Veränderbare Anwendungen in Intel SGX EnklavenPluggable Applications in Intel SGX Enclaves

Introduction

In the last years, a need for secure computing on untrusted host has come up. To achieve this, Intel developed Software Guard Extensions (SGX) [1,2] that allows developers to create secure compartments for their applications, called enclaves. Enclaves are a secure part of applications that can be entered to perform security critical computations while being guarded from an untrusted operating system and attackers by the processor itself. Enclaves operate in completely encrypted memory that only they can access. To ease development of enclaves, Intel released a Software Development Kit (SDK) [0].

Problem statement

Applications inside enclaves are typically fixed, i.e., their code is one statically linked binary blob. This is fine for most applications, however, there are cases, where a plugin-architecture makes sense. In these cases, we would need an enclave, that can swap in and out parts of its code from trusted memory to make space for other parts or different implementations. Furthermore, the enclave should be capable of combining plugins

Task description

To increase flexibility, we want to develop a framework that allows an enclave to modify its own code in a plugin-like architectural way. Therefore the following tasks have to be worked on:

• Dynamically loading enclave code after enclave creation
• Dynamically unloading code after enclave creation
• Redirecting control flow of code to enable or disable plugins
• Development of a sample application, e.g., a pluggable key-value store or database
• Performance evaluation of the framework and application

Prerequisites

• Basic knowledge of Linux systems as we work with SGX exclusively on Linux
• Good knowledge of C/C++
• Knowledge of x86-64 assembler is of advantage