| 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() |
| 11 | // CONSTRUCTOR |
| 12 | // |
| 13 | // private $pwd_cost |
| 14 | // The cost parameter for use with PHP password_hash function. |
| 15 | // |
| 16 | // private $pwd_nonces |
| 17 | // The array of nonces to use for "peppering" passwords. For new hashes, the last one of those will be used. |
| 18 | // Generate a nonce with this command: |openssl rand -base64 48| |
| 19 | // |
| 20 | // function checkPasswordConstraints($new_password, $user_email) |
| 21 | // Check password constraints and return an array of error messages (empty if all constraints are met). |
| 22 | // |
| 23 | // function createSessionKey() |
| 24 | // Return a random session key. |
| 25 | // |
| 26 | // function createVerificationCode() |
| 27 | // Return a random acount/email verification code. |
| 28 | // |
| 29 | // function createTimeCode($session, [$offset], [$validity_minutes]) |
| 30 | // Return a time-based code based on the key and ID of the given session. |
| 31 | // An offset can be given to create a specific code for verification, otherwise and offset will be generated. |
| 32 | // Also, an amount of minutes for the code to stay valid can be handed over, by default 10 minutes will be used. |
| 33 | // |
| 34 | // function verifyTimeCode($timecode_to_verify, $session, [$validity_minutes]) |
| 35 | // Verify a given time-based code and return true if it's valid or false if it's not. |
| 36 | // See createTimeCode() documentation for the session and validity paramerters. |
| 37 | // |
| 38 | // function pwdHash($new_password) |
| 39 | // Return a hash for the given password. |
| 40 | // |
| 41 | // function pwdVerify($password_to_verify, $user) |
| 42 | // Return true if the password verifies against the pwdhash field of the user, false if not. |
| 43 | // |
| 44 | // function pwdNeedsRehash($user) |
| 45 | // Return true if the pwdhash field of the user uses an outdated standard and needs to be rehashed. |
| 46 | |
| 47 | function __construct($settings) { |
| 48 | // *** constructor *** |
| 49 | if (array_key_exists('pwd_nonces', $settings)) { |
| 50 | $this->pwd_nonces = $settings['pwd_nonces']; |
| 51 | } |
| 52 | if (array_key_exists('pwd_cost', $settings)) { |
| 53 | $this->pwd_cost = $settings['pwd_cost']; |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | private $pwd_cost = 10; |
| 58 | private $pwd_nonces = array(); |
| 59 | |
| 60 | function checkPasswordConstraints($new_password, $user_email) { |
| 61 | $errors = array(); |
| 62 | if ($new_password != trim($new_password)) { |
| 63 | $errors[] = _('Password must not start or end with a whitespace character like a space.'); |
| 64 | } |
| 65 | if (strlen($new_password) < 8) { $errors[] = sprintf(_('Password too short (min. %s characters).'), 8); } |
| 66 | if (strlen($new_password) > 70) { $errors[] = sprintf(_('Password too long (max. %s characters).'), 70); } |
| 67 | if ((strtolower($new_password) == strtolower($user_email)) || |
| 68 | in_array(strtolower($new_password), preg_split("/[@\.]+/", strtolower($user_email)))) { |
| 69 | $errors[] = _('The passwort can not be equal to your email or any part of it.'); |
| 70 | } |
| 71 | if ((strlen($new_password) < 15) && (preg_match('/^[a-zA-Z]+$/', $new_password))) { |
| 72 | $errors[] = sprintf(_('Your password must use characters other than normal letters or contain least %s characters.'), 15); |
| 73 | } |
| 74 | if (preg_match('/^\d+$/', $new_password)) { |
| 75 | $errors[] = sprintf(_('Your password cannot consist only of numbers.'), 15); |
| 76 | } |
| 77 | if (strlen(count_chars($new_password, 3)) < 5) { |
| 78 | $errors[] = sprintf(_('Password does have to contain at least %s different characters.'), 5); |
| 79 | } |
| 80 | return $errors; |
| 81 | } |
| 82 | |
| 83 | function createSessionKey() { |
| 84 | return bin2hex(openssl_random_pseudo_bytes(512 / 8)); // Get 512 bits of randomness (128 byte hex string). |
| 85 | } |
| 86 | |
| 87 | function createVerificationCode() { |
| 88 | return bin2hex(openssl_random_pseudo_bytes(512 / 8)); // Get 512 bits of randomness (128 byte hex string). |
| 89 | } |
| 90 | |
| 91 | function createTimeCode($session, $offset = null, $validity_minutes = 10) { |
| 92 | // Matches TOTP algorithms, see https://en.wikipedia.org/wiki/Time-based_One-time_Password_Algorithm |
| 93 | $valid_seconds = intval($validity_minutes) * 60; |
| 94 | if ($valid_seconds < 60) { $valid_seconds = 60; } |
| 95 | $code_digits = 8; |
| 96 | $time = time(); |
| 97 | $rest = is_null($offset)?($time % $valid_seconds):intval($offset); // T0, will be sent as part of code to make it valid for the full duration. |
| 98 | $counter = floor(($time - $rest) / $valid_seconds); |
| 99 | $hmac = mhash(MHASH_SHA1, $counter, $session['id'].$session['sesskey']); |
| 100 | $offset = hexdec(substr(bin2hex(substr($hmac, -1)), -1)); // Get the last 4 bits as a number. |
| 101 | $totp = hexdec(bin2hex(substr($hmac, $offset, 4))) & 0x7FFFFFFF; // Take 4 bytes at the offset, discard highest bit. |
| 102 | $totp_value = sprintf('%0'.$code_digits.'d', substr($totp, -$code_digits)); |
| 103 | return $rest.'.'.$totp_value; |
| 104 | } |
| 105 | |
| 106 | function verifyTimeCode($timecode_to_verify, $session, $validity_minutes = 10) { |
| 107 | if (preg_match('/^(\d+)\.\d+$/', $timecode_to_verify, $regs)) { |
| 108 | return ($timecode_to_verify === $this->createTimeCode($session, $regs[1], $validity_minutes)); |
| 109 | } |
| 110 | return false; |
| 111 | } |
| 112 | |
| 113 | function pwdHash($new_password) { |
| 114 | $hash_prefix = ''; |
| 115 | if (count($this->pwd_nonces)) { |
| 116 | $new_password .= $this->pwd_nonces[count($this->pwd_nonces) - 1]; |
| 117 | $hash_prefix = (count($this->pwd_nonces) - 1).'|'; |
| 118 | } |
| 119 | return $hash_prefix.password_hash($new_password, PASSWORD_DEFAULT, array('cost' => $this->pwd_cost)); |
| 120 | } |
| 121 | |
| 122 | function pwdVerify($password_to_verify, $userdata) { |
| 123 | $pwdhash = $userdata['pwdhash']; |
| 124 | if (preg_match('/^(\d+)\|(.+)$/', $userdata['pwdhash'], $regs)) { |
| 125 | $password_to_verify .= $this->pwd_nonces[$regs[1]]; |
| 126 | $pwdhash = $regs[2]; |
| 127 | } |
| 128 | return password_verify($password_to_verify, $pwdhash); |
| 129 | } |
| 130 | |
| 131 | function pwdNeedsRehash($userdata) { |
| 132 | $nonceid = -1; |
| 133 | $pwdhash = $userdata['pwdhash']; |
| 134 | if (preg_match('/^(\d+)\|(.+)$/', $userdata['pwdhash'], $regs)) { |
| 135 | $nonceid = $regs[1]; |
| 136 | $pwdhash = $regs[2]; |
| 137 | } |
| 138 | if ($nonceid == count($this->pwd_nonces) - 1) { |
| 139 | return password_needs_rehash($pwdhash, PASSWORD_DEFAULT, array('cost' => $this->pwd_cost)); |
| 140 | } |
| 141 | else { |
| 142 | return true; |
| 143 | } |
| 144 | } |
| 145 | } |
| 146 | ?> |