<?php

function keygen()
{
  $chars = "abcdefghijklmnopqrstuvwxyz";
  $chars .= "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  $chars .= "0123456789";
  while (1) {
    $key = '';
    srand((double) microtime() * 1000000);
    for ($i = 0; $i < 16; $i++) {
      $key .= substr($chars, (rand() % (strlen($chars))), 1);
    }
    break;
  }
  return $key;
}

function key32gen()
{
  $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  $chars .= "234567";
  while (1) {
    $key = '';
    srand((double) microtime() * 1000000);
    for ($i = 0; $i < 32; $i++) {
      $key .= substr($chars, (rand() % (strlen($chars))), 1);
    }
    break;
  }
  return $key;
}

function initials($str) {
  $ret = '';
  foreach (explode(' ', $str) as $word)
    $ret .= strtoupper($word[0]);
  return $ret;
}

function removeDirectory($path) {
  if (!file_exists($path)) {
    return;
  }

  $files = glob($path . '/*');
  foreach ($files as $file) {
    is_dir($file) ? removeDirectory($file) : unlink($file);
  }
  rmdir($path);
  return;
}

function get_user_agent() {
  return $_SERVER['HTTP_USER_AGENT'];
}

function get_ip() {
  if(defined("CONST_GET_IP_METHOD")){
    if(CONST_GET_IP_METHOD == "HTTP_X_FORWARDED_FOR"){
      $ip = getenv('HTTP_X_FORWARDED_FOR');
    }
    else{
      $ip = getenv('REMOTE_ADDR');
    }
  }
  else{
    $ip = getenv('REMOTE_ADDR');
  }

  return $ip;
}

function get_web_browser() {
  $user_agent = get_user_agent();
  $browser        =   "Unknown Browser";
  $browser_array  =   array(
    '/msie/i'       =>  'Internet Explorer',
    '/Trident/i'    =>  'Internet Explorer',
    '/firefox/i'    =>  'Firefox',
    '/safari/i'     =>  'Safari',
    '/chrome/i'     =>  'Chrome',
    '/edge/i'       =>  'Edge',
    '/opera/i'      =>  'Opera',
    '/netscape/i'   =>  'Netscape',
    '/maxthon/i'    =>  'Maxthon',
    '/konqueror/i'  =>  'Konqueror',
    '/ubrowser/i'   =>  'UC Browser',
  );
  foreach ($browser_array as $regex => $value) {
    if (preg_match($regex, $user_agent)) {
      $browser    =   $value;
    }
  }
  return $browser;
}

function get_os() {
  $user_agent = get_user_agent();
  $os_platform    =   "Unknown OS";
  $os_array       =   array(
    '/windows nt 10/i'      =>  'Windows 10',
    '/windows nt 6.3/i'     =>  'Windows 8.1',
    '/windows nt 6.2/i'     =>  'Windows 8',
    '/windows nt 6.1/i'     =>  'Windows 7',
    '/windows nt 6.0/i'     =>  'Windows Vista',
    '/windows nt 5.2/i'     =>  'Windows Server 2003/XP x64',
    '/windows nt 5.1/i'     =>  'Windows XP',
    '/windows xp/i'         =>  'Windows XP',
    '/macintosh|mac os x/i' =>  'MacOS',
    '/linux/i'              =>  'Linux',
    '/ubuntu/i'             =>  'Ubuntu',
    '/iphone/i'             =>  'iPhone',
    '/ipod/i'               =>  'iPod',
    '/ipad/i'               =>  'iPad',
    '/android/i'            =>  'Android',
    '/blackberry/i'         =>  'BlackBerry',
    '/webos/i'              =>  'Mobile'
  );
  foreach ($os_array as $regex => $value) {
    if (preg_match($regex, $user_agent)) {
      $os_platform    =   $value;
    }
  }
  return $os_platform;
}

function get_device(){
  $tablet_browser = 0;
  $mobile_browser = 0;
  if (preg_match('/(tablet|ipad|playbook)|(android(?!.*(mobi|opera mini)))/i', strtolower($_SERVER['HTTP_USER_AGENT']))) {
    $tablet_browser++;
  }
  if (preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|android|iemobile)/i', strtolower($_SERVER['HTTP_USER_AGENT']))) {
    $mobile_browser++;
  }
  if ((strpos(strtolower($_SERVER['HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml') > 0) or ((isset($_SERVER['HTTP_X_WAP_PROFILE']) or isset($_SERVER['HTTP_PROFILE'])))) {
    $mobile_browser++;
  }
  $mobile_ua = strtolower(substr(get_user_agent(), 0, 4));
  $mobile_agents = array(
    'w3c ','acs-','alav','alca','amoi','audi','avan','benq','bird','blac',
    'blaz','brew','cell','cldc','cmd-','dang','doco','eric','hipt','inno',
    'ipaq','java','jigs','kddi','keji','leno','lg-c','lg-d','lg-g','lge-',
    'maui','maxo','midp','mits','mmef','mobi','mot-','moto','mwbp','nec-',
    'newt','noki','palm','pana','pant','phil','play','port','prox',
    'qwap','sage','sams','sany','sch-','sec-','send','seri','sgh-','shar',
    'sie-','siem','smal','smar','sony','sph-','symb','t-mo','teli','tim-',
    'tosh','tsm-','upg1','upsi','vk-v','voda','wap-','wapa','wapi','wapp',
    'wapr','webc','winw','winw','xda ','xda-');
  if (in_array($mobile_ua,$mobile_agents)) {
    $mobile_browser++;
  }
  if (strpos(strtolower(get_user_agent()),'opera mini') > 0) {
    $mobile_browser++;
    //Check for tablets on opera mini alternative headers
    $stock_ua = strtolower(isset($_SERVER['HTTP_X_OPERAMINI_PHONE_UA'])?$_SERVER['HTTP_X_OPERAMINI_PHONE_UA']:(isset($_SERVER['HTTP_DEVICE_STOCK_UA'])?$_SERVER['HTTP_DEVICE_STOCK_UA']:''));
    if (preg_match('/(tablet|ipad|playbook)|(android(?!.*mobile))/i', $stock_ua)) {
      $tablet_browser++;
    }
  }
  if ($tablet_browser > 0) {
    //do something for tablet devices
    return 'Tablet';
  }
  else if ($mobile_browser > 0) {
    //do something for mobile devices
    return 'Mobile';
  }
  else {
    //do something for everything else
    return 'Computer';
  }
}

function truncate($text, $chars) {
  if (strlen($text) <= $chars) {
    return $text;
  }
  $text = $text." ";
  $text = substr($text,0,$chars);
  $text = substr($text,0,strrpos($text,' '));
  $text = $text."...";
  return $text;
}

function get_otp($secret_seed) {
  //TOTP seed (String representation)
  $otp = '';
  //number of seconds of otp period
  $time_window = 30;

  //time formating to epoch
  $exact_time = microtime(true);
  $rounded_time = floor($exact_time/$time_window);

  //binary represetation of time without padding
  $packed_time = pack("N", $rounded_time);

  //binary representation of time with padding
  $padded_packed_time = str_pad($packed_time,8, chr(0), STR_PAD_LEFT);

  //binary representation of seed
  $packed_secret_seed = pack("H*", $secret_seed);

  //HMAC SHA1 hash (time + seed)
  $hash = hash_hmac ('sha1', $padded_packed_time, $packed_secret_seed, true);

  $offset = ord($hash[19]) & 0xf;
  $otp = (
      ((ord($hash[$offset+0]) & 0x7f) << 24 ) |
      ((ord($hash[$offset+1]) & 0xff) << 16 ) |
      ((ord($hash[$offset+2]) & 0xff) << 8 ) |
      (ord($hash[$offset+3]) & 0xff)
    ) % pow(10, 6);

  //adding pad to otp, in order to assure a "6" digits
  $otp = str_pad($otp, 6, "0", STR_PAD_LEFT);

  return $otp;
}

function formatPhoneNumber($phoneNumber) {
  $phoneNumber = preg_replace('/[^0-9]/','',$phoneNumber);

  if(strlen($phoneNumber) > 10) {
    $countryCode = substr($phoneNumber, 0, strlen($phoneNumber)-10);
    $areaCode = substr($phoneNumber, -10, 3);
    $nextThree = substr($phoneNumber, -7, 3);
    $lastFour = substr($phoneNumber, -4, 4);

    $phoneNumber = '+'.$countryCode.' ('.$areaCode.') '.$nextThree.'-'.$lastFour;
  }
  else if(strlen($phoneNumber) == 10) {
    $areaCode = substr($phoneNumber, 0, 3);
    $nextThree = substr($phoneNumber, 3, 3);
    $lastFour = substr($phoneNumber, 6, 4);

    $phoneNumber = '('.$areaCode.') '.$nextThree.'-'.$lastFour;
  }
  else if(strlen($phoneNumber) == 7) {
    $nextThree = substr($phoneNumber, 0, 3);
    $lastFour = substr($phoneNumber, 3, 4);

    $phoneNumber = $nextThree.'-'.$lastFour;
  }

  return $phoneNumber;
}

function mkdir_missing($dir) {
  if (!is_dir($dir)) {
    mkdir($dir);
  }
}

//Called during initial setup
//Encrypts the master key with the user's password
function setupFirstUserSpecificKey($user_password, $site_encryption_master_key){
  $iv = keygen();
  $salt = keygen();

  //Generate 128-bit (16 byte/char) kdhash of the users password
  $user_password_kdhash = hash_pbkdf2('sha256', $user_password, $salt, 100000, 16);

  //Encrypt the master key with the users kdf'd hash and the IV
  $ciphertext = openssl_encrypt($site_encryption_master_key, 'aes-128-cbc', $user_password_kdhash, 0, $iv);

  $user_encryption_ciphertext = $salt . $iv . $ciphertext;

  return $user_encryption_ciphertext;
}

/*
For additional users / password changes
New Users: Requires the admin setting up their account have the their own Specific/Session key configured
Password Changes: Will use the current info in the session.
*/
function encryptUserSpecificKey($user_password){
  $iv = keygen();
  $salt = keygen();

  //Get the session info.
  $user_encryption_session_ciphertext = $_SESSION['user_encryption_session_ciphertext'];
  $user_encryption_session_iv =  $_SESSION['user_encryption_session_iv'];
  $user_encryption_session_key = $_COOKIE['user_encryption_session_key'];

  //Decrypt the session key to get the master key
  $site_encryption_master_key = openssl_decrypt($user_encryption_session_ciphertext, 'aes-128-cbc', $user_encryption_session_key, 0, $user_encryption_session_iv);

  //Generate 128-bit (16 byte/char) kdhash of the users (new) password
  $user_password_kdhash = hash_pbkdf2('sha256', $user_password, $salt, 100000, 16);

  //Encrypt the master key with the users kdf'd hash and the IV
  $ciphertext = openssl_encrypt($site_encryption_master_key, 'aes-128-cbc', $user_password_kdhash, 0, $iv);

  $user_encryption_ciphertext = $salt . $iv . $ciphertext;

  return $user_encryption_ciphertext;

}

//Given a ciphertext (incl. IV) and the user's password, returns the site master key
//Ran at login, to facilitate generateUserSessionKey
function decryptUserSpecificKey($user_encryption_ciphertext, $user_password){
  //Get the IV, salt and ciphertext
  $salt = substr($user_encryption_ciphertext, 0, 16);
  $iv = substr($user_encryption_ciphertext, 16, 16);
  $ciphertext = substr($user_encryption_ciphertext, 32);

  //Generate 128-bit (16 byte/char) kdhash of the users password
  $user_password_kdhash = hash_pbkdf2('sha256', $user_password, $salt, 100000, 16);

  //Use this hash to get the original/master key
  $site_encryption_master_key = openssl_decrypt($ciphertext, 'aes-128-cbc', $user_password_kdhash, 0, $iv);
  return $site_encryption_master_key;
}

/*
Generates what is probably best described as an session key (ephemeral-ish)
- Allows us to store the master key on the server whilst the user is using the application, without prompting to type their password everytime they want to decrypt a credential
- Ciphertext/IV is stored on the server in the users session, encryption key is controlled/provided by the user as a cookie
- Only the user can decrypt their session ciphertext to get the master key
- Encryption key never hits the disk in cleartext
*/
function generateUserSessionKey($site_encryption_master_key){

  //Generate both of these using keygen()
  $user_encryption_session_key = keygen();
  $user_encryption_session_iv = keygen();
  $user_encryption_session_ciphertext = openssl_encrypt($site_encryption_master_key, 'aes-128-cbc', $user_encryption_session_key, 0, $user_encryption_session_iv);

  //Store ciphertext in the user's session
  $_SESSION['user_encryption_session_ciphertext'] = $user_encryption_session_ciphertext;
  $_SESSION['user_encryption_session_iv'] = $user_encryption_session_iv;

  //Give the user "their" key as a cookie
  //By default, this should be HTTPS but we can change to HTTP for development via the config.php file (note that the extension won't work without HTTPS)
  include('config.php');
  if($config_https_only){
    //setcookie("user_encryption_session_key", $user_encryption_session_key, 0, "/", "", "true", "true", ['samesite' => 'None']);
    setcookie("user_encryption_session_key", "$user_encryption_session_key", ['path' => '/','secure' => true,'httponly' => true,'samesite' => 'None']);

  }
  else{
    setcookie("user_encryption_session_key", $user_encryption_session_key, 0, "/");
    $_SESSION['alert_message'] = "Unencrypted connection flag set: Using non-secure cookies.";
  }
}

//Decrypts an encrypted password (website/asset login), returns it as a string
function decryptLoginEntry($login_password_ciphertext){

  //Split the login into IV and Ciphertext
  $login_iv =  substr($login_password_ciphertext, 0, 16);
  $login_ciphertext = $salt = substr($login_password_ciphertext, 16);

  //Get the user session info.
  $user_encryption_session_ciphertext = $_SESSION['user_encryption_session_ciphertext'];
  $user_encryption_session_iv =  $_SESSION['user_encryption_session_iv'];
  $user_encryption_session_key = $_COOKIE['user_encryption_session_key'];

  //Decrypt the session key to get the master key
  $site_encryption_master_key = openssl_decrypt($user_encryption_session_ciphertext, 'aes-128-cbc', $user_encryption_session_key, 0, $user_encryption_session_iv);

  //Decrypt the login password using the master key
  $login_password_cleartext = openssl_decrypt($login_ciphertext, 'aes-128-cbc', $site_encryption_master_key, 0, $login_iv);
  return $login_password_cleartext;

}

//Encrypts a website/asset login password
function encryptLoginEntry($login_password_cleartext){
  $iv = keygen();

  //Get the user session info.
  $user_encryption_session_ciphertext = $_SESSION['user_encryption_session_ciphertext'];
  $user_encryption_session_iv =  $_SESSION['user_encryption_session_iv'];
  $user_encryption_session_key = $_COOKIE['user_encryption_session_key'];

  //Decrypt the session key to get the master key
  $site_encryption_master_key = openssl_decrypt($user_encryption_session_ciphertext, 'aes-128-cbc', $user_encryption_session_key, 0, $user_encryption_session_iv);

  //Encrypt the website/asset login using the master key
  $ciphertext = openssl_encrypt($login_password_cleartext, 'aes-128-cbc', $site_encryption_master_key, 0, $iv);

  $login_password_ciphertext = $iv . $ciphertext;
  return $login_password_ciphertext;
}

//For migrating/upgrading to the new encryption scheme
//Have to supply the master key as the cookie might not be set properly (generally requires a refresh)
function encryptUpgradeLoginEntry($login_password_cleartext, $site_encryption_master_key){
  $iv = keygen();

  //Encrypt the website/asset login using the master key
  $ciphertext = openssl_encrypt($login_password_cleartext, 'aes-128-cbc', $site_encryption_master_key, 0, $iv);

  $login_password_ciphertext = $iv . $ciphertext;
  return $login_password_ciphertext;
}

// Get domain expiration date
function getDomainExpirationDate($name){
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, "https://itflow-whois.herokuapp.com/$name");
  curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
  $response = json_decode(curl_exec($ch),1);

  if($response){
    if(is_array($response['expiration_date'])){
      $expiry = new DateTime($response['expiration_date'][1]);
    }
    else{
      $expiry = new DateTime($response['expiration_date']);
    }

    return $expiry->format('Y-m-d');
  }

  // Default return
  return '0000-00-00';
}

?>