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}
 69
 70func stringToG2(h [][]string) (*bn256.G2, error) {
 71	if len(h) <= 2 {
 72		return nil, fmt.Errorf("not enought data for stringToG2")
 73	}
 74	h = h[:2]
 75	hexa := false
 76	if len(h[0][0]) > 1 {
 77		if "0x" == h[0][0][:2] {
 78			hexa = true
 79		}
 80	}
 81	in := ""
 82	var b []byte
 83	var err error
 84	if hexa {
 85		for i := 0; i < len(h); i++ {
 86			for j := 0; j < len(h[i]); j++ {
 87				in += strings.TrimPrefix(h[i][j], "0x")
 88			}
 89		}
 90		b, err = hex.DecodeString(in)
 91		if err != nil {
 92			return nil, err
 93		}
 94	} else {
 95		// TODO TMP
 96		bH, err := stringToBytes(h[0][1])
 97		if err != nil {
 98			return nil, err
 99		}
100		b = append(b, bH...)
101		bH, err = stringToBytes(h[0][0])
102		if err != nil {
103			return nil, err
104		}
105		b = append(b, bH...)
106		bH, err = stringToBytes(h[1][1])
107		if err != nil {
108			return nil, err
109		}
110		b = append(b, bH...)
111		bH, err = stringToBytes(h[1][0])
112		if err != nil {
113			return nil, err
114		}
115		b = append(b, bH...)
116	}
117
118	p := new(bn256.G2)
119	_, err = p.Unmarshal(b)
120	return p, err
121}