ENS_ETHNewYork_Workshop_May_2019.pdf

Transcript

1. How to integrate ENS into your Dapp ETHNewYork, May 2019
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 https://hackathons.ens.domains/?domain=ethglobal.eth
10. 4. EIP1577 https://www.npmjs.com/package/content-hash https://github.com/ensdomains/ens-app/pull/78
11. 5. Fetch ENS Events with Graph Explorer https://thegraph.com/explorer/subgraph/ensdomains/ens
12. 6. ENS as NFT https://medium.com/the-ethereum-name-service/ens-nft-emoji-75259145314f
13. 999. ENS everything at ETHGlobal hackathons $200 x 5 prizes
14. ENS contract and API overview
15. Read the doc! (https://docs.ens.domains )
16. ENS Architecture
17. Resolving a name
18. Contract MyResolver { address me; function MyResolver() { me = msg.sender; } function addr(bytes32 node) constant returns (address) { return me; } } ENS by example: Resolvers
19. Looking up names const address = await ens.resolver(‘arachnid.eth’).addr();
20. Reverse resolution const addr = ‘0x112234455...’ const name = await ens.reverse(‘0x112234455...’).name() //for security const forward = await ens.resolver(name) if(addr === forward){ …. }
21. Setting up reverse resolution reverseRegistrar.setName(‘jefflau.eth’)
22. Putting them altogether
23. Issuing subdomain to new users for your dapp
24. Signup flow example Make sure - User is on the right network - Metamask is unlocked
25. 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!
26. Sign up Subdomain transactions are sent asynchronously so users can start using the platform instantly
27. Verify account Signing a message to verify they hold the account A nounce to prevent replay attacks
28. 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.
29. 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
30. 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”)
31. 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))
32. 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”)
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 Check the name is not taken yet
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 Set the contract to own “makoto.yourdomain.eth”
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 Set the default resolver to “makoto.yourdomain.eth”
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 Set the sender address to “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 Give the ownership of the node to the sender
38. Pro tips - 1. Creating your test ENS name - 2. Deploying ENS locally - 3. ENS is just a smart contract
39. 1. Creating your test ENS name https://manager.ens.domains
40. 2. Deploying ENS locally https://embark.status.im/docs/naming_configuration.html https://github.com/EthWorks/ENSBuilder
41. 3. ENS is just a truffle project/npm module https://www.npmjs.com/package/@ensdomains/ens https://www.npmjs.com/package/@ensdomains/resolvers
42. https://medium.com/the-ethereum-name-service https://docs.ens.domains http://github.com/ensdomains References
43. Questions? makoto@ens.domains