surecookie / inc / modules / auth / controller.php

controller.php in SureCookie – GDPR Cookie Consent Banner, Cookie Scanner & Script Blocking trunk, at inc/modules/auth/controller.php

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1	<?php
2	/**
3	* Auth Controller
4	*
5	* Main controller class for handling authentication functionality.
6	*
7	* @package SureCookie\Inc\Modules\Auth
8	* @since 0.0.1-beta.3
9	*/
10
11	namespace SureCookie\Inc\Modules\Auth;
12
13	use SureCookie\Inc\Functions\Update;
14	use SureCookie\Inc\Modules\SiteScanner\SaasClient;
15	use SureCookie\Inc\Traits\GetInstance;
16	use WP_Error;
17
18	if ( ! defined( 'ABSPATH' ) ) {
19	exit; // Exit if accessed directly.
20	}
21
22	/**
23	* Controller class
24	*
25	* Main controller class for authentication functionality.
26	*/
27	class Controller {
28	use GetInstance;
29
30	/**
31	* Module settings key.
32	*
33	* @since 0.0.1-beta.3
34	*/
35	public const SETTINGS_KEY = 'surecookie_auth';
36
37	/**
38	* TTL for the per-flow encryption key transient (seconds).
39	*
40	* @since 0.0.1-beta.3
41	*/
42	public const FLOW_KEY_TTL = 300;
43
44	/**
45	* Encryption key.
46	*
47	* @since 0.0.1-beta.3
48	* @var string
49	*/
50	public $key;
51
52	/**
53	* Build the auth payload the frontend POSTs to the billing portal (issue #466).
54	*
55	* Returns the action URL + hidden field values for a form-based POST so the
56	* AES key and flow identifier never appear in any URL, browser history,
57	* Referer header, or access log.
58	*
59	* Each call mints a fresh 256-bit key and a fresh flow_id (UUID); the key
60	* is stored server-side under a transient keyed by flow_id (NOT user_id -
61	* eliminates multi-tab key reuse).
62	*
63	* @since 0.0.1-beta.3
64	*
65	* @return array{action_url: string, method: string, fields: array<string, string>}\|WP_Error
66	*/
67	public function get_auth_payload() {
68	try {
69	$this->key = bin2hex( random_bytes( 32 ) );
70	} catch ( \Throwable $e ) {
71	return new WP_Error( 'csprng_unavailable', __( 'Could not generate secure auth key.', 'surecookie' ) );
72	}
73
74	$flow_id = wp_generate_uuid4();
75
76	set_transient( 'scap_auth_key_' . $flow_id, $this->key, self::FLOW_KEY_TTL );
77
78	$token_data = [
79	'redirect-back' => admin_url( 'admin.php?page=surecookie' ),
80	'key' => $this->key,
81	'site-url' => site_url(),
82	'flow_id' => $flow_id,
83	];
84
85	$encoded_token_data = wp_json_encode( $token_data );
86
87	if ( empty( $encoded_token_data ) ) {
88	return new WP_Error( 'failed_to_encode_token_data', __( 'Failed to encode the token data.', 'surecookie' ) );
89	}
90
91	return [
92	'action_url' => SURECOOKIE_BILLING_PORTAL . 'auth/',
93	'method' => 'POST',
94	'fields' => [
95	'token' => base64_encode( $encoded_token_data ), // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode
96	'flow_id' => $flow_id,
97	],
98	];
99	}
100
101	/**
102	* Get Auth status.
103	*
104	* Checks if user is authenticated via stored credentials or via Pro license.
105	*
106	* @since 0.0.1-beta.3
107	* @return bool
108	*/
109	public function get_auth_status() {
110	$auth_status = get_option( self::SETTINGS_KEY, false );
111	$is_authenticated = ! empty( $auth_status );
112
113	/**
114	* Filter to allow Pro plugin to override authentication status.
115	*
116	* @since 0.0.1-beta.3
117	* @param bool $is_authenticated Whether user is authenticated.
118	*/
119	return apply_filters( 'surecookie_is_authenticated', $is_authenticated );
120	}
121
122	/**
123	* Get authenticated user email.
124	*
125	* Retained for UI display ("Logged in as X"). The email is NOT
126	* transmitted to the SaaS scanner on any request after issue #469.
127	*
128	* @since 0.0.1-beta.3
129	* @return string\|null
130	*/
131	public function get_auth_email() {
132	$auth_data = get_option( self::SETTINGS_KEY, [] );
133	return $auth_data['user_email'] ?? null;
134	}
135
136	/**
137	* Get the opaque billing-portal account reference (UUID v4) - issue #469.
138	*
139	* The only identifier sent to the SaaS alongside HMAC site auth.
140	* Returns null for corrupted/non-v4 stored values.
141	*
142	* @since 0.0.1-beta.3
143	*/
144	public function get_account_ref(): ?string {
145	$auth_data = get_option( self::SETTINGS_KEY, [] );
146	$ref = $auth_data['account_ref'] ?? null;
147
148	if ( ! is_string( $ref ) \|\| $ref === '' ) {
149	return null;
150	}
151
152	// RFC 4122 v4: 8-4-4-4-12 hex, version nibble = 4, variant in [89ab].
153	if ( ! preg_match( '/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i', $ref ) ) {
154	return null;
155	}
156
157	return $ref;
158	}
159
160	/**
161	* Save Auth.
162	*
163	* Decrypts the access key using the per-flow transient key and random IV.
164	* Expected input format: base64( iv + ciphertext )
165	*
166	* Issue #466: keyed by flow_id (UUID), not user_id - eliminates multi-tab
167	* key reuse. The WP nonce was removed from the payload (cross-origin nonce
168	* is meaningless; replay protection survives via one-time transient + TTL).
169	*
170	* @since 0.0.1-beta.3
171	* @param string $data Base64-encoded encrypted data.
172	* @param string $flow_id UUID from the inbound POST identifying which key transient to use.
173	* @param string $method Encryption method. Default is AES-256-CBC.
174	* @return bool\|WP_Error
175	*/
176	public function save_auth( $data, $flow_id, $method = 'AES-256-CBC' ) {
177
178	if ( ! is_string( $flow_id ) \|\| ! preg_match( '/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i', $flow_id ) ) {
179	return new WP_Error( 'invalid_flow_id', __( 'Invalid flow identifier.', 'surecookie' ) );
180	}
181
182	// Convert URL-safe base64 (RFC 4648 §5) back to standard base64.
183	$data = strtr( (string) $data, '-_', '+/' );
184
185	$decoded_data = base64_decode( $data ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode
186
187	if ( empty( $decoded_data ) ) {
188	return new WP_Error( 'failed_to_decode', __( 'Failed to decode the access key.', 'surecookie' ) );
189	}
190
191	$iv_length = openssl_cipher_iv_length( $method );
192	if ( $iv_length === false \|\| strlen( $decoded_data ) <= $iv_length ) {
193	return new WP_Error( 'invalid_data_format', __( 'Invalid data format.', 'surecookie' ) );
194	}
195
196	$iv = substr( $decoded_data, 0, $iv_length );
197	$encrypted = substr( $decoded_data, $iv_length );
198
199	$decrypted = $this->attempt_transient_decrypt( $encrypted, $iv, $method, $flow_id );
200
201	// One-time use: consume the transient regardless of decrypt outcome.
202	// Even a failed attempt (wrong ciphertext / wrong key) invalidates the
203	// transient so a captured payload can't be replayed against a fresh attempt.
204	delete_transient( 'scap_auth_key_' . $flow_id );
205
206	if ( empty( $decrypted ) ) {
207	return new WP_Error( 'failed_to_decrypt', __( 'Failed to decrypt the access key.', 'surecookie' ) );
208	}
209
210	$decrypted_data_array = json_decode( $decrypted, true );
211
212	if ( ! is_array( $decrypted_data_array ) \|\| empty( $decrypted_data_array ) ) {
213	return new WP_Error( 'failed_to_json_decode', __( 'Failed to json decode the decrypted data.', 'surecookie' ) );
214	}
215
216	if ( empty( $decrypted_data_array['user_email'] ) ) {
217	return new WP_Error( 'no_user_email', __( 'No user email found in the decrypted data.', 'surecookie' ) );
218	}
219
220	if ( isset( $decrypted_data_array['is_subscribed'] ) ) {
221	$is_subscribed = is_string( $decrypted_data_array['is_subscribed'] )
222	? $decrypted_data_array['is_subscribed'] === 'true'
223	: (bool) $decrypted_data_array['is_subscribed'];
224
225	update_option( 'surecookie_usage_optin', $is_subscribed ? 'yes' : 'no' );
226	unset( $decrypted_data_array['is_subscribed'] );
227	}
228
229	// Strip any stray nonce field the billing portal might still echo for
230	// pre-#466 clients - not validated, just not persisted.
231	unset( $decrypted_data_array['nonce'] );
232
233	// Non-autoloaded - the auth payload is only read by admin/REST paths, never
234	// on the front-end banner render, so it stays out of the alloptions cache.
235	Update::option( self::SETTINGS_KEY, $decrypted_data_array );
236
237	// Push account_ref to SaaS so it can populate Site::tier without
238	// seeing the user's email (issue #469). Fire-and-forget.
239	$account_ref = $decrypted_data_array['account_ref'] ?? null;
240	if ( is_string( $account_ref ) && $account_ref !== '' ) {
241	SaasClient::get_instance()->link_billing_account( $account_ref );
242	}
243
244	return true;
245	}
246
247	/**
248	* Clear Auth data.
249	*
250	* @since 0.0.1-beta.3
251	* @return bool
252	*/
253	public function clear_auth() {
254	return delete_option( self::SETTINGS_KEY );
255	}
256
257	/**
258	* Attempt decryption using the key stored in the per-flow transient.
259	*
260	* The transient holds the hex-encoded key (transport-safe in JSON).
261	* We hex2bin() it here so OpenSSL receives the full 32 raw bytes -
262	* passing the 64-char hex string directly would silently truncate
263	* inside openssl and reduce the AES-256 key to 128 effective bits.
264	*
265	* @since 0.0.1-beta.3
266	* @param string $encrypted Raw encrypted data (without IV).
267	* @param string $iv The initialization vector.
268	* @param string $method Encryption method.
269	* @param string $flow_id UUID identifying which transient to read.
270	* @return string\|false Decrypted string or false on failure.
271	*/
272	private function attempt_transient_decrypt( string $encrypted, string $iv, string $method, string $flow_id ) {
273	$transient_key = get_transient( 'scap_auth_key_' . $flow_id );
274
275	if ( ! is_string( $transient_key ) \|\| strlen( $transient_key ) !== 64 \|\| ! ctype_xdigit( $transient_key ) ) {
276	return false;
277	}
278
279	$key_bytes = hex2bin( $transient_key );
280	if ( ! is_string( $key_bytes ) \|\| strlen( $key_bytes ) !== 32 ) {
281	return false;
282	}
283
284	return openssl_decrypt( $encrypted, $method, $key_bytes, OPENSSL_RAW_DATA, $iv );
285	}
286
287	}
288