use zeroize::{DefaultIsZeroes, Zeroize}; use crypto_bigint::{ U512, U1024, modular::constant_mod::{ResidueParams, Residue}, }; const MODULUS_PADDED_STR: &str = concat!( "00000000000000", "00", "3fffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7cca23e9c44edb49aed63690216cc2728dc58f552378c292ab5844f3", ); impl_modulus!(ScalarModulus, U512, MODULUS_PADDED_STR); type ResidueType = Residue; /// Ed448 Scalar field element. #[derive(Clone, Copy, PartialEq, Eq, Default, Debug)] pub struct Scalar(pub(crate) ResidueType); impl DefaultIsZeroes for Scalar {} const MODULUS_STR: &str = concat!( "3fffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7cca23e9c44edb49aed63690216cc2728dc58f552378c292ab5844f3", ); // 2**446 - 13818066809895115352007386748515426880336692474882178609894547503885 pub(crate) const MODULUS: U512 = U512::from_be_hex(concat!( "00000000000000", "00", "3fffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7cca23e9c44edb49aed63690216cc2728dc58f552378c292ab5844f3", )); const WIDE_MODULUS: U1024 = U1024::from_be_hex(concat!( "0000000000000000000000000000000000000000000000000000000000000000", "0000000000000000000000000000000000000000000000000000000000000000", "00000000000000", "00", "3fffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7cca23e9c44edb49aed63690216cc2728dc58f552378c292ab5844f3", )); field!( Scalar, ResidueType, MODULUS_STR, MODULUS, WIDE_MODULUS, 446, 2, concat!( "0400000000000000000000000000000000000000000000000000000000000000", "0000000000000000000000000000000000000000000000000000000000000000", ), ); impl Scalar { /// Perform a wide reduction to obtain a non-biased Scalar. pub fn wide_reduce(bytes: [u8; 114]) -> Scalar { Scalar(Residue::new(&reduce(U1024::from_le_slice(&[bytes.as_ref(), &[0; 14]].concat())))) } } #[test] fn test_scalar() { ff_group_tests::prime_field::test_prime_field_bits::<_, Scalar>(&mut rand_core::OsRng); }