Entropy Programs

Entropy allows the creation of decentralized signing authorities. Signing authorities exist as WebAssembly programs that can ingest a signature request, and a valid request is signed via a threshold signature scheme from a set of at-stake validators. These requests might include cryptocurrency-based transaction requests, certificate signing requests, or other mediums for cryptographic authentication.

This repository contains libraries, toolchains, utilities, and specifications for writing, configuring, building, and testing the Wasm-based applications for Entropy. Programs can be written in any language that compiles to WebAssembly, which includes all LLVM-supported languages like Rust, AssemblyScript, Zig, and C. All the examples in this repository are written in Rust.

Prerequisites

To edit and compile the programs in the repository, you will need the following tools:

1. The lastest stable Rust toolchain. This can be installed with:

   curl https://sh.rustup.rs -sSf | sh

2. The cargo-component v0.2.0 extension; used for building Wasm components:

   cargo install cargo-component --locked

3. The cargo-generate extension; used to generate project templates:

   cargo install cargo-generate

4. The wasm-tools package. This is used by cargo-component:

   cargo install wasm-tools

5. Verify that you have everything installed by running:

   rustc --version && cargo-component --version && cargo-generate --version && wasm-tools --version

   This should output something like:

   rustc 1.78.0 (9b00956e5 2024-04-29)
   cargo-component 0.11.0 (wasi:040ec92)
   cargo generate 0.21.0
   wasm-tools 1.207.0
   

6. [Optional] Install Docker to run the associated Dockerfiles found within the repository.

Basic length-check program

An example of a barebones program can be found at examples/barebones/src/lib.rs. This example does a simple check on the length of the message to be signed. You can compile the program by running:

cargo component build --release -p template-barebones --target wasm32-unknown-unknown

This builds the program as a Wasm component at target/wasm32-unknown-unknown/release/template_barebones.wasm.

Custody program with configuration

This example validates that an an EVM transaction request recipient exists on a list of allow-listed addresses. It also uses a configuration which allows the user to modify the allow-listed addresses without having to recompile the program.

You can compile the program by running:

cargo component build --release -p example-basic-transaction --target wasm32-unknown-unknown

Writing your own programs

You can get started with a template program using cargo-generate:

cargo generate entropyxyz/programs --name my-program --tag testnet

Make sure to attach the --tag testnet argument. This tells Cargo to use the testnet tag in the github.com/entropyxyz/core repository.

Your template program is now in the ./my-program directory and ready to be edited. You can run tests as you would a normal rust project with cargo test.

You can compile your program with cargo component:

You can generate your types by cargo run generate-types. If you change the type names of UserConfig or AuxData, you will need to change those names in generate-types.

cargo component build --release --target wasm32-unknown-unknown

If you want to make your program publicly available and open source, and make it possible for others to verify that the source code corresponds to the on-chain binary, you can build it with the Dockerfile included in the template:

docker build --output=binary-dir .

This will compile your program and put the .wasm binary file in ./binary-dir.

Running Tests

Before running the runtime tests, you need to build the template-barebones, infinite-loop and example-custom-hash components. To do this, execute:

cargo component build --release -p template-barebones -p infinite-loop -p example-custom-hash --target wasm32-unknown-unknown

This will create the components in target/wasm32-unknown-unknown/release/.

Licensing

For the most part, the code in this repository is licensed under AGPL-3.0.

There are some exceptions however:

• The original code in the examples/risc0-zkvm-verification crate comes from RISC Zero's risc0 project, which is licensed under Apache License 2.0.

Modifications made by Entropy to these crates are licensed under AGPL-3.0.