add secp256r1 testing programs and newhint#17 and #18

Author: mfachal

cairo_programs/doubling_slope_and_div_mod_n.cairo

@@ -0,0 +1,33 @@
+%builtins range_check
+
+// Source: https://github.com/myBraavos/efficient-secp256r1/blob/main/src/secp256r1/ec.cairo#L32
+
+func compute_doubling_slope{range_check_ptr}(point: EcPoint) -> (slope: BigInt3) {
+    // Note that y cannot be zero: assume that it is, then point = -point, so 2 * point = 0, which
+    // contradicts the fact that the size of the curve is odd.
+    %{  from starkware.cairo.common.cairo_secp.secp256r1_utils import SECP256R1_P as SECP_P %}
+    %{  from starkware.cairo.common.cairo_secp.secp256r1_utils import SECP256R1_ALPHA as ALPHA %}
+    // Hint #19
+    %{
+        from starkware.cairo.common.cairo_secp.secp_utils import pack
+        from starkware.python.math_utils import ec_double_slope
+
+        # Compute the slope.
+        x = pack(ids.point.x, PRIME)
+        y = pack(ids.point.y, PRIME)
+        value = slope = ec_double_slope(point=(x, y), alpha=ALPHA, p=SECP_P)
+    %}
+    let (slope: BigInt3) = nondet_bigint3();
+
+    let (x_sqr: UnreducedBigInt3) = unreduced_sqr(point.x);
+    let (slope_y: UnreducedBigInt3) = unreduced_mul(slope, point.y);
+    verify_zero(
+        UnreducedBigInt3(
+            d0=3 * x_sqr.d0 + A0 - 2 * slope_y.d0,
+            d1=3 * x_sqr.d1 + A1 - 2 * slope_y.d1,
+            d2=3 * x_sqr.d2 + A2 - 2 * slope_y.d2,
+        ),
+    );
+
+    return (slope=slope);
+}

cairo_programs/secp256r1_compute_doubling_slope.cairo

@@ -0,0 +1,44 @@
+%builtins range_check
+
+// Sources: https://github.com/myBraavos/efficient-secp256r1/blob/main/src/secp256r1/signature.cairo#L48
+// Sources: https://github.com/myBraavos/efficient-secp256r1/blob/main/src/secp256r1/ec.cairo#L32
+
+from starkware.cairo.common.alloc import alloc
+from starkware.cairo.common.bitwise import bitwise_and
+from starkware.cairo.common.cairo_builtins import BitwiseBuiltin
+from starkware.cairo.common.cairo_secp.bigint import (
+    BASE,
+    BigInt3,
+    UnreducedBigInt3,
+    bigint_mul,
+    nondet_bigint3,
+)
+from starkware.cairo.common.cairo_secp.ec import EcPoint
+from starkware.cairo.common.math import assert_nn, assert_nn_le, assert_not_zero, unsigned_div_rem
+from starkware.cairo.common.math_cmp import RC_BOUND
+from starkware.cairo.common.uint256 import Uint256
+
+func div_mod_n{range_check_ptr}(a: BigInt3, b: BigInt3) -> (res: BigInt3) {
+    %{ from starkware.cairo.common.cairo_secp.secp256r1_utils import SECP256R1_N as N %}
+    %{
+        from starkware.cairo.common.cairo_secp.secp_utils import pack
+        from starkware.python.math_utils import div_mod, safe_div
+
+        a = pack(ids.a, PRIME)
+        b = pack(ids.b, PRIME)
+        value = res = div_mod(a, b, N)
+    %}
+    let (res) = nondet_bigint3();
+
+    return (res=res);
+}
+
+func main{range_check_ptr}(){
+    let x = BigInt3(235, 522, 111);
+    let y = BigInt3(1323, 15124, 796759);
+
+    let a = div_mod_n(x, y);
+    assert a = a;
+    return ();
+
+}

cairo_programs/secp256r1_div_mod_n.cairo

@@ -48,7 +48,7 @@ lazy_static! {
         "115792089210356248762697446949407573530086143415290314195533631308867097853951"
     ).unwrap();
     //SECP256R1_N = 0xFFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551
-    pub(crate) static ref SECP256R1_N: BigUint = BigUint::from_str(
+    pub(crate) static ref SECP256R1_N: BigInt = BigInt::from_str(
         "115792089210356248762697446949407573529996955224135760342422259061068512044369"
     ).unwrap();
     //SECP256R1_ALPHA = 0xFFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFC

src/hint_processor/builtin_hint_processor/secp/secp_utils.rs

@@ -1343,3 +1343,10 @@ fn cairo_run_is_zero() {
     let program_data = include_bytes!("../../cairo_programs/is_zero.json");
     run_program_simple(program_data.as_slice());
 }
+
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn cairo_run_secp256r1_div_mod_n() {
+    let program_data = include_bytes!("../../cairo_programs/secp256r1_div_mod_n.json");
+    run_program_simple(program_data.as_slice());
+}