Privacy: Use a CSPRNG in export filenames for more security.

`rand()` is deterministic and therefore offers much less protection in this context. `wp_generate_password()` is a convenient wrapper around `wp_rand()`, which uses `random_int()` to generate cryptographically-secure psuedorandom numbers.

See #43546.

Built from https://develop.svn.wordpress.org/trunk@43045


git-svn-id: http://core.svn.wordpress.org/trunk@42874 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/file.php

@@ -2042,7 +2042,7 @@ function wp_privacy_generate_personal_data_export_file( $request_id ) {
 
 	$stripped_email       = str_replace( '@', '-at-', $email_address );
 	$stripped_email       = sanitize_title( $stripped_email ); // slugify the email address
-	$obscura              = md5( rand() );
+	$obscura              = wp_generate_password( 32, false, false );
 	$file_basename        = 'wp-personal-data-file-' . $stripped_email . '-' . $obscura;
 	$html_report_filename = $file_basename . '.html';
 	$html_report_pathname = $exports_dir . $html_report_filename;

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43044';
+$wp_version = '5.0-alpha-43045';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.