EVM

How to generate the proof with EVM?

const generate = async (schemaId: string, appid: string) => {
    try {
      // The appid of the project created in dev center
      const appid = "8fb9d43c-2f24-424e-a98d-7ba34a5532f5"
  
      // Create the connector instance
      const connector = new TransgateConnect(appid)
  
      // Check if the TransGate extension is installed
      // If it returns false, please prompt to install it from chrome web store
      const isAvailable = await connector.isTransgateAvailable()
  
      if (isAvailable) {
        // The schema id of the project
        const schemaId = "516a720e-29a4-4307-ae7b-5aec286e446e"
  
        // Launch the process of verification
        // This method can be invoked in a loop when dealing with multiple schemas
        const res = await connector.launch(schemaId)
        
        //If you want to send the result to the blockchain, please add the wallet address as the second parameter.
        //const res = await connector.launch(schemaId, address)
  
        // verifiy the res onchain/offchain based on the requirement     
        
      } else {
        console.log('Please install TransGate')
      }
    } catch (error) {
      console.log('transgate error', error)
    }
  }
  

Verify Allocator Signature

Encode the allocator message struct

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import Web3 from "web3"

const web3 = new Web3()

const { taskId } = res //return by Transgate

const taskIdHex = Web3.utils.stringToHex(taskId)
const schemaIdHex = Web3.utils.stringToHex(schemaId)

const encodeParams = web3.eth.abi.encodeParameters(
  ["bytes32", "bytes32", "address"],
  [taskIdHex, schemaIdHex, validatorAddress]
)
const paramsHash = Web3.utils.soliditySha3(encodeParams)

Recover the allocator address

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const signedAllocatorAddress = web3.eth.accounts.recover(paramsHash, allocatorSignature)

Check if the signed allocator address is registered. The current allocator address is fixed.

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return signedAllocatorAddress === "0x19a567b3b212a5b35bA0E3B600FbEd5c2eE9083d"

Verify Validator Signature

Encode the validator message

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import Web3 from "web3"

const web3 = new Web3()

const { taskId, uHash, publicFieldsHash, recipient } = res //return by Transgate

const taskIdHex = Web3.utils.stringToHex(taskId)
const schemaIdHex = Web3.utils.stringToHex(schemaId)


const types = ["bytes32", "bytes32", "bytes32", "bytes32"]
const values = [taskIdHex, schemaIdHex, uHash, publicFieldsHash]

//If you add the wallet address as the second parameter when launch the Transgate
if (recipient) {
    types.push("address")
    values.push(recipient)
}

const encodeParams = web3.eth.abi.encodeParameters(types, values)

const paramsHash = Web3.utils.soliditySha3(encodeParams)

Recover the validator address

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const signedValidatorAddress = web3.eth.accounts.recover(paramsHash, validatorSignature)

Verify if the signed validator address matches the address assigned by the allocator

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return signedValidatorAddress === validatorAddress