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extern crate rand;
extern crate sha3;
use rand::rngs::EntropyRng;
use rand::{CryptoRng, RngCore};
use crate::constants::{CurveOrder, MODBYTES};
use crate::types::{BigNum, DoubleBigNum};
use amcl::rand::RAND;
use crate::errors::SerzDeserzError;
use sha3::digest::{ExtendableOutput, Input, XofReader};
use sha3::{Digest, Sha3_256, Shake256};
pub fn hash_msg(msg: &[u8]) -> [u8; MODBYTES] {
let mut hasher = Shake256::default();
hasher.input(&msg);
let mut h: [u8; MODBYTES] = [0; MODBYTES];
hasher.xof_result().read(&mut h);
h
}
pub fn get_seeded_RNG_with_rng<R: RngCore + CryptoRng>(entropy_size: usize, rng: &mut R) -> RAND {
let mut entropy = vec![0; entropy_size];
rng.fill_bytes(&mut entropy.as_mut_slice());
get_RAND(entropy_size, entropy.as_slice())
}
pub fn get_seeded_RNG(entropy_size: usize) -> RAND {
let mut entropy = vec![0; entropy_size];
let mut rng = EntropyRng::new();
rng.fill_bytes(&mut entropy.as_mut_slice());
get_RAND(entropy_size, entropy.as_slice())
}
fn get_RAND(entropy_size: usize, entropy: &[u8]) -> RAND {
let mut r = RAND::new();
r.clean();
r.seed(entropy_size, &entropy);
r
}
pub fn barrett_reduction(
x: &DoubleBigNum,
modulus: &BigNum,
k: usize,
u: &BigNum,
v: &BigNum,
) -> BigNum {
let mut q1 = x.clone();
q1.shr(k - 1);
let q1 = BigNum::new_dcopy(&q1);
let q2 = BigNum::mul(&q1, &u);
let mut q3 = q2.clone();
q3.shr(k + 1);
let q3 = BigNum::new_dcopy(&q3);
let mut r1 = x.clone();
r1.mod2m(k + 1);
let r1 = BigNum::new_dcopy(&r1);
let mut r2 = BigNum::mul(&q3, modulus);
r2.mod2m(k + 1);
let r2 = BigNum::new_dcopy(&r2);
let diff = BigNum::comp(&r1, &r2);
let mut r = if diff < 0 {
let m = r2.minus(&r1);
v.minus(&m)
} else {
r1.minus(&r2)
};
r.norm();
while BigNum::comp(&r, modulus) >= 0 {
r = BigNum::minus(&r, modulus);
r.norm();
}
r
}
fn __barrett_reduction__(x: &BigNum, modulus: &BigNum, k: usize, u: &BigNum, v: &BigNum) -> BigNum {
let mut q1 = x.clone();
q1.shr(k - 1);
let q2 = BigNum::mul(&q1, &u);
let mut q3 = q2.clone();
q3.shr(k + 1);
let q3 = BigNum::new_dcopy(&q3);
let mut r1 = x.clone();
r1.mod2m(k + 1);
let mut r2 = BigNum::mul(&q3, modulus);
r2.mod2m(k + 1);
let r2 = BigNum::new_dcopy(&r2);
let diff = BigNum::comp(&r1, &r2);
let mut r = if diff < 0 {
let m = r2.minus(&r1);
v.minus(&m)
} else {
r1.minus(&r2)
};
r.norm();
while BigNum::comp(&r, modulus) >= 0 {
r = BigNum::minus(&r, modulus);
r.norm();
}
r
}
pub fn barrett_reduction_params(modulus: &BigNum) -> (usize, BigNum, BigNum) {
let k = modulus.nbits();
let mut u = DoubleBigNum::new();
u.w[0] = 1;
u.shl(k);
u.shl(k);
let u = u.div(&CurveOrder);
let mut v = BigNum::new_int(1isize);
v.shl(k + 1);
(k, u, v)
}
#[cfg(test)]
mod test {
use super::*;
use crate::constants;
use crate::field_elem::FieldElement;
use crate::group_elem::GroupElement;
use crate::group_elem_g1::G1;
use crate::utils::rand::Rng;
use crate::ECCurve::big::BIG;
use crate::ECCurve::dbig::DBIG;
use crate::ECCurve::ecp::ECP;
use crate::ECCurve::fp::FP;
use std::time::{Duration, Instant};
#[test]
fn timing_fp_big() {
let count = 100;
let elems: Vec<_> = (0..count).map(|_| FieldElement::random()).collect();
let bigs: Vec<_> = elems.iter().map(|f| f.to_bignum()).collect();
let fs: Vec<_> = bigs.iter().map(|b| FP::new_big(&b)).collect();
let mut res_mul = BIG::new_int(1 as isize);
let mut start = Instant::now();
for b in &bigs {
res_mul = BigNum::modmul(&res_mul, &b, &CurveOrder);
}
println!(
"Multiplication time for {} BIGs = {:?}",
count,
start.elapsed()
);
let mut res_mul = FP::new_int(1 as isize);
start = Instant::now();
for f in &fs {
res_mul.mul(&f);
}
println!(
"Multiplication time for {} FPs = {:?}",
count,
start.elapsed()
);
let res_mul = FieldElement::one();
start = Instant::now();
for e in &elems {
res_mul.multiply(&e);
}
println!(
"Multiplication time for {} FieldElements = {:?}",
count,
start.elapsed()
);
let mut inverses_b: Vec<BigNum> = vec![];
let mut inverses_f: Vec<FP> = vec![];
start = Instant::now();
for b in &bigs {
let mut i = b.clone();
i.invmodp(&CurveOrder);
inverses_b.push(i);
}
println!("Inverse time for {} BIGs = {:?}", count, start.elapsed());
for i in 0..count {
let r = BigNum::modmul(&inverses_b[i], &bigs[i], &CurveOrder);
assert_eq!(BigNum::comp(&r, &BigNum::new_int(1 as isize)), 0);
}
start = Instant::now();
for f in &fs {
let mut i = f.clone();
i.inverse();
inverses_f.push(i);
}
println!("Inverse time for {} FPs = {:?}", count, start.elapsed());
for i in 0..count {
let mut c = inverses_f[i].clone();
c.mul(&fs[i]);
assert!(c.equals(&FP::new_int(1 as isize)));
}
let c = 50;
start = Instant::now();
let mut r = bigs[0];
for i in 0..c {
r.add(&bigs[i]);
r.rmod(&CurveOrder);
}
println!("Addition time for {} BIGs = {:?}", c, start.elapsed());
let mut r1 = fs[0];
start = Instant::now();
for i in 0..c {
r1.add(&fs[i]);
}
println!("Addition time for {} FPs = {:?}", c, start.elapsed());
}
#[test]
fn timing_ecp() {
let count = 100;
let mut a = vec![];
let mut b = vec![];
let mut g = Vec::<ECP>::new();
let mut h = Vec::<ECP>::new();
let mut r1 = vec![];
let mut r2 = vec![];
for _ in 0..count {
a.push(FieldElement::random().to_bignum());
b.push(FieldElement::random().to_bignum());
let mut x: G1 = GroupElement::random();
g.push(x.to_ecp());
x = GroupElement::random();
h.push(x.to_ecp());
}
let mut start = Instant::now();
for i in 0..count {
r1.push(g[i].mul2(&a[i], &h[i], &b[i]));
}
println!("mul2 time for {} = {:?}", count, start.elapsed());
start = Instant::now();
for i in 0..count {
let mut _1 = g[i].mul(&a[i]);
_1.add(&h[i].mul(&b[i]));
r2.push(_1);
}
println!("mul+add time for {} = {:?}", count, start.elapsed());
for i in 0..count {
assert!(r1[i].equals(&mut r2[i]))
}
}
#[test]
fn timing_barrett_reduction() {
let (k, u, v) = (
*constants::BarrettRedc_k,
*constants::BarrettRedc_u,
*constants::BarrettRedc_v,
);
let mut xs = vec![];
let mut reduced1 = vec![];
let mut reduced2 = vec![];
let mut rng = rand::thread_rng();
let count = 1000;
for _ in 0..count {
let a: u32 = rng.gen();
let s = BigNum::new_int(a as isize);
let _x = CurveOrder.minus(&s);
xs.push(BigNum::mul(&_x, &_x));
}
let mut start = Instant::now();
for x in &xs {
let r = barrett_reduction(&x, &CurveOrder, k, &u, &v);
reduced1.push(r);
}
println!("Barrett time = {:?}", start.elapsed());
start = Instant::now();
for x in &xs {
let mut y = x.clone();
let z = y.dmod(&CurveOrder);
reduced2.push(z);
}
println!("Normal time = {:?}", start.elapsed());
for i in 0..count {
assert_eq!(BigNum::comp(&reduced1[i], &reduced2[i]), 0);
}
}
#[test]
fn timing_rmod_with_barrett_reduction() {
let (k, u, v) = (
*constants::BarrettRedc_k,
*constants::BarrettRedc_u,
*constants::BarrettRedc_v,
);
let count = 100;
let elems: Vec<_> = (0..count).map(|_| FieldElement::random()).collect();
let bigs: Vec<_> = elems.iter().map(|f| f.to_bignum()).collect();
let mut sum = bigs[0].clone();
let mut start = Instant::now();
for i in 0..count {
sum = BigNum::plus(&sum, &bigs[i]);
sum.rmod(&CurveOrder)
}
println!("rmod time = {:?}", start.elapsed());
let mut sum_b = bigs[0].clone();
start = Instant::now();
for i in 0..count {
sum_b = BigNum::plus(&sum_b, &bigs[i]);
sum_b = __barrett_reduction__(&sum_b, &CurveOrder, k, &u, &v)
}
println!("Barrett time = {:?}", start.elapsed());
assert_eq!(BigNum::comp(&sum, &sum_b), 0)
}
}