embark-area-51/lib/modules/ens/contracts/HashRegistrarSimplified.sol

536 lines
18 KiB
Solidity

pragma solidity ^0.4.18;
/*
Temporary Hash Registrar
========================
This is a simplified version of a hash registrar. It is purporsefully limited:
names cannot be six letters or shorter, new auctions will stop after 4 years.
The plan is to test the basic features and then move to a new contract in at most
2 years, when some sort of renewal mechanism will be enabled.
*/
import './ENS.sol';
import './Deed.sol';
/**
* @title Registrar
* @dev The registrar handles the auction process for each subnode of the node it owns.
*/
contract Registrar {
ENS public ens;
bytes32 public rootNode;
mapping (bytes32 => Entry) _entries;
mapping (address => mapping (bytes32 => Deed)) public sealedBids;
enum Mode { Open, Auction, Owned, Forbidden, Reveal, NotYetAvailable }
uint32 constant totalAuctionLength = 5 days;
uint32 constant revealPeriod = 48 hours;
uint32 public constant launchLength = 8 weeks;
uint constant minPrice = 0.01 ether;
uint public registryStarted;
event AuctionStarted(bytes32 indexed hash, uint registrationDate);
event NewBid(bytes32 indexed hash, address indexed bidder, uint deposit);
event BidRevealed(bytes32 indexed hash, address indexed owner, uint value, uint8 status);
event HashRegistered(bytes32 indexed hash, address indexed owner, uint value, uint registrationDate);
event HashReleased(bytes32 indexed hash, uint value);
event HashInvalidated(bytes32 indexed hash, string indexed name, uint value, uint registrationDate);
struct Entry {
Deed deed;
uint registrationDate;
uint value;
uint highestBid;
}
modifier inState(bytes32 _hash, Mode _state) {
require(state(_hash) == _state);
_;
}
modifier onlyOwner(bytes32 _hash) {
require(state(_hash) == Mode.Owned && msg.sender == _entries[_hash].deed.owner());
_;
}
modifier registryOpen() {
require(now >= registryStarted && now <= registryStarted + 4 years && ens.owner(rootNode) == address(this));
_;
}
/**
* @dev Constructs a new Registrar, with the provided address as the owner of the root node.
*
* @param _ens The address of the ENS
* @param _rootNode The hash of the rootnode.
*/
function Registrar(ENS _ens, bytes32 _rootNode, uint _startDate) public {
ens = _ens;
rootNode = _rootNode;
registryStarted = _startDate > 0 ? _startDate : now;
}
/**
* @dev Start an auction for an available hash
*
* @param _hash The hash to start an auction on
*/
function startAuction(bytes32 _hash) public registryOpen() {
Mode mode = state(_hash);
if (mode == Mode.Auction) return;
require(mode == Mode.Open);
Entry storage newAuction = _entries[_hash];
newAuction.registrationDate = now + totalAuctionLength;
newAuction.value = 0;
newAuction.highestBid = 0;
AuctionStarted(_hash, newAuction.registrationDate);
}
/**
* @dev Start multiple auctions for better anonymity
*
* Anyone can start an auction by sending an array of hashes that they want to bid for.
* Arrays are sent so that someone can open up an auction for X dummy hashes when they
* are only really interested in bidding for one. This will increase the cost for an
* attacker to simply bid blindly on all new auctions. Dummy auctions that are
* open but not bid on are closed after a week.
*
* @param _hashes An array of hashes, at least one of which you presumably want to bid on
*/
function startAuctions(bytes32[] _hashes) public {
for (uint i = 0; i < _hashes.length; i ++) {
startAuction(_hashes[i]);
}
}
/**
* @dev Submit a new sealed bid on a desired hash in a blind auction
*
* Bids are sent by sending a message to the main contract with a hash and an amount. The hash
* contains information about the bid, including the bidded hash, the bid amount, and a random
* salt. Bids are not tied to any one auction until they are revealed. The value of the bid
* itself can be masqueraded by sending more than the value of your actual bid. This is
* followed by a 48h reveal period. Bids revealed after this period will be burned and the ether unrecoverable.
* Since this is an auction, it is expected that most public hashes, like known domains and common dictionary
* words, will have multiple bidders pushing the price up.
*
* @param sealedBid A sealedBid, created by the shaBid function
*/
function newBid(bytes32 sealedBid) public payable {
require(address(sealedBids[msg.sender][sealedBid]) == 0x0);
require(msg.value >= minPrice);
// Creates a new hash contract with the owner
Deed newBid = (new Deed).value(msg.value)(msg.sender);
sealedBids[msg.sender][sealedBid] = newBid;
NewBid(sealedBid, msg.sender, msg.value);
}
/**
* @dev Start a set of auctions and bid on one of them
*
* This method functions identically to calling `startAuctions` followed by `newBid`,
* but all in one transaction.
*
* @param hashes A list of hashes to start auctions on.
* @param sealedBid A sealed bid for one of the auctions.
*/
function startAuctionsAndBid(bytes32[] hashes, bytes32 sealedBid) public payable {
startAuctions(hashes);
newBid(sealedBid);
}
/**
* @dev Submit the properties of a bid to reveal them
*
* @param _hash The node in the sealedBid
* @param _value The bid amount in the sealedBid
* @param _salt The sale in the sealedBid
*/
function unsealBid(bytes32 _hash, uint _value, bytes32 _salt) public {
bytes32 seal = shaBid(_hash, msg.sender, _value, _salt);
Deed bid = sealedBids[msg.sender][seal];
require(address(bid) != 0);
sealedBids[msg.sender][seal] = Deed(0);
Entry storage h = _entries[_hash];
uint value = min(_value, bid.value());
bid.setBalance(value, true);
var auctionState = state(_hash);
if (auctionState == Mode.Owned) {
// Too late! Bidder loses their bid. Gets 0.5% back.
bid.closeDeed(5);
BidRevealed(_hash, msg.sender, value, 1);
} else if (auctionState != Mode.Reveal) {
// Invalid phase
revert();
} else if (value < minPrice || bid.creationDate() > h.registrationDate - revealPeriod) {
// Bid too low or too late, refund 99.5%
bid.closeDeed(995);
BidRevealed(_hash, msg.sender, value, 0);
} else if (value > h.highestBid) {
// New winner
// Cancel the other bid, refund 99.5%
if (address(h.deed) != 0) {
Deed previousWinner = h.deed;
previousWinner.closeDeed(995);
}
// Set new winner
// Per the rules of a vickery auction, the value becomes the previous highestBid
h.value = h.highestBid; // will be zero if there's only 1 bidder
h.highestBid = value;
h.deed = bid;
BidRevealed(_hash, msg.sender, value, 2);
} else if (value > h.value) {
// Not winner, but affects second place
h.value = value;
bid.closeDeed(995);
BidRevealed(_hash, msg.sender, value, 3);
} else {
// Bid doesn't affect auction
bid.closeDeed(995);
BidRevealed(_hash, msg.sender, value, 4);
}
}
/**
* @dev Cancel a bid
*
* @param seal The value returned by the shaBid function
*/
function cancelBid(address bidder, bytes32 seal) public {
Deed bid = sealedBids[bidder][seal];
// If a sole bidder does not `unsealBid` in time, they have a few more days
// where they can call `startAuction` (again) and then `unsealBid` during
// the revealPeriod to get back their bid value.
// For simplicity, they should call `startAuction` within
// 9 days (2 weeks - totalAuctionLength), otherwise their bid will be
// cancellable by anyone.
require(address(bid) != 0 && now >= bid.creationDate() + totalAuctionLength + 2 weeks);
// Send the canceller 0.5% of the bid, and burn the rest.
bid.setOwner(msg.sender);
bid.closeDeed(5);
sealedBids[bidder][seal] = Deed(0);
BidRevealed(seal, bidder, 0, 5);
}
/**
* @dev Finalize an auction after the registration date has passed
*
* @param _hash The hash of the name the auction is for
*/
function finalizeAuction(bytes32 _hash) public onlyOwner(_hash) {
Entry storage h = _entries[_hash];
// Handles the case when there's only a single bidder (h.value is zero)
h.value = max(h.value, minPrice);
h.deed.setBalance(h.value, true);
trySetSubnodeOwner(_hash, h.deed.owner());
HashRegistered(_hash, h.deed.owner(), h.value, h.registrationDate);
}
/**
* @dev The owner of a domain may transfer it to someone else at any time.
*
* @param _hash The node to transfer
* @param newOwner The address to transfer ownership to
*/
function transfer(bytes32 _hash, address newOwner) public onlyOwner(_hash) {
require(newOwner != 0);
Entry storage h = _entries[_hash];
h.deed.setOwner(newOwner);
trySetSubnodeOwner(_hash, newOwner);
}
/**
* @dev After some time, or if we're no longer the registrar, the owner can release
* the name and get their ether back.
*
* @param _hash The node to release
*/
function releaseDeed(bytes32 _hash) public onlyOwner(_hash) {
Entry storage h = _entries[_hash];
Deed deedContract = h.deed;
require(now >= h.registrationDate + 1 years || ens.owner(rootNode) != address(this));
h.value = 0;
h.highestBid = 0;
h.deed = Deed(0);
_tryEraseSingleNode(_hash);
deedContract.closeDeed(1000);
HashReleased(_hash, h.value);
}
/**
* @dev Submit a name 6 characters long or less. If it has been registered,
* the submitter will earn 50% of the deed value.
*
* We are purposefully handicapping the simplified registrar as a way
* to force it into being restructured in a few years.
*
* @param unhashedName An invalid name to search for in the registry.
*/
function invalidateName(string unhashedName) public inState(keccak256(unhashedName), Mode.Owned) {
require(strlen(unhashedName) <= 6);
bytes32 hash = keccak256(unhashedName);
Entry storage h = _entries[hash];
_tryEraseSingleNode(hash);
if (address(h.deed) != 0) {
// Reward the discoverer with 50% of the deed
// The previous owner gets 50%
h.value = max(h.value, minPrice);
h.deed.setBalance(h.value/2, false);
h.deed.setOwner(msg.sender);
h.deed.closeDeed(1000);
}
HashInvalidated(hash, unhashedName, h.value, h.registrationDate);
h.value = 0;
h.highestBid = 0;
h.deed = Deed(0);
}
/**
* @dev Allows anyone to delete the owner and resolver records for a (subdomain of) a
* name that is not currently owned in the registrar. If passing, eg, 'foo.bar.eth',
* the owner and resolver fields on 'foo.bar.eth' and 'bar.eth' will all be cleared.
*
* @param labels A series of label hashes identifying the name to zero out, rooted at the
* registrar's root. Must contain at least one element. For instance, to zero
* 'foo.bar.eth' on a registrar that owns '.eth', pass an array containing
* [keccak256('foo'), keccak256('bar')].
*/
function eraseNode(bytes32[] labels) public {
require(labels.length != 0);
require(state(labels[labels.length - 1]) != Mode.Owned);
_eraseNodeHierarchy(labels.length - 1, labels, rootNode);
}
/**
* @dev Transfers the deed to the current registrar, if different from this one.
*
* Used during the upgrade process to a permanent registrar.
*
* @param _hash The name hash to transfer.
*/
function transferRegistrars(bytes32 _hash) public onlyOwner(_hash) {
address registrar = ens.owner(rootNode);
require(registrar != address(this));
// Migrate the deed
Entry storage h = _entries[_hash];
h.deed.setRegistrar(registrar);
// Call the new registrar to accept the transfer
Registrar(registrar).acceptRegistrarTransfer(_hash, h.deed, h.registrationDate);
// Zero out the Entry
h.deed = Deed(0);
h.registrationDate = 0;
h.value = 0;
h.highestBid = 0;
}
/**
* @dev Accepts a transfer from a previous registrar; stubbed out here since there
* is no previous registrar implementing this interface.
*
* @param hash The sha3 hash of the label to transfer.
* @param deed The Deed object for the name being transferred in.
* @param registrationDate The date at which the name was originally registered.
*/
function acceptRegistrarTransfer(bytes32 hash, Deed deed, uint registrationDate) public {
hash; deed; registrationDate; // Don't warn about unused variables
}
// State transitions for names:
// Open -> Auction (startAuction)
// Auction -> Reveal
// Reveal -> Owned
// Reveal -> Open (if nobody bid)
// Owned -> Open (releaseDeed or invalidateName)
function state(bytes32 _hash) public view returns (Mode) {
Entry storage entry = _entries[_hash];
if (!isAllowed(_hash, now)) {
return Mode.NotYetAvailable;
} else if (now < entry.registrationDate) {
if (now < entry.registrationDate - revealPeriod) {
return Mode.Auction;
} else {
return Mode.Reveal;
}
} else {
if (entry.highestBid == 0) {
return Mode.Open;
} else {
return Mode.Owned;
}
}
}
function entries(bytes32 _hash) public view returns (Mode, address, uint, uint, uint) {
Entry storage h = _entries[_hash];
return (state(_hash), h.deed, h.registrationDate, h.value, h.highestBid);
}
/**
* @dev Determines if a name is available for registration yet
*
* Each name will be assigned a random date in which its auction
* can be started, from 0 to 8 weeks
*
* @param _hash The hash to start an auction on
* @param _timestamp The timestamp to query about
*/
function isAllowed(bytes32 _hash, uint _timestamp) public view returns (bool allowed) {
return _timestamp > getAllowedTime(_hash);
}
/**
* @dev Returns available date for hash
*
* The available time from the `registryStarted` for a hash is proportional
* to its numeric value.
*
* @param _hash The hash to start an auction on
*/
function getAllowedTime(bytes32 _hash) public view returns (uint) {
return registryStarted + ((launchLength * (uint(_hash) >> 128)) >> 128);
// Right shift operator: a >> b == a / 2**b
}
/**
* @dev Hash the values required for a secret bid
*
* @param hash The node corresponding to the desired namehash
* @param value The bid amount
* @param salt A random value to ensure secrecy of the bid
* @return The hash of the bid values
*/
function shaBid(bytes32 hash, address owner, uint value, bytes32 salt) public pure returns (bytes32) {
return keccak256(hash, owner, value, salt);
}
function _tryEraseSingleNode(bytes32 label) internal {
if (ens.owner(rootNode) == address(this)) {
ens.setSubnodeOwner(rootNode, label, address(this));
bytes32 node = keccak256(rootNode, label);
ens.setResolver(node, 0);
ens.setOwner(node, 0);
}
}
function _eraseNodeHierarchy(uint idx, bytes32[] labels, bytes32 node) internal {
// Take ownership of the node
ens.setSubnodeOwner(node, labels[idx], address(this));
node = keccak256(node, labels[idx]);
// Recurse if there are more labels
if (idx > 0) {
_eraseNodeHierarchy(idx - 1, labels, node);
}
// Erase the resolver and owner records
ens.setResolver(node, 0);
ens.setOwner(node, 0);
}
/**
* @dev Assign the owner in ENS, if we're still the registrar
*
* @param _hash hash to change owner
* @param _newOwner new owner to transfer to
*/
function trySetSubnodeOwner(bytes32 _hash, address _newOwner) internal {
if (ens.owner(rootNode) == address(this))
ens.setSubnodeOwner(rootNode, _hash, _newOwner);
}
/**
* @dev Returns the maximum of two unsigned integers
*
* @param a A number to compare
* @param b A number to compare
* @return The maximum of two unsigned integers
*/
function max(uint a, uint b) internal pure returns (uint) {
if (a > b)
return a;
else
return b;
}
/**
* @dev Returns the minimum of two unsigned integers
*
* @param a A number to compare
* @param b A number to compare
* @return The minimum of two unsigned integers
*/
function min(uint a, uint b) internal pure returns (uint) {
if (a < b)
return a;
else
return b;
}
/**
* @dev Returns the length of a given string
*
* @param s The string to measure the length of
* @return The length of the input string
*/
function strlen(string s) internal pure returns (uint) {
s; // Don't warn about unused variables
// Starting here means the LSB will be the byte we care about
uint ptr;
uint end;
assembly {
ptr := add(s, 1)
end := add(mload(s), ptr)
}
for (uint len = 0; ptr < end; len++) {
uint8 b;
assembly { b := and(mload(ptr), 0xFF) }
if (b < 0x80) {
ptr += 1;
} else if (b < 0xE0) {
ptr += 2;
} else if (b < 0xF0) {
ptr += 3;
} else if (b < 0xF8) {
ptr += 4;
} else if (b < 0xFC) {
ptr += 5;
} else {
ptr += 6;
}
}
return len;
}
}