| 1 | <?php |
| 2 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this file, |
| 4 | * You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| 5 | |
| 6 | class AuthUtils { |
| 7 | // KaiRo.at authentication utilities PHP class |
| 8 | // This class contains helper functions for the authentication system. |
| 9 | // |
| 10 | // function __construct($settings, $db) |
| 11 | // CONSTRUCTOR |
| 12 | // Settings are an associative array with a numeric pwd_cost field and an array pwd_nonces field. |
| 13 | // The DB is a PDO object. |
| 14 | // |
| 15 | // public $db |
| 16 | // A PDO database object for interaction. |
| 17 | // |
| 18 | // public $running_on_localhost |
| 19 | // A boolean telling if the system is running on localhost (where https is not required). |
| 20 | // |
| 21 | // private $pwd_cost |
| 22 | // The cost parameter for use with PHP password_hash function. |
| 23 | // |
| 24 | // private $pwd_nonces |
| 25 | // The array of nonces to use for "peppering" passwords. For new hashes, the last one of those will be used. |
| 26 | // Generate a nonce with this command: |openssl rand -base64 48| |
| 27 | // |
| 28 | // function log($code, $additional_info) |
| 29 | // Log an entry for admin purposes, with a code and some additional info. |
| 30 | // |
| 31 | // function checkForSecureConnection() |
| 32 | // Check is the connection is secure and return an array of error messages (empty if it's secure). |
| 33 | // |
| 34 | // function initSession() |
| 35 | // Initialize a session. Returns an associative array of all the DB fields of the session. |
| 36 | // |
| 37 | // function checkPasswordConstraints($new_password, $user_email) |
| 38 | // Check password constraints and return an array of error messages (empty if all constraints are met). |
| 39 | // |
| 40 | // function createSessionKey() |
| 41 | // Return a random session key. |
| 42 | // |
| 43 | // function createVerificationCode() |
| 44 | // Return a random acount/email verification code. |
| 45 | // |
| 46 | // function createTimeCode($session, [$offset], [$validity_minutes]) |
| 47 | // Return a time-based code based on the key and ID of the given session. |
| 48 | // An offset can be given to create a specific code for verification, otherwise and offset will be generated. |
| 49 | // Also, an amount of minutes for the code to stay valid can be handed over, by default 10 minutes will be used. |
| 50 | // |
| 51 | // function verifyTimeCode($timecode_to_verify, $session, [$validity_minutes]) |
| 52 | // Verify a given time-based code and return true if it's valid or false if it's not. |
| 53 | // See createTimeCode() documentation for the session and validity paramerters. |
| 54 | // |
| 55 | // function pwdHash($new_password) |
| 56 | // Return a hash for the given password. |
| 57 | // |
| 58 | // function pwdVerify($password_to_verify, $user) |
| 59 | // Return true if the password verifies against the pwdhash field of the user, false if not. |
| 60 | // |
| 61 | // function pwdNeedsRehash($user) |
| 62 | // Return true if the pwdhash field of the user uses an outdated standard and needs to be rehashed. |
| 63 | |
| 64 | function __construct($settings, $db) { |
| 65 | // *** constructor *** |
| 66 | $this->db = $db; |
| 67 | $this->db->exec("SET time_zone='+00:00';"); // Execute directly on PDO object, set session to UTC to make our gmdate() values match correctly. |
| 68 | $this->running_on_localhost = preg_match('/^((.+\.)?localhost|127\.0\.0\.\d+)$/', $_SERVER['SERVER_NAME']); |
| 69 | if (array_key_exists('pwd_cost', $settings)) { |
| 70 | $this->pwd_cost = $settings['pwd_cost']; |
| 71 | } |
| 72 | if (array_key_exists('pwd_nonces', $settings)) { |
| 73 | $this->pwd_nonces = $settings['pwd_nonces']; |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | public $db = null; |
| 78 | public $running_on_localhost = false; |
| 79 | private $pwd_cost = 10; |
| 80 | private $pwd_nonces = array(); |
| 81 | |
| 82 | function log($code, $info) { |
| 83 | $result = $this->db->prepare('INSERT INTO `auth_log` (`code`, `info`, `ip_addr`) VALUES (:code, :info, :ipaddr);'); |
| 84 | if (!$result->execute(array(':code' => $code, ':info' => $info, ':ipaddr' => $_SERVER['REMOTE_ADDR']))) { |
| 85 | // print($result->errorInfo()[2]); |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | function checkForSecureConnection() { |
| 90 | $errors = array(); |
| 91 | if (($_SERVER['SERVER_PORT'] != 443) && !$this->running_on_localhost) { |
| 92 | $errors[] = _('You are not accessing this site on a secure connection, so authentication doesn\'t work.'); |
| 93 | } |
| 94 | return $errors; |
| 95 | } |
| 96 | |
| 97 | function initSession() { |
| 98 | $session = null; |
| 99 | if (strlen(@$_COOKIE['sessionkey'])) { |
| 100 | // Fetch the session - or at least try to. |
| 101 | $result = $this->db->prepare('SELECT * FROM `auth_sessions` WHERE `sesskey` = :sesskey AND `time_expire` > :expire;'); |
| 102 | $result->execute(array(':sesskey' => $_COOKIE['sessionkey'], ':expire' => gmdate('Y-m-d H:i:s'))); |
| 103 | $row = $result->fetch(PDO::FETCH_ASSOC); |
| 104 | if ($row) { |
| 105 | $session = $row; |
| 106 | } |
| 107 | } |
| 108 | if (is_null($session)) { |
| 109 | // Create new session and set cookie. |
| 110 | $sesskey = $this->createSessionKey(); |
| 111 | setcookie('sessionkey', $sesskey, 0, "", "", !$this->running_on_localhost, true); // Last two params are secure and httponly, secure is not set on localhost. |
| 112 | $result = $this->db->prepare('INSERT INTO `auth_sessions` (`sesskey`, `time_expire`) VALUES (:sesskey, :expire);'); |
| 113 | $result->execute(array(':sesskey' => $sesskey, ':expire' => gmdate('Y-m-d H:i:s', strtotime('+5 minutes')))); |
| 114 | // After insert, actually fetch the session row from the DB so we have all values. |
| 115 | $result = $this->db->prepare('SELECT * FROM auth_sessions WHERE `sesskey` = :sesskey AND `time_expire` > :expire;'); |
| 116 | $result->execute(array(':sesskey' => $sesskey, ':expire' => gmdate('Y-m-d H:i:s'))); |
| 117 | $row = $result->fetch(PDO::FETCH_ASSOC); |
| 118 | if ($row) { |
| 119 | $session = $row; |
| 120 | } |
| 121 | else { |
| 122 | $this->log('session_create_failure', 'key: '.$sesskey); |
| 123 | } |
| 124 | } |
| 125 | return $session; |
| 126 | } |
| 127 | |
| 128 | function checkPasswordConstraints($new_password, $user_email) { |
| 129 | $errors = array(); |
| 130 | if ($new_password != trim($new_password)) { |
| 131 | $errors[] = _('Password must not start or end with a whitespace character like a space.'); |
| 132 | } |
| 133 | if (strlen($new_password) < 8) { $errors[] = sprintf(_('Password too short (min. %s characters).'), 8); } |
| 134 | if (strlen($new_password) > 70) { $errors[] = sprintf(_('Password too long (max. %s characters).'), 70); } |
| 135 | if ((strtolower($new_password) == strtolower($user_email)) || |
| 136 | in_array(strtolower($new_password), preg_split("/[@\.]+/", strtolower($user_email)))) { |
| 137 | $errors[] = _('The passwort can not be equal to your email or any part of it.'); |
| 138 | } |
| 139 | if ((strlen($new_password) < 15) && (preg_match('/^[a-zA-Z]+$/', $new_password))) { |
| 140 | $errors[] = sprintf(_('Your password must use characters other than normal letters or contain least %s characters.'), 15); |
| 141 | } |
| 142 | if (preg_match('/^\d+$/', $new_password)) { |
| 143 | $errors[] = sprintf(_('Your password cannot consist only of numbers.'), 15); |
| 144 | } |
| 145 | if (strlen(count_chars($new_password, 3)) < 5) { |
| 146 | $errors[] = sprintf(_('Password does have to contain at least %s different characters.'), 5); |
| 147 | } |
| 148 | return $errors; |
| 149 | } |
| 150 | |
| 151 | function createSessionKey() { |
| 152 | return bin2hex(openssl_random_pseudo_bytes(512 / 8)); // Get 512 bits of randomness (128 byte hex string). |
| 153 | } |
| 154 | |
| 155 | function createVerificationCode() { |
| 156 | return bin2hex(openssl_random_pseudo_bytes(512 / 8)); // Get 512 bits of randomness (128 byte hex string). |
| 157 | } |
| 158 | |
| 159 | function createTimeCode($session, $offset = null, $validity_minutes = 10) { |
| 160 | // Matches TOTP algorithms, see https://en.wikipedia.org/wiki/Time-based_One-time_Password_Algorithm |
| 161 | $valid_seconds = intval($validity_minutes) * 60; |
| 162 | if ($valid_seconds < 60) { $valid_seconds = 60; } |
| 163 | $code_digits = 8; |
| 164 | $time = time(); |
| 165 | $rest = is_null($offset)?($time % $valid_seconds):intval($offset); // T0, will be sent as part of code to make it valid for the full duration. |
| 166 | $counter = floor(($time - $rest) / $valid_seconds); |
| 167 | $hmac = mhash(MHASH_SHA1, $counter, $session['id'].$session['sesskey']); |
| 168 | $offset = hexdec(substr(bin2hex(substr($hmac, -1)), -1)); // Get the last 4 bits as a number. |
| 169 | $totp = hexdec(bin2hex(substr($hmac, $offset, 4))) & 0x7FFFFFFF; // Take 4 bytes at the offset, discard highest bit. |
| 170 | $totp_value = sprintf('%0'.$code_digits.'d', substr($totp, -$code_digits)); |
| 171 | return $rest.'.'.$totp_value; |
| 172 | } |
| 173 | |
| 174 | function verifyTimeCode($timecode_to_verify, $session, $validity_minutes = 10) { |
| 175 | if (preg_match('/^(\d+)\.\d+$/', $timecode_to_verify, $regs)) { |
| 176 | return ($timecode_to_verify === $this->createTimeCode($session, $regs[1], $validity_minutes)); |
| 177 | } |
| 178 | return false; |
| 179 | } |
| 180 | |
| 181 | function pwdHash($new_password) { |
| 182 | $hash_prefix = ''; |
| 183 | if (count($this->pwd_nonces)) { |
| 184 | $new_password .= $this->pwd_nonces[count($this->pwd_nonces) - 1]; |
| 185 | $hash_prefix = (count($this->pwd_nonces) - 1).'|'; |
| 186 | } |
| 187 | return $hash_prefix.password_hash($new_password, PASSWORD_DEFAULT, array('cost' => $this->pwd_cost)); |
| 188 | } |
| 189 | |
| 190 | function pwdVerify($password_to_verify, $userdata) { |
| 191 | $pwdhash = $userdata['pwdhash']; |
| 192 | if (preg_match('/^(\d+)\|(.+)$/', $userdata['pwdhash'], $regs)) { |
| 193 | $password_to_verify .= $this->pwd_nonces[$regs[1]]; |
| 194 | $pwdhash = $regs[2]; |
| 195 | } |
| 196 | return password_verify($password_to_verify, $pwdhash); |
| 197 | } |
| 198 | |
| 199 | function pwdNeedsRehash($userdata) { |
| 200 | $nonceid = -1; |
| 201 | $pwdhash = $userdata['pwdhash']; |
| 202 | if (preg_match('/^(\d+)\|(.+)$/', $userdata['pwdhash'], $regs)) { |
| 203 | $nonceid = $regs[1]; |
| 204 | $pwdhash = $regs[2]; |
| 205 | } |
| 206 | if ($nonceid == count($this->pwd_nonces) - 1) { |
| 207 | return password_needs_rehash($pwdhash, PASSWORD_DEFAULT, array('cost' => $this->pwd_cost)); |
| 208 | } |
| 209 | else { |
| 210 | return true; |
| 211 | } |
| 212 | } |
| 213 | } |
| 214 | ?> |