72 lines
1.7 KiB
Rust
72 lines
1.7 KiB
Rust
use cryptonum::signed::Signed;
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use cryptonum::traits::*;
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use std::ops::*;
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pub fn modinv<'a,T>(e: &T, phi: &T) -> T
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where
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T: Clone + CryptoNumBase + Ord,
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T: AddAssign + SubAssign + MulAssign + DivAssign,
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T: Add<Output=T> + Sub<Output=T> + Mul<Output=T> + Div<Output=T>,
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&'a T: Sub<Output=T>,
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T: 'a
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{
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let (_, mut x, _) = extended_euclidean(e, phi);
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let int_phi = Signed::<T>::new(phi.clone());
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while x.is_negative() {
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x += &int_phi;
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}
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x.abs()
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}
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pub fn modexp<T>(b: &T, e: &T, m: &T) -> T
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{
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panic!("modexp")
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}
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pub fn extended_euclidean<T>(a: &T, b: &T) -> (Signed<T>, Signed<T>, Signed<T>)
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where
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T: Clone + CryptoNumBase + Div + Mul + Sub
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{
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let posinta = Signed::<T>::new(a.clone());
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let posintb = Signed::<T>::new(b.clone());
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let (mut d, mut x, mut y) = egcd(&posinta, &posintb);
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if d.is_negative() {
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d.negate();
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x.negate();
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y.negate();
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}
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(d, x, y)
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}
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pub fn egcd<T>(a: &Signed<T>, b: &Signed<T>) -> (Signed<T>,Signed<T>,Signed<T>)
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where
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T: Clone + CryptoNumBase + Div + Mul + Sub
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{
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let mut s = Signed::<T>::zero();
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let mut old_s = Signed::<T>::from_u8(1);
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let mut t = Signed::<T>::from_u8(1);
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let mut old_t = Signed::<T>::zero();
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let mut r = b.clone();
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let mut old_r = a.clone();
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while !r.is_zero() {
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let quotient = old_r.clone() / r.clone();
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let prov_r = r.clone();
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let prov_s = s.clone();
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let prov_t = t.clone();
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r = old_r - (r * "ient);
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s = old_s - (s * "ient);
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t = old_t - (t * "ient);
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old_r = prov_r;
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old_s = prov_s;
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old_t = prov_t;
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}
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(old_r, old_s, old_t)
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}
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