1package gocircomprover
 2
 3import (
 4	"encoding/hex"
 5	"fmt"
 6	"math/big"
 7	"strings"
 8
 9	bn256 "github.com/ethereum/go-ethereum/crypto/bn256/cloudflare"
10)
11
12func stringToG1(h []string) (*bn256.G1, error) {
13	if len(h) <= 2 {
14		return nil, fmt.Errorf("not enought data for stringToG1")
15	}
16	h = h[:2]
17	hexa := false
18	if len(h[0]) > 1 {
19		if "0x" == h[0][:2] {
20			hexa = true
21		}
22	}
23	in := ""
24
25	var b []byte
26	var err error
27	if hexa {
28		for i := range h {
29			in += strings.TrimPrefix(h[i], "0x")
30		}
31		b, err = hex.DecodeString(in)
32		if err != nil {
33			return nil, err
34		}
35	} else {
36		// TODO TMP
37		// TODO use stringToBytes()
38		if h[0] == "1" {
39			h[0] = "0"
40		}
41		if h[1] == "1" {
42			h[1] = "0"
43		}
44		bi0, ok := new(big.Int).SetString(h[0], 10)
45		if !ok {
46			return nil, fmt.Errorf("error parsing stringToG1")
47		}
48		bi1, ok := new(big.Int).SetString(h[1], 10)
49		if !ok {
50			return nil, fmt.Errorf("error parsing stringToG1")
51		}
52		b0 := bi0.Bytes()
53		b1 := bi1.Bytes()
54		if len(b0) != 32 {
55			b0 = addZPadding(b0)
56		}
57		if len(b1) != 32 {
58			b1 = addZPadding(b1)
59		}
60
61		b = append(b, b0...)
62		b = append(b, b1...)
63	}
64	p := new(bn256.G1)
65	_, err = p.Unmarshal(b)
66
67	return p, err
68}