1package edwards_curve
 2
 3import (
 4	"math/big"
 5)
 6
 7var (
 8	qEd25519, rEd25519 *big.Int
 9)
10
11func init() {
12	// https://neuromancer.sk/std/other/Ed25519
13	qEd25519, _ = new(big.Int).SetString("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed", 16)
14	n, _ := new(big.Int).SetString("1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3ed", 16)
15	// TODO: is this ok?
16	// h := big.NewInt(8)
17	// rEd25519 = new(big.Int).Mul(n, h)
18	rEd25519 = n
19}
20
21type Ed25519 struct{}
22
23func (fp Ed25519) NbLimbs() uint     { return 4 }
24func (fp Ed25519) BitsPerLimb() uint { return 64 }
25func (fp Ed25519) IsPrime() bool     { return true }
26func (fp Ed25519) Modulus() *big.Int { return qEd25519 }
27
28type Ed25519Scalars struct{}
29
30func (fp Ed25519Scalars) NbLimbs() uint     { return 4 }
31func (fp Ed25519Scalars) BitsPerLimb() uint { return 64 }
32func (fp Ed25519Scalars) IsPrime() bool     { return true }
33func (fp Ed25519Scalars) Modulus() *big.Int { return rEd25519 }
34