1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
// 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
}
func (fe *RemoteFrontend) AskPassword() (string, bool) {
if !fe.enabled {
return "", false
}
err := fe.send(AskPasswordMethod)
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 {
return passwd, true
}
return "", false
}
// 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")
}