kauma/src/tasks/tasks01/gfmul.rs
2024-10-24 22:01:02 +02:00

66 lines
1.9 KiB
Rust

use anyhow::Result;
use base64::prelude::*;
use serde_json::Value;
use crate::utils::poly::{b64_2_num, coefficient_to_binary};
pub fn gfmul(args: &Value) -> Result<String> {
eprintln!("{args}");
// Generate reduction polynomial
let reduction_polynomial_coeffs: Vec<u8> = vec![7, 2, 1, 0];
let red_poly_num: u128 = 340282366920938463463374607431768211591; //coefficient_to_binary(reduction_polynomial_coeffs);
//eprintln!("{:?}", serde_json::from_value(args["a"].clone())?);
let mut poly1: u128 = b64_2_num(&serde_json::from_value(args["a"].clone())?)?;
let poly2: u128 = b64_2_num(&serde_json::from_value(args["b"].clone())?)?;
eprintln!("poly1 is: {}", poly1);
eprintln!("poly2 is: {}", poly2);
/* Begin of magic algorithm
* poly1 = a = X = V ???
* poly2 = b
* result = Z
*/
let mut result: u128 = 0;
if ((poly2 >> 1) & 1) == 1 {
eprintln!("ALHIGLIWhlighliwfhlihliawfhliawfhli");
result ^= poly1;
}
for i in 2..128 {
if ((poly2 >> i) & 1) == 1 {
poly1 = (poly1 << 1) ^ red_poly_num;
result ^= poly1;
} else {
poly1 = (poly1 << 1) ^ red_poly_num;
}
}
poly1 = (poly1 << 1) ^ red_poly_num;
result ^= poly1;
Ok(BASE64_STANDARD.encode(result.to_ne_bytes()))
}
#[cfg(test)]
mod tests {
use serde_json::json;
use std::str::FromStr;
// Note this useful idiom: importing names from outer (for mod tests) scope.
use super::*;
#[test]
fn gfmul_task01() -> Result<()> {
let args: Value = json!({"a": "ARIAAAAAAAAAAAAAAAAAgA==", "b": "AgAAAAAAAAAAAAAAAAAAAA=="});
let result = gfmul(&args)?;
assert_eq!(
result, "hSQAAAAAAAAAAAAAAAAAAA==",
"Failure. Calulated result was: {}",
result
);
Ok(())
}
}