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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
package natspec
import (
"bytes"
"encoding/json"
"fmt"
"github.com/robertkrimen/otto"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/xeth"
)
type abi2method map[[8]byte]*method
type NatSpec struct {
jsvm *otto.Otto
userDocJson, abiDocJson []byte
userDoc userDoc
tx, data string
// abiDoc abiDoc
}
// TODO: should initialise with abi and userdoc jsons
func New(xeth *xeth.XEth, tx string) (self *NatSpec, err error) {
// extract contract address from tx
var obj map[string]json.RawMessage
err = json.Unmarshal([]byte(tx), &obj)
if err != nil {
return
}
var tmp []map[string]string
err = json.Unmarshal(obj["params"], &tmp)
if err != nil {
return
}
contractAddress := tmp[0]["to"]
// retrieve contract hash from state
if !xeth.IsContract(contractAddress) {
err = fmt.Errorf("NatSpec error: contract not found")
return
}
codeHash := xeth.CodeAt(contractAddress)
// retrieve natspec info content hash
statereg := NewStateReg(xeth)
natspecHash, err1 := statereg.GetNatSpec(codeHash)
if err1 != nil {
return nil, err1
}
// retrieve content
content, err2 := statereg.GetContent(natspecHash)
if err2 != nil {
return nil, err2
}
// get abi, userdoc
var obj2 map[string]json.RawMessage
err = json.Unmarshal(content, &obj2)
if err != nil {
return
}
abi := []byte(obj2["abi"])
userdoc := []byte(obj2["userdoc"])
self, err = NewWithDocs(abi, userdoc, tx)
return
}
func NewWithDocs(abiDocJson, userDocJson []byte, tx string) (self *NatSpec, err error) {
var obj map[string]json.RawMessage
err = json.Unmarshal([]byte(tx), &obj)
if err != nil {
return
}
var tmp []map[string]string
err = json.Unmarshal(obj["params"], &tmp)
if err != nil {
return
}
data := tmp[0]["data"]
self = &NatSpec{
jsvm: otto.New(),
abiDocJson: abiDocJson,
userDocJson: userDocJson,
tx: tx,
data: data,
}
_, err = self.jsvm.Run(natspecJS)
if err != nil {
return
}
_, err = self.jsvm.Run("var natspec = require('natspec');")
if err != nil {
return
}
err = json.Unmarshal(userDocJson, &self.userDoc)
// err = parseAbiJson(abiDocJson, &self.abiDoc)
return
}
// type abiDoc []method
// type method struct {
// Name string `json:name`
// Inputs []input `json:inputs`
// abiKey [8]byte
// }
// type input struct {
// Name string `json:name`
// Type string `json:type`
// }
type method struct {
Notice string `json:notice`
name string
}
type userDoc struct {
Methods map[string]*method `json:methods`
}
func (self *NatSpec) makeAbi2method(abiKey [8]byte) (meth *method) {
for signature, m := range self.userDoc.Methods {
name := strings.Split(signature, "(")[0]
hash := []byte(common.Bytes2Hex(crypto.Sha3([]byte(signature))))
var key [8]byte
copy(key[:], hash[:8])
if bytes.Equal(key[:], abiKey[:]) {
meth = m
meth.name = name
return
}
}
return
}
func (self *NatSpec) Notice() (notice string, err error) {
var abiKey [8]byte
if len(self.data) < 10 {
err = fmt.Errorf("Invalid transaction data")
return
}
copy(abiKey[:], self.data[2:10])
meth := self.makeAbi2method(abiKey)
if meth == nil {
err = fmt.Errorf("abi key %x does not match any method %v")
return
}
notice, err = self.noticeForMethod(self.tx, meth.name, meth.Notice)
return
}
func (self *NatSpec) noticeForMethod(tx string, name, expression string) (notice string, err error) {
if _, err = self.jsvm.Run("var transaction = " + tx + ";"); err != nil {
return "", fmt.Errorf("natspec.js error setting transaction: %v", err)
}
if _, err = self.jsvm.Run("var abi = " + string(self.abiDocJson) + ";"); err != nil {
return "", fmt.Errorf("natspec.js error setting abi: %v", err)
}
if _, err = self.jsvm.Run("var method = '" + name + "';"); err != nil {
return "", fmt.Errorf("natspec.js error setting method: %v", err)
}
if _, err = self.jsvm.Run("var expression = \"" + expression + "\";"); err != nil {
return "", fmt.Errorf("natspec.js error setting expression: %v", err)
}
self.jsvm.Run("var call = {method: method,abi: abi,transaction: transaction};")
value, err := self.jsvm.Run("natspec.evaluateExpression(expression, call);")
if err != nil {
return "", fmt.Errorf("natspec.js error evaluating expression: %v", err)
}
evalError := "Natspec evaluation failed, wrong input params"
if value.String() == evalError {
return "", fmt.Errorf("natspec.js error evaluating expression: wrong input params in expression '%s'", expression)
}
if len(value.String()) == 0 {
return "", fmt.Errorf("natspec.js error evaluating expression")
}
return value.String(), nil
}
|
