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Installation Guide


Enarx currently has support for Keeps running in Intel SGX and AMD SEV-SNP TEEs (Trusted Execution Environments). Please check the Requirements. There is also support for application development using a "nil" backend which provides the same runtime, but no security isolation, and can run on a variety of Linux, Mac and Raspberry Pi systems.

In the Initial Setup section, you'll find instructions on how to install dependencies for the various supported architectures and distributions. These dependencies include Rust and the toolchains.

Next, you'll find instructions on how to install Enarx from, GitHub, or Nix.

Finally, in the Running Enarx section, you'll build and run your first Hello World WebAssembly module in Enarx.


  • Enarx requires specific hardware to run Keeps in a TEE instance, namely a CPU with a supported Trusted Execution Environment. Currently, Enarx Keeps are supported with "Intel SGX" and AMD SEV-SNP.
  • For development purposes, we provide the "nil" backend, which does not require special hardware, or even a system running Linux.

Setting up an SGX machine

Enarx requires SGX2 (SGX with EDMM) support.

For Intel, our recommendation would be the 3rd Gen Intel Xeon Scalable Ice Lake. This article provides a comprehensive analysis of the different models. The 5318Y or 5318S provide good value.

$ sudo groupadd -r sgx_prv
$ sudo bash -c "cat > /etc/udev/rules.d/99-sgx.rules" <<EOF
SUBSYSTEM=="misc", KERNEL=="sgx_provision", MODE="0660", GROUP="sgx_prv"
SUBSYSTEM=="misc", KERNEL=="sgx_enclave", MODE="0666"

Setting up an SEV-SNP machine

Hardware requirements for SEV

For AMD our recommendation would be the EPYC 7003 Milan. This article offers an analysis of the different models.

$ wget -O amd_sev_fam19h_model0xh.sbin ""
$ sudo mv amd_sev_fam19h_model0xh.sbin /lib/firmware/amd/amd_sev_fam19h_model0xh.sbin
$ sudo chown root:root /lib/firmware/amd/amd_sev_fam19h_model0xh.sbin
  • Set SEV device node permissions
$ sudo bash -c "echo 'KERNEL=="sev", MODE="0666"' > /etc/udev/rules.d/50-sev.rules"
  • Increase the memlock limit for SEV keeps (need to pin a large number of pages)
$ sudo bash -c "echo '* - memlock 8388608' > /etc/security/limits.d/sev.conf"
  • Enable SEV
$ sudo bash -c "echo 'options kvm_amd sev=1' > /etc/modprobe.d/kvm-amd.conf"

Requirements for the "nil" backend

The nil backend does not require any special hardware, but any of the architectures supported by the wasmtime crate. These are currently:

  • aarch64-apple-darwin
  • x86_64-apple-darwin
  • aarch64-unknown-linux-gnu
  • aarch64-unknown-linux-musl
  • x86_64-unknown-linux-gnu
  • x86_64-unknown-linux-musl

This includes 64-bit Raspberry Pi and Apple M1.

Requirements for KVM as a backend (alternative to "nil" backend)

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V). It consists of a loadable kernel module, kvm.ko, that provides the core virtualization infrastructure and a processor specific module, kvm-intel.ko or kvm-amd.ko.

It's not always possible to have access to hardware with the support for Intel SGX or AMD SEV-SNP, hence, enarx supports KVM to facilitate the testing on more common hardware which have virtualization support. For the KVM support, the Intel VT and AMD-V features must be provided by the hardware.

KVM module is loaded by the Linux kernel automatically if the hardware supports the feature, hence, it's easy for anyone to set it up.

To check if the kvm module is loaded use the following command:

lsmod | grep kvm

If the module is loaded the following output should be expected

kvm_intel    213   0
kvm 10 1 kvm_intel


kvm_amd    23213   0
kvm 10 1 kvm_amd

Initial Setup

Please choose one of the following:

Linux x86_64 Install Dependencies

Please find instructions for your Linux distribution:


$ sudo dnf update -y
$ sudo dnf install -y git curl gcc pkg-config openssl-devel musl-gcc

CentOS 8 / Stream

$ sudo dnf install -y dnf-plugins-core
$ sudo dnf copr -y enable ngompa/musl-libc
$ sudo dnf install -y git curl gcc-toolset-11 openssl-devel musl-gcc
$ source "/opt/rh/gcc-toolset-11/enable"

You may want to add that final source command to a ~/.profile, ~/.bashrc / or ~/.bash_profile equivalent, otherwise you must remember to source that file prior to building enarx.

CentOS 7 / Scientific Linux 7 and other clones

$ sudo yum install -y centos-release-scl-rh

or search for the package on and install it manually with, for example:

$ sudo yum install

and then:

$ sudo yum install -y yum-plugin-copr    
$ sudo yum copr -y enable ngompa/musl-libc
$ sudo yum install -y git curl devtoolset-11 openssl-devel musl-gcc
$ source "/opt/rh/devtoolset-11/enable"

You may want to add that final source command to a ~/.profile, ~/.bashrc / or ~/.bash_profile equivalent, otherwise you must remember to source that file prior to building enarx.

Debian / Ubuntu

$ sudo apt update
$ sudo apt install -y git curl gcc pkg-config libssl-dev musl-tools python3-minimal

The minimum required gcc version is version 9. Something older might build binaries (such as integration test binaries), but may silently drop required compiler flags. Please ensure you're using the minimum required version of gcc. Failure to do so might result in weird failures at runtime.

64-bit Arm build dependencies: (Raspberry Pi or Apple M1) and Apple x86_64

The architectures support development only, using the "nil" backend, so you only need to install the Rust toolchain.

Install Rust

$ curl --proto '=https' --tlsv1.2 -sSf | sh -s -- --default-toolchain nightly -y
$ source $HOME/.cargo/env

Installing Enarx

You can install Enarx from GitHub,, or Nix.

Install from GitHub

$ git clone
$ cd enarx/
$ cargo build

$ cargo install --bin enarx --path ./

Install from


Rust version nightly-2022-05-03 is required when installing Enarx 0.5.1 from

$ rustup toolchain install nightly-2022-05-03 -t x86_64-unknown-linux-musl,x86_64-unknown-linux-gnu,x86_64-unknown-none
$ CARGO_TARGET_X86_64_UNKNOWN_NONE_RUSTFLAGS="-C linker=gcc" cargo +nightly-2022-05-03 -Z bindeps install --bin enarx --version 0.5.1 -- enarx

Install from Nix

Users with nix package manager installed (see should be able to just do in the checked out repository:

$ git clone
$ cd enarx/
$ nix-shell

(on legacy, stable nix installs)


$ nix develop

nix-shell opens file descriptors 3 and 4 and the enarx cargo test fails therefore. nix develop does not seem to have this problem.

Running Enarx

Build and run a WebAssembly module

Install the WebAssembly Rust toolchain:

$ rustup toolchain install nightly -t wasm32-wasi

Create a simple Rust program. First make sure you're not in the repository you already created:

$ cd ~/
$ cargo init --bin hello-world
$ cd hello-world
$ echo 'fn main() { println!("Hello, Enarx!"); }' > src/
$ cargo +nightly build --release --target=wasm32-wasi

Assuming you did install the enarx binary and have it in your $PATH, you can now run the WebAssembly program in an Enarx keep.

$ enarx run target/wasm32-wasi/release/hello-world.wasm
Hello, Enarx!

If you want to suppress the debug output, add 2>/dev/null.

Select a Different Backend

enarx will probe the machine it is running on in an attempt to deduce an appropriate deployment backend. To see what backends are supported on your system, run:

$ enarx info

You can manually select a backend with the --backend option, or by setting the ENARX_BACKEND environment variable:

$ enarx run --backend=sgx target/wasm32-wasi/release/hello-world.wasm
$ ENARX_BACKEND=sgx enarx run target/wasm32-wasi/release/hello-world.wasm
Note about backends

enarx will look for backends in the following order, and use the first which it finds:

  1. SGX or SEV-SNP
  2. KVM
  3. "nil"

The status of whether or not enarx was able to find the driver can be checked with the command enarx info. If the output shows any of the backends with a green "tick" or "checkmark", you are ready to use enarx with that backend.

When you execute the enarx run command, enarx tries to automatically select the appropriate backend. But if you want to specifically use the another supported backend you can pass the backend name ("sgx", "sev", "kvm" or "nil") as a parameter to --backend option, or set the ENARX_BACKEND environment variable with the name:

$ enarx run --backend=nil target/wasm32-wasi/release/hello-world.wasm
$ ENARX_BACKEND=nil enarx run target/wasm32-wasi/release/hello-world.wasm


Congratulations! You were able to run Enarx successfully!

Enarx was built to be simple to use. It abstracts away complex concepts and supports multiple architectures transparently so that users don't have to worry about these.

Enarx provides a WebAssembly runtime, offering developers a wide range of language choices for implementation, including Rust, C, C++, C#, Go, Java, Python and Haskell.

Enarx is CPU-architecture independent, enabling the same application code to be deployed across multiple targets, abstracting issues such as cross-compilation and differing attestation mechanisms between hardware vendors.

License: Apache-2.0