-
Notifications
You must be signed in to change notification settings - Fork 11
/
bech32.go
224 lines (191 loc) · 4.55 KB
/
bech32.go
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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
package btcTransaction
import (
"encoding/hex"
"errors"
"strings"
)
var (
ErrorInvalidAddress = errors.New("Invalid address!")
BTCBech32Alphabet = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
CHARSET_REV = []int8{
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
15, -1, 10, 17, 21, 20, 26, 30, 7, 5, -1, -1, -1, -1, -1, -1,
-1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1,
-1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1}
)
func catBytes(data1 []int8, data2 []int8) []int8 {
return append(data1, data2...)
}
func expandPrefix(prefix string) []int8 {
ret := make([]int8, len(prefix)*2+1)
for i := 0; i < len(prefix); i++ {
c := prefix[i]
ret[i] = int8(c >> 5)
ret[i+len(prefix)+1] = int8(c & 0x1f)
}
ret[len(prefix)] = 0
return ret
}
func polyMod(v []int8) uint32 {
c := uint32(1)
for _, v_i := range v {
c0 := uint8(c >> 25)
c = ((c & 0x1ffffff) << 5) ^ uint32(v_i)
if c0&1 != 0 {
c ^= 0x3b6a57b2
}
if c0&2 != 0 {
c ^= 0x26508e6d
}
if c0&4 != 0 {
c ^= 0x1ea119fa
}
if c0&8 != 0 {
c ^= 0x3d4233dd
}
if c0&16 != 0 {
c ^= 0x2a1462b3
}
}
return c ^ 1
}
func lowerCase(c byte) byte {
if c >= 'A' && c <= 'Z' {
return (c - 'A') + 'a'
}
return c
}
func verifyChecksum(prefix string, data []int8) bool {
return polyMod(catBytes(expandPrefix(prefix), data)) == 0
}
func calcChecksum(prefix string, data []int8) []int8 {
enc := catBytes(expandPrefix(prefix), data)
ret := [6]int8{}
tmp := make([]int8, len(enc)+6)
copy(tmp, enc)
mod := polyMod(tmp)
for i := 0; i < 6; i++ {
ret[i] = int8((mod >> (5 * (5 - uint(i)))) & 0x1f)
}
return ret[:]
}
func byteShl1(in *[]int8) {
tmp := make([]int8, len(*in))
copy(tmp, *in)
for i := 0; i < len(tmp)-1; i++ {
tmp1 := tmp[i] << 1
tmp2 := tmp[i+1] >> 7
tmp2 &= 1
tmp1 |= tmp2
tmp[i] = tmp1
}
tmp[len(tmp)-1] <<= 1
copy(*in, tmp)
}
func byteShl5(in *[]int8) {
for i := 0; i < 5; i++ {
byteShl1(in)
}
}
func extendPayload(payload []int8) []int8 {
length := (len(payload)*8 + 4) / 5
ret := make([]int8, length)
i := 0
j := 0
for i = len(payload) * 8; i >= 5; i -= 5 {
ret[j] = (payload[0] >> 3) & int8(0x1F)
byteShl5(&payload)
j++
}
if i > 0 {
ret[j] = (payload[0] >> 3) & 0x1f
}
return ret
}
func unecxtendPayload(extendedPayload []int8) []int8 {
length := len(extendedPayload) * 5 / 8
ret := make([]int8, length)
for i := 0; i < len(extendedPayload)-1; i++ {
ret[length-1] |= extendedPayload[i]
byteShl5(&ret)
}
ret[length-1] |= extendedPayload[len(extendedPayload)-1]
return ret
}
func Bech32Encode(prefix, alphabet string, payload []byte) string {
int8Payload := make([]int8, len(payload))
for i := 0; i < len(payload); i++ {
int8Payload[i] = int8(payload[i])
}
extendPayload := extendPayload(int8Payload)
extendPayload = append([]int8{0}, extendPayload...)
checksum := calcChecksum(prefix, extendPayload)
combined := catBytes(extendPayload, checksum)
ret := prefix + "1"
for _, b := range combined {
ret += alphabet[b : b+1]
}
return ret
}
func Bech32Decode(address string) ([]byte, error) {
lower := false
upper := false
hasNumber := false
prefixSize := 0
for i := 0; i < len(address); i++ {
c := address[i]
if c >= 'a' && c <= 'z' {
lower = true
continue
}
if c >= 'A' && c <= 'Z' {
upper = true
continue
}
if c == '0' || (c >= '2' && c <= '9') {
hasNumber = true
continue
}
if c == '1' {
if hasNumber || i == 0 || prefixSize != 0 {
return nil, ErrorInvalidAddress
}
prefixSize = i
continue
}
return nil, ErrorInvalidAddress
}
if upper && lower {
return nil, ErrorInvalidAddress
}
prefixStr := strings.Split(address, "1")[0]
prefixSize++
valueSize := len(address) - prefixSize
value := make([]int8, valueSize)
for i := 0; i < valueSize; i++ {
c := address[i+prefixSize]
if c > 127 || CHARSET_REV[c] == -1 {
return nil, ErrorInvalidAddress
}
value[i] = CHARSET_REV[c]
}
if !verifyChecksum(prefixStr, value) {
return nil, ErrorInvalidAddress
}
tmp := make([]int8, len(value)-6)
copy(tmp, value)
ret := unecxtendPayload(tmp)
bytePayload := make([]byte, len(ret))
for i := 0; i < len(ret); i++ {
bytePayload[i] = byte(ret[i])
}
if len(bytePayload) == 33 {
tmp := hex.EncodeToString(bytePayload)[1:65]
bytePayload, _ = hex.DecodeString(tmp)
}
return bytePayload, nil
}