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Hash verification

You may want to verify the authenticity and integrity of the application, deployed on IPFS. It can be done by CID (hash) verifying. In order to do so, you will need to download the source code of the application and build it locally.
See the detailed instructions below.

Steps​

info

Lido Ethereum Staking Widget is taken as example here.

Prerequisites​

You will need these tools installed in your system:

  • Node.js 20+
  • Yarn package manager v1 (classic)

Alternatively, you can use Docker to set up a building environment; read the sections below for the instructions.

1. Clone the repository​

The repo for Ethereum Staking Widget is here: https://github.com/lidofinance/ethereum-staking-widget

2. Git checkout a commit, matching the IPFS version​

You need to git checkout the specific commit, matching the release of an app you want to verify. This way, you can be sure that the app will not include any other changes, which affect the CID.
There are several ways to do it.

Method 1 – using git tags​

Each released version has its own git tag, one can use it for git checkout.

  1. Open the app in your browser and check the right side of its footer. There will be a version number, which is actually a link to a Releases page on GitHub.
  2. Run git fetch --all --tags --prune to fetch all tags.
  3. Run git checkout tags/<version>, where <version> is the version from step 1.

Method 2 – searching on the GitHub Release page​

  1. Open the Releases page of the project's repository on GitHub. For Ethereum Staking Widget it is here.
  2. Search manually for the latest release, where IPFS pinning happened.
  3. Look for the commit hash near the release information.
  4. Run git checkout <hash>, where <hash> is the commit hash from the previous step.

3. Set up the project​

Without Docker​

  1. Add ENV variables as instructed in README.
  2. Remove node_modules directory if the project was set up earlier.
  3. Install node modules using yarn install --frozen-lockfile.
  4. Follow other instructions described in the project's README.

Using Docker​

If you have problems with setting up the environment or if it is your preference, you can use Docker to set up and build the project.

Steps for Docker

  1. Configure build-info.json as instructed in this step.
  2. Create verification.Dockerfile file in the project's root with this content:
# build env
FROM node:20-alpine as build

WORKDIR /app

RUN apk add --no-cache git=~2
COPY package.json yarn.lock ./

RUN yarn install --frozen-lockfile --non-interactive --ignore-scripts && yarn cache clean

COPY . .
RUN NODE_NO_BUILD_DYNAMICS=true yarn typechain && yarn build-ipfs
# public/runtime is used to inject runtime vars; it should exist and user node should have write access there for it
RUN rm -rf /app/public/runtime && mkdir /app/public/runtime && chown node /app/public/runtime

# final image
FROM node:20-alpine as base

WORKDIR /app
RUN apk add --no-cache curl=~8
COPY --from=build /app /app
  1. Add ENV variables as instructed in the project's README.
  2. Run these commands:
docker build --no-cache -t verification:0 -f verification.Dockerfile .
docker create --name verification-container verification:0
docker cp verification-container:/app/out /Users/${Name}/${Path-to-project}/dockerbuild-verification
docker rm verification-container
  1. Run further steps from step 6 of this instruction.

4. Configure build-info.json​

The build-info.json file is located in the project's root, here is the link.
It must contain information about the version of the application, which is currently deployed to IPFS.
You can take this information from the latest GitHub action in which IPFS pinning happened:

  1. Open the app's repo, follow the "Actions" tab.
  2. On the left, in the navigation, find the workflow for IPFS releasing, for the Ethereum Staking Widget it is called "IPFS Release".
  3. Open the latest successful workflow and look for the "prepare-for-ipfs summary" title or the JSON data which looks like this: 
    { "branch": "main", "commit": "56ab68d", "version": "0.0.1" }
  4. Copy the data to your local build-info.json

5. Build the IPFS version​

Run a suitable npm script to build the IPFS version.
In case of Ethereum Staking Widget, it is yarn build-ipfs.

6. Create a CAR file and get its CID (hash)​

For Next.js applications the build files will be in the out directory.
The following command generates a CAR file from the out directory with build files, and it will display the IPFS hash in the console:

npx ipfs-car pack ./out --output ./out.car

7. Get CID (hash) of the application deployed to IPFS​

You will need to get the hash of the latest released CAR file.
It can be found on the Releases page of the repository under the "Assets" collapsible block. Download the CAR file and run the following command:

npx ipfs-car roots ipfs_source_code.car

It will show CID roots found in the CAR header. The CID (hash) must be the same as in the previous step.