includes/legacy/api/v2/class-wc-api-authentication.php
<?php
/**
* WooCommerce API Authentication Class
*
* @author WooThemes
* @category API
* @package WooCommerce\RestApi
* @since 2.1.0
* @version 2.4.0
*/
if ( ! defined( 'ABSPATH' ) ) {
exit; // Exit if accessed directly
}
class WC_API_Authentication {
/**
* Setup class
*
* @since 2.1
*/
public function __construct() {
// To disable authentication, hook into this filter at a later priority and return a valid WP_User
add_filter( 'woocommerce_api_check_authentication', array( $this, 'authenticate' ), 0 );
}
/**
* Authenticate the request. The authentication method varies based on whether the request was made over SSL or not.
*
* @since 2.1
* @param WP_User $user
* @return null|WP_Error|WP_User
*/
public function authenticate( $user ) {
// Allow access to the index by default
if ( '/' === WC()->api->server->path ) {
return new WP_User( 0 );
}
try {
if ( is_ssl() ) {
$keys = $this->perform_ssl_authentication();
} else {
$keys = $this->perform_oauth_authentication();
}
// Check API key-specific permission
$this->check_api_key_permissions( $keys['permissions'] );
$user = $this->get_user_by_id( $keys['user_id'] );
$this->update_api_key_last_access( $keys['key_id'] );
} catch ( Exception $e ) {
$user = new WP_Error( 'woocommerce_api_authentication_error', $e->getMessage(), array( 'status' => $e->getCode() ) );
}
return $user;
}
/**
* SSL-encrypted requests are not subject to sniffing or man-in-the-middle
* attacks, so the request can be authenticated by simply looking up the user
* associated with the given consumer key and confirming the consumer secret
* provided is valid
*
* @since 2.1
* @return array
* @throws Exception
*/
private function perform_ssl_authentication() {
$params = WC()->api->server->params['GET'];
// Get consumer key
if ( ! empty( $_SERVER['PHP_AUTH_USER'] ) ) {
// Should be in HTTP Auth header by default
$consumer_key = $_SERVER['PHP_AUTH_USER'];
} elseif ( ! empty( $params['consumer_key'] ) ) {
// Allow a query string parameter as a fallback
$consumer_key = $params['consumer_key'];
} else {
throw new Exception( __( 'Consumer key is missing.', 'woocommerce' ), 404 );
}
// Get consumer secret
if ( ! empty( $_SERVER['PHP_AUTH_PW'] ) ) {
// Should be in HTTP Auth header by default
$consumer_secret = $_SERVER['PHP_AUTH_PW'];
} elseif ( ! empty( $params['consumer_secret'] ) ) {
// Allow a query string parameter as a fallback
$consumer_secret = $params['consumer_secret'];
} else {
throw new Exception( __( 'Consumer secret is missing.', 'woocommerce' ), 404 );
}
$keys = $this->get_keys_by_consumer_key( $consumer_key );
if ( ! $this->is_consumer_secret_valid( $keys['consumer_secret'], $consumer_secret ) ) {
throw new Exception( __( 'Consumer secret is invalid.', 'woocommerce' ), 401 );
}
return $keys;
}
/**
* Perform OAuth 1.0a "one-legged" (http://oauthbible.com/#oauth-10a-one-legged) authentication for non-SSL requests
*
* This is required so API credentials cannot be sniffed or intercepted when making API requests over plain HTTP
*
* This follows the spec for simple OAuth 1.0a authentication (RFC 5849) as closely as possible, with two exceptions:
*
* 1) There is no token associated with request/responses, only consumer keys/secrets are used
*
* 2) The OAuth parameters are included as part of the request query string instead of part of the Authorization header,
* This is because there is no cross-OS function within PHP to get the raw Authorization header
*
* @link http://tools.ietf.org/html/rfc5849 for the full spec
* @since 2.1
* @return array
* @throws Exception
*/
private function perform_oauth_authentication() {
$params = WC()->api->server->params['GET'];
$param_names = array( 'oauth_consumer_key', 'oauth_timestamp', 'oauth_nonce', 'oauth_signature', 'oauth_signature_method' );
// Check for required OAuth parameters
foreach ( $param_names as $param_name ) {
if ( empty( $params[ $param_name ] ) ) {
throw new Exception( sprintf( __( '%s parameter is missing', 'woocommerce' ), $param_name ), 404 );
}
}
// Fetch WP user by consumer key
$keys = $this->get_keys_by_consumer_key( $params['oauth_consumer_key'] );
// Perform OAuth validation
$this->check_oauth_signature( $keys, $params );
$this->check_oauth_timestamp_and_nonce( $keys, $params['oauth_timestamp'], $params['oauth_nonce'] );
// Authentication successful, return user
return $keys;
}
/**
* Return the keys for the given consumer key
*
* @since 2.4.0
* @param string $consumer_key
* @return array
* @throws Exception
*/
private function get_keys_by_consumer_key( $consumer_key ) {
global $wpdb;
$consumer_key = wc_api_hash( sanitize_text_field( $consumer_key ) );
$keys = $wpdb->get_row( $wpdb->prepare( "
SELECT key_id, user_id, permissions, consumer_key, consumer_secret, nonces
FROM {$wpdb->prefix}woocommerce_api_keys
WHERE consumer_key = '%s'
", $consumer_key ), ARRAY_A );
if ( empty( $keys ) ) {
throw new Exception( __( 'Consumer key is invalid.', 'woocommerce' ), 401 );
}
return $keys;
}
/**
* Get user by ID
*
* @since 2.4.0
* @param int $user_id
* @return WP_User
* @throws Exception
*/
private function get_user_by_id( $user_id ) {
$user = get_user_by( 'id', $user_id );
if ( ! $user ) {
throw new Exception( __( 'API user is invalid', 'woocommerce' ), 401 );
}
return $user;
}
/**
* Check if the consumer secret provided for the given user is valid
*
* @since 2.1
* @param string $keys_consumer_secret
* @param string $consumer_secret
* @return bool
*/
private function is_consumer_secret_valid( $keys_consumer_secret, $consumer_secret ) {
return hash_equals( $keys_consumer_secret, $consumer_secret );
}
/**
* Verify that the consumer-provided request signature matches our generated signature, this ensures the consumer
* has a valid key/secret
*
* @param array $keys
* @param array $params the request parameters
* @throws Exception
*/
private function check_oauth_signature( $keys, $params ) {
$http_method = strtoupper( WC()->api->server->method );
$base_request_uri = rawurlencode( untrailingslashit( get_woocommerce_api_url( '' ) ) . WC()->api->server->path );
// Get the signature provided by the consumer and remove it from the parameters prior to checking the signature
$consumer_signature = rawurldecode( str_replace( ' ', '+', $params['oauth_signature'] ) );
unset( $params['oauth_signature'] );
// Remove filters and convert them from array to strings to void normalize issues
if ( isset( $params['filter'] ) ) {
$filters = $params['filter'];
unset( $params['filter'] );
foreach ( $filters as $filter => $filter_value ) {
$params[ 'filter[' . $filter . ']' ] = $filter_value;
}
}
// Normalize parameter key/values
$params = $this->normalize_parameters( $params );
// Sort parameters
if ( ! uksort( $params, 'strcmp' ) ) {
throw new Exception( __( 'Invalid signature - failed to sort parameters.', 'woocommerce' ), 401 );
}
// Form query string
$query_params = array();
foreach ( $params as $param_key => $param_value ) {
$query_params[] = $param_key . '%3D' . $param_value; // join with equals sign
}
$query_string = implode( '%26', $query_params ); // join with ampersand
$string_to_sign = $http_method . '&' . $base_request_uri . '&' . $query_string;
if ( 'HMAC-SHA1' !== $params['oauth_signature_method'] && 'HMAC-SHA256' !== $params['oauth_signature_method'] ) {
throw new Exception( __( 'Invalid signature - signature method is invalid.', 'woocommerce' ), 401 );
}
$hash_algorithm = strtolower( str_replace( 'HMAC-', '', $params['oauth_signature_method'] ) );
$signature = base64_encode( hash_hmac( $hash_algorithm, $string_to_sign, $keys['consumer_secret'], true ) );
if ( ! hash_equals( $signature, $consumer_signature ) ) {
throw new Exception( __( 'Invalid signature - provided signature does not match.', 'woocommerce' ), 401 );
}
}
/**
* Normalize each parameter by assuming each parameter may have already been
* encoded, so attempt to decode, and then re-encode according to RFC 3986
*
* Note both the key and value is normalized so a filter param like:
*
* 'filter[period]' => 'week'
*
* is encoded to:
*
* 'filter%5Bperiod%5D' => 'week'
*
* This conforms to the OAuth 1.0a spec which indicates the entire query string
* should be URL encoded
*
* @since 2.1
* @see rawurlencode()
* @param array $parameters un-normalized parameters
* @return array normalized parameters
*/
private function normalize_parameters( $parameters ) {
$normalized_parameters = array();
foreach ( $parameters as $key => $value ) {
// Percent symbols (%) must be double-encoded
$key = str_replace( '%', '%25', rawurlencode( rawurldecode( $key ) ) );
$value = str_replace( '%', '%25', rawurlencode( rawurldecode( $value ) ) );
$normalized_parameters[ $key ] = $value;
}
return $normalized_parameters;
}
/**
* Verify that the timestamp and nonce provided with the request are valid. This prevents replay attacks where
* an attacker could attempt to re-send an intercepted request at a later time.
*
* - A timestamp is valid if it is within 15 minutes of now
* - A nonce is valid if it has not been used within the last 15 minutes
*
* @param array $keys
* @param int $timestamp the unix timestamp for when the request was made
* @param string $nonce a unique (for the given user) 32 alphanumeric string, consumer-generated
* @throws Exception
*/
private function check_oauth_timestamp_and_nonce( $keys, $timestamp, $nonce ) {
global $wpdb;
$valid_window = 15 * 60; // 15 minute window
if ( ( $timestamp < time() - $valid_window ) || ( $timestamp > time() + $valid_window ) ) {
throw new Exception( __( 'Invalid timestamp.', 'woocommerce' ), 401 );
}
$used_nonces = maybe_unserialize( $keys['nonces'] );
if ( empty( $used_nonces ) ) {
$used_nonces = array();
}
if ( in_array( $nonce, $used_nonces ) ) {
throw new Exception( __( 'Invalid nonce - nonce has already been used.', 'woocommerce' ), 401 );
}
$used_nonces[ $timestamp ] = $nonce;
// Remove expired nonces
foreach ( $used_nonces as $nonce_timestamp => $nonce ) {
if ( $nonce_timestamp < ( time() - $valid_window ) ) {
unset( $used_nonces[ $nonce_timestamp ] );
}
}
$used_nonces = maybe_serialize( $used_nonces );
$wpdb->update(
$wpdb->prefix . 'woocommerce_api_keys',
array( 'nonces' => $used_nonces ),
array( 'key_id' => $keys['key_id'] ),
array( '%s' ),
array( '%d' )
);
}
/**
* Check that the API keys provided have the proper key-specific permissions to either read or write API resources
*
* @param string $key_permissions
* @throws Exception if the permission check fails
*/
public function check_api_key_permissions( $key_permissions ) {
switch ( WC()->api->server->method ) {
case 'HEAD':
case 'GET':
if ( 'read' !== $key_permissions && 'read_write' !== $key_permissions ) {
throw new Exception( __( 'The API key provided does not have read permissions.', 'woocommerce' ), 401 );
}
break;
case 'POST':
case 'PUT':
case 'PATCH':
case 'DELETE':
if ( 'write' !== $key_permissions && 'read_write' !== $key_permissions ) {
throw new Exception( __( 'The API key provided does not have write permissions.', 'woocommerce' ), 401 );
}
break;
}
}
/**
* Updated API Key last access datetime
*
* @since 2.4.0
*
* @param int $key_id
*/
private function update_api_key_last_access( $key_id ) {
global $wpdb;
$wpdb->update(
$wpdb->prefix . 'woocommerce_api_keys',
array( 'last_access' => current_time( 'mysql' ) ),
array( 'key_id' => $key_id ),
array( '%s' ),
array( '%d' )
);
}
}