Merge pull request #3773 from ethcore/ng-enhanced-multisig

Lower gas usage for creating a Multisig Wallet

js/src/contracts/code/index.js

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-import wallet from './wallet';
+import { wallet } from './wallet';
 
 export {
   wallet

js/src/contracts/snippets/enhanced-wallet.sol

@@ -0,0 +1,460 @@
+//sol Wallet
+// Multi-sig, daily-limited account proxy/wallet.
+// @authors:
+// Gav Wood <g@ethdev.com>
+// inheritable "property" contract that enables methods to be protected by requiring the acquiescence of either a
+// single, or, crucially, each of a number of, designated owners.
+// usage:
+// use modifiers onlyowner (just own owned) or onlymanyowners(hash), whereby the same hash must be provided by
+// some number (specified in constructor) of the set of owners (specified in the constructor, modifiable) before the
+// interior is executed.
+pragma solidity ^0.4.6;
+
+contract multisig {
+    // EVENTS
+
+    // this contract can accept a confirmation, in which case
+    // we record owner and operation (hash) alongside it.
+    event Confirmation(address owner, bytes32 operation);
+    event Revoke(address owner, bytes32 operation);
+
+    // some others are in the case of an owner changing.
+    event OwnerChanged(address oldOwner, address newOwner);
+    event OwnerAdded(address newOwner);
+    event OwnerRemoved(address oldOwner);
+
+    // the last one is emitted if the required signatures change
+    event RequirementChanged(uint newRequirement);
+
+    // Funds has arrived into the wallet (record how much).
+    event Deposit(address _from, uint value);
+    // Single transaction going out of the wallet (record who signed for it, how much, and to whom it's going).
+    event SingleTransact(address owner, uint value, address to, bytes data);
+    // Multi-sig transaction going out of the wallet (record who signed for it last, the operation hash, how much, and to whom it's going).
+    event MultiTransact(address owner, bytes32 operation, uint value, address to, bytes data);
+    // Confirmation still needed for a transaction.
+    event ConfirmationNeeded(bytes32 operation, address initiator, uint value, address to, bytes data);
+}
+
+contract multisigAbi is multisig {
+    function isOwner(address _addr) returns (bool);
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool);
+
+    function confirm(bytes32 _h) returns(bool);
+
+    // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
+    function setDailyLimit(uint _newLimit);
+
+    function addOwner(address _owner);
+
+    function removeOwner(address _owner);
+
+    function changeRequirement(uint _newRequired);
+
+    // Revokes a prior confirmation of the given operation
+    function revoke(bytes32 _operation);
+
+    function changeOwner(address _from, address _to);
+
+    function execute(address _to, uint _value, bytes _data) returns(bool);
+}
+
+contract WalletLibrary is multisig {
+    // TYPES
+
+    // struct for the status of a pending operation.
+    struct PendingState {
+        uint yetNeeded;
+        uint ownersDone;
+        uint index;
+    }
+
+    // Transaction structure to remember details of transaction lest it need be saved for a later call.
+    struct Transaction {
+        address to;
+        uint value;
+        bytes data;
+    }
+
+    /******************************
+     ***** MULTI OWNED SECTION ****
+     ******************************/
+
+    // MODIFIERS
+
+    // simple single-sig function modifier.
+    modifier onlyowner {
+        if (isOwner(msg.sender))
+            _;
+    }
+    // multi-sig function modifier: the operation must have an intrinsic hash in order
+    // that later attempts can be realised as the same underlying operation and
+    // thus count as confirmations.
+    modifier onlymanyowners(bytes32 _operation) {
+        if (confirmAndCheck(_operation))
+            _;
+    }
+
+    // METHODS
+
+    // constructor is given number of sigs required to do protected "onlymanyowners" transactions
+    // as well as the selection of addresses capable of confirming them.
+    function initMultiowned(address[] _owners, uint _required) {
+        m_numOwners = _owners.length + 1;
+        m_owners[1] = uint(msg.sender);
+        m_ownerIndex[uint(msg.sender)] = 1;
+        m_required = _required;
+
+        for (uint i = 0; i < _owners.length; ++i)
+        {
+            m_owners[2 + i] = uint(_owners[i]);
+            m_ownerIndex[uint(_owners[i])] = 2 + i;
+        }
+    }
+
+    // Revokes a prior confirmation of the given operation
+    function revoke(bytes32 _operation) {
+        uint ownerIndex = m_ownerIndex[uint(msg.sender)];
+        // make sure they're an owner
+        if (ownerIndex == 0) return;
+        uint ownerIndexBit = 2**ownerIndex;
+        var pending = m_pending[_operation];
+        if (pending.ownersDone & ownerIndexBit > 0) {
+            pending.yetNeeded++;
+            pending.ownersDone -= ownerIndexBit;
+            Revoke(msg.sender, _operation);
+        }
+    }
+
+    // Replaces an owner `_from` with another `_to`.
+    function changeOwner(address _from, address _to) onlymanyowners(sha3(msg.data)) {
+        if (isOwner(_to)) return;
+        uint ownerIndex = m_ownerIndex[uint(_from)];
+        if (ownerIndex == 0) return;
+
+        clearPending();
+        m_owners[ownerIndex] = uint(_to);
+        m_ownerIndex[uint(_from)] = 0;
+        m_ownerIndex[uint(_to)] = ownerIndex;
+        OwnerChanged(_from, _to);
+    }
+
+    function addOwner(address _owner) onlymanyowners(sha3(msg.data)) {
+        if (isOwner(_owner)) return;
+
+        clearPending();
+        if (m_numOwners >= c_maxOwners)
+            reorganizeOwners();
+        if (m_numOwners >= c_maxOwners)
+            return;
+        m_numOwners++;
+        m_owners[m_numOwners] = uint(_owner);
+        m_ownerIndex[uint(_owner)] = m_numOwners;
+        OwnerAdded(_owner);
+    }
+
+    function removeOwner(address _owner) onlymanyowners(sha3(msg.data)) {
+        uint ownerIndex = m_ownerIndex[uint(_owner)];
+        if (ownerIndex == 0) return;
+        if (m_required > m_numOwners - 1) return;
+
+        m_owners[ownerIndex] = 0;
+        m_ownerIndex[uint(_owner)] = 0;
+        clearPending();
+        reorganizeOwners(); //make sure m_numOwner is equal to the number of owners and always points to the optimal free slot
+        OwnerRemoved(_owner);
+    }
+
+    function changeRequirement(uint _newRequired) onlymanyowners(sha3(msg.data)) {
+        if (_newRequired > m_numOwners) return;
+        m_required = _newRequired;
+        clearPending();
+        RequirementChanged(_newRequired);
+    }
+
+    function isOwner(address _addr) returns (bool) {
+        return m_ownerIndex[uint(_addr)] > 0;
+    }
+
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool) {
+        var pending = m_pending[_operation];
+        uint ownerIndex = m_ownerIndex[uint(_owner)];
+
+        // make sure they're an owner
+        if (ownerIndex == 0) return false;
+
+        // determine the bit to set for this owner.
+        uint ownerIndexBit = 2**ownerIndex;
+        return !(pending.ownersDone & ownerIndexBit == 0);
+    }
+
+    // INTERNAL METHODS
+
+    function confirmAndCheck(bytes32 _operation) internal returns (bool) {
+        // determine what index the present sender is:
+        uint ownerIndex = m_ownerIndex[uint(msg.sender)];
+        // make sure they're an owner
+        if (ownerIndex == 0) return;
+
+        var pending = m_pending[_operation];
+        // if we're not yet working on this operation, switch over and reset the confirmation status.
+        if (pending.yetNeeded == 0) {
+            // reset count of confirmations needed.
+            pending.yetNeeded = m_required;
+            // reset which owners have confirmed (none) - set our bitmap to 0.
+            pending.ownersDone = 0;
+            pending.index = m_pendingIndex.length++;
+            m_pendingIndex[pending.index] = _operation;
+        }
+        // determine the bit to set for this owner.
+        uint ownerIndexBit = 2**ownerIndex;
+        // make sure we (the message sender) haven't confirmed this operation previously.
+        if (pending.ownersDone & ownerIndexBit == 0) {
+            Confirmation(msg.sender, _operation);
+            // ok - check if count is enough to go ahead.
+            if (pending.yetNeeded <= 1) {
+                // enough confirmations: reset and run interior.
+                delete m_pendingIndex[m_pending[_operation].index];
+                delete m_pending[_operation];
+                return true;
+            }
+            else
+            {
+                // not enough: record that this owner in particular confirmed.
+                pending.yetNeeded--;
+                pending.ownersDone |= ownerIndexBit;
+            }
+        }
+    }
+
+    function reorganizeOwners() private {
+        uint free = 1;
+        while (free < m_numOwners)
+        {
+            while (free < m_numOwners && m_owners[free] != 0) free++;
+            while (m_numOwners > 1 && m_owners[m_numOwners] == 0) m_numOwners--;
+            if (free < m_numOwners && m_owners[m_numOwners] != 0 && m_owners[free] == 0)
+            {
+                m_owners[free] = m_owners[m_numOwners];
+                m_ownerIndex[m_owners[free]] = free;
+                m_owners[m_numOwners] = 0;
+            }
+        }
+    }
+
+    function clearPending() internal {
+        uint length = m_pendingIndex.length;
+        for (uint i = 0; i < length; ++i)
+            if (m_pendingIndex[i] != 0)
+                delete m_pending[m_pendingIndex[i]];
+        delete m_pendingIndex;
+    }
+
+
+    /******************************
+     ****** DAY LIMIT SECTION *****
+     ******************************/
+
+    // MODIFIERS
+
+    // simple modifier for daily limit.
+    modifier limitedDaily(uint _value) {
+        if (underLimit(_value))
+            _;
+    }
+
+    // METHODS
+
+    // constructor - stores initial daily limit and records the present day's index.
+    function initDaylimit(uint _limit) {
+        m_dailyLimit = _limit;
+        m_lastDay = today();
+    }
+    // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
+    function setDailyLimit(uint _newLimit) onlymanyowners(sha3(msg.data)) {
+        m_dailyLimit = _newLimit;
+    }
+    // resets the amount already spent today. needs many of the owners to confirm.
+    function resetSpentToday() onlymanyowners(sha3(msg.data)) {
+        m_spentToday = 0;
+    }
+
+    // INTERNAL METHODS
+
+    // checks to see if there is at least `_value` left from the daily limit today. if there is, subtracts it and
+    // returns true. otherwise just returns false.
+    function underLimit(uint _value) internal onlyowner returns (bool) {
+        // reset the spend limit if we're on a different day to last time.
+        if (today() > m_lastDay) {
+            m_spentToday = 0;
+            m_lastDay = today();
+        }
+        // check to see if there's enough left - if so, subtract and return true.
+        // overflow protection                    // dailyLimit check
+        if (m_spentToday + _value >= m_spentToday && m_spentToday + _value <= m_dailyLimit) {
+            m_spentToday += _value;
+            return true;
+        }
+        return false;
+    }
+
+    // determines today's index.
+    function today() private constant returns (uint) { return now / 1 days; }
+
+
+    /******************************
+     ********* WALLET SECTION *****
+     ******************************/
+
+    // METHODS
+
+    // constructor - just pass on the owner array to the multiowned and
+    // the limit to daylimit
+    function initWallet(address[] _owners, uint _required, uint _daylimit) {
+        initMultiowned(_owners, _required);
+        initDaylimit(_daylimit) ;
+    }
+
+    // kills the contract sending everything to `_to`.
+    function kill(address _to) onlymanyowners(sha3(msg.data)) {
+        suicide(_to);
+    }
+
+    // Outside-visible transact entry point. Executes transaction immediately if below daily spend limit.
+    // If not, goes into multisig process. We provide a hash on return to allow the sender to provide
+    // shortcuts for the other confirmations (allowing them to avoid replicating the _to, _value
+    // and _data arguments). They still get the option of using them if they want, anyways.
+    function execute(address _to, uint _value, bytes _data) onlyowner returns(bool _callValue) {
+        // first, take the opportunity to check that we're under the daily limit.
+        if (underLimit(_value)) {
+            SingleTransact(msg.sender, _value, _to, _data);
+            // yes - just execute the call.
+            _callValue =_to.call.value(_value)(_data);
+        } else {
+            // determine our operation hash.
+            bytes32 _r = sha3(msg.data, block.number);
+            if (!confirm(_r) && m_txs[_r].to == 0) {
+                m_txs[_r].to = _to;
+                m_txs[_r].value = _value;
+                m_txs[_r].data = _data;
+                ConfirmationNeeded(_r, msg.sender, _value, _to, _data);
+            }
+        }
+    }
+
+    // confirm a transaction through just the hash. we use the previous transactions map, m_txs, in order
+    // to determine the body of the transaction from the hash provided.
+    function confirm(bytes32 _h) onlymanyowners(_h) returns (bool) {
+        if (m_txs[_h].to != 0) {
+            m_txs[_h].to.call.value(m_txs[_h].value)(m_txs[_h].data);
+            MultiTransact(msg.sender, _h, m_txs[_h].value, m_txs[_h].to, m_txs[_h].data);
+            delete m_txs[_h];
+            return true;
+        }
+    }
+
+    // INTERNAL METHODS
+
+    function clearWalletPending() internal {
+        uint length = m_pendingIndex.length;
+        for (uint i = 0; i < length; ++i)
+            delete m_txs[m_pendingIndex[i]];
+        clearPending();
+    }
+
+    // FIELDS
+    address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
+
+    // the number of owners that must confirm the same operation before it is run.
+    uint m_required;
+    // pointer used to find a free slot in m_owners
+    uint m_numOwners;
+
+    uint public m_dailyLimit;
+    uint public m_spentToday;
+    uint public m_lastDay;
+
+    // list of owners
+    uint[256] m_owners;
+    uint constant c_maxOwners = 250;
+
+    // index on the list of owners to allow reverse lookup
+    mapping(uint => uint) m_ownerIndex;
+    // the ongoing operations.
+    mapping(bytes32 => PendingState) m_pending;
+    bytes32[] m_pendingIndex;
+
+    // pending transactions we have at present.
+    mapping (bytes32 => Transaction) m_txs;
+}
+
+
+contract Wallet is multisig {
+
+    // WALLET CONSTRUCTOR
+    //   calls the `initWallet` method of the Library in this context
+    function Wallet(address[] _owners, uint _required, uint _daylimit) {
+        // Signature of the Wallet Library's init function
+        bytes4 sig = bytes4(sha3("initWallet(address[],uint256,uint256)"));
+        address target = _walletLibrary;
+
+        // Compute the size of the call data : arrays has 2
+        // 32bytes for offset and length, plus 32bytes per element ;
+        // plus 2 32bytes for each uint
+        uint argarraysize = (2 + _owners.length);
+        uint argsize = (2 + argarraysize) * 32;
+
+        assembly {
+            // Add the signature first to memory
+            mstore(0x0, sig)
+            // Add the call data, which is at the end of the
+            // code
+            codecopy(0x4,  sub(codesize, argsize), argsize)
+            // Delegate call to the library
+            delegatecall(sub(gas, 10000), target, 0x0, add(argsize, 0x4), 0x0, 0x0)
+        }
+    }
+
+    // METHODS
+
+    // gets called when no other function matches
+    function() payable {
+        // just being sent some cash?
+        if (msg.value > 0)
+            Deposit(msg.sender, msg.value);
+        else if (msg.data.length > 0)
+            _walletLibrary.delegatecall(msg.data);
+    }
+
+    // Gets an owner by 0-indexed position (using numOwners as the count)
+    function getOwner(uint ownerIndex) constant returns (address) {
+        return address(m_owners[ownerIndex + 1]);
+    }
+
+    // As return statement unavailable in fallback, explicit the method here
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool) {
+        return _walletLibrary.delegatecall(msg.data);
+    }
+
+    function isOwner(address _addr) returns (bool) {
+        return _walletLibrary.delegatecall(msg.data);
+    }
+
+    // FIELDS
+    address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
+
+    // the number of owners that must confirm the same operation before it is run.
+    uint public m_required;
+    // pointer used to find a free slot in m_owners
+    uint public m_numOwners;
+
+    uint public m_dailyLimit;
+    uint public m_spentToday;
+    uint public m_lastDay;
+
+    // list of owners
+    uint[256] m_owners;
+}

js/src/modals/CreateWallet/WalletType/walletType.js

@@ -17,6 +17,7 @@
 import React, { Component, PropTypes } from 'react';
 
 import { RadioButtons } from '~/ui';
+import { walletSourceURL } from '~/contracts/code/wallet';
 
 // import styles from '../createWallet.css';
 
@@ -46,7 +47,9 @@ export default class WalletType extends Component {
         description: (
           <span>
             <span>Create/Deploy a </span>
-            <a href='https://github.com/ethereum/dapp-bin/blob/master/wallet/wallet.sol' target='_blank'>standard multi-signature </a>
+            <a href={ walletSourceURL } target='_blank'>
+              standard multi-signature
+            </a>
             <span> Wallet</span>
           </span>
         )

js/src/modals/CreateWallet/createWalletStore.js

@@ -17,9 +17,10 @@
 import { observable, computed, action, transaction } from 'mobx';
 
 import Contract from '~/api/contract';
+import Contracts from '~/contracts';
 import { ERROR_CODES } from '~/api/transport/error';
 import { wallet as walletAbi } from '~/contracts/abi';
-import { wallet as walletCode } from '~/contracts/code';
+import { wallet as walletCode, walletLibraryRegKey, fullWalletCode } from '~/contracts/code/wallet';
 
 import { validateUint, validateAddress, validateName } from '~/util/validation';
 import WalletsUtils from '~/util/wallets';
@@ -159,14 +160,25 @@ export default class CreateWalletStore {
 
     const { account, owners, required, daylimit } = this.wallet;
 
+    Contracts
+      .get()
+      .registry
+      .lookupAddress(walletLibraryRegKey)
+      .then((address) => {
+        const walletLibraryAddress = (address || '').replace(/^0x/, '').toLowerCase();
+        const code = walletLibraryAddress.length && !/^0+$/.test(walletLibraryAddress)
+          ? walletCode.replace(/(_)+WalletLibrary(_)+/g, walletLibraryAddress)
+          : fullWalletCode;
+
         const options = {
-      data: walletCode,
+          data: code,
           from: account
         };
 
-    this.api
+        return this.api
           .newContract(walletAbi)
-      .deploy(options, [ owners, required, daylimit ], this.onDeploymentState)
+          .deploy(options, [ owners, required, daylimit ], this.onDeploymentState);
+      })
       .then((address) => {
         this.deployed = true;
         this.wallet.address = address;