mirror of https://github.com/status-im/op-geth.git
129 lines
3.1 KiB
Go
129 lines
3.1 KiB
Go
package resolver
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/crypto"
|
|
xe "github.com/ethereum/go-ethereum/xeth"
|
|
)
|
|
|
|
/*
|
|
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 string = "0000000000000000000000000000000000000000000000000000000000001234"
|
|
var HashRegContractAddress string = "0000000000000000000000000000000000000000000000000000000000005678"
|
|
|
|
func CreateContracts(xeth *xe.XEth, addr string) {
|
|
var err error
|
|
URLHintContractAddress, err = xeth.Transact(addr, "", "", "100000000000", "1000000", "100000", ContractCodeURLhint)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
HashRegContractAddress, err = xeth.Transact(addr, "", "", "100000000000", "1000000", "100000", ContractCodeHashReg)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
type Resolver struct {
|
|
backend Backend
|
|
urlHintContractAddress string
|
|
hashRegContractAddress string
|
|
}
|
|
|
|
type Backend interface {
|
|
StorageAt(string, string) string
|
|
}
|
|
|
|
func New(eth Backend, uhca, nrca string) *Resolver {
|
|
return &Resolver{eth, uhca, nrca}
|
|
}
|
|
|
|
func (self *Resolver) KeyToContentHash(khash common.Hash) (chash common.Hash, err error) {
|
|
// look up in hashReg
|
|
key := storageAddress(storageMapping(storageIdx2Addr(1), khash[:]))
|
|
hash := self.backend.StorageAt(self.hashRegContractAddress, key)
|
|
|
|
if hash == "0x0" || len(hash) < 3 {
|
|
err = fmt.Errorf("GetHashReg: content hash not found")
|
|
return
|
|
}
|
|
|
|
copy(chash[:], common.Hex2BytesFixed(hash[2:], 32))
|
|
return
|
|
}
|
|
|
|
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(self.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")
|
|
}
|
|
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])
|
|
return crypto.Sha3(data)
|
|
}
|
|
|
|
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)
|
|
}
|