path: root/swarm/api/config.go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package api

import (
    "crypto/ecdsa"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "os"
    "path/filepath"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/swarm/network"
    "github.com/ethereum/go-ethereum/swarm/services/swap"
    "github.com/ethereum/go-ethereum/swarm/storage"
)

const (
    DefaultHTTPListenAddr = "127.0.0.1"
    DefaultHTTPPort       = "8500"
)

var (
    ensRootAddress = common.HexToAddress("0x112234455c3a32fd11230c42e7bccd4a84e02010")
)

// separate bzz directories
// allow several bzz nodes running in parallel
type Config struct {
    // serialised/persisted fields
    *storage.StoreParams
    *storage.ChunkerParams
    *network.HiveParams
    Swap *swap.SwapParams
    *network.SyncParams
    Path       string
    ListenAddr string
    Port       string
    PublicKey  string
    BzzKey     string
    EnsRoot    common.Address
    NetworkId  uint64
}

// config is agnostic to where private key is coming from
// so managing accounts is outside swarm and left to wrappers
func NewConfig(path string, contract common.Address, prvKey *ecdsa.PrivateKey, networkId uint64) (self *Config, err error) {
    address := crypto.PubkeyToAddress(prvKey.PublicKey) // default beneficiary address
    dirpath := filepath.Join(path, "bzz-"+common.Bytes2Hex(address.Bytes()))
    err = os.MkdirAll(dirpath, os.ModePerm)
    if err != nil {
        return
    }
    confpath := filepath.Join(dirpath, "config.json")
    var data []byte
    pubkey := crypto.FromECDSAPub(&prvKey.PublicKey)
    pubkeyhex := common.ToHex(pubkey)
    keyhex := crypto.Keccak256Hash(pubkey).Hex()

    self = &Config{
        SyncParams:    network.NewSyncParams(dirpath),
        HiveParams:    network.NewHiveParams(dirpath),
        ChunkerParams: storage.NewChunkerParams(),
        StoreParams:   storage.NewStoreParams(dirpath),
        ListenAddr:    DefaultHTTPListenAddr,
        Port:          DefaultHTTPPort,
        Path:          dirpath,
        Swap:          swap.DefaultSwapParams(contract, prvKey),
        PublicKey:     pubkeyhex,
        BzzKey:        keyhex,
        EnsRoot:       ensRootAddress,
        NetworkId:     networkId,
    }
    data, err = ioutil.ReadFile(confpath)

    // if not set in function param, then set default for swarm network, will be overwritten by config file if present
    if networkId == 0 {
        self.NetworkId = network.NetworkId
    }

    if err != nil {
        if !os.IsNotExist(err) {
            return
        }

        // file does not exist
        // write out config file
        err = self.Save()
        if err != nil {
            err = fmt.Errorf("error writing config: %v", err)
        }
        return
    }

    // file exists, deserialise
    err = json.Unmarshal(data, self)
    if err != nil {
        return nil, fmt.Errorf("unable to parse config: %v", err)
    }
    // check public key
    if pubkeyhex != self.PublicKey {
        return nil, fmt.Errorf("public key does not match the one in the config file %v != %v", pubkeyhex, self.PublicKey)
    }
    if keyhex != self.BzzKey {
        return nil, fmt.Errorf("bzz key does not match the one in the config file %v != %v", keyhex, self.BzzKey)
    }

    // if set in function param, replace id set from config file
    if networkId != 0 {
        self.NetworkId = networkId
    }

    self.Swap.SetKey(prvKey)

    if (self.EnsRoot == common.Address{}) {
        self.EnsRoot = ensRootAddress
    }

    return
}

func (self *Config) Save() error {
    data, err := json.MarshalIndent(self, "", "    ")
    if err != nil {
        return err
    }
    err = os.MkdirAll(self.Path, os.ModePerm)
    if err != nil {
        return err
    }
    confpath := filepath.Join(self.Path, "config.json")
    return ioutil.WriteFile(confpath, data, os.ModePerm)
}