Contract Name:
MultiSigWallet
Contract Source Code:
File 1 of 1 : MultiSigWallet
pragma solidity ^0.4.15;
/// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.
/// @author Stefan George - <[email protected]>
contract MultiSigWallet {
/*
* Events
*/
event Confirmation(address indexed sender, uint indexed transactionId);
event Revocation(address indexed sender, uint indexed transactionId);
event Submission(uint indexed transactionId);
event Execution(uint indexed transactionId);
event ExecutionFailure(uint indexed transactionId);
event Deposit(address indexed sender, uint value);
event OwnerAddition(address indexed owner);
event OwnerRemoval(address indexed owner);
event RequirementChange(uint required);
/*
* Constants
*/
uint constant public MAX_OWNER_COUNT = 50;
/*
* Storage
*/
mapping (uint => Transaction) public transactions;
mapping (uint => mapping (address => bool)) public confirmations;
mapping (address => bool) public isOwner;
address[] public owners;
uint public required;
uint public transactionCount;
struct Transaction {
address destination;
uint value;
bytes data;
bool executed;
}
/*
* Modifiers
*/
modifier onlyWallet() {
require(msg.sender == address(this));
_;
}
modifier ownerDoesNotExist(address owner) {
require(!isOwner[owner]);
_;
}
modifier ownerExists(address owner) {
require(isOwner[owner]);
_;
}
modifier transactionExists(uint transactionId) {
require(transactions[transactionId].destination != 0);
_;
}
modifier confirmed(uint transactionId, address owner) {
require(confirmations[transactionId][owner]);
_;
}
modifier notConfirmed(uint transactionId, address owner) {
require(!confirmations[transactionId][owner]);
_;
}
modifier notExecuted(uint transactionId) {
require(!transactions[transactionId].executed);
_;
}
modifier notNull(address _address) {
require(_address != 0);
_;
}
modifier validRequirement(uint ownerCount, uint _required) {
require(ownerCount <= MAX_OWNER_COUNT
&& _required <= ownerCount
&& _required != 0
&& ownerCount != 0);
_;
}
/// @dev Fallback function allows to deposit ether.
function()
payable
{
if (msg.value > 0)
emit Deposit(msg.sender, msg.value);
}
/*
* Public functions
*/
/// @dev Contract constructor sets initial owners and required number of confirmations.
/// @param _owners List of initial owners.
/// @param _required Number of required confirmations.
function MultiSigWallet(address[] _owners, uint _required)
public
validRequirement(_owners.length, _required)
{
for (uint i=0; i<_owners.length; i++) {
require(!isOwner[_owners[i]] && _owners[i] != 0);
isOwner[_owners[i]] = true;
}
owners = _owners;
required = _required;
}
/// @dev Allows to add a new owner. Transaction has to be sent by wallet.
/// @param owner Address of new owner.
function addOwner(address owner)
public
onlyWallet
ownerDoesNotExist(owner)
notNull(owner)
validRequirement(owners.length + 1, required)
{
isOwner[owner] = true;
owners.push(owner);
emit OwnerAddition(owner);
}
/// @dev Allows to remove an owner. Transaction has to be sent by wallet.
/// @param owner Address of owner.
function removeOwner(address owner)
public
onlyWallet
ownerExists(owner)
{
isOwner[owner] = false;
for (uint i=0; i<owners.length - 1; i++)
if (owners[i] == owner) {
owners[i] = owners[owners.length - 1];
break;
}
owners.length -= 1;
if (required > owners.length)
changeRequirement(owners.length);
emit OwnerRemoval(owner);
}
/// @dev Allows to replace an owner with a new owner. Transaction has to be sent by wallet.
/// @param owner Address of owner to be replaced.
/// @param newOwner Address of new owner.
function replaceOwner(address owner, address newOwner)
public
onlyWallet
ownerExists(owner)
ownerDoesNotExist(newOwner)
{
for (uint i=0; i<owners.length; i++)
if (owners[i] == owner) {
owners[i] = newOwner;
break;
}
isOwner[owner] = false;
isOwner[newOwner] = true;
emit OwnerRemoval(owner);
emit OwnerAddition(newOwner);
}
/// @dev Allows to change the number of required confirmations. Transaction has to be sent by wallet.
/// @param _required Number of required confirmations.
function changeRequirement(uint _required)
public
onlyWallet
validRequirement(owners.length, _required)
{
required = _required;
emit RequirementChange(_required);
}
/// @dev Allows an owner to submit and confirm a transaction.
/// @param destination Transaction target address.
/// @param value Transaction ether value.
/// @param data Transaction data payload.
/// @return Returns transaction ID.
function submitTransaction(address destination, uint value, bytes data)
public
returns (uint transactionId)
{
transactionId = addTransaction(destination, value, data);
confirmTransaction(transactionId);
}
/// @dev Allows an owner to confirm a transaction.
/// @param transactionId Transaction ID.
function confirmTransaction(uint transactionId)
public
ownerExists(msg.sender)
transactionExists(transactionId)
notConfirmed(transactionId, msg.sender)
{
confirmations[transactionId][msg.sender] = true;
emit Confirmation(msg.sender, transactionId);
executeTransaction(transactionId);
}
/// @dev Allows an owner to revoke a confirmation for a transaction.
/// @param transactionId Transaction ID.
function revokeConfirmation(uint transactionId)
public
ownerExists(msg.sender)
confirmed(transactionId, msg.sender)
notExecuted(transactionId)
{
confirmations[transactionId][msg.sender] = false;
emit Revocation(msg.sender, transactionId);
}
/// @dev Allows anyone to execute a confirmed transaction.
/// @param transactionId Transaction ID.
function executeTransaction(uint transactionId)
public
ownerExists(msg.sender)
confirmed(transactionId, msg.sender)
notExecuted(transactionId)
{
if (isConfirmed(transactionId)) {
Transaction storage txn = transactions[transactionId];
txn.executed = true;
if (external_call(txn.destination, txn.value, txn.data.length, txn.data))
emit Execution(transactionId);
else {
emit ExecutionFailure(transactionId);
txn.executed = false;
}
}
}
// call has been separated into its own function in order to take advantage
// of the Solidity's code generator to produce a loop that copies tx.data into memory.
function external_call(address destination, uint value, uint dataLength, bytes data) internal returns (bool) {
bool result;
assembly {
let x := mload(0x40) // "Allocate" memory for output (0x40 is where "free memory" pointer is stored by convention)
let d := add(data, 32) // First 32 bytes are the padded length of data, so exclude that
result := call(
sub(gas, 74710), // 34710 is the value that solidity is currently emitting
// It includes callGas (700) + callVeryLow (3, to pay for SUB) + callValueTransferGas (9000) +
// callNewAccountGas (25000, in case the destination address does not exist and needs creating)
destination,
value,
d,
dataLength, // Size of the input (in bytes) - this is what fixes the padding problem
x,
0 // Output is ignored, therefore the output size is zero
)
}
return result;
}
/// @dev Returns the confirmation status of a transaction.
/// @param transactionId Transaction ID.
/// @return Confirmation status.
function isConfirmed(uint transactionId)
public
constant
returns (bool)
{
uint count = 0;
for (uint i=0; i<owners.length; i++) {
if (confirmations[transactionId][owners[i]])
count += 1;
if (count == required)
return true;
}
}
/*
* Internal functions
*/
/// @dev Adds a new transaction to the transaction mapping, if transaction does not exist yet.
/// @param destination Transaction target address.
/// @param value Transaction ether value.
/// @param data Transaction data payload.
/// @return Returns transaction ID.
function addTransaction(address destination, uint value, bytes data)
internal
notNull(destination)
returns (uint transactionId)
{
transactionId = transactionCount;
transactions[transactionId] = Transaction({
destination: destination,
value: value,
data: data,
executed: false
});
transactionCount += 1;
emit Submission(transactionId);
}
/*
* Web3 call functions
*/
/// @dev Returns number of confirmations of a transaction.
/// @param transactionId Transaction ID.
/// @return Number of confirmations.
function getConfirmationCount(uint transactionId)
public
constant
returns (uint count)
{
for (uint i=0; i<owners.length; i++)
if (confirmations[transactionId][owners[i]])
count += 1;
}
/// @dev Returns total number of transactions after filers are applied.
/// @param pending Include pending transactions.
/// @param executed Include executed transactions.
/// @return Total number of transactions after filters are applied.
function getTransactionCount(bool pending, bool executed)
public
constant
returns (uint count)
{
for (uint i=0; i<transactionCount; i++)
if ( pending && !transactions[i].executed
|| executed && transactions[i].executed)
count += 1;
}
/// @dev Returns list of owners.
/// @return List of owner addresses.
function getOwners()
public
constant
returns (address[])
{
return owners;
}
/// @dev Returns array with owner addresses, which confirmed transaction.
/// @param transactionId Transaction ID.
/// @return Returns array of owner addresses.
function getConfirmations(uint transactionId)
public
constant
returns (address[] _confirmations)
{
address[] memory confirmationsTemp = new address[](owners.length);
uint count = 0;
uint i;
for (i=0; i<owners.length; i++)
if (confirmations[transactionId][owners[i]]) {
confirmationsTemp[count] = owners[i];
count += 1;
}
_confirmations = new address[](count);
for (i=0; i<count; i++)
_confirmations[i] = confirmationsTemp[i];
}
/// @dev Returns list of transaction IDs in defined range.
/// @param from Index start position of transaction array.
/// @param to Index end position of transaction array.
/// @param pending Include pending transactions.
/// @param executed Include executed transactions.
/// @return Returns array of transaction IDs.
function getTransactionIds(uint from, uint to, bool pending, bool executed)
public
constant
returns (uint[] _transactionIds)
{
uint[] memory transactionIdsTemp = new uint[](transactionCount);
uint count = 0;
uint i;
for (i=0; i<transactionCount; i++)
if ( pending && !transactions[i].executed
|| executed && transactions[i].executed)
{
transactionIdsTemp[count] = i;
count += 1;
}
_transactionIds = new uint[](to - from);
for (i=from; i<to; i++)
_transactionIds[i - from] = transactionIdsTemp[i];
}
}