diff options
Diffstat (limited to 'common/registrar/registrar.go')
| -rw-r--r-- | common/registrar/registrar.go | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/common/registrar/registrar.go b/common/registrar/registrar.go new file mode 100644 index 000000000..061fe9c2c --- /dev/null +++ b/common/registrar/registrar.go @@ -0,0 +1,398 @@ +package registrar + +import ( + "encoding/binary" + "fmt" + "math/big" + "regexp" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/crypto" + "github.com/ethereum/go-ethereum/logger" + "github.com/ethereum/go-ethereum/logger/glog" +) + +/* +Registrar implements the Ethereum name registrar services mapping +- arbitrary strings to ethereum addresses +- hashes to hashes +- hashes to arbitrary strings +(likely will provide lookup service for all three) + +The Registrar is used by +* the roundtripper transport implementation of +url schemes to resolve domain names and services that register these names +* contract info retrieval (NatSpec). + +The Registrar uses 3 contracts on the blockchain: +* GlobalRegistrar: Name (string) -> Address (Owner) +* HashReg : Key Hash (hash of domain name or contract code) -> Content Hash +* UrlHint : Content Hash -> Url Hint + +These contracts are (currently) not included in the genesis block. +Each Set<X> needs to be called once on each blockchain/network once. + +Contract addresses need to be set (HashReg and UrlHint retrieved from the global +registrar the first time any Registrar method is called in a client session + +So the caller needs to make sure the relevant environment initialised the desired +contracts +*/ +var ( + UrlHintAddr = "0x0" + HashRegAddr = "0x0" + // GlobalRegistrarAddr = "0x0" + GlobalRegistrarAddr = "0xc6d9d2cd449a754c494264e1809c50e34d64562b" + + zero = regexp.MustCompile("^(0x)?0*$") +) + +const ( + trueHex = "0000000000000000000000000000000000000000000000000000000000000001" + falseHex = "0000000000000000000000000000000000000000000000000000000000000000" +) + +func abiSignature(s string) string { + return common.ToHex(crypto.Sha3([]byte(s))[:4]) +} + +var ( + HashRegName = "HashReg" + UrlHintName = "UrlHint" + + registerContentHashAbi = abiSignature("register(uint256,uint256)") + registerUrlAbi = abiSignature("register(uint256,uint8,uint256)") + setOwnerAbi = abiSignature("setowner()") + reserveAbi = abiSignature("reserve(bytes32)") + resolveAbi = abiSignature("addr(bytes32)") + registerAbi = abiSignature("setAddress(bytes32,address,bool)") + addressAbiPrefix = falseHex[:24] +) + +// Registrar's backend is defined as an interface (implemented by xeth, but could be remote) +type Backend interface { + StorageAt(string, string) string + Transact(fromStr, toStr, nonceStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, error) + Call(fromStr, toStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, string, error) +} + +// TODO Registrar should also just implement The Resolver and Registry interfaces +// Simplify for now. +type VersionedRegistrar interface { + Resolver(*big.Int) *Registrar + Registry() *Registrar +} + +type Registrar struct { + backend Backend +} + +func New(b Backend) (res *Registrar) { + res = &Registrar{b} + return +} + +func (self *Registrar) SetGlobalRegistrar(namereg string, addr common.Address) (err error) { + if namereg != "" { + GlobalRegistrarAddr = namereg + return + } + if GlobalRegistrarAddr == "0x0" || GlobalRegistrarAddr == "0x" { + if (addr == common.Address{}) { + err = fmt.Errorf("GlobalRegistrar address not found and sender for creation not given") + return + } else { + GlobalRegistrarAddr, err = self.backend.Transact(addr.Hex(), "", "", "", "800000", "", GlobalRegistrarCode) + if err != nil { + err = fmt.Errorf("GlobalRegistrar address not found and sender for creation failed: %v", err) + return + } + } + } + return +} + +func (self *Registrar) SetHashReg(hashreg string, addr common.Address) (err error) { + if hashreg != "" { + HashRegAddr = hashreg + } else { + if !zero.MatchString(HashRegAddr) { + return + } + nameHex, extra := encodeName(HashRegName, 2) + hashRegAbi := resolveAbi + nameHex + extra + glog.V(logger.Detail).Infof("\ncall HashRegAddr %v with %v\n", GlobalRegistrarAddr, hashRegAbi) + HashRegAddr, _, err = self.backend.Call("", GlobalRegistrarAddr, "", "", "", hashRegAbi) + if err != nil || zero.MatchString(HashRegAddr) { + if (addr == common.Address{}) { + err = fmt.Errorf("HashReg address not found and sender for creation not given") + return + } + + HashRegAddr, err = self.backend.Transact(addr.Hex(), "", "", "", "200000", "", HashRegCode) + if err != nil { + err = fmt.Errorf("HashReg address not found and sender for creation failed: %v", err) + } + glog.V(logger.Detail).Infof("created HashRegAddr @ %v\n", HashRegAddr) + } else { + glog.V(logger.Detail).Infof("HashRegAddr found at @ %v\n", HashRegAddr) + return + } + } + + // register as HashReg + self.ReserveName(addr, HashRegName) + self.SetAddressToName(addr, HashRegName, common.HexToAddress(HashRegAddr)) + + return +} + +func (self *Registrar) SetUrlHint(urlhint string, addr common.Address) (err error) { + if urlhint != "" { + UrlHintAddr = urlhint + } else { + if !zero.MatchString(UrlHintAddr) { + return + } + nameHex, extra := encodeName(UrlHintName, 2) + urlHintAbi := resolveAbi + nameHex + extra + glog.V(logger.Detail).Infof("UrlHint address query data: %s to %s", urlHintAbi, GlobalRegistrarAddr) + UrlHintAddr, _, err = self.backend.Call("", GlobalRegistrarAddr, "", "", "", urlHintAbi) + if err != nil || zero.MatchString(UrlHintAddr) { + if (addr == common.Address{}) { + err = fmt.Errorf("UrlHint address not found and sender for creation not given") + return + } + UrlHintAddr, err = self.backend.Transact(addr.Hex(), "", "", "", "210000", "", UrlHintCode) + if err != nil { + err = fmt.Errorf("UrlHint address not found and sender for creation failed: %v", err) + } + glog.V(logger.Detail).Infof("created UrlHint @ %v\n", HashRegAddr) + } else { + glog.V(logger.Detail).Infof("UrlHint found @ %v\n", HashRegAddr) + return + } + } + + // register as UrlHint + self.ReserveName(addr, UrlHintName) + self.SetAddressToName(addr, UrlHintName, common.HexToAddress(UrlHintAddr)) + + return +} + +// ReserveName(from, name) reserves name for the sender address in the globalRegistrar +// the tx needs to be mined to take effect +func (self *Registrar) ReserveName(address common.Address, name string) (txh string, err error) { + nameHex, extra := encodeName(name, 2) + abi := reserveAbi + nameHex + extra + glog.V(logger.Detail).Infof("Reserve data: %s", abi) + return self.backend.Transact( + address.Hex(), + GlobalRegistrarAddr, + "", "", "", "", + abi, + ) +} + +// SetAddressToName(from, name, addr) will set the Address to address for name +// in the globalRegistrar using from as the sender of the transaction +// the tx needs to be mined to take effect +func (self *Registrar) SetAddressToName(from common.Address, name string, address common.Address) (txh string, err error) { + nameHex, extra := encodeName(name, 6) + addrHex := encodeAddress(address) + + abi := registerAbi + nameHex + addrHex + trueHex + extra + glog.V(logger.Detail).Infof("SetAddressToName data: %s to %s ", abi, GlobalRegistrarAddr) + + return self.backend.Transact( + from.Hex(), + GlobalRegistrarAddr, + "", "", "", "", + abi, + ) +} + +// NameToAddr(from, name) queries the registrar for the address on name +func (self *Registrar) NameToAddr(from common.Address, name string) (address common.Address, err error) { + nameHex, extra := encodeName(name, 2) + abi := resolveAbi + nameHex + extra + glog.V(logger.Detail).Infof("NameToAddr data: %s", abi) + res, _, err := self.backend.Call( + from.Hex(), + GlobalRegistrarAddr, + "", "", "", + abi, + ) + if err != nil { + return + } + address = common.HexToAddress(res) + return +} + +// called as first step in the registration process on HashReg +func (self *Registrar) SetOwner(address common.Address) (txh string, err error) { + return self.backend.Transact( + address.Hex(), + HashRegAddr, + "", "", "", "", + setOwnerAbi, + ) +} + +// registers some content hash to a key/code hash +// e.g., the contract Info combined Json Doc's ContentHash +// to CodeHash of a contract or hash of a domain +func (self *Registrar) SetHashToHash(address common.Address, codehash, dochash common.Hash) (txh string, err error) { + _, err = self.SetOwner(address) + if err != nil { + return + } + codehex := common.Bytes2Hex(codehash[:]) + dochex := common.Bytes2Hex(dochash[:]) + + data := registerContentHashAbi + codehex + dochex + glog.V(logger.Detail).Infof("SetHashToHash data: %s sent to %v\n", data, HashRegAddr) + return self.backend.Transact( + address.Hex(), + HashRegAddr, + "", "", "", "", + data, + ) +} + +// SetUrlToHash(from, hash, url) registers a url to a content hash so that the content can be fetched +// address is used as sender for the transaction and will be the owner of a new +// registry entry on first time use +// FIXME: silently doing nothing if sender is not the owner +// note that with content addressed storage, this step is no longer necessary +func (self *Registrar) SetUrlToHash(address common.Address, hash common.Hash, url string) (txh string, err error) { + hashHex := common.Bytes2Hex(hash[:]) + var urlHex string + urlb := []byte(url) + var cnt byte + n := len(urlb) + + for n > 0 { + if n > 32 { + n = 32 + } + urlHex = common.Bytes2Hex(urlb[:n]) + urlb = urlb[n:] + n = len(urlb) + bcnt := make([]byte, 32) + bcnt[31] = cnt + data := registerUrlAbi + + hashHex + + common.Bytes2Hex(bcnt) + + common.Bytes2Hex(common.Hex2BytesFixed(urlHex, 32)) + txh, err = self.backend.Transact( + address.Hex(), + UrlHintAddr, + "", "", "", "", + data, + ) + if err != nil { + return + } + cnt++ + } + return +} + +// HashToHash(key) resolves contenthash for key (a hash) using HashReg +// resolution is costless non-transactional +// implemented as direct retrieval from db +func (self *Registrar) HashToHash(khash common.Hash) (chash common.Hash, err error) { + // look up in hashReg + at := HashRegAddr[2:] + key := storageAddress(storageMapping(storageIdx2Addr(1), khash[:])) + hash := self.backend.StorageAt(at, key) + + if hash == "0x0" || len(hash) < 3 || (hash == common.Hash{}.Hex()) { + err = fmt.Errorf("content hash not found for '%v'", khash.Hex()) + return + } + copy(chash[:], common.Hex2BytesFixed(hash[2:], 32)) + return +} + +// HashToUrl(contenthash) resolves the url for contenthash using UrlHint +// resolution is costless non-transactional +// implemented as direct retrieval from db +// if we use content addressed storage, this step is no longer necessary +func (self *Registrar) HashToUrl(chash common.Hash) (uri string, err error) { + // look up in URL reg + var str string = " " + var idx uint32 + for len(str) > 0 { + mapaddr := storageMapping(storageIdx2Addr(1), chash[:]) + key := storageAddress(storageFixedArray(mapaddr, storageIdx2Addr(idx))) + hex := self.backend.StorageAt(UrlHintAddr[2:], key) + str = string(common.Hex2Bytes(hex[2:])) + l := len(str) + for (l > 0) && (str[l-1] == 0) { + l-- + } + + str = str[:l] + uri = uri + str + idx++ + } + + l := 0 + for (l < len(uri)) && (uri[l] == 0) { + l++ + } + uri = uri[l:] + + if len(uri) == 0 { + err = fmt.Errorf("GetURLhint: URL hint not found for '%v'", chash.Hex()) + } + return +} + +func storageIdx2Addr(varidx uint32) []byte { + data := make([]byte, 32) + binary.BigEndian.PutUint32(data[28:32], varidx) + return data +} + +func storageMapping(addr, key []byte) []byte { + data := make([]byte, 64) + copy(data[0:32], key[0:32]) + copy(data[32:64], addr[0:32]) + sha := crypto.Sha3(data) + return sha +} + +func storageFixedArray(addr, idx []byte) []byte { + var carry byte + for i := 31; i >= 0; i-- { + var b byte = addr[i] + idx[i] + carry + if b < addr[i] { + carry = 1 + } else { + carry = 0 + } + addr[i] = b + } + return addr +} + +func storageAddress(addr []byte) string { + return common.ToHex(addr) +} + +func encodeAddress(address common.Address) string { + return addressAbiPrefix + address.Hex()[2:] +} + +func encodeName(name string, index uint8) (string, string) { + extra := common.Bytes2Hex([]byte(name)) + if len(name) > 32 { + return fmt.Sprintf("%064x", index), extra + } + return extra + falseHex[len(extra):], "" +} |