Add support for AMB contracts (#199)

README.md

@@ -52,11 +52,12 @@ Additionally there are [Smart Contracts](https://github.com/poanetwork/poa-bridg
 
 ## Operational Modes
 
-The POA TokenBridge provides three operational modes:
+The POA TokenBridge provides four operational modes:
 
 - [x] `Native-to-ERC20` **Coins** on a Home network can be converted to ERC20-compatible **tokens** on a Foreign network. Coins are locked on the Home side and the corresponding amount of ERC20 tokens are minted on the Foreign side. When the operation is reversed, tokens are burnt on the Foreign side and unlocked in the Home network. **More Information: [POA-to-POA20 Bridge](https://medium.com/poa-network/introducing-poa-bridge-and-poa20-55d8b78058ac)**
 - [x] `ERC20-to-ERC20` ERC20-compatible tokens on the Foreign network are locked and minted as ERC20-compatible tokens (ERC677 tokens) on the Home network. When transferred from Home to Foreign, they are burnt on the Home side and unlocked in the Foreign network. This can be considered a form of atomic swap when a user swaps the token "X" in network "A" to the token "Y" in network "B". **More Information: [ERC20-to-ERC20](https://medium.com/poa-network/introducing-the-erc20-to-erc20-tokenbridge-ce266cc1a2d0)**
 - [x] `ERC20-to-Native`: Pre-existing **tokens** in the Foreign network are locked and **coins** are minted in the `Home` network. In this mode, the Home network consensus engine invokes [Parity's Block Reward contract](https://wiki.parity.io/Block-Reward-Contract.html) to mint coins per the bridge contract request. **More Information: [xDai Chain](https://medium.com/poa-network/poa-network-partners-with-makerdao-on-xdai-chain-the-first-ever-usd-stable-blockchain-65a078c41e6a)**
+- [x] `Arbitrary-Message`: Transfer arbitrary data between two networks as so the data could be interpreted as an arbitrary contract method invocation.
 
 ## Initializing the monorepository
 

commons/abis.js

@@ -10,6 +10,9 @@ const ERC677_BRIDGE_TOKEN_ABI = require('../contracts/build/contracts/ERC677Brid
 const BLOCK_REWARD_ABI = require('../contracts/build/contracts/IBlockReward').abi
 const BRIDGE_VALIDATORS_ABI = require('../contracts/build/contracts/BridgeValidators').abi
 const REWARDABLE_VALIDATORS_ABI = require('../contracts/build/contracts/RewardableValidators').abi
+const HOME_AMB_ABI = require('../contracts/build/contracts/HomeAMB').abi
+const FOREIGN_AMB_ABI = require('../contracts/build/contracts/ForeignAMB').abi
+const BOX_ABI = require('../contracts/build/contracts/Box').abi
 
 const { HOME_V1_ABI, FOREIGN_V1_ABI } = require('./v1Abis')
 const { BRIDGE_MODES } = require('./constants')
@@ -60,6 +63,9 @@ function getBridgeABIs(bridgeMode) {
   } else if (bridgeMode === BRIDGE_MODES.NATIVE_TO_ERC_V1) {
     HOME_ABI = HOME_V1_ABI
     FOREIGN_ABI = FOREIGN_V1_ABI
+  } else if (bridgeMode === BRIDGE_MODES.ARBITRARY_MESSAGE) {
+    HOME_ABI = HOME_AMB_ABI
+    FOREIGN_ABI = FOREIGN_AMB_ABI
   } else {
     throw new Error(`Unrecognized bridge mode: ${bridgeMode}`)
   }
@@ -83,5 +89,8 @@ module.exports = {
   REWARDABLE_VALIDATORS_ABI,
   HOME_V1_ABI,
   FOREIGN_V1_ABI,
-  ERC20_BYTES32_ABI
+  ERC20_BYTES32_ABI,
+  HOME_AMB_ABI,
+  FOREIGN_AMB_ABI,
+  BOX_ABI
 }

commons/constants.js

@@ -2,7 +2,8 @@ const BRIDGE_MODES = {
   NATIVE_TO_ERC: 'NATIVE_TO_ERC',
   ERC_TO_ERC: 'ERC_TO_ERC',
   ERC_TO_NATIVE: 'ERC_TO_NATIVE',
-  NATIVE_TO_ERC_V1: 'NATIVE_TO_ERC_V1'
+  NATIVE_TO_ERC_V1: 'NATIVE_TO_ERC_V1',
+  ARBITRARY_MESSAGE: 'ARBITRARY_MESSAGE'
 }
 
 const ERC_TYPES = {
@@ -16,4 +17,8 @@ const FEE_MANAGER_MODE = {
   UNDEFINED: 'UNDEFINED'
 }
 
-module.exports = { BRIDGE_MODES, ERC_TYPES, FEE_MANAGER_MODE }
+module.exports = {
+  BRIDGE_MODES,
+  ERC_TYPES,
+  FEE_MANAGER_MODE
+}

commons/index.js

@@ -1,9 +1,11 @@
 const constants = require('./constants')
 const abis = require('./abis')
 const utils = require('./utils')
+const message = require('./message')
 
 module.exports = {
   ...constants,
   ...abis,
-  ...utils
+  ...utils,
+  ...message
 }

commons/message.js

@@ -0,0 +1,27 @@
+function strip0x(input) {
+  return input.replace(/^0x/, '')
+}
+
+function addTxHashToData({ encodedData, transactionHash }) {
+  return encodedData.slice(0, 2) + strip0x(transactionHash) + encodedData.slice(2)
+}
+
+function parseAMBMessage(message) {
+  message = strip0x(message)
+
+  const txHash = `0x${message.slice(0, 64)}`
+  const sender = `0x${message.slice(64, 104)}`
+  const executor = `0x${message.slice(104, 144)}`
+
+  return {
+    sender,
+    executor,
+    txHash
+  }
+}
+
+module.exports = {
+  addTxHashToData,
+  parseAMBMessage,
+  strip0x
+}

commons/package.json

@@ -8,6 +8,10 @@
     "test": "NODE_ENV=test mocha"
   },
   "dependencies": {
-    "web3-utils": "1.0.0-beta.30"
+    "web3-utils": "1.0.0-beta.34"
+  },
+  "devDependencies": {
+    "bn-chai": "^1.0.1",
+    "chai": "^4.2.0"
   }
 }

commons/test/constants.test.js

@@ -3,7 +3,7 @@ const { BRIDGE_MODES, ERC_TYPES } = require('../constants')
 
 describe('constants', () => {
   it('should contain correct number of bridge types', () => {
-    expect(Object.keys(BRIDGE_MODES).length).to.be.equal(4)
+    expect(Object.keys(BRIDGE_MODES).length).to.be.equal(5)
   })
 
   it('should contain correct number of erc types', () => {

commons/test/message.test.js

@@ -0,0 +1,69 @@
+const { BN } = require('web3-utils')
+const { expect } = require('chai').use(require('bn-chai')(BN))
+const { parseAMBMessage, strip0x, addTxHashToData } = require('../message')
+
+describe('strip0x', () => {
+  it('should remove 0x from input', () => {
+    // Given
+    const input = '0x12345'
+
+    // When
+    const result = strip0x(input)
+
+    // Then
+    expect(result).to.be.equal('12345')
+  })
+  it('should not modify input if 0x is not present', () => {
+    // Given
+    const input = '12345'
+
+    // When
+    const result = strip0x(input)
+
+    // Then
+    expect(result).to.be.equal(input)
+  })
+})
+describe('addTxHashToData', () => {
+  it('should add txHash to encoded data at position 2', () => {
+    // Given
+    const msgSender = '0x003667154bb32e42bb9e1e6532f19d187fa0082e'
+    const msgExecutor = '0xf4bef13f9f4f2b203faf0c3cbbaabe1afe056955'
+    const msgGasLimit = '000000000000000000000000000000000000000000000000000000005b877705'
+    const msgDataType = '00'
+    const msgData = '0xb1591967aed668a4b27645ff40c444892d91bf5951b382995d4d4f6ee3a2ce03'
+    const encodedData = `0x${strip0x(msgSender)}${strip0x(msgExecutor)}${msgGasLimit}${msgDataType}${strip0x(msgData)}`
+
+    const transactionHash = '0xbdceda9d8c94838aca10c687da1411a07b1390e88239c0638cb9cc264219cc10'
+    const message = `0x${strip0x(transactionHash)}${strip0x(msgSender)}${strip0x(
+      msgExecutor
+    )}${msgGasLimit}${msgDataType}${strip0x(msgData)}`
+
+    // When
+    const result = addTxHashToData({ encodedData, transactionHash })
+
+    // Then
+    expect(result).to.be.equal(message)
+  })
+})
+describe('parseAMBMessage', () => {
+  it('should parse data type 00', () => {
+    const msgSender = '0x003667154bb32e42bb9e1e6532f19d187fa0082e'
+    const msgExecutor = '0xf4bef13f9f4f2b203faf0c3cbbaabe1afe056955'
+    const msgTxHash = '0xbdceda9d8c94838aca10c687da1411a07b1390e88239c0638cb9cc264219cc10'
+    const msgGasLimit = '000000000000000000000000000000000000000000000000000000005b877705'
+    const msgDataType = '00'
+    const msgData = '0xb1591967aed668a4b27645ff40c444892d91bf5951b382995d4d4f6ee3a2ce03'
+    const message = `0x${strip0x(msgTxHash)}${strip0x(msgSender)}${strip0x(
+      msgExecutor
+    )}${msgGasLimit}${msgDataType}${strip0x(msgData)}`
+
+    // when
+    const { sender, executor, txHash } = parseAMBMessage(message)
+
+    // then
+    expect(sender).to.be.equal(msgSender)
+    expect(executor).to.be.equal(msgExecutor)
+    expect(txHash).to.be.equal(msgTxHash)
+  })
+})

commons/utils.js

@@ -10,6 +10,8 @@ function decodeBridgeMode(bridgeModeHash) {
       return BRIDGE_MODES.ERC_TO_ERC
     case '0x18762d46':
       return BRIDGE_MODES.ERC_TO_NATIVE
+    case '0x2544fbb9':
+      return BRIDGE_MODES.ARBITRARY_MESSAGE
     default:
       throw new Error(`Unrecognized bridge mode hash: '${bridgeModeHash}'`)
   }

e2e-commons/components-envs/oracle-amb.env

@@ -0,0 +1,23 @@
+
+ORACLE_BRIDGE_MODE=ARBITRARY_MESSAGE
+ORACLE_QUEUE_URL=amqp://rabbit
+ORACLE_REDIS_URL=redis://redis
+COMMON_HOME_RPC_URL=http://parity1:8545
+COMMON_FOREIGN_RPC_URL=http://parity2:8545
+COMMON_HOME_BRIDGE_ADDRESS=0x0AEe1FCD12dDFab6265F7f8956e6E012A9Fe4Aa0
+COMMON_FOREIGN_BRIDGE_ADDRESS=0x0AEe1FCD12dDFab6265F7f8956e6E012A9Fe4Aa0
+ORACLE_VALIDATOR_ADDRESS=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+ORACLE_VALIDATOR_ADDRESS_PRIVATE_KEY=8e829f695aed89a154550f30262f1529582cc49dc30eff74a6b491359e0230f9
+COMMON_HOME_GAS_PRICE_SUPPLIER_URL=https://gasprice.poa.network/
+COMMON_HOME_GAS_PRICE_SPEED_TYPE=standard
+COMMON_HOME_GAS_PRICE_FALLBACK=1000000000
+ORACLE_HOME_GAS_PRICE_UPDATE_INTERVAL=600000
+COMMON_HOME_GAS_PRICE_FACTOR=1
+COMMON_FOREIGN_GAS_PRICE_SUPPLIER_URL=https://gasprice.poa.network/
+COMMON_FOREIGN_GAS_PRICE_SPEED_TYPE=standard
+COMMON_FOREIGN_GAS_PRICE_FALLBACK=10000000000
+ORACLE_FOREIGN_GAS_PRICE_UPDATE_INTERVAL=600000
+COMMON_FOREIGN_GAS_PRICE_FACTOR=1
+ORACLE_HOME_RPC_POLLING_INTERVAL=500
+ORACLE_FOREIGN_RPC_POLLING_INTERVAL=500
+ORACLE_ALLOW_HTTP_FOR_RPC=yes

e2e-commons/constants.json

@@ -37,6 +37,12 @@
     "ui": "http://localhost:3002",
     "monitor": "http://monitor-erc20-native:3012"
   },
+  "amb": {
+    "home": "0x0AEe1FCD12dDFab6265F7f8956e6E012A9Fe4Aa0",
+    "foreign": "0x0AEe1FCD12dDFab6265F7f8956e6E012A9Fe4Aa0",
+    "homeBox": "0x6C4EaAb8756d53Bf599FFe2347FAFF1123D6C8A1",
+    "foreignBox": "0x6C4EaAb8756d53Bf599FFe2347FAFF1123D6C8A1"
+  },
   "homeRPC": {
     "URL": "http://parity1:8545",
     "ID": "77"

e2e-commons/contracts-envs/amb.env

@@ -0,0 +1,25 @@
+BRIDGE_MODE=ARBITRARY_MESSAGE
+DEPLOYMENT_ACCOUNT_PRIVATE_KEY=8e829f695aed89a154550f30262f1529582cc49dc30eff74a6b491359e0230f9
+HOME_DEPLOYMENT_GAS_PRICE=10000000000
+FOREIGN_DEPLOYMENT_GAS_PRICE=10000000000
+GET_RECEIPT_INTERVAL_IN_MILLISECONDS=50
+DEPLOYMENT_GAS_LIMIT_EXTRA=0.2
+
+HOME_RPC_URL=http://parity1:8545
+HOME_BRIDGE_OWNER=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+HOME_VALIDATORS_OWNER=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+HOME_UPGRADEABLE_ADMIN=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+HOME_MAX_AMOUNT_PER_TX=8000000
+HOME_REQUIRED_BLOCK_CONFIRMATIONS=1
+HOME_GAS_PRICE=1000000000
+
+FOREIGN_RPC_URL=http://parity2:8545
+FOREIGN_BRIDGE_OWNER=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+FOREIGN_VALIDATORS_OWNER=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+FOREIGN_UPGRADEABLE_ADMIN=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b
+FOREIGN_MAX_AMOUNT_PER_TX=8000000
+FOREIGN_REQUIRED_BLOCK_CONFIRMATIONS=1
+FOREIGN_GAS_PRICE=10000000000
+
+REQUIRED_NUMBER_OF_VALIDATORS=1
+VALIDATORS=0xaaB52d66283F7A1D5978bcFcB55721ACB467384b

e2e-commons/docker-compose.yml

@@ -61,6 +61,17 @@ services:
     command: "true"
     networks:
       - ultimate
+  oracle-amb:
+    build:
+      context: ..
+      dockerfile: oracle/Dockerfile
+      args:
+        DOT_ENV_PATH: e2e-commons/components-envs/oracle-amb.env
+    environment:
+    - NODE_ENV=production
+    command: "true"
+    networks:
+      - ultimate
   ui:
     build:
       context: ..

e2e-commons/scripts/deploy.sh

@@ -29,3 +29,14 @@ cp "$ENVS_PATH/erc-to-native.env" "$DEPLOY_PATH/.env"
 cd "$DEPLOY_PATH"
 node deploy.js
 cd - > /dev/null
+
+echo -e "\n\n############ Deploying amb ############\n"
+cp "$ENVS_PATH/amb.env" "$DEPLOY_PATH/.env"
+cd "$DEPLOY_PATH"
+node deploy.js
+cd - > /dev/null
+
+echo -e "\n\n############ Deploying test contract for amb ############\n"
+cd "$DEPLOY_PATH"
+node src/utils/deployTestBox.js
+cd - > /dev/null

e2e-commons/up.sh

@@ -9,7 +9,7 @@ docker-compose up -d parity1 parity2 e2e
 
 while [ "$1" != "" ]; do
   if [ "$1" == "oracle" ]; then
-    docker-compose up -d redis rabbit oracle oracle-erc20 oracle-erc20-native
+    docker-compose up -d redis rabbit oracle oracle-erc20 oracle-erc20-native oracle-amb
 
     docker-compose run -d oracle yarn watcher:signature-request
     docker-compose run -d oracle yarn watcher:collected-signatures
@@ -20,6 +20,9 @@ while [ "$1" != "" ]; do
     docker-compose run -d oracle-erc20-native yarn watcher:signature-request
     docker-compose run -d oracle-erc20-native yarn watcher:collected-signatures
     docker-compose run -d oracle-erc20-native yarn watcher:affirmation-request
+    docker-compose run -d oracle-amb yarn watcher:signature-request
+    docker-compose run -d oracle-amb yarn watcher:collected-signatures
+    docker-compose run -d oracle-amb yarn watcher:affirmation-request
     docker-compose run -d oracle yarn sender:home
     docker-compose run -d oracle yarn sender:foreign
   fi

monitor/alerts.js

@@ -3,6 +3,8 @@ const Web3 = require('web3')
 const logger = require('./logger')('alerts')
 const eventsInfo = require('./utils/events')
 const { getBlockNumber } = require('./utils/contract')
+const { processedMsgNotDelivered } = require('./utils/message')
+const { BRIDGE_MODES } = require('../commons')
 
 const { COMMON_HOME_RPC_URL, COMMON_FOREIGN_RPC_URL } = process.env
 
@@ -13,10 +15,23 @@ const foreignProvider = new Web3.providers.HttpProvider(COMMON_FOREIGN_RPC_URL)
 const web3Foreign = new Web3(foreignProvider)
 
 async function main() {
-  const { foreignDeposits, homeDeposits, homeWithdrawals, foreignWithdrawals } = await eventsInfo()
+  const {
+    homeToForeignRequests,
+    homeToForeignConfirmations,
+    foreignToHomeConfirmations,
+    foreignToHomeRequests,
+    bridgeMode
+  } = await eventsInfo()
 
-  const xSignatures = foreignDeposits.filter(findDifferences(homeDeposits))
+  let xSignatures
-  const xAffirmations = homeWithdrawals.filter(findDifferences(foreignWithdrawals))
+  let xAffirmations
+  if (bridgeMode === BRIDGE_MODES.ARBITRARY_MESSAGE) {
+    xSignatures = homeToForeignConfirmations.filter(processedMsgNotDelivered(homeToForeignRequests))
+    xAffirmations = foreignToHomeConfirmations.filter(processedMsgNotDelivered(foreignToHomeRequests))
+  } else {
+    xSignatures = homeToForeignConfirmations.filter(findDifferences(homeToForeignRequests))
+    xAffirmations = foreignToHomeConfirmations.filter(findDifferences(foreignToHomeRequests))
+  }
 
   logger.debug('building misbehavior blocks')
   const [homeBlockNumber, foreignBlockNumber] = await getBlockNumber(web3Home, web3Foreign)

monitor/eventsStats.js

@@ -1,6 +1,7 @@
 require('dotenv').config()
-const logger = require('./logger')('eventsStats')
 const eventsInfo = require('./utils/events')
+const { processedMsgNotDelivered, deliveredMsgNotProcessed } = require('./utils/message')
+const { BRIDGE_MODES } = require('../commons')
 
 function compareDepositsHome(foreign) {
   return homeDeposit => {
@@ -57,19 +58,48 @@ function compareTransferForeign(home) {
 }
 
 async function main() {
-  const { foreignDeposits, homeDeposits, homeWithdrawals, foreignWithdrawals, isExternalErc20 } = await eventsInfo()
+  const {
+    homeToForeignRequests,
+    homeToForeignConfirmations,
+    foreignToHomeConfirmations,
+    foreignToHomeRequests,
+    isExternalErc20,
+    bridgeMode
+  } = await eventsInfo()
 
-  const onlyInHomeDeposits = homeDeposits.filter(compareDepositsHome(foreignDeposits))
+  if (bridgeMode === BRIDGE_MODES.ARBITRARY_MESSAGE) {
-  const onlyInForeignDeposits = foreignDeposits.concat([]).filter(compareDepositsForeign(homeDeposits))
+    return {
+      home: {
+        deliveredMsgNotProcessedInForeign: homeToForeignRequests.filter(
+          deliveredMsgNotProcessed(homeToForeignConfirmations)
+        ),
+        processedMsgNotDeliveredInForeign: foreignToHomeConfirmations.filter(
+          processedMsgNotDelivered(foreignToHomeRequests)
+        )
+      },
+      foreign: {
+        deliveredMsgNotProcessedInHome: foreignToHomeRequests.filter(
+          deliveredMsgNotProcessed(foreignToHomeConfirmations)
+        ),
+        processedMsgNotDeliveredInHome: homeToForeignConfirmations.filter(
+          processedMsgNotDelivered(homeToForeignRequests)
+        )
+      },
+      lastChecked: Math.floor(Date.now() / 1000)
+    }
+  } else {
+    const onlyInHomeDeposits = homeToForeignRequests.filter(compareDepositsHome(homeToForeignConfirmations))
+    const onlyInForeignDeposits = homeToForeignConfirmations
+      .concat([])
+      .filter(compareDepositsForeign(homeToForeignRequests))
 
     const onlyInHomeWithdrawals = isExternalErc20
-    ? homeWithdrawals.filter(compareTransferHome(foreignWithdrawals))
+      ? foreignToHomeConfirmations.filter(compareTransferHome(foreignToHomeRequests))
-    : homeWithdrawals.filter(compareDepositsForeign(foreignWithdrawals))
+      : foreignToHomeConfirmations.filter(compareDepositsForeign(foreignToHomeRequests))
     const onlyInForeignWithdrawals = isExternalErc20
-    ? foreignWithdrawals.filter(compareTransferForeign(homeWithdrawals))
+      ? foreignToHomeRequests.filter(compareTransferForeign(foreignToHomeConfirmations))
-    : foreignWithdrawals.filter(compareDepositsHome(homeWithdrawals))
+      : foreignToHomeRequests.filter(compareDepositsHome(foreignToHomeConfirmations))
 
-  logger.debug('Done')
     return {
       onlyInHomeDeposits,
       onlyInForeignDeposits,
@@ -77,6 +107,7 @@ async function main() {
       onlyInForeignWithdrawals,
       lastChecked: Math.floor(Date.now() / 1000)
     }
+  }
 }
 
 module.exports = main

monitor/getBalances.js

@@ -112,6 +112,12 @@ async function main(bridgeMode) {
       balanceDiff: Number(Web3Utils.fromWei(diff)),
       lastChecked: Math.floor(Date.now() / 1000)
     }
+  } else if (bridgeMode === BRIDGE_MODES.ARBITRARY_MESSAGE) {
+    return {
+      home: {},
+      foreign: {},
+      lastChecked: Math.floor(Date.now() / 1000)
+    }
   } else {
     throw new Error(`Unrecognized bridge mode: '${bridgeMode}'`)
   }

monitor/getShortEventStats.js

@@ -1,19 +1,40 @@
 require('dotenv').config()
 const eventsInfo = require('./utils/events')
+const { BRIDGE_MODES } = require('../commons')
 
 async function main(bridgeMode) {
-  const { foreignDeposits, homeDeposits, homeWithdrawals, foreignWithdrawals } = await eventsInfo(bridgeMode)
+  const {
+    homeToForeignConfirmations,
+    homeToForeignRequests,
+    foreignToHomeConfirmations,
+    foreignToHomeRequests
+  } = await eventsInfo(bridgeMode)
 
+  if (bridgeMode === BRIDGE_MODES.ARBITRARY_MESSAGE) {
     return {
-    depositsDiff: homeDeposits.length - foreignDeposits.length,
+      fromHomeToForeignDiff: homeToForeignRequests.length - homeToForeignConfirmations.length,
-    withdrawalDiff: homeWithdrawals.length - foreignWithdrawals.length,
+      fromForeignToHomeDiff: foreignToHomeConfirmations.length - foreignToHomeRequests.length,
       home: {
-      deposits: homeDeposits.length,
+        toForeign: homeToForeignRequests.length,
-      withdrawals: homeWithdrawals.length
+        fromForeign: foreignToHomeConfirmations.length
       },
       foreign: {
-      deposits: foreignDeposits.length,
+        fromHome: homeToForeignConfirmations.length,
-      withdrawals: foreignWithdrawals.length
+        toHome: foreignToHomeRequests.length
+      }
+    }
+  } else {
+    return {
+      depositsDiff: homeToForeignRequests.length - homeToForeignConfirmations.length,
+      withdrawalDiff: foreignToHomeConfirmations.length - foreignToHomeRequests.length,
+      home: {
+        deposits: homeToForeignRequests.length,
+        withdrawals: foreignToHomeConfirmations.length
+      },
+      foreign: {
+        deposits: homeToForeignConfirmations.length,
+        withdrawals: foreignToHomeRequests.length
+      }
     }
   }
 }

monitor/utils/events.js

@@ -38,41 +38,45 @@ async function main(mode) {
   const homeBridge = new web3Home.eth.Contract(HOME_ABI, COMMON_HOME_BRIDGE_ADDRESS)
   const foreignBridge = new web3Foreign.eth.Contract(FOREIGN_ABI, COMMON_FOREIGN_BRIDGE_ADDRESS)
   const v1Bridge = bridgeMode === BRIDGE_MODES.NATIVE_TO_ERC_V1
+  let isExternalErc20
+  let erc20Contract
+  if (bridgeMode !== BRIDGE_MODES.ARBITRARY_MESSAGE) {
     const erc20MethodName = bridgeMode === BRIDGE_MODES.NATIVE_TO_ERC || v1Bridge ? 'erc677token' : 'erc20token'
     const erc20Address = await foreignBridge.methods[erc20MethodName]().call()
     const tokenType = await getTokenType(
       new web3Foreign.eth.Contract(ERC677_BRIDGE_TOKEN_ABI, erc20Address),
       COMMON_FOREIGN_BRIDGE_ADDRESS
     )
-  const isExternalErc20 = tokenType === ERC_TYPES.ERC20
+    isExternalErc20 = tokenType === ERC_TYPES.ERC20
-  const erc20Contract = new web3Foreign.eth.Contract(ERC20_ABI, erc20Address)
+    erc20Contract = new web3Foreign.eth.Contract(ERC20_ABI, erc20Address)
+  }
 
   logger.debug('getting last block numbers')
   const [homeBlockNumber, foreignBlockNumber] = await getBlockNumber(web3Home, web3Foreign)
 
   logger.debug("calling homeBridge.getPastEvents('UserRequestForSignature')")
-  const homeDeposits = await getPastEvents(homeBridge, {
+  const homeToForeignRequests = await getPastEvents(homeBridge, {
     event: v1Bridge ? 'Deposit' : 'UserRequestForSignature',
     fromBlock: MONITOR_HOME_START_BLOCK,
     toBlock: homeBlockNumber
   })
 
   logger.debug("calling foreignBridge.getPastEvents('RelayedMessage')")
-  const foreignDeposits = await getPastEvents(foreignBridge, {
+  const homeToForeignConfirmations = await getPastEvents(foreignBridge, {
     event: v1Bridge ? 'Deposit' : 'RelayedMessage',
     fromBlock: MONITOR_FOREIGN_START_BLOCK,
     toBlock: foreignBlockNumber
   })
 
   logger.debug("calling homeBridge.getPastEvents('AffirmationCompleted')")
-  const homeWithdrawals = await getPastEvents(homeBridge, {
+  const foreignToHomeConfirmations = await getPastEvents(homeBridge, {
     event: v1Bridge ? 'Withdraw' : 'AffirmationCompleted',
     fromBlock: MONITOR_HOME_START_BLOCK,
     toBlock: homeBlockNumber
   })
 
   logger.debug("calling foreignBridge.getPastEvents('UserRequestForAffirmation')")
-  const foreignWithdrawals = isExternalErc20
+  const foreignToHomeRequests = isExternalErc20
     ? await getPastEvents(erc20Contract, {
         event: 'Transfer',
         fromBlock: MONITOR_FOREIGN_START_BLOCK,
@@ -88,11 +92,12 @@ async function main(mode) {
       })
   logger.debug('Done')
   return {
-    homeDeposits,
+    homeToForeignRequests,
-    foreignDeposits,
+    homeToForeignConfirmations,
-    homeWithdrawals,
+    foreignToHomeConfirmations,
-    foreignWithdrawals,
+    foreignToHomeRequests,
-    isExternalErc20
+    isExternalErc20,
+    bridgeMode
   }
 }
 

monitor/utils/message.js

@@ -0,0 +1,47 @@
+const web3Utils = require('web3').utils
+const { addTxHashToData, parseAMBMessage } = require('../../commons')
+
+function deliveredMsgNotProcessed(processedList) {
+  return deliveredMsg => {
+    const msg = parseAMBMessage(
+      addTxHashToData({
+        encodedData: deliveredMsg.returnValues.encodedData,
+        transactionHash: deliveredMsg.transactionHash
+      })
+    )
+    return (
+      processedList.filter(processedMsg => {
+        return messageEqualsEvent(msg, processedMsg.returnValues)
+      }).length === 0
+    )
+  }
+}
+
+function processedMsgNotDelivered(deliveredList) {
+  return processedMsg => {
+    return (
+      deliveredList.filter(deliveredMsg => {
+        const msg = parseAMBMessage(
+          addTxHashToData({
+            encodedData: deliveredMsg.returnValues.encodedData,
+            transactionHash: deliveredMsg.transactionHash
+          })
+        )
+        return messageEqualsEvent(msg, processedMsg.returnValues)
+      }).length === 0
+    )
+  }
+}
+
+function messageEqualsEvent(parsedMsg, event) {
+  return (
+    web3Utils.toChecksumAddress(parsedMsg.sender) === event.sender &&
+    web3Utils.toChecksumAddress(parsedMsg.executor) === event.executor &&
+    parsedMsg.txHash === event.transactionHash
+  )
+}
+
+module.exports = {
+  deliveredMsgNotProcessed,
+  processedMsgNotDelivered
+}

oracle-e2e/test/amb.js

@@ -0,0 +1,102 @@
+const Web3 = require('web3')
+const assert = require('assert')
+const promiseRetry = require('promise-retry')
+const { user, homeRPC, foreignRPC, amb } = require('../../e2e-commons/constants.json')
+const { generateNewBlock } = require('../../e2e-commons/utils')
+const { BOX_ABI } = require('../../commons')
+
+const { toBN } = Web3.utils
+
+const homeWeb3 = new Web3(new Web3.providers.HttpProvider(homeRPC.URL))
+const foreignWeb3 = new Web3(new Web3.providers.HttpProvider(foreignRPC.URL))
+
+homeWeb3.eth.accounts.wallet.add(user.privateKey)
+foreignWeb3.eth.accounts.wallet.add(user.privateKey)
+
+const homeBox = new homeWeb3.eth.Contract(BOX_ABI, amb.homeBox)
+const foreignBox = new foreignWeb3.eth.Contract(BOX_ABI, amb.foreignBox)
+
+describe('arbitrary message bridging', () => {
+  describe('Home to Foreign', () => {
+    describe('Subsidized Mode', () => {
+      it('should bridge message', async () => {
+        const newValue = 3
+
+        const initialValue = await foreignBox.methods.value().call()
+        assert(!toBN(initialValue).eq(toBN(newValue)), 'initial value should be different from new value')
+
+        const setValueTx = await homeBox.methods
+          .setValueOnOtherNetwork(newValue, amb.home, amb.foreignBox)
+          .send({
+            from: user.address,
+            gas: '400000'
+          })
+          .catch(e => {
+            console.error(e)
+          })
+
+        // Send a trivial transaction to generate a new block since the watcher
+        // is configured to wait 1 confirmation block
+        await generateNewBlock(homeWeb3, user.address)
+
+        // The bridge should create a new transaction with a CollectedSignatures
+        // event so we generate another trivial transaction
+        await promiseRetry(
+          async retry => {
+            const lastBlockNumber = await homeWeb3.eth.getBlockNumber()
+            if (lastBlockNumber >= setValueTx.blockNumber + 2) {
+              await generateNewBlock(homeWeb3, user.address)
+            } else {
+              retry()
+            }
+          },
+          {
+            forever: true,
+            factor: 1,
+            minTimeout: 500
+          }
+        )
+
+        // check that value changed and balance decreased
+        await promiseRetry(async retry => {
+          const value = await foreignBox.methods.value().call()
+          if (!toBN(value).eq(toBN(newValue))) {
+            retry()
+          }
+        })
+      })
+    })
+  })
+  describe('Foreign to Home', () => {
+    describe('Subsidized Mode', () => {
+      it('should bridge message', async () => {
+        const newValue = 7
+
+        const initialValue = await homeBox.methods.value().call()
+        assert(!toBN(initialValue).eq(toBN(newValue)), 'initial value should be different from new value')
+
+        await foreignBox.methods
+          .setValueOnOtherNetwork(newValue, amb.foreign, amb.homeBox)
+          .send({
+            from: user.address,
+            gas: '400000'
+          })
+          .catch(e => {
+            console.error(e)
+          })
+
+        // Send a trivial transaction to generate a new block since the watcher
+        // is configured to wait 1 confirmation block
+        await generateNewBlock(foreignWeb3, user.address)
+
+        // check that value changed and balance decreased
+        await promiseRetry(async retry => {
+          const value = await homeBox.methods.value().call()
+          if (!toBN(value).eq(toBN(newValue))) {
+            retry()
+          }
+        })
+      })
+    })
+  })
+})

oracle/README.md

@@ -10,7 +10,7 @@ The Oracle is deployed on specified validator nodes (only nodes whose private ke
 
 ## Architecture
 
-### Native-to-ERC20
+### Native-to-ERC20 and Arbitrary-Message
 
 ![Native-to-ERC](Native-to-ERC.png)
 
@@ -27,7 +27,7 @@ There are three Watchers:
 - **Signature Request Watcher**: Listens to `UserRequestForSignature` events on the Home network.
 - **Collected Signatures Watcher**: Listens to `CollectedSignatures` events on the Home network.
 - **Affirmation Request Watcher**: Depends on the bridge mode. 
-   - `Native-to-ERC20`: Listens to `UserRequestForAffirmation` raised by the bridge contract.
+   - `Native-to-ERC20` and `Arbitrary-Message`: Listens to `UserRequestForAffirmation` raised by the bridge contract.
    - `ERC20-to-ERC20` and `ERC20-to-Native`: Listens to `Transfer` events raised by the token contract.
 
 ### Sender

oracle/config/base.config.js

@@ -8,7 +8,9 @@ const {
   HOME_ERC_TO_ERC_ABI,
   FOREIGN_ERC_TO_ERC_ABI,
   HOME_ERC_TO_NATIVE_ABI,
-  FOREIGN_ERC_TO_NATIVE_ABI
+  FOREIGN_ERC_TO_NATIVE_ABI,
+  HOME_AMB_ABI,
+  FOREIGN_AMB_ABI
 } = require('../../commons')
 const { web3Home, web3Foreign } = require('../src/services/web3')
 const { privateKeyToAddress } = require('../src/utils/utils')
@@ -35,6 +37,11 @@ switch (process.env.ORACLE_BRIDGE_MODE) {
     foreignAbi = FOREIGN_ERC_TO_NATIVE_ABI
     id = 'erc-native'
     break
+  case BRIDGE_MODES.ARBITRARY_MESSAGE:
+    homeAbi = HOME_AMB_ABI
+    foreignAbi = FOREIGN_AMB_ABI
+    id = 'amb'
+    break
   default:
     if (process.env.NODE_ENV !== 'test') {
       throw new Error(`Bridge Mode: ${process.env.ORACLE_BRIDGE_MODE} not supported.`)

oracle/src/events/processAMBAffirmationRequests/estimateGas.js

@@ -0,0 +1,51 @@
+const { HttpListProviderError } = require('http-list-provider')
+const { AlreadyProcessedError, AlreadySignedError, InvalidValidatorError } = require('../../utils/errors')
+const logger = require('../../services/logger').child({
+  module: 'processAffirmationRequests:estimateGas'
+})
+
+async function estimateGas({ web3, homeBridge, validatorContract, message, address }) {
+  try {
+    const gasEstimate = await homeBridge.methods.executeAffirmation(message).estimateGas({
+      from: address
+    })
+
+    return gasEstimate
+  } catch (e) {
+    if (e instanceof HttpListProviderError) {
+      throw e
+    }
+
+    const messageHash = web3.utils.soliditySha3(message)
+    const senderHash = web3.utils.soliditySha3(address, messageHash)
+
+    // Check if minimum number of validations was already reached
+    logger.debug('Check if minimum number of validations was already reached')
+    const numAffirmationsSigned = await homeBridge.methods.numAffirmationsSigned(messageHash).call()
+    const alreadyProcessed = await homeBridge.methods.isAlreadyProcessed(numAffirmationsSigned).call()
+
+    if (alreadyProcessed) {
+      throw new AlreadyProcessedError(e.message)
+    }
+
+    // Check if the message was already signed by this validator
+    logger.debug('Check if the message was already signed')
+    const alreadySigned = await homeBridge.methods.affirmationsSigned(senderHash).call()
+
+    if (alreadySigned) {
+      throw new AlreadySignedError(e.message)
+    }
+
+    // Check if address is validator
+    logger.debug('Check if address is a validator')
+    const isValidator = await validatorContract.methods.isValidator(address).call()
+
+    if (!isValidator) {
+      throw new InvalidValidatorError(`${address} is not a validator`)
+    }
+
+    throw new Error('Unknown error while processing message')
+  }
+}
+
+module.exports = estimateGas

oracle/src/events/processAMBAffirmationRequests/index.js

@@ -0,0 +1,95 @@
+require('dotenv').config()
+const { HttpListProviderError } = require('http-list-provider')
+const promiseLimit = require('promise-limit')
+const rootLogger = require('../../services/logger')
+const { web3Home } = require('../../services/web3')
+const bridgeValidatorsABI = require('../../../../contracts/build/contracts/BridgeValidators').abi
+const { EXIT_CODES, MAX_CONCURRENT_EVENTS } = require('../../utils/constants')
+const estimateGas = require('./estimateGas')
+const { addTxHashToData, parseAMBMessage } = require('../../../../commons')
+const { AlreadyProcessedError, AlreadySignedError, InvalidValidatorError } = require('../../utils/errors')
+
+const limit = promiseLimit(MAX_CONCURRENT_EVENTS)
+
+let validatorContract = null
+
+function processAffirmationRequestsBuilder(config) {
+  const homeBridge = new web3Home.eth.Contract(config.homeBridgeAbi, config.homeBridgeAddress)
+
+  return async function processAffirmationRequests(affirmationRequests) {
+    const txToSend = []
+
+    if (validatorContract === null) {
+      rootLogger.debug('Getting validator contract address')
+      const validatorContractAddress = await homeBridge.methods.validatorContract().call()
+      rootLogger.debug({ validatorContractAddress }, 'Validator contract address obtained')
+
+      validatorContract = new web3Home.eth.Contract(bridgeValidatorsABI, validatorContractAddress)
+    }
+
+    rootLogger.debug(`Processing ${affirmationRequests.length} AffirmationRequest events`)
+    const callbacks = affirmationRequests
+      .map(affirmationRequest => async () => {
+        const { encodedData } = affirmationRequest.returnValues
+
+        const logger = rootLogger.child({
+          eventTransactionHash: affirmationRequest.transactionHash
+        })
+
+        const message = addTxHashToData({
+          encodedData,
+          transactionHash: affirmationRequest.transactionHash
+        })
+
+        const { sender, executor } = parseAMBMessage(message)
+
+        logger.info({ sender, executor }, `Processing affirmationRequest ${affirmationRequest.transactionHash}`)
+
+        let gasEstimate
+        try {
+          logger.debug('Estimate gas')
+          gasEstimate = await estimateGas({
+            web3: web3Home,
+            homeBridge,
+            validatorContract,
+            message,
+            address: config.validatorAddress
+          })
+          logger.debug({ gasEstimate }, 'Gas estimated')
+        } catch (e) {
+          if (e instanceof HttpListProviderError) {
+            throw new Error('RPC Connection Error: submitSignature Gas Estimate cannot be obtained.')
+          } else if (e instanceof InvalidValidatorError) {
+            logger.fatal({ address: config.validatorAddress }, 'Invalid validator')
+            process.exit(EXIT_CODES.INCOMPATIBILITY)
+          } else if (e instanceof AlreadySignedError) {
+            logger.info(`Already signed affirmationRequest ${affirmationRequest.transactionHash}`)
+            return
+          } else if (e instanceof AlreadyProcessedError) {
+            logger.info(
+              `affirmationRequest ${affirmationRequest.transactionHash} was already processed by other validators`
+            )
+            return
+          } else {
+            logger.error(e, 'Unknown error while processing transaction')
+            throw e
+          }
+        }
+
+        const data = await homeBridge.methods.executeAffirmation(message).encodeABI()
+
+        txToSend.push({
+          data,
+          gasEstimate,
+          transactionReference: affirmationRequest.transactionHash,
+          to: config.homeBridgeAddress
+        })
+      })
+      .map(promise => limit(promise))
+
+    await Promise.all(callbacks)
+    return txToSend
+  }
+}
+
+module.exports = processAffirmationRequestsBuilder

oracle/src/events/processAMBCollectedSignatures/estimateGas.js

@@ -0,0 +1,62 @@
+const Web3 = require('web3')
+const { HttpListProviderError } = require('http-list-provider')
+const { AlreadyProcessedError, IncompatibleContractError, InvalidValidatorError } = require('../../utils/errors')
+const logger = require('../../services/logger').child({
+  module: 'processCollectedSignatures:estimateGas'
+})
+
+const web3 = new Web3()
+const { toBN } = Web3.utils
+
+async function estimateGas({
+  foreignBridge,
+  validatorContract,
+  message,
+  numberOfCollectedSignatures,
+  v,
+  r,
+  s,
+  signatures,
+  txHash,
+  address
+}) {
+  try {
+    const gasEstimate = await foreignBridge.methods.executeSignatures(message, signatures).estimateGas({
+      from: address
+    })
+    return gasEstimate
+  } catch (e) {
+    if (e instanceof HttpListProviderError) {
+      throw e
+    }
+
+    // check if the message was already processed
+    logger.debug('Check if the message was already processed')
+    const alreadyProcessed = await foreignBridge.methods.relayedMessages(txHash).call()
+    if (alreadyProcessed) {
+      throw new AlreadyProcessedError()
+    }
+
+    // check if the number of signatures is enough
+    logger.debug('Check if number of signatures is enough')
+    const requiredSignatures = await validatorContract.methods.requiredSignatures().call()
+    if (toBN(requiredSignatures).gt(toBN(numberOfCollectedSignatures))) {
+      throw new IncompatibleContractError('The number of collected signatures does not match')
+    }
+
+    // check if all the signatures were made by validators
+    for (let i = 0; i < v.length; i++) {
+      const address = web3.eth.accounts.recover(message, web3.utils.toHex(v[i]), r[i], s[i])
+      logger.debug({ address }, 'Check that signature is from a validator')
+      const isValidator = await validatorContract.methods.isValidator(address).call()
+
+      if (!isValidator) {
+        throw new InvalidValidatorError(`Message signed by ${address} that is not a validator`)
+      }
+    }
+
+    throw new Error('Unknown error while processing message')
+  }
+}
+
+module.exports = estimateGas

oracle/src/events/processAMBCollectedSignatures/index.js

@@ -0,0 +1,118 @@
+require('dotenv').config()
+const promiseLimit = require('promise-limit')
+const { HttpListProviderError } = require('http-list-provider')
+const bridgeValidatorsABI = require('../../../../contracts/build/contracts/BridgeValidators').abi
+const rootLogger = require('../../services/logger')
+const { web3Home, web3Foreign } = require('../../services/web3')
+const { signatureToVRS, signatureToVRSAMB, packSignatures } = require('../../utils/message')
+const { parseAMBMessage } = require('../../../../commons')
+const estimateGas = require('./estimateGas')
+const { AlreadyProcessedError, IncompatibleContractError, InvalidValidatorError } = require('../../utils/errors')
+const { MAX_CONCURRENT_EVENTS } = require('../../utils/constants')
+
+const limit = promiseLimit(MAX_CONCURRENT_EVENTS)
+
+let validatorContract = null
+
+function processCollectedSignaturesBuilder(config) {
+  const homeBridge = new web3Home.eth.Contract(config.homeBridgeAbi, config.homeBridgeAddress)
+
+  const foreignBridge = new web3Foreign.eth.Contract(config.foreignBridgeAbi, config.foreignBridgeAddress)
+
+  return async function processCollectedSignatures(signatures) {
+    const txToSend = []
+
+    if (validatorContract === null) {
+      rootLogger.debug('Getting validator contract address')
+      const validatorContractAddress = await foreignBridge.methods.validatorContract().call()
+      rootLogger.debug({ validatorContractAddress }, 'Validator contract address obtained')
+
+      validatorContract = new web3Foreign.eth.Contract(bridgeValidatorsABI, validatorContractAddress)
+    }
+
+    rootLogger.debug(`Processing ${signatures.length} CollectedSignatures events`)
+    const callbacks = signatures
+      .map(colSignature => async () => {
+        const { authorityResponsibleForRelay, messageHash, NumberOfCollectedSignatures } = colSignature.returnValues
+
+        const logger = rootLogger.child({
+          eventTransactionHash: colSignature.transactionHash
+        })
+
+        if (authorityResponsibleForRelay !== web3Home.utils.toChecksumAddress(config.validatorAddress)) {
+          logger.info(`Validator not responsible for relaying CollectedSignatures ${colSignature.transactionHash}`)
+          return
+        }
+
+        logger.info(`Processing CollectedSignatures ${colSignature.transactionHash}`)
+        const message = await homeBridge.methods.message(messageHash).call()
+
+        const requiredSignatures = new Array(NumberOfCollectedSignatures).fill(0)
+
+        const signaturesArray = []
+        const [v, r, s] = [[], [], []]
+        logger.debug('Getting message signatures')
+        const signaturePromises = requiredSignatures.map(async (el, index) => {
+          logger.debug({ index }, 'Getting message signature')
+          const signature = await homeBridge.methods.signature(messageHash, index).call()
+          const vrs = signatureToVRS(signature)
+          v.push(vrs.v)
+          r.push(vrs.r)
+          s.push(vrs.s)
+          const recover = signatureToVRSAMB(signature)
+          signaturesArray.push(recover)
+        })
+
+        await Promise.all(signaturePromises)
+        const signatures = packSignatures(signaturesArray)
+
+        const { txHash } = parseAMBMessage(message)
+
+        let gasEstimate
+        try {
+          logger.debug('Estimate gas')
+          gasEstimate = await estimateGas({
+            foreignBridge,
+            validatorContract,
+            v,
+            r,
+            s,
+            signatures,
+            message,
+            numberOfCollectedSignatures: NumberOfCollectedSignatures,
+            txHash,
+            address: config.validatorAddress
+          })
+          logger.debug({ gasEstimate }, 'Gas estimated')
+        } catch (e) {
+          if (e instanceof HttpListProviderError) {
+            throw new Error('RPC Connection Error: submitSignature Gas Estimate cannot be obtained.')
+          } else if (e instanceof AlreadyProcessedError) {
+            logger.info(`Already processed CollectedSignatures ${colSignature.transactionHash}`)
+            return
+          } else if (e instanceof IncompatibleContractError || e instanceof InvalidValidatorError) {
+            logger.error(`The message couldn't be processed; skipping: ${e.message}`)
+            return
+          } else {
+            logger.error(e, 'Unknown error while processing transaction')
+            throw e
+          }
+        }
+        const data = await foreignBridge.methods.executeSignatures(message, signatures).encodeABI()
+
+        txToSend.push({
+          data,
+          gasEstimate,
+          transactionReference: colSignature.transactionHash,
+          to: config.foreignBridgeAddress
+        })
+      })
+      .map(promise => limit(promise))
+
+    await Promise.all(callbacks)
+
+    return txToSend
+  }
+}
+
+module.exports = processCollectedSignaturesBuilder

oracle/src/events/processAMBSignatureRequests/index.js

@@ -0,0 +1,99 @@
+require('dotenv').config()
+const promiseLimit = require('promise-limit')
+const { HttpListProviderError } = require('http-list-provider')
+const bridgeValidatorsABI = require('../../../../contracts/build/contracts/BridgeValidators').abi
+const rootLogger = require('../../services/logger')
+const { web3Home } = require('../../services/web3')
+const { addTxHashToData, parseAMBMessage } = require('../../../../commons')
+const estimateGas = require('../processSignatureRequests/estimateGas')
+const { AlreadyProcessedError, AlreadySignedError, InvalidValidatorError } = require('../../utils/errors')
+const { EXIT_CODES, MAX_CONCURRENT_EVENTS } = require('../../utils/constants')
+
+const { ORACLE_VALIDATOR_ADDRESS_PRIVATE_KEY } = process.env
+
+const limit = promiseLimit(MAX_CONCURRENT_EVENTS)
+
+let validatorContract = null
+
+function processSignatureRequestsBuilder(config) {
+  const homeBridge = new web3Home.eth.Contract(config.homeBridgeAbi, config.homeBridgeAddress)
+
+  return async function processSignatureRequests(signatureRequests) {
+    const txToSend = []
+
+    if (validatorContract === null) {
+      rootLogger.debug('Getting validator contract address')
+      const validatorContractAddress = await homeBridge.methods.validatorContract().call()
+      rootLogger.debug({ validatorContractAddress }, 'Validator contract address obtained')
+
+      validatorContract = new web3Home.eth.Contract(bridgeValidatorsABI, validatorContractAddress)
+    }
+
+    rootLogger.debug(`Processing ${signatureRequests.length} SignatureRequest events`)
+    const callbacks = signatureRequests
+      .map(signatureRequest => async () => {
+        const { encodedData } = signatureRequest.returnValues
+
+        const logger = rootLogger.child({
+          eventTransactionHash: signatureRequest.transactionHash
+        })
+
+        const message = addTxHashToData({
+          encodedData,
+          transactionHash: signatureRequest.transactionHash
+        })
+
+        const { sender, executor } = parseAMBMessage(message)
+        logger.info({ sender, executor }, `Processing signatureRequest ${signatureRequest.transactionHash}`)
+
+        const signature = web3Home.eth.accounts.sign(message, `0x${ORACLE_VALIDATOR_ADDRESS_PRIVATE_KEY}`)
+
+        let gasEstimate
+        try {
+          logger.debug('Estimate gas')
+          gasEstimate = await estimateGas({
+            web3: web3Home,
+            homeBridge,
+            validatorContract,
+            signature: signature.signature,
+            message,
+            address: config.validatorAddress
+          })
+          logger.debug({ gasEstimate }, 'Gas estimated')
+        } catch (e) {
+          if (e instanceof HttpListProviderError) {
+            throw new Error('RPC Connection Error: submitSignature Gas Estimate cannot be obtained.')
+          } else if (e instanceof InvalidValidatorError) {
+            logger.fatal({ address: config.validatorAddress }, 'Invalid validator')
+            process.exit(EXIT_CODES.INCOMPATIBILITY)
+          } else if (e instanceof AlreadySignedError) {
+            logger.info(`Already signed signatureRequest ${signatureRequest.transactionHash}`)
+            return
+          } else if (e instanceof AlreadyProcessedError) {
+            logger.info(
+              `signatureRequest ${signatureRequest.transactionHash} was already processed by other validators`
+            )
+            return
+          } else {
+            logger.error(e, 'Unknown error while processing transaction')
+            throw e
+          }
+        }
+
+        const data = await homeBridge.methods.submitSignature(signature.signature, message).encodeABI()
+
+        txToSend.push({
+          data,
+          gasEstimate,
+          transactionReference: signatureRequest.transactionHash,
+          to: config.homeBridgeAddress
+        })
+      })
+      .map(promise => limit(promise))
+
+    await Promise.all(callbacks)
+    return txToSend
+  }
+}
+
+module.exports = processSignatureRequestsBuilder

oracle/src/events/processAffirmationRequests/index.js

@@ -28,8 +28,8 @@ function processAffirmationRequestsBuilder(config) {
     }
 
     rootLogger.debug(`Processing ${affirmationRequests.length} AffirmationRequest events`)
-    const callbacks = affirmationRequests.map(affirmationRequest =>
+    const callbacks = affirmationRequests
-      limit(async () => {
+      .map(affirmationRequest => async () => {
         const { recipient, value } = affirmationRequest.returnValues
 
         const logger = rootLogger.child({
@@ -82,7 +82,7 @@ function processAffirmationRequestsBuilder(config) {
           to: config.homeBridgeAddress
         })
       })
-    )
+      .map(promise => limit(promise))
 
     await Promise.all(callbacks)
     return txToSend

oracle/src/events/processCollectedSignatures/index.js

@@ -30,21 +30,23 @@ function processCollectedSignaturesBuilder(config) {
     }
 
     rootLogger.debug(`Processing ${signatures.length} CollectedSignatures events`)
-    const callbacks = signatures.map(colSignature =>
+    const callbacks = signatures
-      limit(async () => {
+      .map(colSignature => async () => {
         const { authorityResponsibleForRelay, messageHash, NumberOfCollectedSignatures } = colSignature.returnValues
 
         const logger = rootLogger.child({
           eventTransactionHash: colSignature.transactionHash
         })
 
-        if (authorityResponsibleForRelay === web3Home.utils.toChecksumAddress(config.validatorAddress)) {
+        if (authorityResponsibleForRelay !== web3Home.utils.toChecksumAddress(config.validatorAddress)) {
+          logger.info(`Validator not responsible for relaying CollectedSignatures ${colSignature.transactionHash}`)
+          return
+        }
+
         logger.info(`Processing CollectedSignatures ${colSignature.transactionHash}`)
         const message = await homeBridge.methods.message(messageHash).call()
 
-          const requiredSignatures = []
+        const requiredSignatures = new Array(NumberOfCollectedSignatures).fill(0)
-          requiredSignatures.length = NumberOfCollectedSignatures
-          requiredSignatures.fill(0)
 
         const [v, r, s] = [[], [], []]
         logger.debug('Getting message signatures')
@@ -93,11 +95,8 @@ function processCollectedSignaturesBuilder(config) {
           transactionReference: colSignature.transactionHash,
           to: config.foreignBridgeAddress
         })
-        } else {
-          logger.info(`Validator not responsible for relaying CollectedSignatures ${colSignature.transactionHash}`)
-        }
       })
-    )
+      .map(promise => limit(promise))
 
     await Promise.all(callbacks)
 

oracle/src/events/processSignatureRequests/index.js

@@ -35,8 +35,8 @@ function processSignatureRequestsBuilder(config) {
     }
 
     rootLogger.debug(`Processing ${signatureRequests.length} SignatureRequest events`)
-    const callbacks = signatureRequests.map(signatureRequest =>
+    const callbacks = signatureRequests
-      limit(async () => {
+      .map(signatureRequest => async () => {
         const { recipient, value } = signatureRequest.returnValues
 
         const logger = rootLogger.child({
@@ -98,7 +98,7 @@ function processSignatureRequestsBuilder(config) {
           to: config.homeBridgeAddress
         })
       })
-    )
+      .map(promise => limit(promise))
 
     await Promise.all(callbacks)
     return txToSend

oracle/src/events/processTransfers/index.js

@@ -27,8 +27,8 @@ function processTransfersBuilder(config) {
     }
 
     rootLogger.debug(`Processing ${transfers.length} Transfer events`)
-    const callbacks = transfers.map(transfer =>
+    const callbacks = transfers
-      limit(async () => {
+      .map(transfer => async () => {
         const { from, value } = transfer.returnValues
 
         const logger = rootLogger.child({
@@ -79,7 +79,7 @@ function processTransfersBuilder(config) {
           to: config.homeBridgeAddress
         })
       })
-    )
+      .map(promise => limit(promise))
 
     await Promise.all(callbacks)
     return txToSend

oracle/src/utils/message.js

@@ -1,10 +1,6 @@
 const assert = require('assert')
 const Web3Utils = require('web3-utils')
-
+const { strip0x } = require('../../../commons')
-// strips leading "0x" if present
-function strip0x(input) {
-  return input.replace(/^0x/, '')
-}
 
 function createMessage({ recipient, value, transactionHash, bridgeAddress, expectedMessageLength }) {
   recipient = strip0x(recipient)
@@ -63,8 +59,32 @@ function signatureToVRS(signature) {
   return { v, r, s }
 }
 
+function signatureToVRSAMB(rawSignature) {
+  const signature = strip0x(rawSignature)
+  const v = signature.substr(64 * 2)
+  const r = signature.substr(0, 32 * 2)
+  const s = signature.substr(32 * 2, 32 * 2)
+  return { v, r, s }
+}
+
+function packSignatures(array) {
+  const length = strip0x(Web3Utils.toHex(array.length))
+  const msgLength = length.length === 1 ? `0${length}` : length
+  let v = ''
+  let r = ''
+  let s = ''
+  array.forEach(e => {
+    v = v.concat(e.v)
+    r = r.concat(e.r)
+    s = s.concat(e.s)
+  })
+  return `0x${msgLength}${v}${r}${s}`
+}
+
 module.exports = {
   createMessage,
   parseMessage,
-  signatureToVRS
+  signatureToVRS,
+  signatureToVRSAMB,
+  packSignatures
 }

oracle/src/watcher.js

@@ -21,6 +21,9 @@ const processSignatureRequests = require('./events/processSignatureRequests')(co
 const processCollectedSignatures = require('./events/processCollectedSignatures')(config)
 const processAffirmationRequests = require('./events/processAffirmationRequests')(config)
 const processTransfers = require('./events/processTransfers')(config)
+const processAMBSignatureRequests = require('./events/processAMBSignatureRequests')(config)
+const processAMBCollectedSignatures = require('./events/processAMBCollectedSignatures')(config)
+const processAMBAffirmationRequests = require('./events/processAMBAffirmationRequests')(config)
 
 const ZERO = toBN(0)
 const ONE = toBN(1)
@@ -97,6 +100,12 @@ function processEvents(events) {
     case 'erc-erc-affirmation-request':
     case 'erc-native-affirmation-request':
       return processTransfers(events)
+    case 'amb-signature-request':
+      return processAMBSignatureRequests(events)
+    case 'amb-collected-signatures':
+      return processAMBCollectedSignatures(events)
+    case 'amb-affirmation-request':
+      return processAMBAffirmationRequests(events)
     default:
       return []
   }