| 1 |
<?php |
| 2 |
if (!defined('ABSPATH')) exit; |
| 3 |
if (!class_exists('WPRWP2FAEmailOTP')) : |
| 4 |
|
| 5 |
class WPRWP2FAEmailOTP { |
| 6 |
const DIGITS = 8; |
| 7 |
const LIFETIME = 600; |
| 8 |
const TRIES = 3; |
| 9 |
const SEND_COOLDOWN = 60; |
| 10 |
const SEND_WINDOW = 900; |
| 11 |
const SENDS_PER_WINDOW = 5; |
| 12 |
const SITE_SECRET_CONSTANT = 'AUTH_SALT'; |
| 13 |
|
| 14 |
public static function hasSiteSecret() { |
| 15 |
return self::siteSecret() !== null; |
| 16 |
} |
| 17 |
|
| 18 |
public static function secondsUntilNextSend($user_id) { |
| 19 |
$rate = self::loadRate($user_id); |
| 20 |
$now = time(); |
| 21 |
|
| 22 |
if ($now - $rate['window_at'] >= self::SEND_WINDOW) { |
| 23 |
return 0; |
| 24 |
} |
| 25 |
|
| 26 |
if ($rate['sends'] >= self::SENDS_PER_WINDOW) { |
| 27 |
return $rate['window_at'] + self::SEND_WINDOW - $now; |
| 28 |
} |
| 29 |
|
| 30 |
return max(0, $rate['last_sent_at'] + self::SEND_COOLDOWN - $now); |
| 31 |
} |
| 32 |
|
| 33 |
public static function hasLiveCode($user_id) { |
| 34 |
$challenge = self::loadChallenge($user_id); |
| 35 |
|
| 36 |
return $challenge !== null && intval($challenge['expires_at']) > time(); |
| 37 |
} |
| 38 |
|
| 39 |
public static function issue($user) { |
| 40 |
$secret = self::siteSecret(); |
| 41 |
if ($secret === null) { |
| 42 |
return null; |
| 43 |
} |
| 44 |
|
| 45 |
if (self::secondsUntilNextSend($user->ID) > 0) { |
| 46 |
return null; |
| 47 |
} |
| 48 |
|
| 49 |
try { |
| 50 |
$number = random_int(0, pow(10, self::DIGITS) - 1); |
| 51 |
} catch (Exception $error) { |
| 52 |
return null; |
| 53 |
} |
| 54 |
|
| 55 |
$code = str_pad(strval($number), self::DIGITS, '0', STR_PAD_LEFT); |
| 56 |
|
| 57 |
$challenge = array( |
| 58 |
'code_hash' => self::codeHash($user->ID, $code, $secret), |
| 59 |
'expires_at' => time() + self::LIFETIME, |
| 60 |
'tries_left' => self::TRIES |
| 61 |
); |
| 62 |
|
| 63 |
if (!self::recordSend($user->ID)) { |
| 64 |
return null; |
| 65 |
} |
| 66 |
|
| 67 |
if (!self::storeChallenge($user->ID, $challenge)) { |
| 68 |
return null; |
| 69 |
} |
| 70 |
|
| 71 |
return $code; |
| 72 |
} |
| 73 |
|
| 74 |
public static function redeem($user, $code) { |
| 75 |
$secret = self::siteSecret(); |
| 76 |
if ($secret === null) { |
| 77 |
return false; |
| 78 |
} |
| 79 |
|
| 80 |
$code = self::parseCode($code); |
| 81 |
if ($code === null) { |
| 82 |
return false; |
| 83 |
} |
| 84 |
|
| 85 |
$challenge = self::loadChallenge($user->ID); |
| 86 |
if ($challenge === null) { |
| 87 |
return false; |
| 88 |
} |
| 89 |
|
| 90 |
if (intval($challenge['expires_at']) <= time()) { |
| 91 |
self::claim($user->ID, $challenge); |
| 92 |
return false; |
| 93 |
} |
| 94 |
|
| 95 |
if (!hash_equals($challenge['code_hash'], self::codeHash($user->ID, $code, $secret))) { |
| 96 |
self::spendTry($user->ID, $challenge); |
| 97 |
return false; |
| 98 |
} |
| 99 |
|
| 100 |
self::discard($user->ID); |
| 101 |
self::clearSendCount($user->ID); |
| 102 |
|
| 103 |
return true; |
| 104 |
} |
| 105 |
|
| 106 |
public static function revoke($user_id) { |
| 107 |
delete_user_meta($user_id, WPRWP2FA::EMAIL_RATE_META_KEY); |
| 108 |
|
| 109 |
return self::discard($user_id); |
| 110 |
} |
| 111 |
|
| 112 |
public static function discard($user_id) { |
| 113 |
delete_user_meta($user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY); |
| 114 |
|
| 115 |
return !metadata_exists('user', $user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY); |
| 116 |
} |
| 117 |
|
| 118 |
private static function spendTry($user_id, $challenge) { |
| 119 |
if (intval($challenge['tries_left']) <= 1) { |
| 120 |
self::claim($user_id, $challenge); |
| 121 |
return; |
| 122 |
} |
| 123 |
|
| 124 |
$spent = $challenge; |
| 125 |
$spent['tries_left'] = intval($challenge['tries_left']) - 1; |
| 126 |
|
| 127 |
if (update_user_meta($user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY, $spent, $challenge) === false) { |
| 128 |
self::claim($user_id, $challenge); |
| 129 |
} |
| 130 |
} |
| 131 |
|
| 132 |
# Proving inbox control clears the window cap, so logging in repeatedly does |
| 133 |
# not lock someone out. The cooldown is kept so codes still cannot be pulled |
| 134 |
# back to back, and a failed write only means the budget is not returned. |
| 135 |
private static function clearSendCount($user_id) { |
| 136 |
$current = self::loadRate($user_id); |
| 137 |
$next = array( |
| 138 |
'sends' => 0, |
| 139 |
'window_at' => time(), |
| 140 |
'last_sent_at' => $current['last_sent_at'] |
| 141 |
); |
| 142 |
|
| 143 |
update_user_meta($user_id, WPRWP2FA::EMAIL_RATE_META_KEY, $next, $current); |
| 144 |
} |
| 145 |
|
| 146 |
private static function loadRate($user_id) { |
| 147 |
$blank = array('sends' => 0, 'window_at' => 0, 'last_sent_at' => 0); |
| 148 |
$rate = get_user_meta($user_id, WPRWP2FA::EMAIL_RATE_META_KEY, true); |
| 149 |
|
| 150 |
if (!self::validRate($rate, $blank)) { |
| 151 |
delete_user_meta($user_id, WPRWP2FA::EMAIL_RATE_META_KEY); |
| 152 |
return $blank; |
| 153 |
} |
| 154 |
|
| 155 |
return $rate; |
| 156 |
} |
| 157 |
|
| 158 |
private static function validRate($rate, $blank) { |
| 159 |
if (!is_array($rate)) { |
| 160 |
return false; |
| 161 |
} |
| 162 |
|
| 163 |
foreach ($blank as $field => $default) { |
| 164 |
if (!isset($rate[$field]) || !is_int($rate[$field]) || $rate[$field] < 0) { |
| 165 |
return false; |
| 166 |
} |
| 167 |
} |
| 168 |
|
| 169 |
return true; |
| 170 |
} |
| 171 |
|
| 172 |
private static function recordSend($user_id) { |
| 173 |
$now = time(); |
| 174 |
$current = self::loadRate($user_id); |
| 175 |
|
| 176 |
$window_at = $current['window_at']; |
| 177 |
$sends = $current['sends']; |
| 178 |
if ($now - $window_at >= self::SEND_WINDOW) { |
| 179 |
$window_at = $now; |
| 180 |
$sends = 0; |
| 181 |
} |
| 182 |
|
| 183 |
$next = array( |
| 184 |
'sends' => $sends + 1, |
| 185 |
'window_at' => $window_at, |
| 186 |
'last_sent_at' => $now |
| 187 |
); |
| 188 |
|
| 189 |
# $current is left untouched: it is the value the update guards on. |
| 190 |
return update_user_meta($user_id, WPRWP2FA::EMAIL_RATE_META_KEY, $next, $current) !== false; |
| 191 |
} |
| 192 |
|
| 193 |
private static function claim($user_id, $challenge) { |
| 194 |
return delete_user_meta($user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY, $challenge) === true; |
| 195 |
} |
| 196 |
|
| 197 |
private static function loadChallenge($user_id) { |
| 198 |
$challenge = get_user_meta($user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY, true); |
| 199 |
|
| 200 |
if (!is_array($challenge) || !isset($challenge['code_hash'], $challenge['expires_at'], $challenge['tries_left'])) { |
| 201 |
return null; |
| 202 |
} |
| 203 |
|
| 204 |
if (!is_string($challenge['code_hash']) || !is_int($challenge['expires_at']) || !is_int($challenge['tries_left'])) { |
| 205 |
return null; |
| 206 |
} |
| 207 |
|
| 208 |
return $challenge; |
| 209 |
} |
| 210 |
|
| 211 |
private static function storeChallenge($user_id, $challenge) { |
| 212 |
return update_user_meta($user_id, WPRWP2FA::EMAIL_CHALLENGE_META_KEY, $challenge) !== false; |
| 213 |
} |
| 214 |
|
| 215 |
private static function codeHash($user_id, $code, $secret) { |
| 216 |
return hash_hmac('sha256', intval($user_id) . "\0" . $code, $secret); |
| 217 |
} |
| 218 |
|
| 219 |
private static function siteSecret() { |
| 220 |
return WPRHelper::configSalt(self::SITE_SECRET_CONSTANT); |
| 221 |
} |
| 222 |
|
| 223 |
private static function parseCode($code) { |
| 224 |
if (!is_string($code)) { |
| 225 |
return null; |
| 226 |
} |
| 227 |
|
| 228 |
$code = trim($code); |
| 229 |
|
| 230 |
return WPRHelper::safePregMatch('/^\d{' . self::DIGITS . '}$/D', $code) === 1 ? $code : null; |
| 231 |
} |
| 232 |
} |
| 233 |
endif; |
| 234 |
|
