The iDEAL certificates sometimes expire. To support both old and new certificates for a transition period, include this gem.
In your Gemfile:
gem "activemerchant" gem "active_merchant_ideal" gem "active_merchant_ideal_multicert"
(Order does matter)
In your ActiveMerchant initializer, configure multiple certificates like this:
ActiveMerchant::Billing::IdealGateway.ideal_certificate_files = [ "/path/to/certificate1", "/path/to/certificate2" ]
Every time a transaction is verified, the message signature is verified with the proper certificate identified by the message fingerprint.
active_merchant_ideal_multicert is Copyright (c) 2011 Voormedia B.V. and distributed under the MIT license. See the LICENSE file for more info.