core/crypto/_edwards25519: Initial import

core/crypto/_edwards25519/edwards25519_scalar.odin

@@ -0,0 +1,61 @@
+package _edwards25519
+
+import "base:intrinsics"
+import field "core:crypto/_fiat/field_scalar25519"
+import "core:mem"
+
+Scalar :: field.Montgomery_Domain_Field_Element
+
+// WARNING: This is non-canonical and only to be used when checking if
+// a group element is on the prime-order subgroup.
+@(private)
+SC_ELL := field.Non_Montgomery_Domain_Field_Element {
+	field.ELL[0],
+	field.ELL[1],
+	field.ELL[2],
+	field.ELL[3],
+}
+
+sc_set_u64 :: proc "contextless" (sc: ^Scalar, i: u64) {
+	tmp := field.Non_Montgomery_Domain_Field_Element{i, 0, 0, 0}
+	field.fe_to_montgomery(sc, &tmp)
+
+	mem.zero_explicit(&tmp, size_of(tmp))
+}
+
+@(require_results)
+sc_set_bytes :: proc "contextless" (sc: ^Scalar, b: []byte) -> bool {
+	if len(b) != 32 {
+		intrinsics.trap()
+	}
+	b_ := transmute(^[32]byte)(raw_data(b))
+	return field.fe_from_bytes(sc, b_)
+}
+
+sc_set_bytes_rfc8032 :: proc "contextless" (sc: ^Scalar, b: []byte) {
+	if len(b) != 32 {
+		intrinsics.trap()
+	}
+	b_ := transmute(^[32]byte)(raw_data(b))
+	field.fe_from_bytes_rfc8032(sc, b_)
+}
+
+sc_clear :: proc "contextless" (sc: ^Scalar) {
+	mem.zero_explicit(sc, size_of(Scalar))
+}
+
+sc_set :: field.fe_set
+sc_set_bytes_wide :: field.fe_from_bytes_wide
+sc_bytes :: field.fe_to_bytes
+
+sc_zero :: field.fe_zero
+sc_one :: field.fe_one
+
+sc_add :: field.fe_add
+sc_sub :: field.fe_sub
+sc_negate :: field.fe_opp
+sc_mul :: field.fe_mul
+sc_square :: field.fe_square
+
+sc_cond_assign :: field.fe_cond_assign
+sc_equal :: field.fe_equal