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use super::*;
#[cfg(any(debug_assertions, test))]
#[allow(unused_imports)]
use crate::algebra::EqIndex;
#[cfg(any(debug_assertions, test))]
use crate::crypto::prg::KEY_SIZE;
pub struct ShareGen<D: Domain> {
next_idx: usize,
shares: [D::Share; BATCH_SIZE],
batches: [[D::Batch; PLAYERS]; PACKED],
gens: [BatchGen<D>; PACKED],
}
impl<D: Domain> ShareGen<D> {
pub fn new(keys: &[[Key; PLAYERS]; PACKED], omit: [usize; PACKED]) -> Self {
#[cfg(debug_assertions)]
for i in 0..PACKED {
debug_assert!(omit[i] <= PLAYERS);
if omit[i] < PLAYERS {
debug_assert_eq!(keys[i][omit[i]], [0u8; KEY_SIZE]);
}
}
Self::new_from_batch_gen([
BatchGen::new(&keys[0], omit[0]), BatchGen::new(&keys[1], omit[1]), BatchGen::new(&keys[2], omit[2]), BatchGen::new(&keys[3], omit[3]),
BatchGen::new(&keys[4], omit[4]),
BatchGen::new(&keys[5], omit[5]),
BatchGen::new(&keys[6], omit[6]),
BatchGen::new(&keys[7], omit[7]),
])
}
pub fn new_from_batch_gen(gens: [BatchGen<D>; PACKED]) -> Self {
let mut share_gen = ShareGen {
next_idx: BATCH_SIZE,
shares: unsafe { MaybeUninit::zeroed().assume_init() },
batches: unsafe { MaybeUninit::zeroed().assume_init() },
gens,
};
for i in 0..PACKED {
for j in 0..PLAYERS {
share_gen.batches[i][j] = Default::default();
}
}
share_gen
}
#[allow(clippy::should_implement_trait)]
pub fn next(&mut self) -> D::Share {
if self.next_idx >= BATCH_SIZE {
for i in 0..PACKED {
self.gens[i].gen(&mut self.batches[i]);
}
D::batches_to_shares(&mut self.shares, &self.batches);
self.next_idx = 0;
}
let share = self.shares[self.next_idx];
self.next_idx += 1;
share
}
}
#[cfg(test)]
mod tests {
use rand::rngs::OsRng;
use rand::{Rng, RngCore};
use super::*;
use crate::algebra;
fn share_generator<D: Domain>() {
let mut keys = [[[0u8; KEY_SIZE]; PLAYERS]; PACKED];
for i in 0..keys.len() {
for j in 0..keys[i].len() {
OsRng.fill_bytes(&mut keys[i][j]);
}
}
let n: usize = OsRng.gen::<usize>() % 100_000;
let mut gen = ShareGen::<D>::new(&keys, [PLAYERS; PACKED]);
let mut shares: Vec<D::Share> = vec![];
for _ in 0..n {
shares.push(gen.next());
}
let omit: [usize; PACKED] = [
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
OsRng.gen::<usize>() % (PLAYERS + 1),
];
for i in 0..keys.len() {
if omit[i] < PLAYERS {
keys[i][omit[i]] = [0u8; KEY_SIZE];
}
}
let mut gen = ShareGen::<D>::new(&keys, omit);
let mut partial_shares: Vec<D::Share> = vec![];
for _ in 0..n {
partial_shares.push(gen.next());
}
let zero = D::Share::default();
for m in 0..n {
for i in 0..PACKED {
for j in 0..PLAYERS {
if j == omit[i] {
debug_assert!(
D::Share::compare_index(i, j, &zero, i, j, &partial_shares[m]),
"partial_share[m] = {:?}, omit[i] = {}, rep = {}",
&partial_shares[m],
omit[i],
i
);
} else {
debug_assert!(D::Share::compare_index(
i,
j,
&shares[m],
i,
j,
&partial_shares[m]
));
}
}
}
}
}
#[test]
fn share_generator_test() {
share_generator::<algebra::gf2::Domain>();
}
}