package common

import (
	"crypto/sha512"

	"kesim.org/seal/curve"
)

// Common functions for the various proofs

type Scalar = curve.Curve25519Scalar
type Point = curve.Curve25519Point

var Curve = curve.Curve25519
var G = Curve.Generator()
var One = Curve.ScalarOne()

type Bytes interface {
	Bytes() []byte
}

type Bites []byte

func (b Bites) Bytes() []byte { return b }

func Challenge(bs ...Bytes) *Scalar {
	h512 := sha512.New()
	for _, p := range bs {
		h512.Write(p.Bytes())
	}
	ch, e := Curve.ScalarFromBytes(h512.Sum(nil))
	if e != nil {
		panic(e)
	}
	return ch
}