advagg_sri.advagg.inc

<?php


/**
 * @file
 * Advanced aggregation sri module.
 */

/**
 * @addtogroup advagg_hooks
 * @{
 */

/**
 * Implements hook_advagg_save_aggregate_alter().
 *
 * Save the hash of the file.
 */
function advagg_sri_advagg_save_aggregate_alter(array &$files_to_save, array $aggregate_settings, array $other_parameters) {
    // * @param array $files_to_save
    // *   Array($uri => $contents).
    // * @param array $aggregate_settings
    // *   Array of settings.
    // * @param array $other_parameters
    // *   Array of containing $files and $type.
    foreach ($files_to_save as $uri => $contents) {
        // Skip gzip/brotli files.
        $ext = strtolower(pathinfo($uri, PATHINFO_EXTENSION));
        if ($ext === 'gz' || $ext === 'br') {
            continue;
        }
        $hashes = advagg_sri_compute_hashes($contents);
        // Save to the database.
        $filename = basename($uri);
        advagg_sri_set_filename_hashes($filename, $hashes);
    }
}

/**
 * Implements hook_advagg_build_aggregate_plans_post_alter().
 */
function advagg_sri_advagg_build_aggregate_plans_post_alter(array &$plans) {
    // * @param array $plans
    // *   Array of aggregate files.
    $advagg_sri = variable_get('advagg_sri', ADVAGG_SRI);
    if (empty($advagg_sri)) {
        return;
    }
    if ($advagg_sri == 1) {
        $sha_bits = 'sha256';
    }
    if ($advagg_sri == 2) {
        $sha_bits = 'sha384';
    }
    if ($advagg_sri == 3) {
        $sha_bits = 'sha512';
    }
    // Get all aggregates.
    $files = array();
    $filenames = array();
    foreach ($plans as $key => $values) {
        if ($values['type'] !== 'file' || empty($values['cache'])) {
            continue;
        }
        $files[$values['filename']] = $key;
        $filenames[$values['filepath']] = $values['filename'];
    }
    // Lookup hashes.
    $hashes = array();
    if (!empty($filenames)) {
        $hashes = advagg_sri_get_filenames_hashes($filenames);
    }
    // Set attributes.
    foreach ($hashes as $filename => $hash) {
        if (isset($files[$filename]) && isset($plans[$files[$filename]])) {
            $plans[$files[$filename]]['attributes']['integrity'] = $sha_bits . '-' . $hash[$sha_bits];
        }
    }
}

/**
 * Implements hook_advagg_build_aggregate_plans_alter().
 */
function advagg_sri_advagg_build_aggregate_plans_alter() {
    if (module_exists('httprl') && variable_get('advagg_use_httprl', ADVAGG_USE_HTTPRL) && variable_get('advagg_sri_file_generation', ADVAGG_SRI_FILE_GENERATION)) {
        $GLOBALS['conf']['advagg_use_httprl'] = FALSE;
    }
}

/**
 * Implements hook_advagg_missing_root_file().
 */
function advagg_sri_advagg_missing_root_file($aggregate_filename, $filename, $cache) {
    // Remove entries from the DB.
    if (!empty($aggregate_filename) && !empty($cache)) {
        advagg_sri_del_filename_hashes($aggregate_filename);
    }
    // Remove entries from the Cache.
    $ext = strtolower(pathinfo($aggregate_filename, PATHINFO_EXTENSION));
    $cid = "advagg:{$ext}:";
    cache_clear_all($cid, 'cache_advagg_aggregates', TRUE);
}

/**
 * Implements hook_advagg_removed_aggregates().
 */
function advagg_sri_advagg_removed_aggregates($kill_list) {
    foreach ($kill_list as $uri) {
        if (is_object($uri) && property_exists($uri, 'uri')) {
            $temp = $uri->uri;
            unset($uri);
            $uri = $temp;
        }
        // Skip gzip/brotli files.
        $ext = strtolower(pathinfo($uri, PATHINFO_EXTENSION));
        if ($ext === 'gz' || $ext === 'br') {
            continue;
        }
        $filename = basename($uri);
        advagg_sri_del_filename_hashes($filename);
    }
}

/**
 * @} End of "addtogroup advagg_hooks".
 */

/**
 * Store settings associated with hash.
 *
 * @param string $filename
 *   The name of the aggregated filename.
 * @param array $hashes
 *   An array of SHA hashes of the contents of this filename.
 *
 * @return MergeQuery
 *   value from db_merge
 */
function advagg_sri_set_filename_hashes($filename, array $hashes) {
    return db_merge('advagg_sri')->key(array(
        'filename' => $filename,
    ))
        ->fields(array(
        'filename' => $filename,
        'hashes' => serialize($hashes),
    ))
        ->execute();
}

/**
 * Store settings associated with hash.
 *
 * @param string $filename
 *   The name of the aggregated filename.
 *
 * @return DeleteQuery
 *   value from db_delete
 */
function advagg_sri_del_filename_hashes($filename) {
    return db_delete('advagg_sri')->condition('filename', $filename)
        ->execute();
}

/**
 * Returns the hashes settings.
 *
 * @param array $filenames
 *   An array of filenames.
 *
 * @return array
 *   The hashes for the given filenames.
 */
function advagg_sri_get_filenames_hashes(array $filenames) {
    $hashes = array();
    // Do not use the DB if in development mode.
    if (variable_get('advagg_cache_level', ADVAGG_CACHE_LEVEL) < 0) {
        $rows = db_select('advagg_sri', 'advagg_sri')->fields('advagg_sri', array(
            'filename',
            'hashes',
        ))
            ->condition('filename', $filenames, 'IN')
            ->execute();
        foreach ($rows as $row) {
            $hashes[$row->filename] = unserialize($row->hashes);
        }
    }
    // If the hash is not in the database, generate it on demand.
    $db_filenames = array_keys($hashes);
    $not_in_db = array_diff($filenames, $db_filenames);
    foreach ($not_in_db as $file) {
        $filepath = array_search($file, $filenames);
        if (is_readable($filepath)) {
            // Do not use advagg_file_get_contents here.
            $contents = (string) @file_get_contents($filepath);
            if (!empty($contents)) {
                $hashes[$file] = advagg_sri_compute_hashes($contents);
                advagg_sri_set_filename_hashes($file, $hashes[$file]);
            }
        }
    }
    // Check to make sure we have all hashes.
    $all_hashes = array_keys($hashes);
    $not_hashed = array_diff($filenames, $all_hashes);
    if (!empty($not_hashed)) {
        drupal_page_is_cacheable(FALSE);
        // Disable saving to the cache if a sri is missing.
        if (variable_get('advagg_cache_level', ADVAGG_CACHE_LEVEL) > 1) {
            $GLOBALS['conf']['advagg_cache_level'] = 0;
        }
        if (!module_exists('httprl') || !variable_get('advagg_use_httprl', ADVAGG_USE_HTTPRL)) {
            watchdog('advagg_sri', 'The subresource integrity hashes could not be generated for these files: %files', array(
                '%files' => print_r($not_hashed, TRUE),
            ));
        }
    }
    return $hashes;
}

/**
 * Returns an array of hashes.
 *
 * @param string $contents
 *   The string to hash.
 *
 * @return array
 *   The hashes for the given string.
 */
function advagg_sri_compute_hashes($contents) {
    // Generate hashes.
    $hashes = array(
        'sha512' => base64_encode(hash('sha512', $contents, TRUE)),
        'sha384' => base64_encode(hash('sha384', $contents, TRUE)),
        'sha256' => base64_encode(hash('sha256', $contents, TRUE)),
    );
    return $hashes;
}