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pragma solidity ^0.4.24;
import "../common/MerkleProof.sol";
import "../common/Controlled.sol";
import "../token/ERC20Token.sol";
import "../token/ApproveAndCallFallBack.sol";
import "../ens/ENS.sol";
import "../ens/PublicResolver.sol";
/**
* @author Ricardo Guilherme Schmidt (Status Research & Development GmbH)
* @notice Registers usernames as ENS subnodes of the domain `ensNode`
*/
contract UsernameRegistrar is Controlled, ApproveAndCallFallBack {
ERC20Token public token;
ENS public ensRegistry;
PublicResolver public resolver;
address public parentRegistry;
uint256 public constant releaseDelay = 365 days;
mapping (bytes32 => Account) public accounts;
mapping (bytes32 => SlashReserve) reservedSlashers;
//Slashing conditions
uint256 public usernameMinLength;
bytes32 public reservedUsernamesMerkleRoot;
event RegistryState(RegistrarState state);
event RegistryPrice(uint256 price);
event RegistryMoved(address newRegistry);
event UsernameOwner(bytes32 indexed nameHash, address owner);
enum RegistrarState { Inactive, Active, Moved }
bytes32 public ensNode;
uint256 public price;
RegistrarState public state;
uint256 public reserveAmount;
struct Account {
uint256 balance;
uint256 creationTime;
address owner;
}
struct SlashReserve {
address reserver;
uint256 blockNumber;
}
/**
* @notice Callable only by `parentRegistry()` to continue migration of ENSSubdomainRegistry.
*/
modifier onlyParentRegistry {
require(msg.sender == parentRegistry, "Migration only.");
_;
}
/**
* @notice Initializes UsernameRegistrar contract.
* The only parameter from this list that can be changed later is `_resolver`.
* Other updates require a new contract and migration of domain.
* @param _token ERC20 token with optional `approveAndCall(address,uint256,bytes)` for locking fee.
* @param _ensRegistry Ethereum Name Service root contract address.
* @param _resolver Public Resolver for resolving usernames.
* @param _ensNode ENS node (domain) being used for usernames subnodes (subdomain)
* @param _usernameMinLength Minimum length of usernames
* @param _reservedUsernamesMerkleRoot Merkle root of reserved usernames
* @param _parentRegistry Address of old registry (if any) for optional account migration.
*/
constructor(
ERC20Token _token,
ENS _ensRegistry,
PublicResolver _resolver,
bytes32 _ensNode,
uint256 _usernameMinLength,
bytes32 _reservedUsernamesMerkleRoot,
address _parentRegistry
)
public
{
require(address(_token) != address(0), "No ERC20Token address defined.");
require(address(_ensRegistry) != address(0), "No ENS address defined.");
require(address(_resolver) != address(0), "No Resolver address defined.");
require(_ensNode != bytes32(0), "No ENS node defined.");
token = _token;
ensRegistry = _ensRegistry;
resolver = _resolver;
ensNode = _ensNode;
usernameMinLength = _usernameMinLength;
reservedUsernamesMerkleRoot = _reservedUsernamesMerkleRoot;
parentRegistry = _parentRegistry;
setState(RegistrarState.Inactive);
}
/**
* @notice Registers `_label` username to `ensNode` setting msg.sender as owner.
* Terms of name registration:
* - SNT is deposited, not spent; the amount is locked up for 1 year.
* - After 1 year, the user can release the name and receive their deposit back (at any time).
* - User deposits are completely protected. The contract controller cannot access them.
* - User's address(es) will be publicly associated with the ENS name.
* - User must authorise the contract to transfer `price` `token.name()` on their behalf.
* - Usernames registered with less then `usernameMinLength` characters can be slashed.
* - Usernames contained in the merkle tree of root `reservedUsernamesMerkleRoot` can be slashed.
* - Usernames starting with `0x` and bigger then 12 characters can be slashed.
* - If terms of the contract change—e.g. Status makes contract upgrades—the user has the right to release the username and get their deposit back.
* @param _label Choosen unowned username hash.
* @param _account Optional address to set at public resolver.
* @param _pubkeyA Optional pubkey part A to set at public resolver.
* @param _pubkeyB Optional pubkey part B to set at public resolver.
*/
function register(
bytes32 _label,
address _account,
bytes32 _pubkeyA,
bytes32 _pubkeyB
)
external
returns(bytes32 namehash)
{
return registerUser(msg.sender, _label, _account, _pubkeyA, _pubkeyB);
}
/**
* @notice Release username and retrieve locked fee, needs to be called
* after `releasePeriod` from creation time by ENS registry owner of domain
* or anytime by account owner when domain migrated to a new registry.
* @param _label Username hash.
*/
function release(
bytes32 _label
)
external
{
bytes32 namehash = keccak256(abi.encodePacked(ensNode, _label));
Account memory account = accounts[_label];
require(account.creationTime > 0, "Username not registered.");
if (state == RegistrarState.Active) {
require(msg.sender == ensRegistry.owner(namehash), "Not owner of ENS node.");
require(block.timestamp > account.creationTime + releaseDelay, "Release period not reached.");
} else {
require(msg.sender == account.owner, "Not the former account owner.");
}
delete accounts[_label];
if (account.balance > 0) {
reserveAmount -= account.balance;
require(token.transfer(msg.sender, account.balance), "Transfer failed");
}
if (state == RegistrarState.Active) {
ensRegistry.setSubnodeOwner(ensNode, _label, address(this));
ensRegistry.setResolver(namehash, address(0));
ensRegistry.setOwner(namehash, address(0));
} else {
address newOwner = ensRegistry.owner(ensNode);
//Low level call, case dropUsername not implemented or failing, proceed release.
//Invert (!) to supress warning, return of this call have no use.
!newOwner.call.gas(80000)(
abi.encodeWithSignature(
"dropUsername(bytes32)",
_label
)
);
}
emit UsernameOwner(namehash, address(0));
}
/**
* @notice update account owner, should be called by new ens node owner
* to update this contract registry, otherwise former owner can release
* if domain is moved to a new registry.
* @param _label Username hash.
**/
function updateAccountOwner(
bytes32 _label
)
external
{
bytes32 namehash = keccak256(abi.encodePacked(ensNode, _label));
require(msg.sender == ensRegistry.owner(namehash), "Caller not owner of ENS node.");
require(accounts[_label].creationTime > 0, "Username not registered.");
require(ensRegistry.owner(ensNode) == address(this), "Registry not owner of registry.");
accounts[_label].owner = msg.sender;
emit UsernameOwner(namehash, msg.sender);
}
/**
* @notice secretly reserve the slashing reward to `msg.sender`
* @param _secret keccak256(abi.encodePacked(namehash, creationTime, reserveSecret))
*/
function reserveSlash(bytes32 _secret) external {
require(reservedSlashers[_secret].blockNumber == 0, "Already Reserved");
reservedSlashers[_secret] = SlashReserve(msg.sender, block.number);
}
/**
* @notice Slash username smaller then `usernameMinLength`.
* @param _username Raw value of offending username.
*/
function slashSmallUsername(
string _username,
uint256 _reserveSecret
)
external
{
bytes memory username = bytes(_username);
require(username.length < usernameMinLength, "Not a small username.");
slashUsername(username, _reserveSecret);
}
/**
* @notice Slash username starting with "0x" and with length greater than 12.
* @param _username Raw value of offending username.
*/
function slashAddressLikeUsername(
string _username,
uint256 _reserveSecret
)
external
{
bytes memory username = bytes(_username);
require(username.length > 12, "Too small to look like an address.");
require(username[0] == byte("0"), "First character need to be 0");
require(username[1] == byte("x"), "Second character need to be x");
for(uint i = 2; i < 7; i++){
byte b = username[i];
require((b >= 48 && b <= 57) || (b >= 97 && b <= 102), "Does not look like an address");
}
slashUsername(username, _reserveSecret);
}
/**
* @notice Slash username that is exactly a reserved name.
* @param _username Raw value of offending username.
* @param _proof Merkle proof that name is listed on merkle tree.
*/
function slashReservedUsername(
string _username,
bytes32[] _proof,
uint256 _reserveSecret
)
external
{
bytes memory username = bytes(_username);
require(
MerkleProof.verifyProof(
_proof,
reservedUsernamesMerkleRoot,
keccak256(username)
),
"Invalid Proof."
);
slashUsername(username, _reserveSecret);
}
/**
* @notice Slash username that contains a non alphanumeric character.
* @param _username Raw value of offending username.
* @param _offendingPos Position of non alphanumeric character.
*/
function slashInvalidUsername(
string _username,
uint256 _offendingPos,
uint256 _reserveSecret
)
external
{
bytes memory username = bytes(_username);
require(username.length > _offendingPos, "Invalid position.");
byte b = username[_offendingPos];
require(!((b >= 48 && b <= 57) || (b >= 97 && b <= 122)), "Not invalid character.");
slashUsername(username, _reserveSecret);
}
/**
* @notice Clear resolver and ownership of unowned subdomians.
* @param _labels Sequence to erase.
*/
function eraseNode(
bytes32[] _labels
)
external
{
uint len = _labels.length;
require(len != 0, "Nothing to erase");
bytes32 label = _labels[len - 1];
bytes32 subnode = keccak256(abi.encodePacked(ensNode, label));
require(ensRegistry.owner(subnode) == address(0), "First slash/release top level subdomain");
ensRegistry.setSubnodeOwner(ensNode, label, address(this));
if(len > 1) {
eraseNodeHierarchy(len - 2, _labels, subnode);
}
ensRegistry.setResolver(subnode, 0);
ensRegistry.setOwner(subnode, 0);
}
/**
* @notice Migrate account to new registry, opt-in to new contract.
* @param _label Username hash.
**/
function moveAccount(
bytes32 _label,
UsernameRegistrar _newRegistry
)
external
{
require(state == RegistrarState.Moved, "Wrong contract state");
require(msg.sender == accounts[_label].owner, "Callable only by account owner.");
require(ensRegistry.owner(ensNode) == address(_newRegistry), "Wrong update");
Account memory account = accounts[_label];
delete accounts[_label];
token.approve(_newRegistry, account.balance);
_newRegistry.migrateUsername(
_label,
account.balance,
account.creationTime,
account.owner
);
}
/**
* @notice Activate registration.
* @param _price The price of registration.
*/
function activate(
uint256 _price
)
external
onlyController
{
require(state == RegistrarState.Inactive, "Registry state is not Inactive");
require(ensRegistry.owner(ensNode) == address(this), "Registry does not own registry");
price = _price;
setState(RegistrarState.Active);
emit RegistryPrice(_price);
}
/**
* @notice Updates Public Resolver for resolving users.
* @param _resolver New PublicResolver.
*/
function setResolver(
address _resolver
)
external
onlyController
{
resolver = PublicResolver(_resolver);
}
/**
* @notice Updates registration price.
* @param _price New registration price.
*/
function updateRegistryPrice(
uint256 _price
)
external
onlyController
{
require(state == RegistrarState.Active, "Registry not owned");
price = _price;
emit RegistryPrice(_price);
}
/**
* @notice Transfer ownership of ensNode to `_newRegistry`.
* Usernames registered are not affected, but they would be able to instantly release.
* @param _newRegistry New UsernameRegistrar for hodling `ensNode` node.
*/
function moveRegistry(
UsernameRegistrar _newRegistry
)
external
onlyController
{
require(_newRegistry != this, "Cannot move to self.");
require(ensRegistry.owner(ensNode) == address(this), "Registry not owned anymore.");
setState(RegistrarState.Moved);
ensRegistry.setOwner(ensNode, _newRegistry);
_newRegistry.migrateRegistry(price);
emit RegistryMoved(_newRegistry);
}
/**
* @notice Opt-out migration of username from `parentRegistry()`.
* Clear ENS resolver and subnode owner.
* @param _label Username hash.
*/
function dropUsername(
bytes32 _label
)
external
onlyParentRegistry
{
require(accounts[_label].creationTime == 0, "Already migrated");
bytes32 namehash = keccak256(abi.encodePacked(ensNode, _label));
ensRegistry.setSubnodeOwner(ensNode, _label, address(this));
ensRegistry.setResolver(namehash, address(0));
ensRegistry.setOwner(namehash, address(0));
}
/**
* @notice Withdraw not reserved tokens
* @param _token Address of ERC20 withdrawing excess, or address(0) if want ETH.
* @param _beneficiary Address to send the funds.
**/
function withdrawExcessBalance(
address _token,
address _beneficiary
)
external
onlyController
{
require(_beneficiary != address(0), "Cannot burn token");
if (_token == address(0)) {
_beneficiary.transfer(address(this).balance);
} else {
ERC20Token excessToken = ERC20Token(_token);
uint256 amount = excessToken.balanceOf(address(this));
if(_token == address(token)){
require(amount > reserveAmount, "Is not excess");
amount -= reserveAmount;
} else {
require(amount > 0, "No balance");
}
excessToken.transfer(_beneficiary, amount);
}
}
/**
* @notice Withdraw ens nodes not belonging to this contract.
* @param _domainHash Ens node namehash.
* @param _beneficiary New owner of ens node.
**/
function withdrawWrongNode(
bytes32 _domainHash,
address _beneficiary
)
external
onlyController
{
require(_beneficiary != address(0), "Cannot burn node");
require(_domainHash != ensNode, "Cannot withdraw main node");
require(ensRegistry.owner(_domainHash) == address(this), "Not owner of this node");
ensRegistry.setOwner(_domainHash, _beneficiary);
}
/**
* @notice Gets registration price.
* @return Registration price.
**/
function getPrice()
external
view
returns(uint256 registryPrice)
{
return price;
}
/**
* @notice reads amount tokens locked in username
* @param _label Username hash.
* @return Locked username balance.
**/
function getAccountBalance(bytes32 _label)
external
view
returns(uint256 accountBalance)
{
accountBalance = accounts[_label].balance;
}
/**
* @notice reads username account owner at this contract,
* which can release or migrate in case of upgrade.
* @param _label Username hash.
* @return Username account owner.
**/
function getAccountOwner(bytes32 _label)
external
view
returns(address owner)
{
owner = accounts[_label].owner;
}
/**
* @notice reads when the account was registered
* @param _label Username hash.
* @return Registration time.
**/
function getCreationTime(bytes32 _label)
external
view
returns(uint256 creationTime)
{
creationTime = accounts[_label].creationTime;
}
/**
* @notice calculate time where username can be released
* @param _label Username hash.
* @return Exact time when username can be released.
**/
function getExpirationTime(bytes32 _label)
external
view
returns(uint256 releaseTime)
{
uint256 creationTime = accounts[_label].creationTime;
if (creationTime > 0){
releaseTime = creationTime + releaseDelay;
}
}
/**
* @notice calculate reward part an account could payout on slash
* @param _label Username hash.
* @return Part of reward
**/
function getSlashRewardPart(bytes32 _label)
external
view
returns(uint256 partReward)
{
uint256 balance = accounts[_label].balance;
if (balance > 0) {
partReward = balance / 3;
}
}
/**
* @notice Support for "approveAndCall". Callable only by `token()`.
* @param _from Who approved.
* @param _amount Amount being approved, need to be equal `getPrice()`.
* @param _token Token being approved, need to be equal `token()`.
* @param _data Abi encoded data with selector of `register(bytes32,address,bytes32,bytes32)`.
*/
function receiveApproval(
address _from,
uint256 _amount,
address _token,
bytes _data
)
public
{
require(_amount == price, "Wrong value");
require(_token == address(token), "Wrong token");
require(_token == address(msg.sender), "Wrong call");
require(_data.length <= 132, "Wrong data length");
bytes4 sig;
bytes32 label;
address account;
bytes32 pubkeyA;
bytes32 pubkeyB;
(sig, label, account, pubkeyA, pubkeyB) = abiDecodeRegister(_data);
require(
sig == bytes4(0xb82fedbb), //bytes4(keccak256("register(bytes32,address,bytes32,bytes32)"))
"Wrong method selector"
);
registerUser(_from, label, account, pubkeyA, pubkeyB);
}
/**
* @notice Continues migration of username to new registry.
* @param _label Username hash.
* @param _tokenBalance Amount being transfered from `parentRegistry()`.
* @param _creationTime Time user registrated in `parentRegistry()` is preserved.
* @param _accountOwner Account owner which migrated the account.
**/
function migrateUsername(
bytes32 _label,
uint256 _tokenBalance,
uint256 _creationTime,
address _accountOwner
)
external
onlyParentRegistry
{
if (_tokenBalance > 0) {
require(
token.transferFrom(
parentRegistry,
address(this),
_tokenBalance
),
"Error moving funds from old registar."
);
reserveAmount += _tokenBalance;
}
accounts[_label] = Account(_tokenBalance, _creationTime, _accountOwner);
}
/**
* @dev callable only by parent registry to continue migration
* of registry and activate registration.
* @param _price The price of registration.
**/
function migrateRegistry(
uint256 _price
)
external
onlyParentRegistry
{
require(state == RegistrarState.Inactive, "Not Inactive");
require(ensRegistry.owner(ensNode) == address(this), "ENS registry owner not transfered.");
price = _price;
setState(RegistrarState.Active);
emit RegistryPrice(_price);
}
/**
* @notice Registers `_label` username to `ensNode` setting msg.sender as owner.
* @param _owner Address registering the user and paying registry price.
* @param _label Choosen unowned username hash.
* @param _account Optional address to set at public resolver.
* @param _pubkeyA Optional pubkey part A to set at public resolver.
* @param _pubkeyB Optional pubkey part B to set at public resolver.
*/
function registerUser(
address _owner,
bytes32 _label,
address _account,
bytes32 _pubkeyA,
bytes32 _pubkeyB
)
internal
returns(bytes32 namehash)
{
require(state == RegistrarState.Active, "Registry not active.");
namehash = keccak256(abi.encodePacked(ensNode, _label));
require(ensRegistry.owner(namehash) == address(0), "ENS node already owned.");
require(accounts[_label].creationTime == 0, "Username already registered.");
accounts[_label] = Account(price, block.timestamp, _owner);
if(price > 0) {
require(token.allowance(_owner, address(this)) >= price, "Unallowed to spend.");
require(
token.transferFrom(
_owner,
address(this),
price
),
"Transfer failed"
);
reserveAmount += price;
}
bool resolvePubkey = _pubkeyA != 0 || _pubkeyB != 0;
bool resolveAccount = _account != address(0);
if (resolvePubkey || resolveAccount) {
//set to self the ownership to setup initial resolver
ensRegistry.setSubnodeOwner(ensNode, _label, address(this));
ensRegistry.setResolver(namehash, resolver); //default resolver
if (resolveAccount) {
resolver.setAddr(namehash, _account);
}
if (resolvePubkey) {
resolver.setPubkey(namehash, _pubkeyA, _pubkeyB);
}
ensRegistry.setOwner(namehash, _owner);
} else {
//transfer ownership of subdone directly to registrant
ensRegistry.setSubnodeOwner(ensNode, _label, _owner);
}
emit UsernameOwner(namehash, _owner);
}
/**
* @dev Removes account hash of `_username` and send account.balance to msg.sender.
* @param _username Username being slashed.
*/
function slashUsername(
bytes _username,
uint256 _reserveSecret
)
internal
{
bytes32 label = keccak256(_username);
bytes32 namehash = keccak256(abi.encodePacked(ensNode, label));
uint256 amountToTransfer = 0;
uint256 creationTime = accounts[label].creationTime;
address owner = ensRegistry.owner(namehash);
if(creationTime == 0) {
require(
owner != address(0) ||
ensRegistry.resolver(namehash) != address(0),
"Nothing to slash."
);
} else {
assert(creationTime != block.timestamp);
amountToTransfer = accounts[label].balance;
delete accounts[label];
}
ensRegistry.setSubnodeOwner(ensNode, label, address(this));
ensRegistry.setResolver(namehash, address(0));
ensRegistry.setOwner(namehash, address(0));
if (amountToTransfer > 0) {
reserveAmount -= amountToTransfer;
uint256 partialDeposit = amountToTransfer / 3;
amountToTransfer = partialDeposit * 2; // reserve 1/3 to network (controller)
bytes32 secret = keccak256(abi.encodePacked(namehash, creationTime, _reserveSecret));
SlashReserve memory reserve = reservedSlashers[secret];
require(reserve.reserver != address(0), "Not reserved.");
require(reserve.blockNumber < block.number, "Cannot reveal in same block");
delete reservedSlashers[secret];
require(token.transfer(reserve.reserver, amountToTransfer), "Error in transfer.");
}
emit UsernameOwner(namehash, address(0));
}
function setState(RegistrarState _state) private {
state = _state;
emit RegistryState(_state);
}
/**
* @notice recursively erase all _labels in _subnode
* @param _idx recursive position of _labels to erase
* @param _labels list of subnode labes
* @param _subnode subnode being erased
*/
function eraseNodeHierarchy(
uint _idx,
bytes32[] _labels,
bytes32 _subnode
)
private
{
// Take ownership of the node
ensRegistry.setSubnodeOwner(_subnode, _labels[_idx], address(this));
bytes32 subnode = keccak256(abi.encodePacked(_subnode, _labels[_idx]));
// Recurse if there are more labels
if (_idx > 0) {
eraseNodeHierarchy(_idx - 1, _labels, subnode);
}
// Erase the resolver and owner records
ensRegistry.setResolver(subnode, 0);
ensRegistry.setOwner(subnode, 0);
}
/**
* @dev Decodes abi encoded data with selector for "register(bytes32,address,bytes32,bytes32)".
* @param _data Abi encoded data.
* @return Decoded registry call.
*/
function abiDecodeRegister(
bytes _data
)
private
pure
returns(
bytes4 sig,
bytes32 label,
address account,
bytes32 pubkeyA,
bytes32 pubkeyB
)
{
assembly {
sig := mload(add(_data, add(0x20, 0)))
label := mload(add(_data, 36))
account := mload(add(_data, 68))
pubkeyA := mload(add(_data, 100))
pubkeyB := mload(add(_data, 132))
}
}
}
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