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First enclave


You can find a sample app in the hello-world directory of your SDK. You can use this app as a template for your own if you want a quick start. We will cover:

  1. How to set up your machine.
  2. How to compile and run the sample app.
  3. How to write the sample app.

Setting up your machine

You need Java 8 or 11 (your choice) and Gradle, so make sure you've installed those first. Alternatively use an IDE like IntelliJ IDEA, which can download and set up both Gradle and the Java Development Kit (JDK) for you.

Currently, we support developing enclaves on Windows, macOS and Linux. However, executing enclaves without using the "mock mode" requires Linux or a Linux container (e.g. via Docker or Windows Subsystem for Linux) and there are no plans to change this. Apple doesn't support SGX and the Windows API support is too limited for use at this time. Fortunately for day to day development, the mock API is plenty sufficient and allows you to debug into enclave calls as well. Compiling a real enclave is only needed for integration testing or real deployment.

Enclaves can run in simulation mode without requiring any special setup of Linux or SGX capable hardware. However you of course get no hardware protections. To run against real SGX hardware you must perform some additional machine setup.

Compiling the sample enclave

Step 1: Import the project

Import the project

Step 2: Look at the Conclave SDK's top level directory

Look at the SDK's top level directory

Step 3: Click "import" when notified that there's a Gradle build script

Import Gradle script

Step 4: If on Linux or Windows, double-click on :host:assemble. Voila! 😄 You have just built your first enclave.

Double-click on :host:assemble

Now explore the build folder.

Explore the build folder.

As normal with Gradle, the assemble task has bundled the program into a zip, with startup scripts. These scripts are nothing special - they just set up the classpath. You could also e.g. make a fat JAR if you want.

Running the host and client

You will need Linux to test your enclave. Just run the host app like any app - no special startup scripts or setup is required with Conclave!

cd host/build/distributions
tar xvf host.tar

If your Linux machine doesn't have SGX, you should see something like this:

This platform currently only supports enclaves in simulation mode: SGX_DISABLED_UNSUPPORTED_CPU: SGX is not supported by the CPU in this system
This attestation requires 2163 bytes.
Remote attestation for enclave F86798C4B12BE12073B87C3F57E66BCE7A541EE3D0DDA4FE8853471139C9393F:
  - Code signing key hash: 01280A6F7EAC8799C5CFDB1F11FF34BC9AE9A5BC7A7F7F54C77475F445897E3B
  - Public signing key: 302A300506032B65700321000568034F335BE25386FD405A5997C25F49508AA173E0B413113F9A80C9BBF542
  - Public encryption key: A0227D6D11078AAB73407D76DB9135C0D43A22BEACB0027D166937C18C5A7973
  - Product ID: 1
  - Revocation level: 0

Assessed security level at 2020-07-17T16:31:51.894697Z is INSECURE
  - Enclave is running in simulation mode.

Reversing Hello World!: !dlrow olleH

Listening on port 9999. Use the client app to send strings for reversal.

The host has loaded the enclave, obtained its remote attestation (the EnclaveInstanceInfo object), printed it out, asked the enclave to reverse a string and finally opened up a TCP port which will now listen for requests from remote clients.

So, let's run the client app:

./gradlew client:run --args="reverse me!"

The client will connect to the host, download the EnclaveInstanceInfo, check it, and then send an encrypted string to reverse. The host will deliver this encrypted string to the enclave, and the enclave will send back to the client the encrypted reversed response:

Reading a remote attestation of length 2163 bytes.
Sending the encrypted mail to the host.
Reading reply mail of length 196 bytes.
Enclave reversed 'reverse me!' and gave us the answer '!em esrever'

Try this:

./gradlew client:run --args="aibohphobia"


Aibohphobia is the fear of palindromes.

Testing on Windows

If you're on Windows, you could test locally in simulation mode using a Docker container. Follow these instructions:

Step 1: Create a container and install Java 8

Replace c:/ws/sdk with the path to the Conclave SDK:

docker run --name hello-world -it -d -v c:/ws/sdk:/sdk -w /sdk ubuntu bash
docker exec -ti hello-world apt update
docker exec -ti hello-world apt install -y openjdk-8-jdk

Step 2: Unpack the artifacts and run the host binaries

docker exec -ti hello-world tar xf /sdk/hello-world/host/build/distributions/host.tar -C /tmp/  
docker exec -ti hello-world /tmp/host/bin/host  

Step 3: You may want to create an IntelliJ launch configuration to incorporate the build and deploy stages. Put the commands above in a .cmd batch file and then use the "Shell script" launch configuration type, and add a Gradle task in the "Before launch" section. You will then be able to click the run icon in your IDE to build and start up the Java host app inside the Docker container.

import project

Step 4: When done with testing remove the container, to stop it using up resources.

docker rm hello-world -f

If you get stuck please contact and ask for help!