2019 Summer Mentee Project Update: Hyperledger Fabric SDK for Node.js security extension

What I worked on

I’m Hengming Zhang, a member of this summer’s Hyperledger Mentorship Program.

The general goal of my project was extending the security scope of the Hyperledger Fabric SDK for Node.js. Key objectives included:

• Fix integration test failures on various operating systems.
• Refactor the key store class design by object-oriented method.
• Enhance the compatibilities of Hardware Security Module (HSM).
• Construct an applicable offline signing scheme.

After having the first talk with my mentor, David Liu, I set out the milestones and deliverables with this project:

1. Completing a list of checklist items that were established before the beginning of Hyperledger Mentorship Program. The checklist contains preparing:
   • AWS cloud account
   • Virtual machine snapshot for the on-premise desktop
   • Mobile devices
2. Fixing  the integration test failures on macOS and Ubuntu by the 1^st Quarter Evaluation.
3. Refactoring Key store class design by the Midterm Quarter Evaluation.
4. Enhancing HSM compatibility by the 3rd Quarter Evaluation.
5. Offline signing of a client by the Final Evaluation.

Once I had finished the initial set up from the checklist, I started development for this project. During the development, the proudest of experience were using the right Hyperledger channels:

• Technology – Hyperledger Fabric, Hyperledger Fabric CA, and Hyperledger SDK for Node.js.

• Tools – Hyperledger Wiki, Hyperledger Gerrit, Hyperledger Chat and Hyperledger Jira.

By the end of this internship, I had finished 6/7 of the deliverables I had created above.

In conclusion, I think my work on the offline signing scheme could have the most impact on the Hyperledger or larger communities. I have constructed an applicable client offline signing scheme using Flutter as the client for the fabric-client-flutter project and Node as the server for the fabric-server-node project.

At last, there are our mentor and mentee’s information for this summer’s Hyperledger Mentorship Program:

What I learned or accomplished

As I mentioned in the “What I worked on” section, the six deliverables I completed include:

• Setting up an AWS cloud account
• Creating a virtual machine snapshot for the on-premise desktop
• Preparing mobile devices
• Fixing the integration test failures on macOS and Ubuntu
• Enhancing HSM compatibility
• Offline signing of client

However, there are no such shortcut path as things moved forward. Below are some of the issues I had to overcome: 

• Running AWS CloudHSM on EC2 instance: Ubuntu 18 / Windows Server 2019 / Red Hat Enterprise Linux
• Installing SoftHSM on Windows 10 virtual machine snapshot
• Constructing a PKCS#8 standard RSA asymmetric keys that can be used to interact with Hyperledger Fabric network as the user’s local key store
• Constructing a Certificate Signing Request (CSR) using RSA keys on the client side
• Building an interactive model between Hyperledger Fabric and Flutter mobile client
• Refactoring current CryptoKeyStore mixin class to an object-oriented class model

Plus, there are also some of the insights I got and lessons I learned from the Hyperledger community:

1. Communicate with others (e.g., project maintainers, mentors)
2. Connect and work remotely
3. Document ideas, issues, and reports
4. Clean code and use state-of-the-art technologies

So, at this time, I would like to share with you some advice regarding working in an open source community:

1. Clean code and annotations are necessary: it means when others look at your project, they can quickly understand what your code does.
2. Communication is important: it can help to deduplicate works, find solutions, and so on.

For example, in my internship experience, leveraging the second piece of  advice, I found out that the community was refactoring the code base that I was working on. Therefore, the duplicated work could be avoided.

What comes next

The ending of the internship journey is not the destination. I have some recommended next steps for the project:

• Advancing and improving the fabric-client-flutter project, such as extend it to support other platforms: Windows, macOS, and even IoT devices for them to use Hyperledger Fabric.

• Refactoring and improving the fabric-server-node project to common Hyperledger Fabric servers that can be serving any request from any Hyperledger Fabric client.
• Continuously contributing to the fabric-sdk-node project.

In the future, I would like to be a long-term contributor to the Hyperledger or the larger open source community.

With this internship experience, I hope I can move forward as a recognized engineer and cryptographic researcher.

For more details, see my project report here.