Merge pull request #15 from ConsenSys/generateSwap

Implement generate swap for Bitcoin and Ethereum

src/index.js

@@ -311,6 +311,43 @@ export default class ChainAbstractionLayer {
     const secret = crypto.hash160(signedMessage)
     return secret
   }
+
+  /**
+   * Generate swap transaction data
+   */
+  generateSwap (recipientAddress, refundAddress, secretHash, expiration) {
+    this._checkMethod('generateSwap')
+
+    if (!isString(recipientAddress)) {
+      throw new Error('Recipient address should be a string')
+    }
+
+    if (!isString(refundAddress)) {
+      throw new Error('Refund address should be a string')
+    }
+
+    if (!isString(secretHash)) {
+      throw new Error('Secret hash should be a string')
+    }
+
+    if (!(/^[A-Fa-f0-9]+$/.test(recipientAddress))) {
+      throw new Error('Recipient address should be a valid hex string')
+    }
+
+    if (!(/^[A-Fa-f0-9]+$/.test(refundAddress))) {
+      throw new Error('Refund address should be a valid hex string')
+    }
+
+    if (!(/^[A-Fa-f0-9]+$/.test(secretHash))) {
+      throw new Error('Secret hash should be a valid hex string')
+    }
+
+    if (!isNumber(expiration)) {
+      throw new Error('Invalid expiration time')
+    }
+
+    return this.provider.generateSwap(recipientAddress, refundAddress, secretHash, expiration)
+  }
 }
 
 ChainAbstractionLayer.Provider = Provider

src/providers/bitcoin/BitcoinSwapProvider.js

@@ -0,0 +1,38 @@
+import Provider from '../../Provider'
+import crypto from './BitcoinCrypto'
+const { addressToPubKeyHash } = crypto
+
+export default class BitcoinSwapProvider extends Provider {
+  generateSwap (recipientAddress, refundAddress, secretHash, expiration) {
+    let expirationHex = expiration.toString(16)
+    if (expirationHex.length % 2 === 1) {
+      expirationHex = '0' + expirationHex
+    }
+    expirationHex = expirationHex.match(/.{2}/g).reverse()
+    expirationHex.length = Math.min(expirationHex.length, 5)
+    expirationHex[expirationHex.length - 1] = '00'
+
+    const recipientPubKeyHash = addressToPubKeyHash(recipientAddress)
+    const refundPubKeyHash = addressToPubKeyHash(refundAddress)
+    const expirationPushDataOpcode = expirationHex.length.toString(16).padStart(2, '0')
+    const expirationHexEncoded = expirationHex.join('')
+
+    return [
+      '76', 'a9', // OP_DUP OP_HASH160
+      '72', // OP_2SWAP
+      '63', // OP_IF
+      'a8', // OP_SHA256
+      '20', secretHash, // OP_PUSHDATA20 {secretHash}
+      '88', // OP_EQUALVERIFY
+      '14', recipientPubKeyHash, // OP_PUSHDATA20 {recipientPubKeyHash}
+      '67', // OP_ELSE
+      expirationPushDataOpcode, // OP_PUSHDATA{expirationHexLength}
+      expirationHexEncoded, // {expirationHexEncoded}
+      'b1', // OP_CHECKLOCKTIMEVERIFY
+      '6d', // OP_2DROP
+      '14', refundPubKeyHash, // OP_PUSHDATA20 {refundPubKeyHash}
+      '68', // OP_ENDIF
+      '88', 'ac' // OP_EQUALVERIFY OP_CHECKSIG
+    ].join('')
+  }
+}

src/providers/bitcoin/index.js

@@ -0,0 +1,11 @@
+import BitcoinRPCProvider from './BitcoinRPCProvider'
+import BitcoinLedgerProvider from './BitcoinLedgerProvider'
+import BitcoinCrypto from './BitcoinCrypto'
+import BitcoinSwapProvider from './BitcoinSwapProvider'
+
+export default {
+  BitcoinRPCProvider,
+  BitcoinLedgerProvider,
+  crypto: BitcoinCrypto,
+  BitcoinSwapProvider
+}

src/providers/ethereum/EthereumMetaMaskProvider.js

@@ -66,4 +66,24 @@ export default class EthereumMetaMaskProvider extends Provider {
     txHash = ensureEthFormat(txHash)
     return this._toMM('eth_getTransactionByHash', txHash)
   }
+
+  generateSwap (recipientAddress, refundAddress, secretHash, expiration) {
+    const dataSizeBase = 112
+    const redeemDestinationBase = 66
+    const refundDestinationBase = 89
+    const expirationHex = expiration.toString(16)
+    const expirationEncoded = expirationHex.length % 2 ? '0' + expirationHex : expirationHex // Pad with 0
+    const expirationSize = expirationEncoded.length / 2
+    const redeemDestinationEncoded = (redeemDestinationBase + expirationSize).toString(16)
+    const refundDestinationEncoded = (refundDestinationBase + expirationSize).toString(16)
+    const expirationPushOpcode = (0x5f + expirationSize).toString(16)
+    const dataSizeEncoded = (dataSizeBase + expirationSize).toString(16)
+    const recipientAddressEncoded = recipientAddress.replace('0x', '') // Remove 0x if exists
+    const refundAddressEncoded = refundAddress.replace('0x', '') // Remove 0x if exists
+    const secretHashEncoded = secretHash.replace('0x', '') // Remove 0x if exists
+    return `60${dataSizeEncoded}80600b6000396000f36020806000803760218160008060026048f17f\
+${secretHashEncoded}602151141660${redeemDestinationEncoded}57\
+${expirationPushOpcode}${expirationEncoded}421160${refundDestinationEncoded}\
+57005b73${recipientAddressEncoded}ff5b73${refundAddressEncoded}ff`
+  }
 }

src/providers/ethereum/EthereumSwapProvider.js

@@ -0,0 +1,77 @@
+import Provider from '../../Provider'
+
+export default class EthereumSwapProvider extends Provider {
+  generateSwap (recipientAddress, refundAddress, secretHash, expiration) {
+    const dataSizeBase = 112
+    const redeemDestinationBase = 66
+    const refundDestinationBase = 89
+    const expirationHex = expiration.toString(16)
+    const expirationEncoded = expirationHex.length % 2 ? '0' + expirationHex : expirationHex // Pad with 0
+    const expirationSize = expirationEncoded.length / 2
+    const expirationPushOpcode = (0x60 - 1 + expirationSize).toString(16)
+    const redeemDestinationEncoded = (redeemDestinationBase + expirationSize).toString(16)
+    const refundDestinationEncoded = (refundDestinationBase + expirationSize).toString(16)
+    const dataSizeEncoded = (dataSizeBase + expirationSize).toString(16)
+    const recipientAddressEncoded = recipientAddress.replace('0x', '') // Remove 0x if exists
+    const refundAddressEncoded = refundAddress.replace('0x', '') // Remove 0x if exists
+    const secretHashEncoded = secretHash.replace('0x', '') // Remove 0x if exists
+
+    return [
+      // Constructor
+      '60', dataSizeEncoded, // PUSH1 {dataSizeEncoded}
+      '80', // DUP1
+      '60', '0b', // PUSH1 0b
+      '60', '00', // PUSH1 00
+      '39', // CODECOPY
+      '60', '00', // PUSH1 00
+      'f3', // RETURN
+
+      // Contract
+      '60', '20', // PUSH1 20
+
+      // Get secret
+      '80', // DUP1
+      '60', '00', // PUSH1 00
+      '80', // DUP1
+      '37', // CALLDATACOPY
+
+      // SHA256
+      '60', '21', // PUSH1 21
+      '81', // DUP2
+      '60', '00', // PUSH1 00
+      '80', // DUP1
+      '60', '02', // PUSH1 02
+      '60', '48', // PUSH1 48
+      'f1', // CALL
+
+      // Validate with secretHash
+      '7f', secretHashEncoded, // PUSH32 {secretHashEncoded}
+      '60', '21', // PUSH1 21
+      '51', // MLOAD
+      '14', // EQ
+      '16', // AND (to make sure CALL succeeded)
+      // Redeem if secret is valid
+      '60', redeemDestinationEncoded, // PUSH1 {redeemDestinationEncoded}
+      '57', // JUMPI
+
+      // Check time lock
+      expirationPushOpcode, // PUSH{expirationSize}
+      expirationEncoded, // {expirationEncoded}
+      '42', // TIMESTAMP
+      '11', // GT
+      // Refund if timelock passed
+      '60', refundDestinationEncoded, // PUSH1 {refundDestinationEncoded}
+      '57',
+
+      '00', // STOP
+
+      '5b', // JUMPDEST
+      '73', recipientAddressEncoded, // PUSH20 {recipientAddressEncoded}
+      'ff', // SUICIDE
+
+      '5b', // JUMPDEST
+      '73', refundAddressEncoded, // PUSH20 {refundAddressEncoded}
+      'ff' // SUICIDE
+    ].join('')
+  }
+}

src/providers/ethereum/index.js

@@ -0,0 +1,11 @@
+import EthereumRPCProvider from './EthereumRPCProvider'
+import EthereumLedgerProvider from './EthereumLedgerProvider'
+import EthereumMetaMaskProvider from './EthereumMetaMaskProvider'
+import EthereumSwapProvider from './EthereumSwapProvider'
+
+export default {
+  EthereumRPCProvider,
+  EthereumLedgerProvider,
+  EthereumMetaMaskProvider,
+  EthereumSwapProvider
+}

src/providers/index.js

@@ -1,20 +1,7 @@
-import BitcoinRPCProvider from './bitcoin/BitcoinRPCProvider'
-import BitcoinLedgerProvider from './bitcoin/BitcoinLedgerProvider'
-import BitcoinCrypto from './bitcoin/BitcoinCrypto'
-
-import EthereumRPCProvider from './ethereum/EthereumRPCProvider'
-import EthereumLedgerProvider from './ethereum/EthereumLedgerProvider'
-import EthereumMetaMaskProvider from './ethereum/EthereumMetaMaskProvider'
+import bitcoin from './bitcoin/'
+import ethereum from './ethereum/'
 
 export default {
-  bitcoin: {
-    BitcoinRPCProvider,
-    BitcoinLedgerProvider,
-    crypto: BitcoinCrypto
-  },
-  ethereum: {
-    EthereumRPCProvider,
-    EthereumLedgerProvider,
-    EthereumMetaMaskProvider
-  }
+  bitcoin,
+  ethereum
 }

test/BitcoinSwapProvider.js

@@ -0,0 +1,22 @@
+/* eslint-env mocha */
+
+const chai = require('chai')
+const chaiAsPromised = require('chai-as-promised')
+chai.use(chaiAsPromised)
+const { expect } = chai
+
+const ChainAbstractionLayer = require('../')
+
+const lib = new ChainAbstractionLayer.providers.bitcoin.BitcoinSwapProvider()
+
+describe('Bitcoin Swap provider', () => {
+  describe('Generate swap', () => {
+    it('should generate correct bytecode', () => {
+      return expect(lib.generateSwap('1J7eFp9p48g3U3yCREyhd6LJzhnkywhi5s',
+        '1GZQKjsC97yasxRj1wtYf5rC61AxpR1zmr',
+        'ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff',
+        1532622116403))
+        .to.equal('76a97263a820ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff8814bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb6705339665d700b16d14aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa6888ac')
+    })
+  })
+})

test/EthereumSwapProvider.js

@@ -0,0 +1,30 @@
+/* eslint-env mocha */
+
+const chai = require('chai')
+const chaiAsPromised = require('chai-as-promised')
+chai.use(chaiAsPromised)
+const { expect } = chai
+
+const ChainAbstractionLayer = require('../')
+
+const lib = new ChainAbstractionLayer.providers.ethereum.EthereumSwapProvider()
+
+describe('Ethereum Swap provider', () => {
+  describe('Generate swap', () => {
+    it('should generate correct bytecode', () => {
+      return expect(lib.generateSwap('0x5acbf79d0cf4139a6c3eca85b41ce2bd23ced04f',
+        '0x0a81e8be41b21f651a71aab1a85c6813b8bbccf8',
+        '0x91d6a24697ed31932537ae598d3de3131e1fcd0641b9ac4be7afcb376386d71e',
+        255))
+        .to.equal('607180600b6000396000f36020806000803760218160008060026048f17f91d6a24697ed31932537ae598d3de3131e1fcd0641b9ac4be7afcb376386d71e602151141660435760ff4211605a57005b735acbf79d0cf4139a6c3eca85b41ce2bd23ced04fff5b730a81e8be41b21f651a71aab1a85c6813b8bbccf8ff')
+    })
+
+    it('should generate correct bytecode with different expiration length', () => {
+      return expect(lib.generateSwap('0x5acbf79d0cf4139a6c3eca85b41ce2bd23ced04f',
+        '0x0a81e8be41b21f651a71aab1a85c6813b8bbccf8',
+        '0x91d6a24697ed31932537ae598d3de3131e1fcd0641b9ac4be7afcb376386d71e',
+        6016519))
+        .to.equal('607380600b6000396000f36020806000803760218160008060026048f17f91d6a24697ed31932537ae598d3de3131e1fcd0641b9ac4be7afcb376386d71e6021511416604557625bce074211605c57005b735acbf79d0cf4139a6c3eca85b41ce2bd23ced04fff5b730a81e8be41b21f651a71aab1a85c6813b8bbccf8ff')
+    })
+  })
+})