参考文档

官方文档地址 https://loopring.github.io/relay-cluster/relay_api_spec_v2.html#loopring_notifytransactionsubmitted。

接口

loopring_notifyTransactionSubmitted

参数含义

• hash - The txHash.
• nonce - The owner newest nonce.
• to - The target address to send.
• value - The value in transaction.
• gasPrice.
• gas.
• input - The value input in transaction.
• from - The transaction sender.
• v - ECDSA signature parameter v.
• r - ECDSA signature parameter r.
• s - ECDSA signature parameter s.

其中，input, v, r, s含义如下：

input

input是交易时的data（详见 https://github.com/ethereum/wiki/wiki/JavaScript-API#web3ethsendtransaction)。 普通交易时data是附带的二进制信息，创建合约时data为合约代码。

参照路印的实现 data 经过 web3swift对实体encode得到。而这个实体有方法名（string），输入参数（array），输出参数（arry）三个属性 实体构造分为 以下几种情况得到

• convert weth -> eth
  name: “withdraw”, inputParameters: [amount] //amount为转换eth或者weth金额
• convert eth -> weth
  name: “deposit”, inputParameters: []
• 创建合约
  name: “approve”, inputParameters: [delegateAddress, tokenAmount] //delegateAddress: loorping delegate address，tokenAmount为转账金额
• 取消合约 （用于取消订单）
  name: “cancelAllOrdersByTradingPair”, inputParameters: [tokenA, tokenB, timestamp] // tokenA tokenB 为代币的缩写
• 转帐 eth
  不需要实体encode得到data，直接由字符串’‘0x’转成二进制
• 转账非eth transfer tokens
  name: “transfer”, inputParameters: [toAddress, tokenAmount]// 收款地址，转账金额

v、 r、 s

组装待签名消息

因loopring_notifyTransactionSubmitted接口未实现，该部分选用loopring_submitOrder作为示例，接口文档见 https://loopring.github.io/relay-cluster/relay_api_spec_v2.html#loopring_submitorder

• 把订单信息打平组装成Hash，用16进制数据依次拼接，顺序依次为
  • delegate
  • address
  • tokenS
  • tokenB
  • walletAddress
  • authAddr
  • amountS
  • amountB
  • validSince
  • validUntil
  • lrcFee
  • buyNoMoreThanAmountB
  • marginSplitPercentage

    func getOrderHash(order: OriginalOrder) -> Data {
        var result: Data = Data()
        result.append(contentsOf: order.delegate.hexBytes)
        result.append(contentsOf: order.address.hexBytes)
        let tokens = TokenDataManager.shared.getAddress(by: order.tokenSell)!
        result.append(contentsOf: tokens.hexBytes)
        let tokenb = TokenDataManager.shared.getAddress(by: order.tokenBuy)!
        result.append(contentsOf: tokenb.hexBytes)
        result.append(contentsOf: order.walletAddress.hexBytes)
        result.append(contentsOf: order.authAddr.hexBytes)
        result.append(contentsOf: _encode(order.amountSell, order.tokenSell))
        result.append(contentsOf: _encode(order.amountBuy, order.tokenBuy))
        result.append(contentsOf: _encode(order.validSince))
        result.append(contentsOf: _encode(order.validUntil))
        result.append(contentsOf: _encode(order.lrcFee, "LRC"))
        let flag: [UInt8] = order.buyNoMoreThanAmountB ? [1] : [0]
        result.append(contentsOf: flag)
        result.append(contentsOf: [order.marginSplitPercentage])
        return result
    }

keccak256加密(通用，与具体交易和参数无关)

• 对message进行keccak256加密
• 加密后的字符串，加上”\u{0019}Ethereum Signed Message:\n32”前缀
• 对合并后的字符串再进行keccak256加密，作为待签名的字符串
• 用交易主账户签名
• 签名后的Hash，[0,32)是r, [32,64)是s,[64,65)的int形式是v

    open class func sign(message: Data, keystore: GethKeyStore, account: GethAccount, passphrase: String) -> (SignatureData?, String?) {
        let hashedMessage = message.sha3(SHA3.Variant.keccak256)
        let header: Data = "\u{0019}Ethereum Signed Message:\n32".data(using: .utf8)!
        let newData: Data = header + hashedMessage
        let secret = newData.sha3(SHA3.Variant.keccak256)
        
        do {
            // TODO:- Add timed Unlock
            _ = try? keystore.unlock(account, passphrase: passphrase)
            let accountAddress = account.getAddress()
            print("############### use address \(accountAddress?.getHex()) to sign")
            let hashedSignedMessage = try keystore.signHash(accountAddress, hash: secret)
            // let hashedSignedMessage = try keystore.signHash(accountAddress, hash: hashedMessage)
            let r = hashedSignedMessage.subdata(in: Range(0..<32))
            let s = hashedSignedMessage.subdata(in: Range(32..<64))
            let v = hashedSignedMessage.subdata(in: Range(64..<65)) // TODO:- Use length
        
            if let recId = Int(v.toHexString()) {
                let headerByte = recId + 27
                let hash = "0x" + hashedMessage.hexString
                let signature = (SignatureData(v: headerByte, r: r, s: s))
                return (signature, hash)
            } else {
                return (nil, nil)
            }
        } catch {
            print("Failed to signhash \(error)")
            return (nil, nil)
        }
    }

返回值

• String - txHash和 SignatureData实体.

  调用举例