Add 'normalize' to Group trait for converting something into affine.

src/groups/mod.rs

@@ -130,7 +130,7 @@ impl<P: GroupParams> G<P> {
 }
 
 impl<P: GroupParams> AffineG<P> {
-    fn to_jacobian(&self) -> G<P> {
+    pub fn to_jacobian(&self) -> G<P> {
         G {
             x: self.x,
             y: self.y,

src/lib.rs

@@ -73,6 +73,7 @@ pub trait Group:
     fn one() -> Self;
     fn random<R: Rng>(rng: &mut R) -> Self;
     fn is_zero(&self) -> bool;
+    fn normalize(&mut self);
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, RustcDecodable, RustcEncodable)]
@@ -84,6 +85,14 @@ impl Group for G1 {
     fn one() -> Self { G1(groups::G1::one()) }
     fn random<R: Rng>(rng: &mut R) -> Self { G1(groups::G1::random(rng)) }
     fn is_zero(&self) -> bool { self.0.is_zero() }
+    fn normalize(&mut self) {
+        let new = match self.0.to_affine() {
+            Some(a) => a,
+            None => return
+        };
+
+        self.0 = new.to_jacobian();
+    }
 }
 
 impl Add<G1> for G1 {
@@ -119,6 +128,14 @@ impl Group for G2 {
     fn one() -> Self { G2(groups::G2::one()) }
     fn random<R: Rng>(rng: &mut R) -> Self { G2(groups::G2::random(rng)) }
     fn is_zero(&self) -> bool { self.0.is_zero() }
+    fn normalize(&mut self) {
+        let new = match self.0.to_affine() {
+            Some(a) => a,
+            None => return
+        };
+
+        self.0 = new.to_jacobian();
+    }
 }
 
 impl Add<G2> for G2 {

tests/serialization.rs

@@ -36,6 +36,10 @@ fn group_serialization_and_deserialization() {
 
         assert!(reserialize(a) == a);
         assert!(reserialize(reserialize(a)) == a);
+        let mut c = a;
+        c.normalize();
+
+        assert!(a == c);
     }
 
     let mut a = G2::one();
@@ -44,6 +48,11 @@ fn group_serialization_and_deserialization() {
 
         assert!(reserialize(a) == a);
         assert!(reserialize(reserialize(a)) == a);
+        let mut c = a;
+        c.normalize();
+
+        assert!(a == c);
+
     }
 }