WIP feat: initial gfmul algo. Not working yet.

src/tasks/tasks01/block2poly.rs

@@ -1,6 +1,6 @@
 use std::{str::Bytes, string};
 
-use crate::utils::poly::{self, get_coefficients};
+use crate::utils::poly::{self, block_2_number, get_coefficients};
 use anyhow::Result;
 use base64::prelude::*;
 use serde_json::Value;
@@ -9,11 +9,7 @@ pub fn block2poly(val: &Value) -> Result<Vec<u8>> {
     // Convert JSON data in to a u128
     // TODO: Transfer decoding into own function?
     let string: String = serde_json::from_value(val["block"].clone())?;
-    let decoded: Vec<u8> = BASE64_STANDARD.decode(string)?;
-
-    let mut bytes: [u8; 16] = [0u8; 16];
-    bytes.copy_from_slice(&decoded);
-    let number: u128 = <u128>::from_ne_bytes(bytes);
+    let number: u128 = block_2_number(string)?;
 
     let coefficients: Vec<u8> = get_coefficients(number);
 

src/tasks/tasks01/gfmul.rs

@@ -0,0 +1,62 @@
+use anyhow::Result;
+use base64::prelude::*;
+use serde_json::Value;
+
+use crate::utils::poly::{block_2_number, coefficient_to_binary};
+
+pub fn gfmul(args: &Value) -> Result<String> {
+    eprintln!("{args}");
+    // Generate reduction polynomial
+    let reduction_polynomial_coeffs: Vec<u8> = vec![127, 126, 125, 121];
+    let red_poly_num: u128 = coefficient_to_binary(reduction_polynomial_coeffs);
+    //eprintln!("{:?}", serde_json::from_value(args["a"].clone())?);
+
+    let mut poly1: u128 = block_2_number(serde_json::from_value(args["a"].clone())?)?;
+    let poly2: u128 = block_2_number(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;
+
+    for i in 0..128 {
+        // If poly2 at pos i is 1 then...
+        if ((poly2 >> i) & 1) == 1 {
+            result ^= poly1;
+        }
+
+        // If poly1 at pos 127 is 0 then...
+        if ((poly1 >> 127) & 0) == 0 {
+            poly1 = poly1 >> 1;
+        } else {
+            poly1 = (poly1 >> 1) ^ red_poly_num;
+        }
+    }
+
+    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(())
+    }
+}

src/tasks/tasks01/mod.rs

@@ -1,3 +1,3 @@
 pub mod block2poly;
+pub mod gfmul;
 pub mod poly2block;
-