Software Defined Networking (SDN) becomes a de facto standard for the future Internet. SDN decouples the control plane from the data plane of a proprietary network asset to ensure better programmability and security for designing more innovative future network applications. Presently, the SDN framework does not have proper access control mechanism among different entities, namely SDN applications, SDN controllers and switches. To achieve this goal, this paper proposes a blockchain-based access control scheme for the SDN framework. The proposed scheme has the capability to resist various well-known attacks and alleviate the existing single point of controller failure issue in SDN.