Merge branch 'master' of gitlab.binets.fr:william.koch/mental-poker

src/coin_flipping.rs

-mod gen_prime
-mod quadratic_residues
+/* coin_flipping.rs
+ * Part of the Mental Poker project
+ * Course: MAA313-2020
+ * Members: William Koch,
+ *          Mihails Valtusovs,
+ *          Olavi Äikäs
+ * See git history for contributions
+ */
+
+// mod prime_gen;
+use super::prime_gen;
+mod quadratic_residues;
+mod astarzstar;
+mod jacobi;
+mod gcd;
+use rand::prelude::*;
+
+fn check_quadratic_residuoity(y: &BigUint, N: &BigUint, P: &BigUint, Q: &BigUint) -> bool {
+    if gcd::compute(y, N) != 1 {
+        return false;
+    }   
+    if jacobi::compute(y, N) == -1 {
+        return false;
+    }
+    let qr_p : bool = quadratic_residues::is_quadratic_residue(y, P);
+    let qr_q : bool = quadratic_residues::is_quadratic_residue(y, Q);
+
+    return (qr_p && qr_q);
+}
 
 // Returns A_N, N, y, P, Q
-pub fn generate_keys() -> (Vec::<BigUint> A_N, BigUint, BigUint, BigUint, BigUint) {
-    let P = prime_gen::gen_prime(512);
-    let Q = prime_gen::gen_prime(512);
+pub fn generate_keys(size: usize) -> (BigUint, BigUint, BigUint , BigUint) {
+    // I really hate constants - Mihails
+    let P = prime_gen::gen_prime(size);
+    let Q = prime_gen::gen_prime(size);
 
     let N = P * Q;
 
-    // TODO: Generate A_N
-    // A_N = 
+    let mut y = astarzstar::rand_astar(&N);
+    while !check_quadratic_residuoity(&y, &N, &P, &Q) {
+        y = astarzstar::rand_astar(&N);
+    }
+
+    // publicize N, y
+    // keep private P, Q
+    return (N, y, P, Q);
+}
 
-    /*
-    let mut y = sample_from_A_N()
-    while !is_quad_res(y, p) {
-        y = sample_from_A_N
+pub fn guess_whether_quadratic_residue(N: &BigUint, y: &BigUint, q: &BigUint) -> bool {
+    let jacobi = jacobi::compute(q, N);
+
+    if (jacobi == -1) {
+        return false;
     }
 
-    */
+    let mut rng = thread_rng();
+    let flip : bool = rng.gen();
+
+    return flip;
 }
\ No newline at end of file