-
Notifications
You must be signed in to change notification settings - Fork 0
/
bignum_serialize.go
53 lines (48 loc) · 1.42 KB
/
bignum_serialize.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
/*
* Copyright (C) 2021 Zilliqa
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package core
import (
"math/big"
)
type BIGNumSerialize struct{}
func (bn *BIGNumSerialize) SetNumber(dst []byte, offset uint, size uint, value *big.Int) []byte {
// check for offset overflow
if offset+size < size {
// overflow detected
return nil
}
bytes := value.Bytes()
actualByteNumber := len(bytes)
if actualByteNumber <= int(size) {
if offset+size > uint(len(dst)) {
newDst := make([]byte, int(offset+size))
copy(newDst, dst)
dst = newDst
}
// pad with zeroes as needed
sizeDiff := size - uint(actualByteNumber)
for i := uint(0); i < sizeDiff; i++ {
dst[offset+i] = 0x00
}
for i := 0; i < actualByteNumber; i++ {
dst[offset+sizeDiff+uint(i)] = bytes[i]
}
} else {
// big num size > declared size
}
return dst
}