Bytecode decompiler

[SimiHunjan]

Problem

Users especially developers will occasionally want to learn more about a contracts contents. This usually requires verification first to ensure the matching code. However, it is possible given bytecode to decompile the bytecode and get a sense of the method flows in the contract.

This is useful for debugging situations to have a better understanding of a contract contents when the original source code is not available it may be useful to decompile the run time bytecode to have a better understanding

Examples of usage can be seen at https://etherscan.io/bytecode-decompiler & https://ethervm.io/decompile

User Story

1. As a user I want to obtain a more human readable form of the contract code to troubleshoot when I don’t have access to the actual contract files

Solution

Add feature to decompile bytecode

Alternatives

No response

[SimiHunjan]

@Nana-EC what is the latest on this issue? I know @quiet-node was working on this last and hit some blockers.

[quiet-node]

Hello, @SimiHunjan, thank you for opening this ticket! I've come across a highly maintained decompiler project called Heimdall-rs that seems perfect for this task. However, integrating Heimdall-rs into Hashscan presents certain challenges, considering that Heimdall-rs is fully engineered in Rust while Hashscan operates with Typescript. To implement Heimdall-rs, we're exploring two solutions:

1. Hosting Heimdall-rs as a RESTful service

• Pros:
  • Easy to implement and build
  • Simple decompilation of Bytecode into Solidity smart contracts through RESTful requests
  • Customizable returned RESTful object
• Cons:
  • Requires a new instance for server deployment
  • Demands ongoing maintenance
  • Potential latency due to a client-server relationship
• Status: Completed with a POC at https://github.com/quiet-node/evm-decompiler-rest

2. Building Heimdall-rs into an NPM package using wasm-pack library

• Pros:
  • No need for deployment
  • Seamless integration into Hashscan as an NPM package (minimal latency)
• Cons:
  • Challenges arising from Heimdall-rs being CLI-first and intricately linked with various Rust packages at its foundation. Building this decompiler into an NPM package using wasm-pack requires expertise in Rust and wasm-pack.
• Status: Blocked. I've opened a ticket on the Heimdall-rs' repo regarding this issue. The challenge involves expertise in Rust and wasm-pack. The maintainer, acknowledging a lack of wasm technology experience, has initiated a feature ticket to support wasm within the repo. However, no visible progress has been made.

I currently remain open to and seeking alternative solutions if wasm doesn't work out

cc: @Nana-EC @ericleponner @svienot

[Jon-Becker]

Hey! Maintainer of heimdall here. In order for heimdall to support wasm, I would need to remove all instances of the std library and completely overhaul the existing library. Your best bet as of now is to host heimdall as a restful service. Let me know if you need any assistance there :)