multisig

gistfile1.txt

contract multisig {   
	function multisig() { 
		// when a contract has a function with the same name as itself, 
		// then that function is run at startup
		m_numOwners = 1; 
		m_required = m_numOwners; 
		m_owners[msg.sender] = m_numOwners; 
	}
    
	function transact(address _to, uint _value) external onlyowner {
		// Each transaction is converted in a hash and awaits confirmation
        if (confirm(m_owners[msg.sender], sha3(_to, _value)))
            _to.send(_value);
    }
	
	function addOwner(address _newOwner) external onlyowner {
		// Any owner can invite more, and all transactions need to be approved by more than half of them
		if (!(isOwner(_newOwner))) {
			m_numOwners++;
			m_required = m_numOwners / 2 + 1;
			m_owners[_newOwner] = m_numOwners;	
		}
	}
	
    function confirm(uint _owner, bytes32 _hash) internal returns (bool) {
		// Does some bitshifting magic to confirm transactions
        uint ownerBit = 2**_owner;
        if (m_pending[_hash].confirmed & ownerBit == 0) {
            m_pending[_hash].confirmed &= ownerBit;
            if (++m_pending[_hash].numConfirmations >= m_required) { 
                delete m_pending[_hash];
                return true;
            }
        } 
    }
	// What follows are variables that are used to describe the function
    modifier onlyowner() { if (isOwner(msg.sender)) _ }
	
	// Accessors to allow reading function variables
    function isOwner(address addr) returns (bool) { return m_owners[addr] > 0; }
    function totalOwners() returns (uint) { return m_numOwners; }
    function totalRequiredConfirmations() returns (uint) { return m_required; }
	function pendingConfirmations(address _to, uint _value) returns (uint) { return m_pending[sha3(_to, _value)].numConfirmations; }
	
	// Declaring the contract structure
    uint m_numOwners;
    uint m_required;
    mapping(address => uint) m_owners;
    mapping(bytes32 => Pending) m_pending;
    struct Pending {
        uint confirmed;
        uint numConfirmations;
    }
}

gistfile2.js

var ABI = [   {      "constant" : false,      "inputs" : [],      "name" : "totalOwners",      "outputs" : [         {            "name" : "",            "type" : "uint256"         }      ],      "type" : "function"   },   {      "constant" : false,      "inputs" : [         {            "name" : "addr",            "type" : "address"         }      ],      "name" : "isOwner",      "outputs" : [         {            "name" : "",            "type" : "bool"         }      ],      "type" : "function"   },   {      "constant" : false,      "inputs" : [],      "name" : "totalRequiredConfirmations",      "outputs" : [         {            "name" : "",            "type" : "uint256"         }      ],      "type" : "function"   },   {      "constant" : false,      "inputs" : [         {            "name" : "_newOwner",            "type" : "address"         }      ],      "name" : "addOwner",      "outputs" : [],      "type" : "function"   },   {      "constant" : false,      "inputs" : [         {            "name" : "_to",            "type" : "address"         },         {            "name" : "_value",            "type" : "uint256"         }      ],      "name" : "pendingConfirmations",      "outputs" : [         {            "name" : "",            "type" : "uint256"         }      ],      "type" : "function"   },   {      "constant" : false,      "inputs" : [         {            "name" : "_to",            "type" : "address"         },         {            "name" : "_value",            "type" : "uint256"         }      ],      "name" : "transact",      "outputs" : [],      "type" : "function"   }]