How to integrate ENS into your Dapp @ ETHcc

Transcript

1. How to integrate ENS into your Dapp @ ETHcc makoto@ens.domains
2. Speakers @makoto_inoue
3. Also known for...
4. Agenda - 1. What can you do with ENS? - 2. ENS contracts and API overview - 3. Pro tips
5. What can you do with your ENS?
6. 1. Name your address (aka lookup)
7. 2. Show names (aka reverse lookup)
8. Custom swags?
9. 3. Give subdomains
10. 4. Universal Login (Day 3- 13:30)
11. 5. Decentralised Web with Dappnode (Day 3 - 16:25)
12. EIP1577 https://www.npmjs.com/package/content-hash https://github.com/ensdomains/ens-app/pull/78
13. 6. Fetch ENS Events with Graph Explorer https://thegraph.com/explorer/subgraph/ensdomains/ens
14. 999. ENS everything at ETHGlobal hackathons
15. ENS contract and API overview
16. Read the doc! (https://docs.ens.domains )
17. ENS Architecture
18. Resolving a name
19. Contract MyResolver { address me; function MyResolver() { me = msg.sender; } function addr(bytes32 node) constant returns (address) { return me; } } ENS by example: Resolvers
20. Using ENS from Javascript https://ens.gitbook.io/ens/developer-guide/working-with-ens
21. Looking up names const address = await ens.resolver(‘arachnid.eth’).addr();
22. Reverse resolution const addr = ‘0x112234455...’ const name = await ens.reverse(‘0x112234455...’).name() //for security const forward = await ens.resolver(name) if(addr === forward){ …. }
23. Setting up reverse resolution reverseRegistrar.setName(‘jefflau.eth’)
24. Contracts in web3 var testContract = web3.eth.contract( [{"constant":true,"inputs":...}]) var test = testContract.at(“0x0904dac3347ea47d208f...”);
25. Contracts in ENS const contract = ens.resolver(‘arachnid.eth’).instance(); contract.myContractMethod()
26. Issuing subdomain to new users for your dapp
27. Signup flow example Make sure - User is on the right network - Metamask is unlocked
28. Getting ENS subdomain Check if the ENS subdomain already exists - If yes, then check if it is owned by the address currently on metamask - If yes then its a sign in, make them sign a message to prove they actually hold the acount they are signing up for. If it doesnt exist then they can have it!
29. Sign up Subdomain transactions are sent asynchronously so users can start using the platform instantly
30. Verify account Signing a message to verify they hold the account A nounce to prevent replay attacks
31. Account Users are logged in regardless of the status of transactions. (UX comment) Since Zinc sends the transactions and the messages are verified on chain, they are also verified off chain to prevent sending transactions which are guaranteed to fail.
32. The actual code of zinc
33. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code
34. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code web3.utils.sha3(“makoto”)
35. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code keccak256(abi.encodePacked(“yourdomain.eth”, label))
36. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code web3.utils.sha3(“makoto.yourdomain.eth”)
37. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code Check the name is not taken yet
38. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code Set the contract to own “makoto.yourdomain.eth”
39. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code Set the default resolver to “makoto.yourdomain.eth”
40. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code Set the sender address to “makoto.yourdomain.eth”
41. Contract MyAweSomeApp { function register(bytes32 label) public { bytes32 node = getNode(label); require(ens.owner(node) == address(0)) ens.setSubnodeOwner(rootNode, label, this); ens.setResolver(node, resolver); resolver.setAddr(node, msg.sender); ens.setOwner(node, msg.sender); } } The code Give the ownership of the node to the sender
42. Pro tips - 1. Creating your test ENS name - 2. Deploying ENS locally - 3. ENS is just a smart contract
43. 1. Creating your test ENS name https://manager.ens.domains
44. 2. Deploying ENS locally https://embark.status.im/docs/naming_configuration.html https://github.com/EthWorks/ENSBuilder
45. 3. ENS is just a truffle project/npm module https://www.npmjs.com/package/@ensdomains/ens https://www.npmjs.com/package/@ensdomains/resolvers
46. https://medium.com/the-ethereum-name-service https://docs.ens.domains http://github.com/ensdomains References
47. Questions? makoto@ens.domains