_true', dest='wpa_conf',
                    help='generate wpa_supplicant config file without configuring the system')
parser.add_argument("--gui", action='store', dest='gui',
                    help='one of: tty, tkinter, zenity, kdialog, yad - use this GUI system if present, falling back to standard choice if not')
ARGS = parser.parse_args()
if ARGS.debug:
    DEBUG_ON = True
    print("Running debug mode")


def debug(msg) -> None:
    """Print debugging messages to stdout"""
    if not DEBUG_ON:
        return
    else:
        print("DEBUG:" + str(msg))


def byte_to_string(barray: List) -> str:
    """conversion utility"""
    return "".join([chr(x) for x in barray])


debug(sys.version_info.major)

try:
    import dbus
except ImportError:
    print("WARNING: Cannot import the dbus module - please install dbus-python!")
    debug("Cannot import the dbus module")
    NM_AVAILABLE = False


try:
    from OpenSSL import crypto
    crypto.load_pkcs12 # missing in newer versions
except (ImportError, AttributeError):  # AttributeError sometimes thrown by old/broken OpenSSL versions
    CRYPTO_AVAILABLE = False


def detect_desktop_environment() -> str:
    """
    Detect what desktop type is used. This method is prepared for
    possible future use with password encryption on supported distros

    the function below was partially copied from
    https://ubuntuforums.org/showthread.php?t=1139057
    """
    desktop_environment = 'generic'
    if os.environ.get('KDE_FULL_SESSION') == 'true':
        desktop_environment = 'kde'
    elif os.environ.get('GNOME_DESKTOP_SESSION_ID'):
        desktop_environment = 'gnome'
    else:
        try:
            shell_command = subprocess.Popen(['xprop', '-root',
                                              '_DT_SAVE_MODE'],
                                             stdout=subprocess.PIPE,
                                             stderr=subprocess.PIPE)
            out, _ = shell_command.communicate()
            info = out.decode('utf-8').strip()
        except (OSError, RuntimeError):
            pass
        else:
            if ' = "xfce4"' in info:
                desktop_environment = 'xfce'
    return desktop_environment


def get_system() -> List:
    """
    Detect Linux platform. Not used at this stage.
    It is meant to enable password encryption in distros
    that can handle this well.
    """
    system = platform.system_alias(
        platform.system(),
        platform.release(),
        platform.version()
    )
    return [system, detect_desktop_environment()]


def get_config_path() -> str:
    """
    Return XDG_CONFIG_HOME path if exists otherwise $HOME/.config
    """

    xdg_config_home_path = os.environ.get('XDG_CONFIG_HOME')
    if not xdg_config_home_path:
        home_path = os.environ.get('HOME')
        return '{}/.config'.format(home_path)
    return xdg_config_home_path


def run_installer() -> None:
    """
    This is the main installer part. It tests for NM availability
    gets user credentials and starts a proper installer.
    """
    global ARGS
    global NM_AVAILABLE
    username = ''
    password = ''
    silent = False
    pfx_file = ''
    gui = ''
    wpa_conf = False

    if ARGS.username:
        username = ARGS.username
    if ARGS.password:
        password = ARGS.password
    if ARGS.silent:
        silent = ARGS.silent
    if ARGS.pfx_file:
        pfx_file = ARGS.pfx_file
    if ARGS.wpa_conf:
        wpa_conf = ARGS.wpa_conf
    if ARGS.gui:
        gui = ARGS.gui
    debug(get_system())
    debug("Calling InstallerData")
    installer_data = InstallerData(silent=silent, username=username,
                                   password=password, pfx_file=pfx_file, gui=gui)

    if wpa_conf:
        NM_AVAILABLE = False

    # test dbus connection
    if NM_AVAILABLE:
        config_tool = CatNMConfigTool()
        if config_tool.connect_to_nm() is None:
            NM_AVAILABLE = False
    if not NM_AVAILABLE and not wpa_conf:
        # no dbus so ask if the user will want wpa_supplicant config
        if installer_data.ask(Messages.save_wpa_conf, Messages.cont, 1):
            sys.exit(1)
    installer_data.get_user_cred()
    installer_data.save_ca()
    if NM_AVAILABLE:
        config_tool.add_connections(installer_data)
    else:
        wpa_config = WpaConf()
        wpa_config.create_wpa_conf(Config.ssids, installer_data)
    installer_data.show_info(Messages.installation_finished)


class Messages:
    """
    These are initial definitions of messages, but they will be
    overridden with translated strings.
    """
    quit = "Really quit?"
    credentials_prompt = "Please, enter your credentials:"
    username_prompt = "enter your userid"
    enter_password = "enter password"
    enter_import_password = "enter your import password"
    incorrect_password = "incorrect password"
    repeat_password = "repeat your password"
    passwords_differ = "passwords do not match"
    installation_finished = "Installation successful"
    cat_dir_exists = "Directory {} exists; some of its files may be " \
                     "overwritten."
    cont = "Continue?"
    nm_not_supported = "This NetworkManager version is not supported"
    cert_error = "Certificate file not found, looks like a CAT error"
    unknown_version = "Unknown version"
    dbus_error = "DBus connection problem, a sudo might help"
    ok = "OK"
    yes = "Y"
    nay = "N"
    p12_filter = "personal certificate file (p12 or pfx)"
    all_filter = "All files"
    p12_title = "personal certificate file (p12 or pfx)"
    save_wpa_conf = "NetworkManager configuration failed. " \
                    "Ensure you have the dbus-python package for your distro installed on your system. " \
                    "We may generate a wpa_supplicant configuration file " \
                    "if you wish. Be warned that your connection password will be saved " \
                    "in this file as clear text."
    save_wpa_confirm = "Write the file"
    wrongUsernameFormat = "Error: Your username must be of the form " \
                          "'xxx@institutionID' e.g. 'john@example.net'!"
    wrong_realm = "Error: your username must be in the form of 'xxx@{}'. " \
                  "Please enter the username in the correct format."
    wrong_realm_suffix = "Error: your username must be in the form of " \
                         "'xxx@institutionID' and end with '{}'. Please enter the username " \
                         "in the correct format."
    user_cert_missing = "personal certificate file not found"
    # "File %s exists; it will be overwritten."
    # "Output written to %s"


class Config:
    """
    This is used to prepare settings during installer generation.
    """
    instname = ""
    profilename = ""
    url = ""
    email = ""
    title = "eduroam CAT"
    servers = []
    ssids = []
    del_ssids = []
    eap_outer = ''
    eap_inner = ''
    use_other_tls_id = False
    server_match = ''
    anonymous_identity = ''
    CA = ""
    init_info = ""
    init_confirmation = ""
    tou = ""
    sb_user_file = ""
    verify_user_realm_input = False
    user_realm = ""
    hint_user_input = False


class InstallerData:
    """
    General user interaction handling, supports zenity, KDialog, yad and
    standard command-line interface
    """

    def __init__(self, silent: bool = False, username: str = '',
                 password: str = '', pfx_file: str = '', gui: str = '') -> None:
        self.graphics = ''
        self.username = username
        self.password = password
        self.silent = silent
        self.pfx_file = pfx_file
        if gui in ('tty', 'tkinter', 'yad', 'zenity', 'kdialog'):
            self.gui = gui
        else:
            self.gui = ''
        debug("starting constructor")
        if silent:
            self.graphics = 'tty'
        else:
            self.__get_graphics_support()
        self.show_info(Config.init_info.format(Config.instname,
                                               Config.email, Config.url))
        if self.ask(Config.init_confirmation.format(Config.instname,
                                                    Config.profilename),
                    Messages.cont, 1):
            sys.exit(1)
        if Config.tou != '':
            if self.ask(Config.tou, Messages.cont, 1):
                sys.exit(1)
        if os.path.exists(get_config_path() + '/cat_installer'):
            if self.ask(Messages.cat_dir_exists.format(
                    get_config_path() + '/cat_installer'),
                    Messages.cont, 1):
                sys.exit(1)
        else:
            os.mkdir(get_config_path() + '/cat_installer', 0o700)

    @staticmethod
    def save_ca() -> None:
        """
        Save CA certificate to cat_installer directory
        (create directory if needed)
        """
        certfile = get_config_path() + '/cat_installer/ca.pem'
        debug("saving cert")
        with open(certfile, 'w') as cert:
            cert.write(Config.CA + "\n")

    def ask(self, question: str, prompt: str = '', default: bool = None) -> int:
        """
        Prompt user for a Y/N reply, possibly supplying a default answer
        """
        if self.silent:
            return 0
        if self.graphics == 'tty':
            yes = Messages.yes[:1].upper()
            nay = Messages.nay[:1].upper()
            print("\n-------\n" + question + "\n")
            while True:
                tmp = prompt + " (" + Messages.yes + "/" + Messages.nay + ") "
                if default == 1:
                    tmp += "[" + yes + "]"
                elif default == 0:
                    tmp += "[" + nay + "]"
                inp = input(tmp)
                if inp == '':
                    if default == 1:
                        return 0
                    if default == 0:
                        return 1
                i = inp[:1].upper()
                if i == yes:
                    return 0
                if i == nay:
                    return 1
        elif self.graphics == 'tkinter':
            from tkinter import messagebox
            return 0 if messagebox.askyesno(Config.title, question + "\n\n" + prompt) else 1
        else:
            command = []
            if self.graphics == "zenity":
                command = ['zenity', '--title=' + Config.title, '--width=500',
                           '--question', '--text=' + question + "\n\n" + prompt]
            elif self.graphics == 'kdialog':
                command = ['kdialog', '--yesno', question + "\n\n" + prompt,
                           '--title=' + Config.title]
            elif self.graphics == 'yad':
                command = ['yad', '--image="dialog-question"',
                           '--button=gtk-yes:0',
                           '--button=gtk-no:1',
                           '--width=500',
                           '--wrap',
                           '--text=' + question + "\n\n" + prompt,
                           '--title=' + Config.title]
            returncode = subprocess.call(command, stderr=subprocess.DEVNULL)
            return returncode

    def show_info(self, data: str) -> None:
        """
        Show a piece of information
        """
        if self.silent:
            return
        if self.graphics == 'tty':
            print(data)
        elif self.graphics == 'tkinter':
            from tkinter import messagebox
            messagebox.showinfo(Config.title, data)
        else:
            if self.graphics == "zenity":
                command = ['zenity', '--info', '--width=500', '--text=' + data]
            elif self.graphics == "kdialog":
                command = ['kdialog', '--msgbox', data, '--title=' + Config.title]
            elif self.graphics == "yad":
                command = ['yad', '--button=OK', '--width=500', '--text=' + data]
            else:
                sys.exit(1)
            subprocess.call(command, stderr=subprocess.DEVNULL)

    def confirm_exit(self) -> None:
        """
        Confirm exit from installer
        """
        ret = self.ask(Messages.quit)
        if ret == 0:
            sys.exit(1)

    def alert(self, text: str) -> None:
        """Generate alert message"""
        if self.silent:
            return
        if self.graphics == 'tty':
            print(text)
        elif self.graphics == 'tkinter':
            from tkinter import messagebox
            messagebox.showwarning(Config.title, text)
        else:
            if self.graphics == 'zenity':
                command = ['zenity', '--warning', '--text=' + text]
            elif self.graphics == "kdialog":
                command = ['kdialog', '--sorry', text, '--title=' + Config.title]
            elif self.graphics == "yad":
                command = ['yad', '--text=' + text]
            else:
                sys.exit(1)
            subprocess.call(command, stderr=subprocess.DEVNULL)

    def prompt_nonempty_string(self, show: int, prompt: str, val: str = '') -> str:
        """
        Prompt user for input
        """
        if self.graphics == 'tty':
            if show == 0:
                while True:
                    inp = str(getpass.getpass(prompt + ": "))
                    output = inp.strip()
                    if output != '':
                        return output
            while True:
                inp = input(prompt + ": ")
                output = inp.strip()
                if output != '':
                    return output
        elif self.graphics == 'tkinter':
            from tkinter import simpledialog
            while True:
                output = simpledialog.askstring(Config.title, prompt,
                                                initialvalue=val,
                                                show="*" if show == 0 else "")
                if output:
                    return output
                
        else:
            command = []
            if self.graphics == 'zenity':
                if val == '':
                    default_val = ''
                else:
                    default_val = '--entry-text=' + val
                if show == 0:
                    hide_text = '--hide-text'
                else:
                    hide_text = ''
                command = ['zenity', '--entry', hide_text, default_val,
                           '--width=500', '--text=' + prompt]
            elif self.graphics == 'kdialog':
                if show == 0:
                    hide_text = '--password'
                else:
                    hide_text = '--inputbox'
                command = ['kdialog', hide_text, prompt, '--title=' + Config.title]
            elif self.graphics == 'yad':
                if show == 0:
                    hide_text = ':H'
                else:
                    hide_text = ''
                command = ['yad', '--form', '--field=' + hide_text,
                           '--text=' + prompt, val]

            output = ''
            while not output:
                shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                                 stderr=subprocess.PIPE)
                out, _ = shell_command.communicate()
                output = out.decode('utf-8')
                if self.graphics == 'yad':
                    output = output[:-2]
                output = output.strip()
                if shell_command.returncode == 1:
                    self.confirm_exit()
            return output

    def __get_username_password_atomic(self) -> None:
        """
        use single form to get username, password and password confirmation
        """
        output_fields_separator = "\n\n\n\n\n"
        while True:
            password = "a"
            password1 = "b"
            if self.graphics == 'tkinter':
                import tkinter as tk
                
                root = tk.Tk()
                root.title(Config.title)

                desc_label = tk.Label(root, text=Messages.credentials_prompt)
                desc_label.grid(row=0, column=0, columnspan=2, sticky=tk.W)
    
                username_label = tk.Label(root, text=Messages.username_prompt)
                username_label.grid(row=1, column=0, sticky=tk.W)

                username_entry = tk.Entry(root, textvariable=tk.StringVar(root, value=self.username))
                username_entry.grid(row=1, column=1)

                password_label = tk.Label(root, text=Messages.enter_password)
                password_label.grid(row=2, column=0, sticky=tk.W)

                password_entry = tk.Entry(root, show="*")
                password_entry.grid(row=2, column=1)

                password1_label = tk.Label(root, text=Messages.repeat_password)
                password1_label.grid(row=3, column=0, sticky=tk.W)

                password1_entry = tk.Entry(root, show="*")
                password1_entry.grid(row=3, column=1)
                
                def submit(installer):
                    def inner():
                        nonlocal password, password1
                        (installer.username, password, password1) = (username_entry.get(), password_entry.get(), password1_entry.get())
                        root.destroy()
                    return inner
                
                login_button = tk.Button(root, text=Messages.ok, command=submit(self))
                login_button.grid(row=4, column=0, columnspan=2)
                
                root.mainloop()
            else:
                if self.graphics == 'zenity':
                    command = ['zenity', '--forms', '--width=500',
                               f"--title={Config.title}",
                               f"--text={Messages.credentials_prompt}",
                               f"--add-entry={Messages.username_prompt}",
                               f"--add-password={Messages.enter_password}",
                               f"--add-password={Messages.repeat_password}",
                               "--separator", output_fields_separator]
                elif self.graphics == 'yad':
                    command = ['yad', '--form',
                               f"--title={Config.title}",
                               f"--text={Messages.credentials_prompt}",
                               f"--field={Messages.username_prompt}", self.username,
                               f"--field={Messages.enter_password}:H",
                               f"--field={Messages.repeat_password}:H",
                               "--separator", output_fields_separator]

                output = ''
                while not output:
                    shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                                     stderr=subprocess.PIPE)
                    out, _ = shell_command.communicate()
                    output = out.decode('utf-8')
                    if self.graphics == 'yad':
                        output = output[:-(len(output_fields_separator)+1)]
                    output = output.strip()
                    if shell_command.returncode == 1:
                        self.confirm_exit()

                if self.graphics in ('zenity', 'yad'):
                    self.username, password, password1 = output.split(output_fields_separator)

            if not self.__validate_user_name():
                continue
            if password != password1:
                self.alert(Messages.passwords_differ)
                continue
            self.password = password
            break

    def get_user_cred(self) -> None:
        """
        Get user credentials both username/password and personal certificate
        based
        """
        if Config.eap_outer in ('PEAP', 'TTLS'):
            self.__get_username_password()
        elif Config.eap_outer == 'TLS':
            self.__get_p12_cred()

    def __get_username_password(self) -> None:
        """
        read user password and set the password property
        do nothing if silent mode is set
        """
        if self.silent:
            return
        elif self.graphics in ('tkinter', 'zenity', 'yad'):
            self.__get_username_password_atomic()
        else:
            password = "a"
            password1 = "b"
            if self.username:
                user_prompt = self.username
            elif Config.hint_user_input:
                user_prompt = '@' + Config.user_realm
            else:
                user_prompt = ''
            while True:
                self.username = self.prompt_nonempty_string(
                    1, Messages.username_prompt, user_prompt)
                if self.__validate_user_name():
                    break
            while password != password1:
                password = self.prompt_nonempty_string(
                    0, Messages.enter_password)
                password1 = self.prompt_nonempty_string(
                    0, Messages.repeat_password)
                if password != password1:
                    self.alert(Messages.passwords_differ)
            self.password = password

    def __check_graphics(self, command) -> bool:
        shell_command = subprocess.Popen(['which', command],
                                         stdout=subprocess.PIPE,
                                         stderr=subprocess.PIPE)
        shell_command.wait()
        if shell_command.returncode == 0:
            self.graphics = command
            return True
        else:
            return False

    def __get_graphics_support(self) -> None:
        self.graphics = 'tty'
        if self.gui == 'tty':
            return
        if os.environ.get('DISPLAY') is None:
            return
        if self.gui != 'tkinter':
            if self.__check_graphics(self.gui):
                return            
            try:
                import tkinter
                self.graphics = 'tkinter'
                return
            except:
                pass
            for cmd in ('yad', 'zenity', 'kdialog'):
                if self.__check_graphics(cmd):
                    return

    def __process_p12(self) -> bool:
        debug('process_p12')
        pfx_file = get_config_path() + '/cat_installer/user.p12'
        if CRYPTO_AVAILABLE:
            debug("using crypto")
            try:
                p12 = crypto.load_pkcs12(open(pfx_file, 'rb').read(),
                                         self.password)
            except crypto.Error as error:
                debug("Incorrect password ({}).".format(error))
                return False
            else:
                if Config.use_other_tls_id:
                    return True
                try:
                    self.username = p12.get_certificate(). \
                        get_subject().commonName
                except crypto.Error:
                    self.username = p12.get_certificate().\
                        get_subject().emailAddress
                return True
        else:
            debug("using openssl")
            command = ['openssl', 'pkcs12', '-in', pfx_file, '-passin',
                       'pass:' + self.password, '-nokeys', '-clcerts']
            shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                             stderr=subprocess.PIPE)
            out, _ = shell_command.communicate()
            if shell_command.returncode != 0:
                debug("first password run failed")
                command1 = ['openssl', 'pkcs12', '-legacy', '-in', pfx_file, '-passin',
                            'pass:' + self.password, '-nokeys', '-clcerts']
                shell_command1 = subprocess.Popen(command1, stdout=subprocess.PIPE,
                                                  stderr=subprocess.PIPE)
                out, err = shell_command1.communicate()
                if shell_command1.returncode != 0:
                    return False
            if Config.use_other_tls_id:
                return True
            out_str = out.decode('utf-8').strip()
            # split only on commas that are not inside double quotes
            subject = re.split(r'\s*[/,]\s*(?=([^"]*"[^"]*")*[^"]*$)',
                               re.findall(r'subject=/?(.*)$',
                                          out_str, re.MULTILINE)[0])
            cert_prop = {}
            for field in subject:
                if field:
                    cert_field = re.split(r'\s*=\s*', field)
                    cert_prop[cert_field[0].lower()] = cert_field[1]
            if cert_prop['cn'] and re.search(r'@', cert_prop['cn']):
                debug('Using cn: ' + cert_prop['cn'])
                self.username = cert_prop['cn']
            elif cert_prop['emailaddress'] and \
                    re.search(r'@', cert_prop['emailaddress']):
                debug('Using email: ' + cert_prop['emailaddress'])
                self.username = cert_prop['emailaddress']
            else:
                self.username = ''
                self.alert("Unable to extract username "
                           "from the certificate")
            return True

    def __select_p12_file(self) -> str:
        """
        prompt user for the PFX file selection
        this method is not being called in the silent mode
        therefore there is no code for this case
        """
        if self.graphics == 'tty':
            my_dir = os.listdir(".")
            p_count = 0
            pfx_file = ''
            for my_file in my_dir:
                if my_file.endswith(('.p12', '*.pfx', '.P12', '*.PFX')):
                    p_count += 1
                    pfx_file = my_file
            prompt = "personal certificate file (p12 or pfx)"
            default = ''
            if p_count == 1:
                default = '[' + pfx_file + ']'

            while True:
                inp = input(prompt + default + ": ")
                output = inp.strip()

                if default != '' and output == '':
                    return pfx_file
                default = ''
                if os.path.isfile(output):
                    return output
                print("file not found")

        cert = ""
        if self.graphics == 'zenity':
            command = ['zenity', '--file-selection',
                       '--file-filter=' + Messages.p12_filter +
                       ' | *.p12 *.P12 *.pfx *.PFX', '--file-filter=' +
                       Messages.all_filter + ' | *',
                       '--title=' + Messages.p12_title]
            shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                             stderr=subprocess.PIPE)
            cert, _ = shell_command.communicate()
        if self.graphics == 'kdialog':
            command = ['kdialog', '--getopenfilename',
                       '.', '*.p12 *.P12 *.pfx *.PFX | ' +
                       Messages.p12_filter, '--title=' + Messages.p12_title]
            shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                             stderr=subprocess.DEVNULL)
            cert, _ = shell_command.communicate()
        if self.graphics == 'yad':
            command = ['yad', '--file',
                       '--file-filter=*.p12 *.P12 *.pfx *.PFX',
                       '-file-filter=*', '--title=' + Messages.p12_title]
            shell_command = subprocess.Popen(command, stdout=subprocess.PIPE,
                                             stderr=subprocess.DEVNULL)
            cert, _ = shell_command.communicate()
        if self.graphics == 'tkinter':
            from tkinter import filedialog as fd
            return fd.askopenfilename(title=Messages.p12_title,
                                      filetypes=(("Certificate file",
                                                  ("*.p12", "*.P12", "*.pfx",
                                                   "*.PFX")),))

            
        return cert.decode('utf-8').strip()

    @staticmethod
    def __save_sb_pfx() -> None:
        """write the user PFX file"""
        cert_file = get_config_path() + '/cat_installer/user.p12'
        with open(cert_file, 'wb') as cert:
            cert.write(base64.b64decode(Config.sb_user_file))

    def __get_p12_cred(self):
        """get the password for the PFX file"""
        if Config.eap_inner == 'SILVERBULLET':
            self.__save_sb_pfx()
        else:
            if not self.silent:
                self.pfx_file = self.__select_p12_file()
            try:
                copyfile(self.pfx_file, get_config_path() +
                         '/cat_installer/user.p12')
            except (OSError, RuntimeError):
                print(Messages.user_cert_missing)
                sys.exit(1)
        if self.silent:
            username = self.username
            if not self.__process_p12():
                sys.exit(1)
            if username:
                self.username = username
        else:
            while not self.password:
                self.password = self.prompt_nonempty_string(
                    0, Messages.enter_import_password)
                if not self.__process_p12():
                    self.alert(Messages.incorrect_password)
                    self.password = ''
            if not self.username:
                self.username = self.prompt_nonempty_string(
                    1, Messages.username_prompt)

    def __validate_user_name(self) -> bool:
        # locate the @ character in username
        pos = self.username.find('@')
        debug("@ position: " + str(pos))
        # trailing @
        if pos == len(self.username) - 1:
            debug("username ending with @")
            self.alert(Messages.wrongUsernameFormat)
            return False
        # no @ at all
        if pos == -1:
            if Config.verify_user_realm_input:
                debug("missing realm")
                self.alert(Messages.wrongUsernameFormat)
                return False
            debug("No realm, but possibly correct")
            return True
        # @ at the beginning
        if pos == 0:
            debug("missing user part")
            self.alert(Messages.wrongUsernameFormat)
            return False
        pos += 1
        if Config.verify_user_realm_input:
            if Config.hint_user_input:
                if self.username.endswith('@' + Config.user_realm, pos - 1):
                    debug("realm equal to the expected value")
                    return True
                debug("incorrect realm; expected:" + Config.user_realm)
                self.alert(Messages.wrong_realm.format(Config.user_realm))
                return False
            if self.username.endswith(Config.user_realm, pos):
                debug("realm ends with expected suffix")
                return True
            debug("realm suffix error; expected: " + Config.user_realm)
            self.alert(Messages.wrong_realm_suffix.format(
                Config.user_realm))
            return False
        pos1 = self.username.find('@', pos)
        if pos1 > -1:
            debug("second @ character found")
            self.alert(Messages.wrongUsernameFormat)
            return False
        pos1 = self.username.find('.', pos)
        if pos1 == pos:
            debug("a dot immediately after the @ character")
            self.alert(Messages.wrongUsernameFormat)
            return False
        debug("all passed")
        return True


class WpaConf:
    """
    Prepare and save wpa_supplicant config file
    """

    @staticmethod
    def __prepare_network_block(ssid: str, user_data: Type[InstallerData]) -> str:
        interface = """network={
        ssid=\"""" + ssid + """\"
        key_mgmt=WPA-EAP
        pairwise=CCMP
        group=CCMP TKIP
        eap=""" + Config.eap_outer + """
        ca_cert=\"""" + get_config_path() + """/cat_installer/ca.pem\"""""""
        identity=\"""" + user_data.username + """\"""""""
        altsubject_match=\"""" + ";".join(Config.servers) + """\"
        """

        if Config.eap_outer in ('PEAP', 'TTLS'):
            interface += f"phase2=\"auth={Config.eap_inner}\"\n" \
                         f"\tpassword=\"{user_data.password}\"\n"
            if Config.anonymous_identity != '':
                interface += f"\tanonymous_identity=\"{Config.anonymous_identity}\"\n"

        elif Config.eap_outer == 'TLS':
            interface += f"\tprivate_key_passwd=\"{user_data.password}\"\n" \
                         f"\tprivate_key=\"{os.environ.get('HOME')}/.cat_installer/user.p12"

        interface += "\n}"
        return interface

    def create_wpa_conf(self, ssids, user_data: Type[InstallerData]) -> None:
        """Create and save the wpa_supplicant config file"""
        wpa_conf = get_config_path() + '/cat_installer/cat_installer.conf'
        with open(wpa_conf, 'w') as conf:
            for ssid in ssids:
                net = self.__prepare_network_block(ssid, user_data)
                conf.write(net)


class IwdConfiguration:
    """ support the iNet wireless daemon by Intel """
    def __init__(self):
        self.config = ""

    def write_config(self) -> None:
        for ssid in Config.ssids:
            with open('/var/lib/iwd/{}.8021x'.format(ssid), 'w') as config_file:
                config_file.write(self.config)

    def _create_eap_pwd_config(self, ssid: str, user_data: Type[InstallerData]) -> None:
        """ create EAP-PWD configuration """
        self.conf = """
        [Security]
        EAP-Method=PWD
        EAP-Identity={username}
        EAP-Password={password}

        [Settings]
        AutoConnect=True
        """.format(username=user_data.username,
                   password=user_data.password)

    def _create_eap_peap_config(self, ssid: str, user_data: Type[InstallerData]) -> None:
        """ create EAP-PEAP configuration """
        self.conf = """
        [Security]
        EAP-Method=PEAP
        EAP-Identity={anonymous_identity}
        EAP-PEAP-CACert={ca_cert}
        EAP-PEAP-ServerDomainMask={servers}
        EAP-PEAP-Phase2-Method=MSCHAPV2
        EAP-PEAP-Phase2-Identity={username}@{realm}
        EAP-PEAP-Phase2-Password={password}

        [Settings]
        AutoConnect=true
        """.format(anonymous_identity=Config.anonymous_identity,
                   ca_cert=Config.CA, servers=Config.servers,
                   username=user_data.username,
                   realm=Config.user_realm,
                   password=user_data.password)

    def _create_ttls_pap_config(self, ssid: str, user_data: Type[InstallerData]) -> None:
        """ create TTLS-PAP configuration"""
        self.conf = """
        [Security]
        EAP-Method=TTLS
        EAP-Identity={anonymous_identity}
        EAP-TTLS-CACert={ca_cert}
        EAP-TTLS-ServerDomainMask={servers}
        EAP-TTLS-Phase2-Method=Tunneled-PAP
        EAP-TTLS-Phase2-Identity={username}@{realm}
        EAP-TTLS-Phase2-Password={password}

        [Settings]
        AutoConnect=true
        """.format(anonymous_identity=Config.anonymous_identity,
                   ca_cert=Config.CA, servers=Config.servers,
                   username=user_data.username,
                   realm=Config.user_realm,
                   password=user_data.password)


class CatNMConfigTool:
    """
    Prepare and save NetworkManager configuration
    """

    def __init__(self):
        self.cacert_file = None
        self.settings_service_name = None
        self.connection_interface_name = None
        self.system_service_name = "org.freedesktop.NetworkManager"
        self.nm_version = None
        self.pfx_file = None
        self.settings = None
        self.user_data = None
        self.bus = None

    def connect_to_nm(self) -> Union[bool, None]:
        """
        connect to DBus
        """
        try:
            self.bus = dbus.SystemBus()
        except AttributeError:
            # since dbus existed but is empty we have an empty package
            # this gets shipped by pyqt5
            print("DBus not properly installed")
            return None
        except dbus.exceptions.DBusException:
            print("Can't connect to DBus")
            return None
        # check NM version
        self.__check_nm_version()
        debug("NM version: " + self.nm_version)
        if self.nm_version in ("0.9", "1.0"):
            self.settings_service_name = self.system_service_name
            self.connection_interface_name = \
                "org.freedesktop.NetworkManager.Settings.Connection"
            # settings proxy
            sysproxy = self.bus.get_object(
                self.settings_service_name,
                "/org/freedesktop/NetworkManager/Settings")
            # settings interface
            self.settings = dbus.Interface(sysproxy, "org.freedesktop."
                                                     "NetworkManager.Settings")
        elif self.nm_version == "0.8":
            self.settings_service_name = "org.freedesktop.NetworkManager"
            self.connection_interface_name = "org.freedesktop.NetworkMana" \
                                             "gerSettings.Connection"
            # settings proxy
            sysproxy = self.bus.get_object(
                self.settings_service_name,
                "/org/freedesktop/NetworkManagerSettings")
            # settings interface
            self.settings = dbus.Interface(
                sysproxy, "org.freedesktop.NetworkManagerSettings")
        else:
            print(Messages.nm_not_supported)
            return None
        debug("NM connection worked")
        return True

    def __check_opts(self) -> None:
        """
        set certificate files paths and test for existence of the CA cert
        """
        self.cacert_file = get_config_path() + '/cat_installer/ca.pem'
        self.pfx_file = get_config_path() + '/cat_installer/user.p12'
        if not os.path.isfile(self.cacert_file):
            print(Messages.cert_error)
            sys.exit(2)

    def __check_nm_version(self) -> None:
        """
        Get the NetworkManager version
        """
        try:
            proxy = self.bus.get_object(
                self.system_service_name, "/org/freedesktop/NetworkManager")
            props = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
            version = props.Get("org.freedesktop.NetworkManager", "Version")
        except dbus.exceptions.DBusException:
            version = ""
        if re.match(r'^1\.', version):
            self.nm_version = "1.0"
            return
        if re.match(r'^0\.9', version):
            self.nm_version = "0.9"
            return
        if re.match(r'^0\.8', version):
            self.nm_version = "0.8"
            return
        self.nm_version = Messages.unknown_version

    def __delete_existing_connection(self, ssid: str) -> None:
        """
        checks and deletes earlier connection
        """
        try:
            conns = self.settings.ListConnections()
        except dbus.exceptions.DBusException:
            print(Messages.dbus_error)
            exit(3)
        for each in conns:
            con_proxy = self.bus.get_object(self.system_service_name, each)
            connection = dbus.Interface(
                con_proxy,
                "org.freedesktop.NetworkManager.Settings.Connection")
            try:
                connection_settings = connection.GetSettings()
                if connection_settings['connection']['type'] == '802-11-' \
                                                                'wireless':
                    conn_ssid = byte_to_string(
                        connection_settings['802-11-wireless']['ssid'])
                    if conn_ssid == ssid:
                        debug("deleting connection: " + conn_ssid)
                        connection.Delete()
            except dbus.exceptions.DBusException:
                pass

    def __add_connection(self, ssid: str) -> None:
        debug("Adding connection: " + ssid)
        server_alt_subject_name_list = dbus.Array(Config.servers)
        server_name = Config.server_match
        if self.nm_version in ("0.9", "1.0"):
            match_key = 'altsubject-matches'
            match_value = server_alt_subject_name_list
        else:
            match_key = 'subject-match'
            match_value = server_name
        s_8021x_data = {
            'eap': [Config.eap_outer.lower()],
            'identity': self.user_data.username,
            'ca-cert': dbus.ByteArray(
                "file://{0}\0".format(self.cacert_file).encode('utf8')),
            match_key: match_value}
        if Config.eap_outer in ('PEAP', 'TTLS'):
            s_8021x_data['password'] = self.user_data.password
            s_8021x_data['phase2-auth'] = Config.eap_inner.lower()
            if Config.anonymous_identity != '':
                s_8021x_data['anonymous-identity'] = Config.anonymous_identity
            s_8021x_data['password-flags'] = 0
        elif Config.eap_outer == 'TLS':
            s_8021x_data['client-cert'] = dbus.ByteArray(
                "file://{0}\0".format(self.pfx_file).encode('utf8'))
            s_8021x_data['private-key'] = dbus.ByteArray(
                "file://{0}\0".format(self.pfx_file).encode('utf8'))
            s_8021x_data['private-key-password'] = self.user_data.password
            s_8021x_data['private-key-password-flags'] = 0
        s_con = dbus.Dictionary({
            'type': '802-11-wireless',
            'uuid': str(uuid.uuid4()),
            'permissions': ['user:' + os.environ.get('USER')],
            'id': ssid
        })
        s_wifi = dbus.Dictionary({
            'ssid': dbus.ByteArray(ssid.encode('utf8')),
            'security': '802-11-wireless-security'
        })
        s_wsec = dbus.Dictionary({
            'key-mgmt': 'wpa-eap',
            'proto': ['rsn'],
            'pairwise': ['ccmp'],
            'group': ['ccmp', 'tkip']
        })
        s_8021x = dbus.Dictionary(s_8021x_data)
        s_ip4 = dbus.Dictionary({'method': 'auto'})
        s_ip6 = dbus.Dictionary({'method': 'auto'})
        con = dbus.Dictionary({
            'connection': s_con,
            '802-11-wireless': s_wifi,
            '802-11-wireless-security': s_wsec,
            '802-1x': s_8021x,
            'ipv4': s_ip4,
            'ipv6': s_ip6
        })
        self.settings.AddConnection(con)

    def add_connections(self, user_data: Type[InstallerData]):
        """Delete and then add connections to the system"""
        self.__check_opts()
        self.user_data = user_data
        for ssid in Config.ssids:
            self.__delete_existing_connection(ssid)
            self.__add_connection(ssid)
        for ssid in Config.del_ssids:
            self.__delete_existing_connection(ssid)