diff options
Diffstat (limited to 'common/resolver/resolver.go')
| -rw-r--r-- | common/resolver/resolver.go | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/common/resolver/resolver.go b/common/resolver/resolver.go deleted file mode 100644 index 9016547e1..000000000 --- a/common/resolver/resolver.go +++ /dev/null @@ -1,232 +0,0 @@ -package resolver - -import ( - "encoding/binary" - "fmt" - - "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" -) - -/* -Resolver implements the Ethereum DNS mapping -HashReg : Key Hash (hash of domain name or contract code) -> Content Hash -UrlHint : Content Hash -> Url Hint - -The resolver is meant to be called by the roundtripper transport implementation -of a url scheme -*/ - -// // contract addresses will be hardcoded after they're created -var UrlHintContractAddress, HashRegContractAddress string - -const ( - txValue = "0" - txGas = "100000" - txGasPrice = "1000000000000" -) - -func abi(s string) string { - return common.ToHex(crypto.Sha3([]byte(s))[:4]) -} - -var ( - registerContentHashAbi = abi("register(uint256,uint256)") - registerUrlAbi = abi("register(uint256,uint8,uint256)") - setOwnerAbi = abi("setowner()") -) - -type Backend interface { - StorageAt(string, string) string - Transact(fromStr, toStr, nonceStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, error) -} - -type Resolver struct { - backend Backend -} - -func New(eth Backend) *Resolver { - return &Resolver{eth} -} - -// for testing and play temporarily -// ideally the HashReg and UrlHint contracts should be in the genesis block -// if we got build-in support for natspec/contract info -// there should be only one of these officially endorsed -// addresses as constants -// TODO: could get around this with namereg, check -func (self *Resolver) CreateContracts(addr common.Address) (err error) { - HashRegContractAddress, err = self.backend.Transact(addr.Hex(), "", "", txValue, txGas, txGasPrice, ContractCodeHashReg) - if err != nil { - return - } - UrlHintContractAddress, err = self.backend.Transact(addr.Hex(), "", "", txValue, txGas, txGasPrice, ContractCodeURLhint) - glog.V(logger.Detail).Infof("HashReg @ %v\nUrlHint @ %v\n", HashRegContractAddress, UrlHintContractAddress) - return -} - -// called as first step in the registration process on HashReg -func (self *Resolver) SetOwner(address common.Address) (txh string, err error) { - return self.backend.Transact( - address.Hex(), - HashRegContractAddress, - "", txValue, txGas, txGasPrice, - 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 -// kept -func (self *Resolver) RegisterContentHash(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 - return self.backend.Transact( - address.Hex(), - HashRegContractAddress, - "", txValue, txGas, txGasPrice, - data, - ) -} - -// 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 -// it could be purely -func (self *Resolver) RegisterUrl(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(), - UrlHintContractAddress, - "", txValue, txGas, txGasPrice, - data, - ) - if err != nil { - return - } - cnt++ - } - return -} - -func (self *Resolver) Register(address common.Address, codehash, dochash common.Hash, url string) (txh string, err error) { - - _, err = self.RegisterContentHash(address, codehash, dochash) - if err != nil { - return - } - return self.RegisterUrl(address, dochash, url) -} - -// resolution is costless non-transactional -// implemented as direct retrieval from db -func (self *Resolver) KeyToContentHash(khash common.Hash) (chash common.Hash, err error) { - // look up in hashReg - at := common.Bytes2Hex(common.FromHex(HashRegContractAddress)) - key := storageAddress(storageMapping(storageIdx2Addr(1), khash[:])) - hash := self.backend.StorageAt(at, key) - - if hash == "0x0" || len(hash) < 3 { - err = fmt.Errorf("content hash not found for '%v'", khash.Hex()) - return - } - copy(chash[:], common.Hex2BytesFixed(hash[2:], 32)) - return -} - -// retrieves the url-hint for the content hash - -// if we use content addressed storage, this step is no longer necessary -func (self *Resolver) ContentHashToUrl(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(UrlHintContractAddress, 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++ - } - - if len(uri) == 0 { - err = fmt.Errorf("GetURLhint: URL hint not found for '%v'", chash.Hex()) - } - return -} - -func (self *Resolver) KeyToUrl(key common.Hash) (uri string, hash common.Hash, err error) { - // look up in urlHint - hash, err = self.KeyToContentHash(key) - if err != nil { - return - } - uri, err = self.ContentHashToUrl(hash) - 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) -} |