Saataa andagii !

keygen/.gitignore

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+/target
+Cargo.lock

keygen/Cargo.toml

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+[package]
+name = "rust_rsa_key_gen"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+num-bigint-dig = "0.8.4"
+rand = "0.8.5"

keygen/src/main.rs

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+mod rsa;
+use rsa::gen_keys;
+use std::io::Write;
+
+use std::io;
+
+fn main() {
+    let mut input = String::new();
+
+    print!("Enter an integer: ");
+    io::stdout().flush().unwrap();
+    io::stdin().read_line(&mut input).expect("Failed to read line");
+
+    let num: i32 = input.trim().parse().expect("Invalid input");
+
+    let (e, d, n) = gen_keys(num.try_into().unwrap());
+
+    println!("e : {}", e);
+    println!("d : {}", d);
+    println!("n : {}", n);
+}

keygen/src/rsa.rs

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+use num_bigint_dig::{ToBigUint, RandBigInt, BigUint};
+use num_bigint_dig::traits::ModInverse;
+
+fn get_s_and_d(n: &BigUint) -> (BigUint, BigUint) {
+	let mut d = n - 1.to_biguint().unwrap();
+	let mut s = 0.to_biguint().unwrap();
+
+	while &d % 2.to_biguint().unwrap() == 0.to_biguint().unwrap() {
+		s += 1.to_biguint().unwrap();
+		d /= 2.to_biguint().unwrap();
+	}
+
+	(d, s)
+}
+
+fn miller_witness(n: &BigUint, a: &BigUint) -> bool {
+	let (d, s) = get_s_and_d(&n);
+
+	let mut x = a.modpow(&d, &n);
+
+	if x == 1.to_biguint().unwrap() {
+		return false;
+	}
+
+	let mut i = 0.to_biguint().unwrap();
+	while i < s.clone(){
+		if x == n.clone() - 1.to_biguint().unwrap() {
+			return false;
+		}
+
+		x = x.modpow(&2.to_biguint().unwrap(), &n);
+
+		i += 1.to_biguint().unwrap();
+	}
+
+	true
+}
+
+fn is_prime(n: BigUint, k: u16) -> bool {
+
+	if n.clone() == 3.to_biguint().unwrap() || n.clone() == 2.to_biguint().unwrap() {
+		return true;
+	}
+	if n.clone() == 1.to_biguint().unwrap() {
+		return false;
+	}
+	if n.clone() % 2.to_biguint().unwrap() == 0.to_biguint().unwrap() {
+		return false;
+	}
+
+	for _ in 0..k {
+    	let mut rng = rand::thread_rng();
+    	let min = 2.to_biguint().unwrap();
+	    let max = n.clone() - 1.to_biguint().unwrap();
+	    let a = rng.gen_biguint_range(&min, &max);
+
+	    if miller_witness(&n, &a) {
+	    	return false;
+	    }
+	}
+
+	return true;
+}
+
+fn gen_prime_number(lenght: usize) -> BigUint {
+    let mut rng = rand::thread_rng();
+
+    let mut a = rng.gen_biguint(lenght);
+
+    while !is_prime(a.clone(), 50) {
+    	a = rng.gen_biguint(lenght);
+    }
+
+    a
+}
+
+pub fn gen_keys(lenght: usize) -> (BigUint, BigUint, BigUint) {
+	let p = gen_prime_number(lenght / 2);
+	let mut q = gen_prime_number(lenght / 2);
+
+	while p == q {
+		q = gen_prime_number(lenght / 2);
+	}
+
+	let n = &p * &q;
+	let phi_n = (&p - 1.to_biguint().unwrap()) * (&q - 1.to_biguint().unwrap());
+	let e = 65537.to_biguint().unwrap();
+	let d = e.clone().mod_inverse(&phi_n).unwrap().to_biguint().expect("error");
+
+	(e, d, n)
+}