| 1 |
<?php |
| 2 |
namespace FluentForm\App\Modules\Form; |
| 3 |
|
| 4 |
defined('ABSPATH') or die; |
| 5 |
|
| 6 |
use FluentForm\App\Helpers\Helper; |
| 7 |
use FluentForm\App\Helpers\Protector; |
| 8 |
use FluentForm\Framework\Helpers\ArrayHelper as Arr; |
| 9 |
|
| 10 |
class TokenBasedSpamProtection |
| 11 |
{ |
| 12 |
|
| 13 |
public function __construct($app) |
| 14 |
{ |
| 15 |
if (!$this->isEnabled()) { |
| 16 |
return; |
| 17 |
} |
| 18 |
|
| 19 |
$app->addAction('wp_ajax_fluentform_generate_protection_token', [$this, 'ajaxGenerateToken']); |
| 20 |
$app->addAction('wp_ajax_nopriv_fluentform_generate_protection_token', [$this, 'ajaxGenerateToken']); |
| 21 |
|
| 22 |
add_filter('fluentform/global_form_vars', function ($vars){ |
| 23 |
$vars['token_nonce'] = wp_create_nonce('fluentform_generate_token_nonce'); |
| 24 |
return $vars; |
| 25 |
}); |
| 26 |
|
| 27 |
} |
| 28 |
|
| 29 |
public function renderTokenField($form) |
| 30 |
{ |
| 31 |
if (!$this->isEnabled($form->id)) { |
| 32 |
return; |
| 33 |
} |
| 34 |
|
| 35 |
$fieldName = $this->getFieldName($form->id); |
| 36 |
?> |
| 37 |
<input type="hidden" id="<?php echo esc_attr($fieldName); ?>" class="fluent-form-token-field" name="<?php echo esc_attr($fieldName); ?>"> |
| 38 |
<?php |
| 39 |
} |
| 40 |
|
| 41 |
public function ajaxGenerateToken() |
| 42 |
{ |
| 43 |
// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Nonce verified on next line |
| 44 |
$nonce = sanitize_text_field(Arr::get($_POST, 'nonce')); |
| 45 |
// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Nonce verified on next line |
| 46 |
$formId = (int)Arr::get($_POST,'form_id'); |
| 47 |
|
| 48 |
$nonceVerified = wp_verify_nonce($nonce, 'fluentform_generate_token_nonce'); |
| 49 |
if (!$formId || !$nonceVerified) { |
| 50 |
wp_send_json_error([ |
| 51 |
'message' => __('Invalid request', 'fluentform') |
| 52 |
]); |
| 53 |
} |
| 54 |
|
| 55 |
$token = $this->generateToken($formId); |
| 56 |
$response = apply_filters('fluentform/token_based_protection_response', [ |
| 57 |
'token' => $token |
| 58 |
], $formId); |
| 59 |
|
| 60 |
wp_send_json_success($response); |
| 61 |
} |
| 62 |
|
| 63 |
private function generateToken($formId) |
| 64 |
{ |
| 65 |
$timeStamp = current_time('timestamp'); |
| 66 |
$fieldName = $this->getFieldName($formId); |
| 67 |
$data = implode('|', [$timeStamp, $formId, $fieldName]); |
| 68 |
|
| 69 |
return apply_filters('fluentform/generated_protection_token', Protector::encrypt($data), $formId, $timeStamp); |
| 70 |
} |
| 71 |
|
| 72 |
/** |
| 73 |
* SECURITY (FINDING-25): mint a token input for the conversational form so it is carried in the |
| 74 |
* submission (the conversational JS forwards every extra_input) and the token check can be |
| 75 |
* enforced server-side instead of being skippable via the client isFFConversational flag. This |
| 76 |
* is static and self-contained to avoid the constructor's action registrations; it mirrors |
| 77 |
* isEnabled() / getFieldName() / generateToken() above (same filters, same payload format, so |
| 78 |
* validateToken() accepts it). |
| 79 |
* |
| 80 |
* @param int $formId |
| 81 |
* @return array |
| 82 |
*/ |
| 83 |
public static function getConversationalTokenInput($formId) |
| 84 |
{ |
| 85 |
$option = get_option('_fluentform_global_form_settings'); |
| 86 |
$enabled = 'yes' === Arr::get($option, 'misc.tokenBasedProtectionStatus'); |
| 87 |
$enabled = apply_filters('fluentform/token_based_spam_protection_status', $enabled, $formId); |
| 88 |
if (!$enabled) { |
| 89 |
return []; |
| 90 |
} |
| 91 |
|
| 92 |
$fieldName = apply_filters('fluentform/token_protection_name', '__fluent_protection_token_' . $formId, $formId); |
| 93 |
$timeStamp = current_time('timestamp'); |
| 94 |
$data = implode('|', [$timeStamp, $formId, $fieldName]); |
| 95 |
$token = apply_filters('fluentform/generated_protection_token', Protector::encrypt($data), $formId, $timeStamp); |
| 96 |
|
| 97 |
return [$fieldName => $token]; |
| 98 |
} |
| 99 |
|
| 100 |
public function verify($insertData, $requestData, $formId) |
| 101 |
{ |
| 102 |
// SECURITY (FINDING-25): do NOT skip the check for conversational forms based on the |
| 103 |
// client-supplied isFFConversational flag — that let an attacker bypass token protection by |
| 104 |
// adding one parameter. The conversational renderer now injects a valid token into the |
| 105 |
// submission (getConversationalTokenInput via extra_inputs), so the check is enforced for |
| 106 |
// conversational and regular forms alike; only a genuinely-disabled feature is skipped. |
| 107 |
if (!$this->isEnabled($formId)) { |
| 108 |
return; |
| 109 |
} |
| 110 |
|
| 111 |
$fieldName = $this->getFieldName($formId); |
| 112 |
$token = sanitize_text_field(Arr::get($requestData, $fieldName)); |
| 113 |
if (!$token || !$this->validateToken($token, $formId)) { |
| 114 |
$errorMessage = apply_filters( |
| 115 |
'fluentform/token_based_validation_error_message', |
| 116 |
__('Suspicious activity detected. Form submission blocked', 'fluentform'), |
| 117 |
$formId |
| 118 |
); |
| 119 |
|
| 120 |
$this->handleSpam($errorMessage); |
| 121 |
} |
| 122 |
} |
| 123 |
|
| 124 |
private function validateToken($token, $formId) |
| 125 |
{ |
| 126 |
try { |
| 127 |
|
| 128 |
$decrypted = Protector::decrypt($token); |
| 129 |
if (!$decrypted) { |
| 130 |
return false; |
| 131 |
} |
| 132 |
|
| 133 |
$parts = explode('|', $decrypted); |
| 134 |
if (count($parts) !== 3) { |
| 135 |
return false; |
| 136 |
} |
| 137 |
|
| 138 |
[$timestamp, $tokenFormId, $fieldName] = $parts; |
| 139 |
|
| 140 |
// Ensure all components are valid |
| 141 |
if (!is_numeric($timestamp) || !is_numeric($tokenFormId)) { |
| 142 |
return false; |
| 143 |
} |
| 144 |
|
| 145 |
$expirationTime = apply_filters('fluentform/token_expiration_time', 3600, $formId); //1 hour |
| 146 |
if ($timestamp + $expirationTime < current_time('timestamp')) { |
| 147 |
return false; |
| 148 |
} |
| 149 |
|
| 150 |
$isValid = (int)$tokenFormId === $formId && $fieldName === $this->getFieldName($formId); |
| 151 |
|
| 152 |
// NOTE (FINDING-27): a per-token single-use cap was intentionally NOT implemented here. |
| 153 |
// Storing one WordPress transient per minted token would create unbounded options-table |
| 154 |
// writes on this high-frequency public path (tokens are cheaply minted via the public |
| 155 |
// endpoint and expired transients are not proactively cleaned). The token remains a |
| 156 |
// defence-in-depth anti-bot control (a bot must fetch a nonce-gated, form/field-bound, |
| 157 |
// time-limited token); replay within the expiration window is the accepted LOW residual. |
| 158 |
|
| 159 |
return apply_filters('fluentform/token_based_validation_result', |
| 160 |
$isValid, |
| 161 |
$timestamp, |
| 162 |
$tokenFormId, |
| 163 |
$formId); |
| 164 |
|
| 165 |
} catch (\Exception $e) { |
| 166 |
return false; |
| 167 |
} |
| 168 |
} |
| 169 |
|
| 170 |
|
| 171 |
private function handleSpam($reason) |
| 172 |
{ |
| 173 |
do_action('fluentform/spam_attempt_caught', $reason); |
| 174 |
|
| 175 |
wp_send_json([ |
| 176 |
'errors' => $reason |
| 177 |
], 422); |
| 178 |
} |
| 179 |
|
| 180 |
public function isEnabled($formId = false) |
| 181 |
{ |
| 182 |
$option = get_option('_fluentform_global_form_settings'); |
| 183 |
$status = 'yes' === Arr::get($option, 'misc.tokenBasedProtectionStatus'); |
| 184 |
return apply_filters('fluentform/token_based_spam_protection_status', $status, $formId); |
| 185 |
} |
| 186 |
|
| 187 |
private function getFieldName($formId) |
| 188 |
{ |
| 189 |
$tokenInputName = '__fluent_protection_token_'. $formId; |
| 190 |
return apply_filters('fluentform/token_protection_name', $tokenInputName, $formId); |
| 191 |
} |
| 192 |
} |
| 193 |
|
