wp_trusted_keys example

sprintf(
                /* translators: %s: The filename of the package. */
                __( 'The authenticity of %s could not be verified as no signature was found.' ),
                '<span class="code">' . esc_html( $filename_for_errors ) . '</span>'
            ),
            array(
                'filename' => $filename_for_errors,
            )
        );
    }

    $trusted_keys = wp_trusted_keys();
    $file_hash    = hash_file( 'sha384', $filename, true );

    mbstring_binary_safe_encoding();

    $skipped_key       = 0;
    $skipped_signature = 0;

    foreach ( (array) $signatures as $signature ) {
        $signature_raw = base64_decode( $signature );

        // Ensure only valid-length signatures are considered.