There was a law suite filed by Judicial Watch in June 2017 that was over turned. Over the 400 million. Before October 13, 2017, the IRGC was blocked under Executive Orders 13382 (relating to WMD proliferation.) Obama might have sent the money as a humanitarian donations from a personal account to the Iranian individual officials. The Iranian government is not completely blocked off as a terrorist country which is how Obama got away with this.
From US Treasury dept site:
U.S. financial institutions are authorized to process noncommercial, personal remittances to Iran, which may include a personal transfer of funds from the United States to Iran to assist a friend or family member, provided that the transfer complies with the requirements of sections 560.516 and 560.550 of the ITSR. [11-17-2017]
https://www.treasury.gov/resource-center/faqs/Sanctions/Pages/faq_iran.aspx
Thank you so much for that information and insight.