Merge pull request #4 from iden3/fix/verify

Fix mutation of inputs in Verify

verifier/verifier.go

@@ -32,7 +32,7 @@ func Verify(vk *types.Vk, proof *types.Proof, inputs []*big.Int) bool {
 	}
 	vkX = new(bn256.G1).Add(vkX, vk.IC[0])
 
-	g1 := []*bn256.G1{proof.A, vk.Alpha.Neg(vk.Alpha), vkX.Neg(vkX), proof.C.Neg(proof.C)}
+	g1 := []*bn256.G1{proof.A, new(bn256.G1).Neg(vk.Alpha), vkX.Neg(vkX), new(bn256.G1).Neg(proof.C)}
 	g2 := []*bn256.G2{proof.B, vk.Beta, vk.Gamma, vk.Delta}
 	return bn256.PairingCheck(g1, g2)
 }

verifier/verifier_test.go

@@ -27,6 +27,10 @@ func TestVerify1(t *testing.T) {
 
 	v := Verify(vk, proof, public)
 	assert.True(t, v)
+
+	// Verify again to check that `Verify` hasn't mutated the inputs
+	v = Verify(vk, proof, public)
+	assert.True(t, v)
 }
 
 func BenchmarkVerify(b *testing.B) {