Helper functions for future confidential transactions on secp256k1

Cargo.toml

@@ -17,3 +17,6 @@ smplx-std = "0.0.8"
 anyhow = { version = "1.0.101" }
 rand = { version = "0.8.6" }
 primitive-types = { version = "0.14" }
+num-bigint = { version = "0.5.1" }
+num-traits = { version = "0.2.19" }
+secp256k1-zkp = { version = "0.11.0", features = ["rand"] }

simf/asserts_test.simf

@@ -1,9 +1,15 @@
-use crate::lib::asserts::{assert_eq_8, assert_eq_16, assert_eq_32, assert_eq_64,assert_eq_128, assert_eq_256, assert_none_8, assert_none_16, assert_none_32, assert_none_64, assert_none_128, assert_none_256};
+use crate::lib::asserts::{
+    assert_eq_1, assert_eq_8, assert_eq_16, assert_eq_32, assert_eq_64,assert_eq_128, assert_eq_256,
+    assert_none_1, assert_none_8, assert_none_16, assert_none_32, assert_none_64, assert_none_128, assert_none_256
+};
 use crate::helper::if_test_this_function;
 
 fn main() {
     let fn_idx: u8 = witness::FUNCTION_INDEX;
 
+    let a_u1: Option<u1> = witness::FIRST_ARG_U1;
+    let b_u1: Option<u1> = witness::SECOND_ARG_U1;
+
     let a_u8: Option<u8> = witness::FIRST_ARG_U8;
     let b_u8: Option<u8> = witness::SECOND_ARG_U8;
 
@@ -23,18 +29,20 @@ fn main() {
     let b_u256: Option<u256> = witness::SECOND_ARG_U256;
 
     // Assert Eq
-    match if_test_this_function(0, fn_idx) { true => { assert_eq_8(unwrap(a_u8), unwrap(b_u8)); }, false => (), };
-    match if_test_this_function(1, fn_idx) { true => { assert_eq_16(unwrap(a_u16), unwrap(b_u16)); }, false => (), };
-    match if_test_this_function(2, fn_idx) { true => { assert_eq_32(unwrap(a_u32), unwrap(b_u32)); }, false => (), };
-    match if_test_this_function(3, fn_idx) { true => { assert_eq_64(unwrap(a_u64), unwrap(b_u64)); }, false => (), };
-    match if_test_this_function(4, fn_idx) { true => { assert_eq_128(unwrap(a_u128), unwrap(b_u128)); }, false => (), };
-    match if_test_this_function(5, fn_idx) { true => { assert_eq_256(unwrap(a_u256), unwrap(b_u256)); }, false => (), };
+    match if_test_this_function(0, fn_idx) { true => { assert_eq_1(unwrap(a_u1), unwrap(b_u1)); }, false => (), };
+    match if_test_this_function(1, fn_idx) { true => { assert_eq_8(unwrap(a_u8), unwrap(b_u8)); }, false => (), };
+    match if_test_this_function(2, fn_idx) { true => { assert_eq_16(unwrap(a_u16), unwrap(b_u16)); }, false => (), };
+    match if_test_this_function(3, fn_idx) { true => { assert_eq_32(unwrap(a_u32), unwrap(b_u32)); }, false => (), };
+    match if_test_this_function(4, fn_idx) { true => { assert_eq_64(unwrap(a_u64), unwrap(b_u64)); }, false => (), };
+    match if_test_this_function(5, fn_idx) { true => { assert_eq_128(unwrap(a_u128), unwrap(b_u128)); }, false => (), };
+    match if_test_this_function(6, fn_idx) { true => { assert_eq_256(unwrap(a_u256), unwrap(b_u256)); }, false => (), };
 
     // Assert None
-    match if_test_this_function(6, fn_idx) { true => { assert_none_8(a_u8); }, false => (), };
-    match if_test_this_function(7, fn_idx) { true => { assert_none_16(a_u16); }, false => (), };
-    match if_test_this_function(8, fn_idx) { true => { assert_none_32(a_u32); }, false => (), };
-    match if_test_this_function(9, fn_idx) { true => { assert_none_64(a_u64); }, false => (), };
-    match if_test_this_function(10, fn_idx) { true => { assert_none_128(a_u128); }, false => (), };
-    match if_test_this_function(11, fn_idx) { true => { assert_none_256(a_u256); }, false => (), };
+    match if_test_this_function(7, fn_idx) { true => { assert_none_1(a_u1); }, false => (), };
+    match if_test_this_function(8, fn_idx) { true => { assert_none_8(a_u8); }, false => (), };
+    match if_test_this_function(9, fn_idx) { true => { assert_none_16(a_u16); }, false => (), };
+    match if_test_this_function(10, fn_idx) { true => { assert_none_32(a_u32); }, false => (), };
+    match if_test_this_function(11, fn_idx) { true => { assert_none_64(a_u64); }, false => (), };
+    match if_test_this_function(12, fn_idx) { true => { assert_none_128(a_u128); }, false => (), };
+    match if_test_this_function(13, fn_idx) { true => { assert_none_256(a_u256); }, false => (), };
 }

simf/lib/asserts.simf

@@ -1,4 +1,9 @@
-use crate::lib::u128::{eq_128};
+use crate::lib::u128::eq_128;
+
+/// Asserts that two `u1` are equal
+pub fn assert_eq_1(a: u1, b: u1) {
+    assert!(jet::eq_1(a, b))
+}
 
 /// Asserts that two u8 are equal
 pub fn assert_eq_8(a: u8, b: u8) {
@@ -30,6 +35,11 @@ pub fn assert_eq_256(a: u256, b: u256) {
     assert!(jet::eq_256(a, b));
 }
 
+/// Asserts that provided `Option<u1>` value is a `None`
+pub fn assert_none_1(val: Option<u1>) {
+    assert!(is_none::<u1>(val));
+}
+
 /// Asserts that provided u8 Option value is a None
 pub fn assert_none_8(val: Option<u8>) {
     assert!(is_none::<u8>(val));

simf/lib/secp256k1/operations.simf

@@ -0,0 +1,109 @@
+use crate::lib::logical_operations::and;
+use crate::lib::asserts::{assert_eq_1, assert_eq_256};
+
+/// Compress an affine point to `(parity, x)`, where `parity = 1` iff `y` is odd.
+pub fn ge_to_point(p: Ge) -> Point {
+    let (x, y): (Fe, Fe) = p;
+
+    match jet::fe_is_odd(y) {
+        true => (1, x),
+        false => (0, x),
+    }
+}
+
+/// Decompress a `Point` into a Jacobian point with `z = 1`.
+pub fn point_to_gej(p: Point) -> Gej {
+    (unwrap(jet::decompress(p)), 1)
+}
+
+/// Convert the point into affine coordinates.
+pub fn safe_gej_normalize(p: Gej) -> Ge {
+    unwrap(jet::gej_normalize(p))
+}
+
+/// Subtract two field elements.
+pub fn fe_sub(a: Fe, b: Fe) -> Fe {
+    jet::fe_add(a, jet::fe_negate(b))
+}
+
+/// Subtract two scalars.
+pub fn scalar_sub(a: Scalar, b: Scalar) -> Scalar {
+    jet::scalar_add(a, jet::scalar_negate(b))
+}
+
+/// Subtract two points.
+pub fn gej_sub(p: Gej, q: Gej) -> Gej {
+    jet::gej_add(p, jet::gej_negate(q))
+}
+
+/// Field equality modulo `p`.
+pub fn fe_eq(a: Fe, b: Fe) -> bool {
+    jet::fe_is_zero(fe_sub(a, b))
+}
+
+/// Scalar equality modulo `n`.
+pub fn scalar_eq(a: Scalar, b: Scalar) -> bool {
+    jet::scalar_is_zero(scalar_sub(a, b))
+}
+
+/// Affine point equality.
+pub fn ge_eq(a: Ge, b: Ge) -> bool {
+    let (ax, ay): (Fe, Fe) = a;
+    let (bx, by): (Fe, Fe) = b;
+    and(fe_eq(ax, bx), fe_eq(ay, by))
+}
+
+/// Check if two points are equal.
+pub fn point_point_eq(a: Point, b: Point) -> bool {
+    let (ap, ax): (u1, u256) = a;
+    let (bp, bx): (u1, u256) = b;
+    and(jet::eq_256(ax, bx), jet::eq_1(ap, bp))
+}
+
+/// Check if two points represent the same point
+pub fn gej_point_eq(a: Gej, p: Point) -> bool {
+    jet::gej_ge_equiv(a, unwrap(jet::decompress(p)))
+}
+
+/// Field equality modulo `p`.
+pub fn assert_fe_eq(a: Fe, b: Fe) {
+    assert!(fe_eq(a, b));
+}
+
+/// Scalar equality modulo `n`.
+pub fn assert_scalar_eq(a: Scalar, b: Scalar) {
+    assert!(scalar_eq(a, b));
+}
+
+/// Affine point equality.
+pub fn assert_ge_eq(a: Ge, b: Ge) {
+    let (ax, ay): (Fe, Fe) = a;
+    let (bx, by): (Fe, Fe) = b;
+
+    assert_fe_eq(ax, bx);
+    assert_fe_eq(ay, by);
+}
+
+/// Check if two points are equal.
+pub fn assert_point_eq(a: Point, b: Point) {
+    let (ap, ax): (u1, u256) = a;
+    let (bp, bx): (u1, u256) = b;
+
+    assert_eq_256(ax, bx);
+    assert_eq_1(ap, bp);
+}
+
+/// Check if two points represent the same point.
+pub fn assert_gej_point_eq(a: Gej, p: Point) {
+    assert!(gej_point_eq(a, p));
+}
+
+/// Check if two points represent the same point.
+pub fn assert_gej_eq(a: Gej, b: Gej) {
+    assert!(jet::gej_equiv(a, b));
+}
+
+/// Check if two points represent the same point.
+pub fn assert_gej_ge_eq(a: Gej, b: Ge) {
+    assert!(jet::gej_ge_equiv(a, b));
+}

simf/lib/u64.simf

@@ -67,3 +67,8 @@ pub fn gt_64(a: u64, b: u64) -> bool {
 pub fn ge_64(a: u64, b: u64) -> bool {
     jet::le_64(b, a)
 }
+
+/// Widen `u64` to a `u256` scalar.
+pub fn u64_widen(val: u64) -> u256 {
+    <(u64, u64, u64, u64)>::into((0, 0, 0, val))
+}