You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
106 lines
2.6 KiB
106 lines
2.6 KiB
package utils
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/hex"
|
|
"fmt"
|
|
"math/big"
|
|
"strings"
|
|
)
|
|
|
|
// NewIntFromString creates a new big.Int from a decimal integer encoded as a
|
|
// string. It will panic if the string is not a decimal integer.
|
|
func NewIntFromString(s string) *big.Int {
|
|
v, ok := new(big.Int).SetString(s, 10)
|
|
if !ok {
|
|
panic(fmt.Sprintf("Bad base 10 string %s", s))
|
|
}
|
|
return v
|
|
}
|
|
|
|
// SwapEndianness swaps the endianness of the value encoded in xs. If xs is
|
|
// Big-Endian, the result will be Little-Endian and viceversa.
|
|
func SwapEndianness(xs []byte) []byte {
|
|
ys := make([]byte, len(xs))
|
|
for i, b := range xs {
|
|
ys[len(xs)-1-i] = b
|
|
}
|
|
return ys
|
|
}
|
|
|
|
// BigIntLEBytes encodes a big.Int into an array in Little-Endian.
|
|
func BigIntLEBytes(v *big.Int) [32]byte {
|
|
le := SwapEndianness(v.Bytes())
|
|
res := [32]byte{}
|
|
copy(res[:], le)
|
|
return res
|
|
}
|
|
|
|
// SetBigIntFromLEBytes sets the value of a big.Int from a Little-Endian
|
|
// encoded value.
|
|
func SetBigIntFromLEBytes(v *big.Int, leBuf []byte) *big.Int {
|
|
beBuf := SwapEndianness(leBuf)
|
|
return v.SetBytes(beBuf)
|
|
}
|
|
|
|
// Hex is a byte slice type that can be marshalled and unmarshaled in hex
|
|
type Hex []byte
|
|
|
|
// MarshalText encodes buf as hex
|
|
func (buf Hex) MarshalText() ([]byte, error) {
|
|
return []byte(hex.EncodeToString(buf)), nil
|
|
}
|
|
|
|
// String encodes buf as hex
|
|
func (buf Hex) String() string {
|
|
return hex.EncodeToString(buf)
|
|
}
|
|
|
|
// HexEncode encodes an array of bytes into a string in hex.
|
|
func HexEncode(bs []byte) string {
|
|
return fmt.Sprintf("0x%s", hex.EncodeToString(bs))
|
|
}
|
|
|
|
// HexDecode decodes a hex string into an array of bytes.
|
|
func HexDecode(h string) ([]byte, error) {
|
|
if strings.HasPrefix(h, "0x") {
|
|
h = h[2:]
|
|
}
|
|
return hex.DecodeString(h)
|
|
}
|
|
|
|
// HexDecodeInto decodes a hex string into an array of bytes (dst), verifying
|
|
// that the decoded array has the same length as dst.
|
|
func HexDecodeInto(dst []byte, h []byte) error {
|
|
if bytes.HasPrefix(h, []byte("0x")) {
|
|
h = h[2:]
|
|
}
|
|
if len(h)/2 != len(dst) {
|
|
return fmt.Errorf("expected %v bytes in hex string, got %v", len(dst), len(h)/2)
|
|
}
|
|
n, err := hex.Decode(dst, h)
|
|
if err != nil {
|
|
return err
|
|
} else if n != len(dst) {
|
|
return fmt.Errorf("expected %v bytes when decoding hex string, got %v", len(dst), n)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// CheckBigIntInField checks if given big.Int fits in a Field Q element
|
|
func CheckBigIntInField(a *big.Int, q *big.Int) bool {
|
|
if a.Cmp(q) != -1 {
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
// CheckBigIntArrayInField checks if given big.Int fits in a Field Q element
|
|
func CheckBigIntArrayInField(arr []*big.Int, q *big.Int) bool {
|
|
for _, a := range arr {
|
|
if !CheckBigIntInField(a, q) {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|