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October 11, 2018 01:12
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pragma solidity ^0.4.18; | |
// File: contracts/ECRecovery.sol | |
library ECRecovery { | |
/** | |
* @dev Recover signer address from a message by using their signature | |
* @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address. | |
* @param sig bytes signature, the signature is generated using web3.eth.sign() | |
*/ | |
function recover(bytes32 hash, bytes sig) public pure returns (address) { | |
bytes32 r; | |
bytes32 s; | |
uint8 v; | |
//Check the signature length | |
if (sig.length != 65) { | |
return (address(0)); | |
} | |
// Divide the signature in r, s and v variables | |
assembly { | |
r := mload(add(sig, 32)) | |
s := mload(add(sig, 64)) | |
v := byte(0, mload(add(sig, 96))) | |
} | |
// Version of signature should be 27 or 28, but 0 and 1 are also possible versions | |
if (v < 27) { | |
v += 27; | |
} | |
// If the version is correct return the signer address | |
if (v != 27 && v != 28) { | |
return (address(0)); | |
} else { | |
return ecrecover(hash, v, r, s); | |
} | |
} | |
} | |
// File: contracts/SafeMath.sol | |
/** | |
* @title SafeMath | |
* @dev Math operations with safety checks that throw on error | |
*/ | |
library SafeMath { | |
/** | |
* @dev Multiplies two numbers, throws on overflow. | |
*/ | |
function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
if (a == 0) { | |
return 0; | |
} | |
uint256 c = a * b; | |
assert(c / a == b); | |
return c; | |
} | |
/** | |
* @dev Integer division of two numbers, truncating the quotient. | |
*/ | |
function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
// assert(b > 0); // Solidity automatically throws when dividing by 0 | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
/** | |
* @dev Substracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend). | |
*/ | |
function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
assert(b <= a); | |
return a - b; | |
} | |
/** | |
* @dev Adds two numbers, throws on overflow. | |
*/ | |
function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
uint256 c = a + b; | |
assert(c >= a); | |
return c; | |
} | |
} | |
// File: contracts/LavaWallet.sol | |
/* | |
This is a token wallet contract | |
Store your tokens in this contract to give them super powers | |
Tokens can be spent from the contract with only an ecSignature from the owner - onchain approve is not needed | |
*/ | |
contract ERC20Interface { | |
function totalSupply() public constant returns (uint); | |
function balanceOf(address tokenOwner) public constant returns (uint balance); | |
function allowance(address tokenOwner, address spender) public constant returns (uint remaining); | |
function transfer(address to, uint tokens) public returns (bool success); | |
function approve(address spender, uint tokens) public returns (bool success); | |
function transferFrom(address from, address to, uint tokens) public returns (bool success); | |
event Transfer(address indexed from, address indexed to, uint tokens); | |
event Approval(address indexed tokenOwner, address indexed spender, uint tokens); | |
} | |
contract ERC918Interface { | |
function totalSupply() public constant returns (uint); | |
function getMiningDifficulty() public constant returns (uint); | |
function getMiningTarget() public constant returns (uint); | |
function getMiningReward() public constant returns (uint); | |
function balanceOf(address tokenOwner) public constant returns (uint balance); | |
function mint(uint256 nonce, bytes32 challenge_digest) public returns (bool success); | |
event Mint(address indexed from, uint reward_amount, uint epochCount, bytes32 newChallengeNumber); | |
} | |
contract MiningKingInterface { | |
function getMiningKing() public returns (address); | |
function transferKing(address newKing) public; | |
function mint(uint256 nonce, bytes32 challenge_digest) returns (bool); | |
event TransferKing(address from, address to); | |
} | |
contract ApproveAndCallFallBack { | |
function receiveApproval(address from, uint256 tokens, address token, bytes data) public; | |
} | |
contract LavaWallet { | |
using SafeMath for uint; | |
// balances[tokenContractAddress][EthereumAccountAddress] = 0 | |
mapping(address => mapping (address => uint256)) balances; | |
//token => owner => spender : amount | |
mapping(address => mapping (address => mapping (address => uint256))) allowed; | |
//mapping(address => uint256) depositedTokens; | |
mapping(bytes32 => uint256) burnedSignatures; | |
address relayKingContract; | |
event Deposit(address token, address user, uint amount, uint balance); | |
event Withdraw(address token, address user, uint amount, uint balance); | |
event Transfer(address indexed from, address indexed to,address token, uint tokens); | |
event Approval(address indexed tokenOwner, address indexed spender,address token, uint tokens); | |
function LavaWallet(address relayKingContractAddress ) public { | |
relayKingContract = relayKingContractAddress; | |
} | |
//do not allow ether to enter | |
function() public payable { | |
revert(); | |
} | |
//Remember you need pre-approval for this - nice with ApproveAndCall | |
function depositTokens(address from, address token, uint256 tokens ) public returns (bool success) | |
{ | |
//we already have approval so lets do a transferFrom - transfer the tokens into this contract | |
if(!ERC20Interface(token).transferFrom(from, this, tokens)) revert(); | |
balances[token][from] = balances[token][from].add(tokens); | |
// depositedTokens[token] = depositedTokens[token].add(tokens); | |
Deposit(token, from, tokens, balances[token][from]); | |
return true; | |
} | |
//No approve needed, only from msg.sender | |
function withdrawTokens(address token, uint256 tokens) public returns (bool success){ | |
balances[token][msg.sender] = balances[token][msg.sender].sub(tokens); | |
if(!ERC20Interface(token).transfer(msg.sender, tokens)) revert(); | |
Withdraw(token, msg.sender, tokens, balances[token][msg.sender]); | |
return true; | |
} | |
//Requires approval so it can be public | |
function withdrawTokensFrom( address from, address to,address token, uint tokens) public returns (bool success) { | |
balances[token][from] = balances[token][from].sub(tokens); | |
allowed[token][from][to] = allowed[token][from][to].sub(tokens); | |
if(!ERC20Interface(token).transfer(to, tokens)) revert(); | |
Withdraw(token, from, tokens, balances[token][from]); | |
return true; | |
} | |
function balanceOf(address token,address user) public constant returns (uint) { | |
return balances[token][user]; | |
} | |
function allowance(address token, address tokenOwner, address spender) public constant returns (uint remaining) { | |
return allowed[token][tokenOwner][spender]; | |
} | |
//Can also be used to remove approval by using a 'tokens' value of 0. P.S. it makes no sense to do an ApproveTokensFrom | |
function approveTokens(address spender, address token, uint tokens) public returns (bool success) { | |
allowed[token][msg.sender][spender] = tokens; | |
Approval(msg.sender, token, spender, tokens); | |
return true; | |
} | |
///transfer tokens within the lava balances | |
//No approve needed, only from msg.sender | |
function transferTokens(address to, address token, uint tokens) public returns (bool success) { | |
balances[token][msg.sender] = balances[token][msg.sender].sub(tokens); | |
balances[token][to] = balances[token][to].add(tokens); | |
Transfer(msg.sender, token, to, tokens); | |
return true; | |
} | |
///transfer tokens within the lava balances | |
//Can be public because it requires approval | |
function transferTokensFrom( address from, address to,address token, uint tokens) public returns (bool success) { | |
balances[token][from] = balances[token][from].sub(tokens); | |
allowed[token][from][to] = allowed[token][from][to].sub(tokens); | |
balances[token][to] = balances[token][to].add(tokens); | |
Transfer(token, from, to, tokens); | |
return true; | |
} | |
//Nonce is the same thing as a 'check number' | |
//EIP 712 | |
function getLavaTypedDataHash(bytes methodname, address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce) public constant returns (bytes32) | |
{ | |
bytes32 hardcodedSchemaHash = 0x8fd4f9177556bbc74d0710c8bdda543afd18cc84d92d64b5620d5f1881dceb37; //with methodname | |
bytes32 typedDataHash = sha3( | |
hardcodedSchemaHash, | |
sha3(methodname,from,to,this,token,tokens,relayerReward,expires,nonce) | |
); | |
return typedDataHash; | |
} | |
function tokenApprovalWithSignature(bool requiresKing, address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, bytes32 sigHash, bytes signature) internal returns (bool success) | |
{ | |
address recoveredSignatureSigner = ECRecovery.recover(sigHash,signature); | |
//make sure the signer is the depositor of the tokens | |
if(from != recoveredSignatureSigner) revert(); | |
if(msg.sender != getRelayingKing() && requiresKing ) revert(); // you must be the 'king of the hill' to relay | |
//make sure the signature has not expired | |
if(block.number > expires) revert(); | |
uint burnedSignature = burnedSignatures[sigHash]; | |
burnedSignatures[sigHash] = 0x1; //spent | |
if(burnedSignature != 0x0 ) revert(); | |
//approve the relayer reward | |
allowed[token][from][msg.sender] = relayerReward; | |
Approval(from, token, msg.sender, relayerReward); | |
//transferRelayerReward | |
if(!transferTokensFrom(from, msg.sender, token, relayerReward)) revert(); | |
//approve transfer of tokens | |
allowed[token][from][to] = tokens; | |
Approval(from, token, to, tokens); | |
return true; | |
} | |
function approveTokensFromAnyWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
bytes32 sigHash = getLavaTypedDataHash('anyApprove',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(false,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
return true; | |
} | |
function approveTokensFromKingWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
bytes32 sigHash = getLavaTypedDataHash('kingApprove',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(true,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
return true; | |
} | |
//the tokens remain in lava wallet | |
function transferTokensFromAnyWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
//check to make sure that signature == ecrecover signature | |
bytes32 sigHash = getLavaTypedDataHash('anyTransfer',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(false,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
//it can be requested that fewer tokens be sent that were approved -- the whole approval will be invalidated though | |
if(!transferTokensFrom( from, to, token, tokens)) revert(); | |
return true; | |
} | |
//The tokens are withdrawn from the lava wallet and transferred into the To account | |
function transferTokensFromKingWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
//check to make sure that signature == ecrecover signature | |
bytes32 sigHash = getLavaTypedDataHash('kingTransfer',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(true,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
//it can be requested that fewer tokens be sent that were approved -- the whole approval will be invalidated though | |
if(!transferTokensFrom( from, to, token, tokens)) revert(); | |
return true; | |
} | |
//the tokens remain in lava wallet | |
function withdrawTokensFromAnyWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
//check to make sure that signature == ecrecover signature | |
bytes32 sigHash = getLavaTypedDataHash('anyWithdraw',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(false,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
//it can be requested that fewer tokens be sent that were approved -- the whole approval will be invalidated though | |
if(!withdrawTokensFrom( from, to, token, tokens)) revert(); | |
return true; | |
} | |
//The tokens are withdrawn from the lava wallet and transferred into the To account | |
function withdrawTokensFromKingWithSignature(address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
//check to make sure that signature == ecrecover signature | |
bytes32 sigHash = getLavaTypedDataHash('kingWithdraw',from,to,token,tokens,relayerReward,expires,nonce); | |
if(!tokenApprovalWithSignature(true,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
//it can be requested that fewer tokens be sent that were approved -- the whole approval will be invalidated though | |
if(!withdrawTokensFrom( from, to, token, tokens)) revert(); | |
return true; | |
} | |
function burnSignature(bytes methodname, address from, address to, address token, uint256 tokens, uint256 relayerReward, uint256 expires, uint256 nonce, bytes signature) public returns (bool success) | |
{ | |
bytes32 sigHash = getLavaTypedDataHash(methodname,from,to,token,tokens,relayerReward,expires,nonce); | |
address recoveredSignatureSigner = ECRecovery.recover(sigHash,signature); | |
//make sure the invalidator is the signer | |
if(recoveredSignatureSigner != from) revert(); | |
//only the original packet owner can burn signature, not a relay | |
if(from != msg.sender) revert(); | |
//make sure this signature has never been used | |
uint burnedSignature = burnedSignatures[sigHash]; | |
burnedSignatures[sigHash] = 0x2; //invalidated | |
if(burnedSignature != 0x0 ) revert(); | |
return true; | |
} | |
function signatureBurnStatus(bytes32 digest) public view returns (uint) | |
{ | |
return (burnedSignatures[digest]); | |
} | |
/* | |
Receive approval to spend tokens and perform any action all in one transaction | |
*/ | |
function receiveApproval(address from, uint256 tokens, address token, bytes data) public returns (bool success) { | |
return depositTokens(from, token, tokens ); | |
} | |
/* | |
Approve lava tokens for a smart contract and call the contracts receiveApproval method all in one fell swoop | |
One issue: the data is not being signed and so it could be manipulated | |
*/ | |
function approveAndCall(bytes methodname, address from, address to, address token, uint256 tokens, uint256 relayerReward, | |
uint256 expires, uint256 nonce, bytes signature ) public { | |
bytes32 sigHash = getLavaTypedDataHash(methodname,from,to,token,tokens,relayerReward,expires,nonce); | |
bool requiresKing = getRequiresKing(methodname); | |
if(!tokenApprovalWithSignature(requiresKing,from,to,token,tokens,relayerReward,expires,sigHash,signature)) revert(); | |
ApproveAndCallFallBack(to).receiveApproval(from, tokens, token, methodname); | |
} | |
function getRelayingKing() public returns (address) | |
{ | |
return MiningKingInterface(relayKingContract).getMiningKing(); | |
} | |
function getRequiresKing(bytes methodname) pure internal returns (bool) | |
{ | |
return (bytesEqual(methodname,'kingTransfer') || bytesEqual(methodname,'kingWithdraw') || bytesEqual(methodname,'kingApprove')); | |
} | |
function bytesEqual(bytes b1,bytes b2) pure internal returns (bool) | |
{ | |
if(b1.length != b2.length) return false; | |
for (uint i=0; i<b1.length; i++) { | |
if(b1[i] != b2[i]) return false; | |
} | |
return true; | |
} | |
} |
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