diff options
Diffstat (limited to 'veto')
| -rw-r--r-- | veto/veto.go | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/veto/veto.go b/veto/veto.go index cb526d6..6a64c82 100644 --- a/veto/veto.go +++ b/veto/veto.go @@ -14,6 +14,8 @@ import ( type Scalar = Curve25519Scalar type Point = Curve25519Point +var Curve = Curve25519 + // Representation of a vote with veto (if set to true) type Vote struct { veto bool @@ -63,16 +65,16 @@ func proof(x *Scalar, id *Point) (pr *Proof, e error) { pr = &Proof{Id: id} // choose random v - v, e := Curve25519.ScalarFromReader(nil) + v, e := Curve.ScalarFromReader(nil) if e != nil { return nil, e } // calculate g^v - pr.PV = Curve25519.Exp(v) + pr.PV = Curve.Exp(v) // calculate g^x - gx := Curve25519.Exp(x) + gx := Curve.Exp(x) // calculate h := H(g, g^v, g^x, i) h, e := hash(pr.PV, gx, id) @@ -91,12 +93,12 @@ func proof(x *Scalar, id *Point) (pr *Proof, e error) { // Calculate h := H(g, g^v, g^x, i) func hash(gv, gx *Point, id *Point) (*Scalar, error) { h512 := sha512.New() - h512.Write(Curve25519.Identity().Bytes()) + h512.Write(Curve.Identity().Bytes()) h512.Write(gv.Bytes()) h512.Write(gx.Bytes()) h512.Write(id.Bytes()) hb := h512.Sum(nil) - return Curve25519.ScalarFromBytes(hb) + return Curve.ScalarFromBytes(hb) } func combineErr(es ...error) error { @@ -125,10 +127,9 @@ func verifyProof(V *Point, Gx *Point, r *Scalar, id *Point) (ok bool) { gxh := Gx.Exp(h) // Calculate g^r - gr := Curve25519.Exp(r) + gr := Curve.Exp(r) // Calculate g^r*g^(x*h) - // Note that the edwards25519 package uses Addtion as the group grgxh := gr.Mult(gxh) // Return true if g^v == g^r*g^(x*h) @@ -148,22 +149,18 @@ func newVoteWithRand(veto bool, rand io.Reader) (v *Vote, e error) { v = &Vote{ veto: veto, } - var e1, e2, e3 error - v.private.id, e1 = Curve25519.ScalarFromReader(rand) - v.private.x, e2 = Curve25519.ScalarFromReader(rand) - v.private.r, e3 = Curve25519.ScalarFromReader(rand) + v.private.id = Curve.RandomScalar() + v.private.x = Curve.RandomScalar() + v.private.r = Curve.RandomScalar() - e = combineErr(e1, e2, e3) - if e != nil { - return nil, e - } + var e1, e2 error c := new(Commitment) v.com = c - c.Id = Curve25519.Exp(v.private.id) - c.Points.X = Curve25519.Exp(v.private.x) - c.Points.R = Curve25519.Exp(v.private.r) + c.Id = Curve.Exp(v.private.id) + c.Points.X = Curve.Exp(v.private.x) + c.Points.R = Curve.Exp(v.private.r) c.Proofs.X, e1 = proof(v.private.x, c.Id) c.Proofs.R, e2 = proof(v.private.r, c.Id) @@ -195,7 +192,7 @@ func (c *Commitment) String() string { type coms []*Commitment func (coms coms) prod() (product *Point) { - product = Curve25519.Identity() + product = Curve.Identity() for _, com := range coms { product = product.Mult(com.Points.X) } @@ -249,7 +246,7 @@ type points []*Point // received the g^(c_i*y_i) from all other participants and calculates the product // of them. If the result is the unit element of the group, no veto was present. func (pts points) IsVetoed() bool { - product := Curve25519.Product(pts) - one := Curve25519.Identity() + product := Curve.Product(pts) + one := Curve.Identity() return !one.Equal(product) }
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