expose size of the base field (lurk-lang#262)

src/provider/bn256_grumpkin.rs

@@ -47,15 +47,17 @@ impl_traits!(
   Bn256Compressed,
   Bn256Point,
   Bn256Affine,
-  "30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001"
+  "30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001",
+  "30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47"
 );
 
 impl_traits!(
   grumpkin,
   GrumpkinCompressed,
   GrumpkinPoint,
   GrumpkinAffine,
-  "30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47"
+  "30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47",
+  "30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001"
 );
 
 #[cfg(test)]

src/provider/mod.rs

@@ -218,7 +218,8 @@ macro_rules! impl_traits {
     $name_compressed:ident,
     $name_curve:ident,
     $name_curve_affine:ident,
-    $order_str:literal
+    $order_str:literal,
+    $base_str:literal
   ) => {
     impl Group for $name::Point {
       type Base = $name::Base;
@@ -228,12 +229,13 @@ macro_rules! impl_traits {
       type TE = Keccak256Transcript<Self>;
       type CE = CommitmentEngine<Self>;
 
-      fn get_curve_params() -> (Self::Base, Self::Base, BigInt) {
+      fn get_curve_params() -> (Self::Base, Self::Base, BigInt, BigInt) {
         let A = $name::Point::a();
         let B = $name::Point::b();
         let order = BigInt::from_str_radix($order_str, 16).unwrap();
+        let base = BigInt::from_str_radix($base_str, 16).unwrap();
 
-        (A, B, order)
+        (A, B, order, base)
       }
     }
 

src/provider/pasta.rs

@@ -56,7 +56,8 @@ macro_rules! impl_traits {
     $name_compressed:ident,
     $name_curve:ident,
     $name_curve_affine:ident,
-    $order_str:literal
+    $order_str:literal,
+    $base_str:literal
   ) => {
     impl Group for $name::Point {
       type Base = $name::Base;
@@ -66,12 +67,13 @@ macro_rules! impl_traits {
       type TE = Keccak256Transcript<Self>;
       type CE = CommitmentEngine<Self>;
 
-      fn get_curve_params() -> (Self::Base, Self::Base, BigInt) {
+      fn get_curve_params() -> (Self::Base, Self::Base, BigInt, BigInt) {
         let A = $name::Point::a();
         let B = $name::Point::b();
         let order = BigInt::from_str_radix($order_str, 16).unwrap();
+        let base = BigInt::from_str_radix($base_str, 16).unwrap();
 
-        (A, B, order)
+        (A, B, order, base)
       }
     }
 
@@ -201,15 +203,17 @@ impl_traits!(
   PallasCompressedElementWrapper,
   Ep,
   EpAffine,
-  "40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001"
+  "40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001",
+  "40000000000000000000000000000000224698fc094cf91b992d30ed00000001"
 );
 
 impl_traits!(
   vesta,
   VestaCompressedElementWrapper,
   Eq,
   EqAffine,
-  "40000000000000000000000000000000224698fc094cf91b992d30ed00000001"
+  "40000000000000000000000000000000224698fc094cf91b992d30ed00000001",
+  "40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001"
 );
 
 #[cfg(test)]

src/provider/secp_secq.rs

@@ -44,15 +44,17 @@ impl_traits!(
   Secp256k1Compressed,
   Secp256k1,
   Secp256k1Affine,
-  "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141"
+  "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141",
+  "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f"
 );
 
 impl_traits!(
   secq256k1,
   Secq256k1Compressed,
   Secq256k1,
   Secq256k1Affine,
-  "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f"
+  "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
+  "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141"
 );
 
 #[cfg(test)]

src/traits/mod.rs

@@ -38,8 +38,8 @@ pub trait Group: Clone + Copy + Debug + Send + Sync + Sized + Eq + PartialEq {
   /// A type that defines a commitment engine over scalars in the group
   type CE: CommitmentEngineTrait<Self>;
 
-  /// Returns A, B, and the order of the group as a big integer
-  fn get_curve_params() -> (Self::Base, Self::Base, BigInt);
+  /// Returns A, B, the order of the group, the size of the base field as big integers
+  fn get_curve_params() -> (Self::Base, Self::Base, BigInt, BigInt);
 }
 
 /// A helper trait to absorb different objects in RO