Merge bb6340fd95 into df67e299e6

Cargo.toml

@@ -44,6 +44,7 @@ harness = false
 required-features = ["alloc"]
 
 [dependencies]
+rustler = { version = "0.29.1", optional = true}
 ff = { version = "0.13", default-features = false }
 group = { version = "0.13", default-features = false }
 rand = { version = "0.8", default-features = false }
@@ -72,3 +73,4 @@ sqrt-table = ["alloc", "lazy_static"]
 repr-c = []
 uninline-portable = []
 serde = ["hex", "serde_crate"]
+repr-erlang=["rustler"]

src/curves.rs

@@ -16,6 +16,8 @@ use group::{
     Curve as _, Group as _, GroupEncoding,
 };
 use rand::RngCore;
+#[cfg(feature = "repr-erlang")]
+use rustler::NifRecord;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
 #[cfg(feature = "alloc")]
@@ -26,12 +28,17 @@ use super::{Fp, Fq};
 #[cfg(feature = "alloc")]
 use crate::arithmetic::{Coordinates, CurveAffine, CurveExt};
 
+#[cfg(feature = "repr-erlang")]
+use alloc::format;
+
 macro_rules! new_curve_impl {
     (($($privacy:tt)*), $name:ident, $name_affine:ident, $iso:ident, $base:ident, $scalar:ident,
-     $curve_id:literal, $a_raw:expr, $b_raw:expr, $curve_type:ident) => {
+     $curve_id:literal, $a_raw:expr, $b_raw:expr, $curve_type:ident, $name_string:literal, $name_affine_string:literal) => {
         /// Represents a point in the projective coordinate space.
         #[derive(Copy, Clone, Debug)]
         #[cfg_attr(feature = "repr-c", repr(C))]
+        #[cfg_attr(feature = "repr-erlang", derive(NifRecord))]
+        #[cfg_attr(feature = "repr-erlang", tag = $name_string)]
         $($privacy)* struct $name {
             x: $base,
             y: $base,
@@ -51,6 +58,8 @@ macro_rules! new_curve_impl {
         /// Represents a point in the affine coordinate space (or the point at
         /// infinity).
         #[derive(Copy, Clone)]
+        #[cfg_attr(feature = "repr-erlang", derive(NifRecord))]
+        #[cfg_attr(feature = "repr-erlang", tag = $name_affine_string)]
         #[cfg_attr(feature = "repr-c", repr(C))]
         $($privacy)* struct $name_affine {
             x: $base,
@@ -955,7 +964,9 @@ new_curve_impl!(
     "pallas",
     [0, 0, 0, 0],
     [5, 0, 0, 0],
-    special_a0_b5
+    special_a0_b5,
+    "Ep",
+    "EpAffine"
 );
 new_curve_impl!(
     (pub),
@@ -967,7 +978,9 @@ new_curve_impl!(
     "vesta",
     [0, 0, 0, 0],
     [5, 0, 0, 0],
-    special_a0_b5
+    special_a0_b5,
+    "Eq",
+    "EqAffine"
 );
 new_curve_impl!(
     (pub(crate)),
@@ -984,7 +997,9 @@ new_curve_impl!(
         0x18354a2eb0ea8c9c,
     ],
     [1265, 0, 0, 0],
-    general
+    general,
+    "IsoEp",
+    "IsoEpAffine"
 );
 new_curve_impl!(
     (pub(crate)),
@@ -1001,7 +1016,9 @@ new_curve_impl!(
         0x267f9b2ee592271a,
     ],
     [1265, 0, 0, 0],
-    general
+    general,
+    "IsoEq",
+    "IsoEqAffine"
 );
 
 impl Ep {

src/fields/fp.rs

@@ -5,6 +5,9 @@ use ff::{Field, FromUniformBytes, PrimeField, WithSmallOrderMulGroup};
 use rand::RngCore;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
+#[cfg(feature = "repr-erlang")]
+use rustler::{Decoder, Encoder, Env, NifResult, Term};
+
 #[cfg(feature = "sqrt-table")]
 use lazy_static::lazy_static;
 
@@ -185,6 +188,21 @@ impl<T: ::core::borrow::Borrow<Fp>> ::core::iter::Product<T> for Fp {
     }
 }
 
+#[cfg(feature = "repr-erlang")]
+impl Encoder for Fp {
+    fn encode<'a>(&self, env: Env<'a>) -> Term<'a> {
+        (self.0[0], self.0[1], self.0[2], self.0[3]).encode(env)
+    }
+}
+
+#[cfg(feature = "repr-erlang")]
+impl<'a> Decoder<'a> for Fp {
+    fn decode(term: Term<'a>) -> NifResult<Self> {
+        let tuple: NifResult<(u64, u64, u64, u64)> = Decoder::decode(term);
+        tuple.map(|res| Fp([res.0, res.1, res.2, res.3]))
+    }
+}
+
 /// INV = -(p^{-1} mod 2^64) mod 2^64
 const INV: u64 = 0x992d30ecffffffff;
 

src/fields/fq.rs

@@ -5,6 +5,9 @@ use ff::{Field, FromUniformBytes, PrimeField, WithSmallOrderMulGroup};
 use rand::RngCore;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
 
+#[cfg(feature = "repr-erlang")]
+use rustler::{Decoder, Encoder, Env, NifResult, Term};
+
 #[cfg(feature = "sqrt-table")]
 use lazy_static::lazy_static;
 
@@ -103,6 +106,21 @@ impl ConditionallySelectable for Fq {
     }
 }
 
+#[cfg(feature = "repr-erlang")]
+impl Encoder for Fq {
+    fn encode<'a>(&self, env: Env<'a>) -> Term<'a> {
+        (self.0[0], self.0[1], self.0[2], self.0[3]).encode(env)
+    }
+}
+
+#[cfg(feature = "repr-erlang")]
+impl<'a> Decoder<'a> for Fq {
+    fn decode(term: Term<'a>) -> NifResult<Self> {
+        let tuple: NifResult<(u64, u64, u64, u64)> = Decoder::decode(term);
+        tuple.map(|res| Fq([res.0, res.1, res.2, res.3]))
+    }
+}
+
 /// Constant representing the modulus
 /// q = 0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001
 const MODULUS: Fq = Fq([