This project demonstrates how Occlum support font with a Java demo in SGX enclaves.
Both the unmodified OpenJDK 11, which is imported from Alpine Linux, and the Alibaba Dragonwell, which is a downstream version of OpenJDK, are supported now. We have already installed OpenJDK and Dragonwell while building the Docker image, the OpenJDK is installed at /opt/occlum/toolchains/jvm/java-11-openjdk, and the Dragonwell is installed at /opt/occlum/toolchains/jvm/java-11-alibaba-dragonwell.
Our demos use Dragonwell as the default JDK, you are free to change to OpenJDK by setting the JAVA_HOME to point to the installation directory of OpenJDK and copying it into Occlum instance.
We provide an excel file writting demo to show how to make occlum support font inside SGX enclaves.
The excel writting demo is created in create_java_font_app.sh, and the script also creates a build.gradle to build demo. Then a docker container is created to build the demo and we will get a fat jar file. The docker container is based on Alpine, we will collect all dependent libs and font in document font-lib from the container.
Create occlum instance and copy all libs into occlum image which font depends in occlum container, then build the occlum image and run the demo.
Step 1: Create and build demo, it also collects the font dependencies
./create_java_font_app.sh
Step 2: Create occlum instance and run the demo in occlum's latest docker image
docker run -it --device /dev/isgx --rm -v `pwd`:`pwd` -w `pwd` occlum/occlum:[latest version]-ubuntu18.04 `pwd`/run_java_font_app_internal.sh
Step 3: To check whether it works, a Demo.xlsx file should be created in the host path of occlum instance.