Source-Verify is a service that verifies Ethereum bytecode was compiled from a certain Solidity source code and maintains a public repository of contract metadata.
The repository indexes metadata with IPFS or Swarm hashes which the solc compiler embeds in contract bytecode. By fetching code on chain and extracting this hash, you can obtain related metadata from Source-Verify's records.
More information can be found in Solidity metadata documentation
If you have any question please ask us on gitter.
$ npm install
$ git submodule update --init
The service has three components:
-
a "monitor" which watches public Ethereum networks for contract deployments and tries to associate them with sources and metadata published to Swarm or IPFS. It currently watches:
- mainnet
- ropsten
- rinkeby
- kovan
- goerli
-
a website which allows you to submit sources and metadata for a specific contract address
- https://verification.komputing.org/ (Stable)
- https://verificationstaging.komputing.org/ (Unstable)
-
a public metadata repository that contains uploaded (or discovered) metadata and their sources:
- https://contractrepo.komputing.org/ (Stable)
- https://contractrepostaging.komputing.org/ (Unstable)
Getting metadata
Using solc directly on the commandline:
solc --metadata --metadata-literal <mySource.sol>
or with JSON/IO
{
"settings": {
"metadata": { "useLiteralContent": true }
}
}
Using the monitor
If your Solidity code compiles with solc >= 0.6.0, you just need to upload your contract metadata and sources to IPFS as part of your deployment process. The monitor service will automatically add your files to the metadata repository when it sees your contract created on the network.
A simple example for Truffle projects can be found at cgewecke/metacoin-source-verify which contains a script to publish to IPFS directly from a Truffle compilation artifact.
Please note that source code verification is only reliable if it is performed on the creation bytecode, i.e. the bytecode payload used when the contract was created. The deployed bytecode, i.e. the bytecode stored in the blockchain as code is not sufficient, because the constructor can still be different and set arbitrary storage entries.
Furthermore, if the constructor requires parameters, these have to be checked as well.
Also note that there can still be differences in the source code that are not visible in the bytecode. Variables can be renamed or unused code can be introduced. Since the bytecode contains a hash of the source code, such modifications have to be prepared at deploy time, but it is still a possibility.
Using the repository
There is a repository which contains all the files that monitor and server have found on one of the networks they are scraping.
Repository is located on this link.
When you go to the link, UI looks like this:
There you have options to search, donwload or open folders.
For example to download:
Or if you want to search something:
Metadata inside is visible as raw, and you can download it like that
or if you want to take a look of the contract in browser you can open it like this:
- cope with metadata that does not have in-place source code
- automatically retrieve the metadata and the source code from SWARM or IPFS, so you only need to supply the metadata hash or bytecode
- perform source verification given only an address instead of the bytecode or the metadata
Prepare environment and start by running
If you want to build images locally run:
docker-compose -f geth.yaml -f ipfs.yaml -f localchain.yaml -f monitor.yaml -f repository.yaml -f s3.yaml -f server.yaml -f ui.yaml -f build-ipfs.yaml -f build-localchain.yaml -f build-monitor.yaml -f build-repository.yaml -f build-s3.yaml -f build-server.yaml -f build-ui.yaml build --parallel
If you just want to run it do:
docker-compose -f ipfs.yaml -f localchain.yaml -f monitor.yaml -f repository.yaml -f s3.yaml -f server.yaml -f ui.yaml up -d (-d flag means that output won't be printed in stdout)
Note: you don't need to run all the services, just the ones you want.
Launch
cp .env.testing .env
docker-compose -f ipfs.yaml -f localchain.yaml -f monitor.yaml -f repository.yaml -f s3.yaml -f server.yaml -f ui.yaml up -d
Other approach would be to run every service in docker except one that you are working on.
This will build the project in docker containers, launching the monitor and server.
Verified sources and contract addresses will be stored in repository and db folders
in your project root. The directories are created automatically if they don't exist.
/ui/dist/index.html will be served to http://localhost:1234
UI
To help with manual UI testing, some contracts whose sources and metadata can be found in the
test/sources/all folder are automatically deployed to a local ganache instance running
on port 8545. Their contract addresses are deterministically generated at:
| Contracts | Addresses |
|---|---|
| Simple.sol | 0x8168f192F7432C93FCb16e039B57FB890AaB3230 |
| SimpleWithImport.sol | 0x0Ef7de872C7110d6020fa5e62d7cD31Fd90FF811 |
Similar sources are also pre-deployed to Ropsten and can be found in the test/sources/ropsten folder:
| Contracts | Addresses |
|---|---|
| Simple.sol | 0xEB6Cf7952c666F81f1a5678E80D4fC5Ce3a7bF0b |
| SimpleWithImport.sol | 0x4668b709182F41837c4e06C8de1D3568df7778D9 |
Shutdown Stop the docker run with ctrl-c
Run tests with:
npm test
test/sources contains contracts, compilation artifacts and metadata files which can be used for
building test cases.
- contracts/: Solidity files (browser tests)
- metadata/: raw metadata files (browser tests)
- pass/: compilation artifacts which should verify (unit tests)
- fail/: compilation artifacts which should not verify (unit tests)
- compiler.json: compiler config for generating more cases
Test sources are compiled with 0x's sol-compiler. This lets you pick any compiler version or
settings by modifying the compiler.json file as needed.
To generate more test data, go to the test/sources directory, add Solidity files to the
contracts folder and run:
npx sol-compiler
Compilation artifacts will be written to an artifacts folder.