cerc-io/plugeth
18
0
Fork 1
Code Issues 4 Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #1635 from bas-vk/useragent

Browse Source 
support for user agents
This commit is contained in:
Jeffrey Wilcke 2015-08-13 16:25:33 -07:00
commit 28b14d3e6d
19 changed files with 363 additions and 90 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
cmd/geth/js.go
View File

@ -145,19 +145,15 @@ func apiWordCompleter(line string, pos int) (head string, completions []string,
return begin, completionWords, end
}
func newLightweightJSRE(libPath string, client comms.EthereumClient, interactive bool, f xeth.Frontend) *jsre {
func newLightweightJSRE(libPath string, client comms.EthereumClient, interactive bool) *jsre {
js := &jsre{ps1: "> "}
js.wait = make(chan *big.Int)
js.client = client
js.ds = docserver.New("/")
if f == nil {
f = js
}
// update state in separare forever blocks
js.re = re.New(libPath)
if err := js.apiBindings(f); err != nil {
if err := js.apiBindings(js); err != nil {
utils.Fatalf("Unable to initialize console - %v", err)
}
@ -291,7 +287,7 @@ func (js *jsre) apiBindings(f xeth.Frontend) error {
utils.Fatalf("Unable to determine supported api's: %v", err)
}
jeth := rpc.NewJeth(api.Merge(apiImpl...), js.re, js.client)
jeth := rpc.NewJeth(api.Merge(apiImpl...), js.re, js.client, f)
js.re.Set("jeth", struct{}{})
t, _ := js.re.Get("jeth")
jethObj := t.Object()

2
cmd/geth/main.go
View File

@ -425,7 +425,7 @@ func attach(ctx *cli.Context) {
ctx.GlobalString(utils.JSpathFlag.Name),
client,
true,
nil)
)
if ctx.GlobalString(utils.ExecFlag.Name) != "" {
repl.batch(ctx.GlobalString(utils.ExecFlag.Name))

25
cmd/utils/flags.go
View File

@ -21,30 +21,32 @@ import (
"fmt"
"log"
"math/big"
"net"
"net/http"
"os"
"path/filepath"
"runtime"
"strconv"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/metrics"
"github.com/codegangsta/cli"
"github.com/ethereum/ethash"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/eth"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/p2p/nat"
"github.com/ethereum/go-ethereum/rpc/api"
"github.com/ethereum/go-ethereum/rpc/codec"
"github.com/ethereum/go-ethereum/rpc/comms"
"github.com/ethereum/go-ethereum/rpc/shared"
"github.com/ethereum/go-ethereum/rpc/useragent"
"github.com/ethereum/go-ethereum/xeth"
)
@ -518,15 +520,20 @@ func StartIPC(eth *eth.Ethereum, ctx *cli.Context) error {
Endpoint: IpcSocketPath(ctx),
}
xeth := xeth.New(eth, nil)
codec := codec.JSON
initializer := func(conn net.Conn) (shared.EthereumApi, error) {
fe := useragent.NewRemoteFrontend(conn, eth.AccountManager())
xeth := xeth.New(eth, fe)
codec := codec.JSON
apis, err := api.ParseApiString(ctx.GlobalString(IPCApiFlag.Name), codec, xeth, eth)
if err != nil {
return err
apis, err := api.ParseApiString(ctx.GlobalString(IPCApiFlag.Name), codec, xeth, eth)
if err != nil {
return nil, err
}
return api.Merge(apis...), nil
}
return comms.StartIpc(config, codec, api.Merge(apis...))
return comms.StartIpc(config, codec.JSON, initializer)
}
func StartRPC(eth *eth.Ethereum, ctx *cli.Context) error {

9
rpc/api/admin.go
View File

@ -37,6 +37,7 @@ import (
"github.com/ethereum/go-ethereum/rpc/codec"
"github.com/ethereum/go-ethereum/rpc/comms"
"github.com/ethereum/go-ethereum/rpc/shared"
"github.com/ethereum/go-ethereum/rpc/useragent"
"github.com/ethereum/go-ethereum/xeth"
)
@ -71,6 +72,7 @@ var (
"admin_httpGet": (*adminApi).HttpGet,
"admin_sleepBlocks": (*adminApi).SleepBlocks,
"admin_sleep": (*adminApi).Sleep,
"admin_enableUserAgent": (*adminApi).EnableUserAgent,
}
)
@ -474,3 +476,10 @@ func (self *adminApi) HttpGet(req *shared.Request) (interface{}, error) {
return string(resp), nil
}
func (self *adminApi) EnableUserAgent(req *shared.Request) (interface{}, error) {
if fe, ok := self.xeth.Frontend().(*useragent.RemoteFrontend); ok {
fe.Enable()
}
return true, nil
}

3
rpc/api/net.go
View File

@ -32,7 +32,7 @@ var (
netMapping = map[string]nethandler{
"net_peerCount": (*netApi).PeerCount,
"net_listening": (*netApi).IsListening,
"net_version": (*netApi).Version,
"net_version": (*netApi).Version,
}
)
@ -97,4 +97,3 @@ func (self *netApi) IsListening(req *shared.Request) (interface{}, error) {
func (self *netApi) Version(req *shared.Request) (interface{}, error) {
return self.xeth.NetworkVersion(), nil
}

22
rpc/api/personal.go
View File

@ -17,6 +17,7 @@
package api
import (
"fmt"
"time"
"github.com/ethereum/go-ethereum/common"
@ -125,18 +126,17 @@ func (self *personalApi) UnlockAccount(req *shared.Request) (interface{}, error)
return nil, shared.NewDecodeParamError(err.Error())
}
var err error
if len(args.Passphrase) == 0 {
fe := self.xeth.Frontend()
if fe == nil {
return false, fmt.Errorf("No password provided")
}
return fe.UnlockAccount(common.HexToAddress(args.Address).Bytes()), nil
}
am := self.ethereum.AccountManager()
addr := common.HexToAddress(args.Address)
if args.Duration == -1 {
err = am.Unlock(addr, args.Passphrase)
} else {
err = am.TimedUnlock(addr, args.Passphrase, time.Duration(args.Duration)*time.Second)
}
if err == nil {
return true, nil
}
return false, err
err := am.TimedUnlock(addr, args.Passphrase, time.Duration(args.Duration)*time.Second)
return err == nil, err
}

22
rpc/api/personal_args.go
View File

@ -86,10 +86,10 @@ func (args *UnlockAccountArgs) UnmarshalJSON(b []byte) (err error) {
return shared.NewDecodeParamError(err.Error())
}
args.Duration = -1
args.Duration = 0
if len(obj) < 2 {
return shared.NewInsufficientParamsError(len(obj), 2)
if len(obj) < 1 {
return shared.NewInsufficientParamsError(len(obj), 1)
}
if addrstr, ok := obj[0].(string); ok {
@ -98,10 +98,18 @@ func (args *UnlockAccountArgs) UnmarshalJSON(b []byte) (err error) {
return shared.NewInvalidTypeError("address", "not a string")
}
if passphrasestr, ok := obj[1].(string); ok {
args.Passphrase = passphrasestr
} else {
return shared.NewInvalidTypeError("passphrase", "not a string")
if len(obj) >= 2 && obj[1] != nil {
if passphrasestr, ok := obj[1].(string); ok {
args.Passphrase = passphrasestr
} else {
return shared.NewInvalidTypeError("passphrase", "not a string")
}
}
if len(obj) >= 3 && obj[2] != nil {
if duration, ok := obj[2].(float64); ok {
args.Duration = int(duration)
}
}
return nil

0
rpc/api/ssh_js.go → rpc/api/shh_js.go
View File

2
rpc/codec/codec.go
View File

@ -31,6 +31,8 @@ type ApiCoder interface {
ReadRequest() ([]*shared.Request, bool, error)
// Parse response message from underlying stream
ReadResponse() (interface{}, error)
// Read raw message from underlying stream
Recv() (interface{}, error)
// Encode response to encoded form in underlying stream
WriteResponse(interface{}) error
// Decode single message from data

43
rpc/codec/json.go
View File

@ -21,6 +21,7 @@ import (
"fmt"
"net"
"time"
"strings"
"github.com/ethereum/go-ethereum/rpc/shared"
)
@ -73,35 +74,41 @@ func (self *JsonCodec) ReadRequest() (requests []*shared.Request, isBatch bool,
return nil, false, err
}
func (self *JsonCodec) ReadResponse() (interface{}, error) {
bytesInBuffer := 0
buf := make([]byte, MAX_RESPONSE_SIZE)
deadline := time.Now().Add(READ_TIMEOUT * time.Second)
if err := self.c.SetDeadline(deadline); err != nil {
func (self *JsonCodec) Recv() (interface{}, error) {
var msg json.RawMessage
err := self.d.Decode(&msg)
if err != nil {
self.c.Close()
return nil, err
}
for {
n, err := self.c.Read(buf[bytesInBuffer:])
if err != nil {
return nil, err
}
bytesInBuffer += n
return msg, err
}
var failure shared.ErrorResponse
if err = json.Unmarshal(buf[:bytesInBuffer], &failure); err == nil && failure.Error != nil {
func (self *JsonCodec) ReadResponse() (interface{}, error) {
in, err := self.Recv()
if err != nil {
return nil, err
}
if msg, ok := in.(json.RawMessage); ok {
var req *shared.Request
if err = json.Unmarshal(msg, &req); err == nil && strings.HasPrefix(req.Method, "agent_") {
return req, nil
}
var failure *shared.ErrorResponse
if err = json.Unmarshal(msg, &failure); err == nil && failure.Error != nil {
return failure, fmt.Errorf(failure.Error.Message)
}
var success shared.SuccessResponse
if err = json.Unmarshal(buf[:bytesInBuffer], &success); err == nil {
var success *shared.SuccessResponse
if err = json.Unmarshal(msg, &success); err == nil {
return success, nil
}
}
self.c.Close()
return nil, fmt.Errorf("Unable to read response")
return in, err
}
// Decode data

2
rpc/comms/comms.go
View File

@ -49,7 +49,7 @@ var (
)
type EthereumClient interface {
// Close underlaying connection
// Close underlying connection
Close()
// Send request
Send(interface{}) error

2
rpc/comms/inproc.go
View File

@ -60,7 +60,7 @@ func (self *InProcClient) Send(req interface{}) error {
}
func (self *InProcClient) Recv() (interface{}, error) {
return self.lastRes, self.lastErr
return *shared.NewRpcResponse(self.lastId, self.lastJsonrpc, self.lastRes, self.lastErr), nil
}
func (self *InProcClient) SupportedModules() (map[string]string, error) {

35
rpc/comms/ipc.go
View File

@ -44,35 +44,18 @@ func (self *ipcClient) Close() {
func (self *ipcClient) Send(req interface{}) error {
var err error
if r, ok := req.(*shared.Request); ok {
if err = self.coder.WriteResponse(r); err != nil {
if _, ok := err.(*net.OpError); ok { // connection lost, retry once
if err = self.reconnect(); err == nil {
err = self.coder.WriteResponse(r)
}
if err = self.coder.WriteResponse(req); err != nil {
if _, ok := err.(*net.OpError); ok { // connection lost, retry once
if err = self.reconnect(); err == nil {
err = self.coder.WriteResponse(req)
}
}
return err
}
return fmt.Errorf("Invalid request (%T)", req)
return err
}
func (self *ipcClient) Recv() (interface{}, error) {
res, err := self.coder.ReadResponse()
if err != nil {
return nil, err
}
if r, ok := res.(shared.SuccessResponse); ok {
return r.Result, nil
}
if r, ok := res.(shared.ErrorResponse); ok {
return r.Error, nil
}
return res, err
return self.coder.ReadResponse()
}
func (self *ipcClient) SupportedModules() (map[string]string, error) {
@ -91,7 +74,7 @@ func (self *ipcClient) SupportedModules() (map[string]string, error) {
return nil, err
}
if sucRes, ok := res.(shared.SuccessResponse); ok {
if sucRes, ok := res.(*shared.SuccessResponse); ok {
data, _ := json.Marshal(sucRes.Result)
modules := make(map[string]string)
err = json.Unmarshal(data, &modules)
@ -109,8 +92,8 @@ func NewIpcClient(cfg IpcConfig, codec codec.Codec) (*ipcClient, error) {
}
// Start IPC server
func StartIpc(cfg IpcConfig, codec codec.Codec, offeredApi shared.EthereumApi) error {
return startIpc(cfg, codec, offeredApi)
func StartIpc(cfg IpcConfig, codec codec.Codec, initializer func(conn net.Conn) (shared.EthereumApi, error)) error {
return startIpc(cfg, codec, initializer)
}
func newIpcConnId() int {

9
rpc/comms/ipc_unix.go
View File

@ -48,7 +48,7 @@ func (self *ipcClient) reconnect() error {
return err
}
func startIpc(cfg IpcConfig, codec codec.Codec, api shared.EthereumApi) error {
func startIpc(cfg IpcConfig, codec codec.Codec, initializer func(conn net.Conn) (shared.EthereumApi, error)) error {
os.Remove(cfg.Endpoint) // in case it still exists from a previous run
l, err := net.Listen("unix", cfg.Endpoint)
@ -69,6 +69,13 @@ func startIpc(cfg IpcConfig, codec codec.Codec, api shared.EthereumApi) error {
id := newIpcConnId()
glog.V(logger.Debug).Infof("New IPC connection with id %06d started\n", id)
api, err := initializer(conn)
if err != nil {
glog.V(logger.Error).Infof("Unable to initialize IPC connection - %v\n", err)
conn.Close()
continue
}
go handle(id, conn, api, codec)
}

9
rpc/comms/ipc_windows.go
View File

@ -667,7 +667,7 @@ func (self *ipcClient) reconnect() error {
return err
}
func startIpc(cfg IpcConfig, codec codec.Codec, api shared.EthereumApi) error {
func startIpc(cfg IpcConfig, codec codec.Codec, initializer func(conn net.Conn) (shared.EthereumApi, error)) error {
os.Remove(cfg.Endpoint) // in case it still exists from a previous run
l, err := Listen(cfg.Endpoint)
@ -687,6 +687,13 @@ func startIpc(cfg IpcConfig, codec codec.Codec, api shared.EthereumApi) error {
id := newIpcConnId()
glog.V(logger.Debug).Infof("New IPC connection with id %06d started\n", id)
api, err := initializer(conn)
if err != nil {
glog.V(logger.Error).Infof("Unable to initialize IPC connection - %v\n", err)
conn.Close()
continue
}
go handle(id, conn, api, codec)
}

89
rpc/jeth.go
View File

@ -18,12 +18,17 @@ package rpc
import (
"encoding/json"
"fmt"
"github.com/ethereum/go-ethereum/cmd/utils"
"github.com/ethereum/go-ethereum/jsre"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rpc/comms"
"github.com/ethereum/go-ethereum/rpc/shared"
"github.com/ethereum/go-ethereum/rpc/useragent"
"github.com/ethereum/go-ethereum/xeth"
"github.com/robertkrimen/otto"
)
@ -31,10 +36,21 @@ type Jeth struct {
ethApi shared.EthereumApi
re *jsre.JSRE
client comms.EthereumClient
fe xeth.Frontend
}
func NewJeth(ethApi shared.EthereumApi, re *jsre.JSRE, client comms.EthereumClient) *Jeth {
return &Jeth{ethApi, re, client}
func NewJeth(ethApi shared.EthereumApi, re *jsre.JSRE, client comms.EthereumClient, fe xeth.Frontend) *Jeth {
// enable the jeth as the user agent
req := shared.Request{
Id: 0,
Method: useragent.EnableUserAgentMethod,
Jsonrpc: shared.JsonRpcVersion,
Params: []byte("[]"),
}
client.Send(&req)
client.Recv()
return &Jeth{ethApi, re, client, fe}
}
func (self *Jeth) err(call otto.FunctionCall, code int, msg string, id interface{}) (response otto.Value) {
@ -72,16 +88,34 @@ func (self *Jeth) Send(call otto.FunctionCall) (response otto.Value) {
if err != nil {
return self.err(call, -32603, err.Error(), req.Id)
}
respif, err = self.client.Recv()
recv:
respif, err = self.client.Recv()
if err != nil {
return self.err(call, -32603, err.Error(), req.Id)
}
agentreq, isRequest := respif.(*shared.Request)
if isRequest {
self.handleRequest(agentreq)
goto recv // receive response after agent interaction
}
sucres, isSuccessResponse := respif.(*shared.SuccessResponse)
errres, isErrorResponse := respif.(*shared.ErrorResponse)
if !isSuccessResponse && !isErrorResponse {
return self.err(call, -32603, fmt.Sprintf("Invalid response type (%T)", respif), req.Id)
}
call.Otto.Set("ret_jsonrpc", shared.JsonRpcVersion)
call.Otto.Set("ret_id", req.Id)
res, _ := json.Marshal(respif)
var res []byte
if isSuccessResponse {
res, err = json.Marshal(sucres.Result)
} else if isErrorResponse {
res, err = json.Marshal(errres.Error)
}
call.Otto.Set("ret_result", string(res))
call.Otto.Set("response_idx", i)
@ -105,3 +139,48 @@ func (self *Jeth) Send(call otto.FunctionCall) (response otto.Value) {
return
}
// handleRequest will handle user agent requests by interacting with the user and sending
// the user response back to the geth service
func (self *Jeth) handleRequest(req *shared.Request) bool {
var err error
var args []interface{}
if err = json.Unmarshal(req.Params, &args); err != nil {
glog.V(logger.Info).Infof("Unable to parse agent request - %v\n", err)
return false
}
switch req.Method {
case useragent.AskPasswordMethod:
return self.askPassword(req.Id, req.Jsonrpc, args)
case useragent.ConfirmTransactionMethod:
return self.confirmTransaction(req.Id, req.Jsonrpc, args)
}
return false
}
// askPassword will ask the user to supply the password for a given account
func (self *Jeth) askPassword(id interface{}, jsonrpc string, args []interface{}) bool {
var err error
var passwd string
if len(args) >= 1 {
if account, ok := args[0].(string); ok {
fmt.Printf("Unlock account %s\n", account)
passwd, err = utils.PromptPassword("Passphrase: ", true)
} else {
return false
}
}
if err = self.client.Send(shared.NewRpcResponse(id, jsonrpc, passwd, err)); err != nil {
glog.V(logger.Info).Infof("Unable to send user agent ask password response - %v\n", err)
}
return err == nil
}
func (self *Jeth) confirmTransaction(id interface{}, jsonrpc string, args []interface{}) bool {
// Accept all tx which are send from this console
return self.client.Send(shared.NewRpcResponse(id, jsonrpc, true, nil)) == nil
}

24
rpc/useragent/agent.go Normal file
View File

@ -0,0 +1,24 @@
// Copyright 2015 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 user agent provides frontends and agents which can interact with the user
package useragent
var (
AskPasswordMethod = "agent_askPassword"
ConfirmTransactionMethod = "agent_confirmTransaction"
EnableUserAgentMethod = "admin_enableUserAgent"
)

141
rpc/useragent/remote_frontend.go Normal file
View File

@ -0,0 +1,141 @@
// Copyright 2015 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 useragent
import (
"encoding/json"
"fmt"
"net"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rpc/shared"
)
// remoteFrontend implements xeth.Frontend and will communicate with an external
// user agent over a connection
type RemoteFrontend struct {
enabled bool
mgr *accounts.Manager
d *json.Decoder
e *json.Encoder
n int
}
// NewRemoteFrontend creates a new frontend which will interact with an user agent
// over the given connection
func NewRemoteFrontend(conn net.Conn, mgr *accounts.Manager) *RemoteFrontend {
return &RemoteFrontend{false, mgr, json.NewDecoder(conn), json.NewEncoder(conn), 0}
}
// Enable will enable user interaction
func (fe *RemoteFrontend) Enable() {
fe.enabled = true
}
// UnlockAccount asks the user agent for the user password and tries to unlock the account.
// It will try 3 attempts before giving up.
func (fe *RemoteFrontend) UnlockAccount(address []byte) bool {
if !fe.enabled {
return false
}
err := fe.send(AskPasswordMethod, common.Bytes2Hex(address))
if err != nil {
glog.V(logger.Error).Infof("Unable to send password request to agent - %v\n", err)
return false
}
passwdRes, err := fe.recv()
if err != nil {
glog.V(logger.Error).Infof("Unable to recv password response from agent - %v\n", err)
return false
}
if passwd, ok := passwdRes.Result.(string); ok {
err = fe.mgr.Unlock(common.BytesToAddress(address), passwd)
}
if err == nil {
return true
}
glog.V(logger.Debug).Infoln("3 invalid account unlock attempts")
return false
}
// ConfirmTransaction asks the user for approval
func (fe *RemoteFrontend) ConfirmTransaction(tx string) bool {
if !fe.enabled {
return true // backwards compatibility
}
err := fe.send(ConfirmTransactionMethod, tx)
if err != nil {
glog.V(logger.Error).Infof("Unable to send tx confirmation request to agent - %v\n", err)
return false
}
confirmResponse, err := fe.recv()
if err != nil {
glog.V(logger.Error).Infof("Unable to recv tx confirmation response from agent - %v\n", err)
return false
}
if confirmed, ok := confirmResponse.Result.(bool); ok {
return confirmed
}
return false
}
// send request to the agent
func (fe *RemoteFrontend) send(method string, params ...interface{}) error {
fe.n += 1
p, err := json.Marshal(params)
if err != nil {
glog.V(logger.Info).Infof("Unable to send agent request %v\n", err)
return err
}
req := shared.Request{
Method: method,
Jsonrpc: shared.JsonRpcVersion,
Id: fe.n,
Params: p,
}
return fe.e.Encode(&req)
}
// recv user response from agent
func (fe *RemoteFrontend) recv() (*shared.SuccessResponse, error) {
var res json.RawMessage
if err := fe.d.Decode(&res); err != nil {
return nil, err
}
var response shared.SuccessResponse
if err := json.Unmarshal(res, &response); err == nil {
return &response, nil
}
return nil, fmt.Errorf("Invalid user agent response")
}

4
xeth/xeth.go
View File

@ -885,6 +885,10 @@ func isAddress(addr string) bool {
return addrReg.MatchString(addr)
}
func (self *XEth) Frontend() Frontend {
return self.frontend
}
func (self *XEth) Transact(fromStr, toStr, nonceStr, valueStr, gasStr, gasPriceStr, codeStr string) (string, error) {
// this minimalistic recoding is enough (works for natspec.js)