Add setting to configure hash appends

includes/admin/class-wc-admin-post-types.php

@@ -838,6 +838,10 @@ class WC_Admin_Post_Types {
 			return $full_filename;
 		}
 
+		if ( 'no' === get_option( 'woocommerce_downloads_add_hash_to_filename' ) ) {
+			return $full_filename;
+		}
+
 		return $this->unique_filename( $full_filename, $ext );
 	}
 
@@ -850,7 +854,7 @@ class WC_Admin_Post_Types {
 	 * @return string Modified filename.
 	 */
 	public function unique_filename( $full_filename, $ext ) {
-		$ideal_random_char_length = 32;
+		$ideal_random_char_length = 6;   // Not going with a larger length because then downloaded filename will not be pretty.
 		$max_filename_length      = 255; // Max file name length for most file systems.
 		$length_to_prepend        = min( $ideal_random_char_length, $max_filename_length - strlen( $full_filename ) - 1 );
 

includes/admin/settings/class-wc-settings-products.php

@@ -260,6 +260,19 @@ class WC_Settings_Products extends WC_Settings_Page {
 						'autoload'      => false,
 					),
 
+					array(
+						'title' => __( 'Filename', 'woocommerce' ),
+						'desc' => __( 'Append a unique string to filename for security', 'woocommerce' ),
+						'id' => 'woocommerce_downloads_add_hash_to_filename',
+						'type' => 'checkbox',
+						'default' => 'yes',
+						'desc_tip' => sprintf(
+							// translators: Link to WooCommerce Docs.
+							__( "Not required if you download directory is protected. <a href='%s'>See this guide</a> for more details. Files already uploaded will not be affected.", 'woocommerce' ),
+							'link to woocommerce docs' // TODO: Change this after updating docs.
+						),
+					),
+
 					array(
 						'type' => 'sectionend',
 						'id'   => 'digital_download_options',

tests/unit-tests/core/post-types-admin.php

@@ -33,7 +33,7 @@ class WC_Test_Admin_Post_Types extends WC_Unit_Test_Case {
 		$ext = '.csv';
 
 		$unique_filename = $this->wc_cpt->unique_filename( $full_filename, $ext );
-		$this->assertEquals( strlen( $full_filename ) + 32 + 1, strlen( $unique_filename ) );
+		$this->assertEquals( strlen( $full_filename ) + 6 + 1, strlen( $unique_filename ) );
 		$this->assertEquals( $ext, substr( $unique_filename, -4 ) );
 	}