// Copyright 2018 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 mru
import (
"bytes"
"encoding/json"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/swarm/storage"
)
// updateRequestJSON represents a JSON-serialized UpdateRequest
type updateRequestJSON struct {
Name string `json:"name,omitempty"`
Frequency uint64 `json:"frequency,omitempty"`
StartTime uint64 `json:"startTime,omitempty"`
Owner string `json:"ownerAddr,omitempty"`
RootAddr string `json:"rootAddr,omitempty"`
MetaHash string `json:"metaHash,omitempty"`
Version uint32 `json:"version,omitempty"`
Period uint32 `json:"period,omitempty"`
Data string `json:"data,omitempty"`
Multihash bool `json:"multiHash"`
Signature string `json:"signature,omitempty"`
}
// Request represents an update and/or resource create message
type Request struct {
SignedResourceUpdate
metadata ResourceMetadata
isNew bool
}
var zeroAddr = common.Address{}
// NewCreateUpdateRequest returns a ready to sign request to create and initialize a resource with data
func NewCreateUpdateRequest(metadata *ResourceMetadata) (*Request, error) {
request, err := NewCreateRequest(metadata)
if err != nil {
return nil, err
}
// get the current time
now := TimestampProvider.Now().Time
request.version = 1
request.period, err = getNextPeriod(metadata.StartTime.Time, now, metadata.Frequency)
if err != nil {
return nil, err
}
return request, nil
}
// NewCreateRequest returns a request to create a new resource
func NewCreateRequest(metadata *ResourceMetadata) (request *Request, err error) {
if metadata.StartTime.Time == 0 { // get the current time
metadata.StartTime = TimestampProvider.Now()
}
if metadata.Owner == zeroAddr {
return nil, NewError(ErrInvalidValue, "OwnerAddr is not set")
}
request = &Request{
metadata: *metadata,
}
request.rootAddr, request.metaHash, _, err = request.metadata.serializeAndHash()
request.isNew = true
return request, nil
}
// Frequency returns the resource's expected update frequency
func (r *Request) Frequency() uint64 {
return r.metadata.Frequency
}
// Name returns the resource human-readable name
func (r *Request) Name() string {
return r.metadata.Name
}
// Multihash returns true if the resource data should be interpreted as a multihash
func (r *Request) Multihash() bool {
return r.multihash
}
// Period returns in which period the resource will be published
func (r *Request) Period() uint32 {
return r.period
}
// Version returns the resource version to publish
func (r *Request) Version() uint32 {
return r.version
}
// RootAddr returns the metadata chunk address
func (r *Request) RootAddr() storage.Address {
return r.rootAddr
}
// StartTime returns the time that the resource was/will be created at
func (r *Request) StartTime() Timestamp {
return r.metadata.StartTime
}
// Owner returns the resource owner's address
func (r *Request) Owner() common.Address {
return r.metadata.Owner
}
// Sign executes the signature to validate the resource and sets the owner address field
func (r *Request) Sign(signer Signer) error {
if r.metadata.Owner != zeroAddr && r.metadata.Owner != signer.Address() {
return NewError(ErrInvalidSignature, "Signer does not match current owner of the resource")
}
if err := r.SignedResourceUpdate.Sign(signer); err != nil {
return err
}
r.metadata.Owner = signer.Address()
return nil
}
// SetData stores the payload data the resource will be updated with
func (r *Request) SetData(data []byte, multihash bool) {
r.data = data
r.multihash = multihash
r.signature = nil
if !r.isNew {
r.metadata.Frequency = 0 // mark as update
}
}
func (r *Request) IsNew() bool {
return r.metadata.Frequency > 0 && (r.period <= 1 || r.version <= 1)
}
func (r *Request) IsUpdate() bool {
return r.signature != nil
}
// fromJSON takes an update request JSON and populates an UpdateRequest
func (r *Request) fromJSON(j *updateRequestJSON) error {
r.version = j.Version
r.period = j.Period
r.multihash = j.Multihash
r.metadata.Name = j.Name
r.metadata.Frequency = j.Frequency
r.metadata.StartTime.Time = j.StartTime
if err := decodeHexArray(r.metadata.Owner[:], j.Owner, "ownerAddr"); err != nil {
return err
}
var err error
if j.Data != "" {
r.data, err = hexutil.Decode(j.Data)
if err != nil {
return NewError(ErrInvalidValue, "Cannot decode data")
}
}
var declaredRootAddr storage.Address
var declaredMetaHash []byte
declaredRootAddr, err = decodeHexSlice(j.RootAddr, storage.AddressLength, "rootAddr")
if err != nil {
return err
}
declaredMetaHash, err = decodeHexSlice(j.MetaHash, 32, "metaHash")
if err != nil {
return err
}
if r.IsNew() {
// for new resource creation, rootAddr and metaHash are optional because
// we can derive them from the content itself.
// however, if the user sent them, we check them for consistency.
r.rootAddr, r.metaHash, _, err = r.metadata.serializeAndHash()
if err != nil {
return err
}
if j.RootAddr != "" && !bytes.Equal(declaredRootAddr, r.rootAddr) {
return NewError(ErrInvalidValue, "rootAddr does not match resource metadata")
}
if j.MetaHash != "" && !bytes.Equal(declaredMetaHash, r.metaHash) {
return NewError(ErrInvalidValue, "metaHash does not match resource metadata")
}
} else {
//Update message
r.rootAddr = declaredRootAddr
r.metaHash = declaredMetaHash
}
if j.Signature != "" {
sigBytes, err := hexutil.Decode(j.Signature)
if err != nil || len(sigBytes) != signatureLength {
return NewError(ErrInvalidSignature, "Cannot decode signature")
}
r.signature = new(Signature)
r.updateAddr = r.UpdateAddr()
copy(r.signature[:], sigBytes)
}
return nil
}
func decodeHexArray(dst []byte, src, name string) error {
bytes, err := decodeHexSlice(src, len(dst), name)
if err != nil {
return err
}
if bytes != nil {
copy(dst, bytes)
}
return nil
}
func decodeHexSlice(src string, expectedLength int, name string) (bytes []byte, err error) {
if src != "" {
bytes, err = hexutil.Decode(src)
if err != nil || len(bytes) != expectedLength {
return nil, NewErrorf(ErrInvalidValue, "Cannot decode %s", name)
}
}
return bytes, nil
}
// UnmarshalJSON takes a JSON structure stored in a byte array and populates the Request object
// Implements json.Unmarshaler interface
func (r *Request) UnmarshalJSON(rawData []byte) error {
var requestJSON updateRequestJSON
if err := json.Unmarshal(rawData, &requestJSON); err != nil {
return err
}
return r.fromJSON(&requestJSON)
}
// MarshalJSON takes an update request and encodes it as a JSON structure into a byte array
// Implements json.Marshaler interface
func (r *Request) MarshalJSON() (rawData []byte, err error) {
var signatureString, dataHashString, rootAddrString, metaHashString string
if r.signature != nil {
signatureString = hexutil.Encode(r.signature[:])
}
if r.data != nil {
dataHashString = hexutil.Encode(r.data)
}
if r.rootAddr != nil {
rootAddrString = hexutil.Encode(r.rootAddr)
}
if r.metaHash != nil {
metaHashString = hexutil.Encode(r.metaHash)
}
var ownerAddrString string
if r.metadata.Frequency == 0 {
ownerAddrString = ""
} else {
ownerAddrString = hexutil.Encode(r.metadata.Owner[:])
}
requestJSON := &updateRequestJSON{
Name: r.metadata.Name,
Frequency: r.metadata.Frequency,
StartTime: r.metadata.StartTime.Time,
Version: r.version,
Period: r.period,
Owner: ownerAddrString,
Data: dataHashString,
Multihash: r.multihash,
Signature: signatureString,
RootAddr: rootAddrString,
MetaHash: metaHashString,
}
return json.Marshal(requestJSON)
}
