You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: signer.rb
    path of file: ./repos/gitlabhq/lib/gitlab/email/smime
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require 'openssl'

module Gitlab
  module Email
    module Smime
      # Tooling for signing and verifying da
    
        def self.verify_signature(ca_certs: nil, signed_data:)
          store = OpenSSL::X509::Store.new
          store.set_default_paths
          Array.wrap(ca_certs).compact.each { |ca_cert| store.add_cert(ca_cert) }

          signed_smime = OpenSSL::PKCS7.read_smime(signed_data)

          # The S/MIME certificate(s) are included in the message and the trusted
          # CAs are in the store parameter, so we pass no certs as parameters
          # to `PKCS7.verify`
          # See https://www.openssl.org/docs/manmaster/man3/PKCS7_verify.html
          signed_smime if signed_smime.verify(nil, store)
        end