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Linux SGX Remote Attestation

The related code/working directory of this example resides in directory {WAMR_DIR}/samples/sgx-ra
This sample demonstrates how to execute Remote Attestation on SGX with librats and run it with iwasm. It can only build on SGX supported processors, please check it.


SGX-RA requires to have installed:
  • the WASI-SDK, located in /opt/wasi-sdk

Intel SGX dependencies

Before starting, we need to download and install SGX SDK and SGX DCAP Library referring to this guide.
The following commands are an example of the SGX environment installation on Ubuntu 20.04.
# Set your platform, you can get the platforms list on
$ cd $HOME
$ OS_PLATFORM=ubuntu20.04
# install the dependencies
$ sudo apt-get update
$ sudo apt-get install -y build-essential ocaml automake autoconf libtool wget python3 libssl-dev dkms zip cmake
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 1
# install SGX Driver
$ wget$SGX_RELEASE_VERSION/linux/distro/$SGX_PLATFORM/sgx_linux_x64_driver_$SGX_DRIVER_VERSION.bin
$ chmod +x sgx_linux_x64_driver_$SGX_DRIVER_VERSION.bin
$ sudo ./sgx_linux_x64_driver_$SGX_DRIVER_VERSION.bin
# install SGX SDK
$ wget$SGX_RELEASE_VERSION/linux/distro/$SGX_PLATFORM/sgx_linux_x64_sdk_$SGX_SDK_VERSION.bin
$ chmod +x sgx_linux_x64_sdk_$SGX_SDK_VERSION.bin
$ sudo ./sgx_linux_x64_sdk_$SGX_SDK_VERSION.bin --prefix /opt/intel
# install SGX DCAP Library
$ echo 'deb [arch=amd64] focal main' | sudo tee /etc/apt/sources.list.d/intel-sgx.list
$ wget -O - | sudo apt-key add
$ sudo apt-get update
$ sudo apt-get install -y libsgx-epid libsgx-quote-ex libsgx-dcap-ql libsgx-enclave-common-dev libsgx-dcap-ql-dev libsgx-dcap-default-qpl-dev libsgx-dcap-quote-verify-dev
# install SGX SSL Library
$ git clone
$ cd linux-sgx && make preparation
$ sudo cp external/toolset/$OS_PLATFORM/* /usr/local/bin
$ # Verify that the paths are correctly set
$ which ar as ld objcopy objdump ranlib
$ cd ../
$ git clone
$ wget -O intel-sgx-ssl/openssl_source/openssl-1.1.1v.tar.gz
$ cd intel-sgx-ssl/Linux
$ source /opt/intel/sgxsdk/environment
$ make all
$ sudo make install
You can optionally grant users to communicate with the SDK platform using the following command. Otherwise, enclaves must be launched with root privileges.
sudo usermod -a -G sgx_prv <username>

Intel Provisioning Certification Service (Intel PCS)

Intel DCAP connects to Intel PCS to download the attestation collateral for SGX-enabled machines. Intel provides a quick install guide to set up a simplified environment. This section summarizes the commands to issue for setting up a working environment on Ubuntu 20.04.

Subscribe to Intel PCS Web services

Intel SGX DCAP requires a complimentary subscription to the Intel PCS. To subscribe to the service, browse the Intel SGX Software Services page. A the end of the subscription process, save the primary and the secondary keys.

Set up the Intel Provisioning Certification Caching Service (Intel PCCS)

Intel PCCS is a caching mechanism for attestation collateral, preventing continuously communicating with Intel PCS during attestation. Intel provides an implementation of the cache mechanism.
The following commands set up Intel PCCS.
# install Node.js
$ curl -fsSL | sudo -E bash - && sudo apt-get install -y nodejs
# install PCCS software
$ sudo apt-get install -y cracklib-runtime
$ sudo apt-get install -y sgx-dcap-pccs
The installation will run the PCCS setup script, asking you several questions.
Do you want to configure PCCS now? (Y/N)
Answer "Y" to this question.
Set HTTPS listening port [8081] (1024-65535)
Accept the default listening port of 8081.
Set the PCCS service to accept local connections only? [Y] (Y/N)
Answer "N" to this question. We want the PCCS service to accept connections from other systems.
Set your Intel PCS API key (Press ENTER to skip)
Enter either your primary or secondary key retrieved from the previous subsection. If you already subscribed, you can retrieve them here.
Choose caching fill method : [LAZY] (LAZY/OFFLINE/REQ)
Answer "REQ" to this question. This places the caching service in the "on request" mode, which means it will fetch the attestation collateral for hosts as provisioning requests are received.
Set PCCS server administrator password:
Re-enter administrator password:
Set PCCS server user password:
Re-enter user password:
Enter two passwords for the PCCS server.
Do you want to generate insecure HTTPS key and cert for PCCS service? [Y] (Y/N)
Answer "Y" to this question.

Provisioning a system into Intel PCCS

Now that the PCCS is up and running, it's time to provision an Intel SGX-enabled platform. We use the tool PCKIDRetrievalTool to get the attestation collateral of the current machine.
$ sudo apt-get install -y sgx-pck-id-retrieval-tool
Adapt the configuration file of PCKIDRetrievalTool located in /opt/intel/sgx-pck-id-retrieval-tool/network_setting.conf and make the following changes:
  • Change the PCCS_URL to match your caching service's location.
  • Uncomment the user_token parameter, and set it to the user password you created when configuring the PCCS.
  • Set the proxy_type to fit your environment (most likely, this will be direct)
  • Ensure USE_SECURE_CERT is set to FALSE since we're using a self-signed certificate for testing purposes.
Save your changes and run the provisioning tool.
$ sudo PCKIDRetrievalTool
Intel(R) Software Guard Extensions PCK Cert ID Retrieval Tool Version
Registration status has been set to completed status.
the data has been sent to cache server successfully and pckid_retrieval.csv has been generated successfully!
You may get some warnings during this execution of the tool. A correct insertion into the cache server usually means the retrieval of the attestation collateral worked. Execute the following command to verify the collateral could be stored in your instance of Intel PCCS:
curl -k https://localhost:8081/sgx/certification/v3/qe/identity
This should print a JSON value with the attestation collateral.

Runtime configuration

Edit the configuration file, /etc/sgx_default_qcnl.conf, and make the following changes:
  • Set the PCCS_URL parameter to the location of our PCCS server.
  • Set USE_SECURE_CERT to FALSE since we're using a self-signed certificate for testing purposes.
This system is now ready to run Intel SGX workloads with generate evidence for remote attestation.

Build and executing the sample

$ mkdir build && cd build
$ cmake ..
$ make
$ # run the sample
$ ./iwasm wasm-app/test.wasm
The sample will print the evidence in JSON and the message: Evidence is trusted.

Further readings