src/tasks/tasks01/pfmath.rs

@@ -112,7 +112,7 @@ pub fn gfpoly_gcd(args: &Value) -> Result<Polynomial> {
     let poly_a = Polynomial::from_c_array(&args["A"].clone());
     let poly_b = Polynomial::from_c_array(&args["B"].clone());
 
-    let result = gcd(poly_a.monic(), poly_b.monic());
+    let result = gcd(&poly_a.monic(), &poly_b.monic());
 
     Ok(result)
 }

src/utils/field.rs

@@ -14,7 +14,7 @@ use super::{
     poly::gfmul,
 };
 
-#[derive(Debug, serde::Serialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 pub struct FieldElement {
     field_element: Vec<u8>,
 }

src/utils/mod.rs

@@ -1,6 +1,9 @@
 pub mod ciphers;
+pub mod dff;
+pub mod edf;
 pub mod field;
 pub mod math;
 pub mod net;
 pub mod parse;
 pub mod poly;
+pub mod sff;

src/utils/poly.rs

@@ -12,7 +12,7 @@ use serde_json::Value;
 
 use super::field::FieldElement;
 
-#[derive(Debug, serde::Serialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 pub struct Polynomial {
     polynomial: Vec<FieldElement>,
 }
@@ -178,13 +178,16 @@ impl Polynomial {
     }
 
     // Returns (quotient, remainder)
-    pub fn div(self, rhs: &Self) -> (Self, Self) {
+    pub fn div(&self, rhs: &Self) -> (Self, Self) {
         // Div by zero check ommitted since data is guaranteed to be non 0
 
         eprintln!("{:?}, {:?}", self.polynomial.len(), rhs.polynomial.len());
 
         if self.polynomial.len() < rhs.polynomial.len() {
-            return (Polynomial::new(vec![FieldElement::new(vec![0; 16])]), self);
+            return (
+                Polynomial::new(vec![FieldElement::new(vec![0; 16])]),
+                self.clone(),
+            );
         }
 
         let mut remainder = self.clone();
@@ -483,12 +486,13 @@ impl Ord for Polynomial {
     }
 }
 
-pub fn gcd(a: Polynomial, b: Polynomial) -> Polynomial {
+pub fn gcd(a: &Polynomial, b: &Polynomial) -> Polynomial {
     if a.is_zero() {
-        return b;
+        return b.clone();
     }
 
-    return gcd(b.div(&a).1.monic(), a);
+    let monic_b = b.div(&a).1.monic();
+    return gcd(&monic_b, a);
 }
 
 pub fn sort_polynomial_array(mut polys: Vec<Polynomial>) -> Result<Vec<Polynomial>> {
@@ -1300,7 +1304,7 @@ mod tests {
         let a: Polynomial = Polynomial::from_c_array(&a);
         let b: Polynomial = Polynomial::from_c_array(&b);
 
-        let result = gcd(a.monic(), b.monic());
+        let result = gcd(&a.monic(), &b.monic());
 
         assert_eq!(json!(result.to_c_array()), expected);
     }
@@ -1314,7 +1318,7 @@ mod tests {
         let a: Polynomial = Polynomial::from_c_array(&a);
         let b: Polynomial = Polynomial::from_c_array(&b);
 
-        let result = gcd(a.monic(), b.monic());
+        let result = gcd(&a.monic(), &b.monic());
 
         assert_eq!(json!(result.to_c_array()), expected);
     }

src/utils/sff.rs

@@ -0,0 +1,91 @@
+use serde::{Deserialize, Serialize};
+
+use crate::utils::{
+    field::FieldElement,
+    poly::{gcd, polynomial_2_block},
+};
+
+use super::poly::Polynomial;
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Factors {
+    factor: Vec<String>,
+    exponent: u32,
+}
+
+pub fn sff(mut f: Polynomial) -> Vec<(Polynomial, u32)> {
+    let mut c = gcd(&f, &f.clone().diff());
+    f = f.div(&c).0;
+    let mut z: Vec<(Polynomial, u32)> = vec![];
+    let mut e: u32 = 1;
+
+    let one_element = Polynomial::new(vec![FieldElement::new(
+        polynomial_2_block(vec![0], "gcm").unwrap(),
+    )]);
+
+    while f != one_element {
+        let y = gcd(&f, &c);
+        if f != y {
+            z.push(((f.div(&y).0), e));
+        }
+
+        f = y.clone();
+        c = c.div(&y).0;
+        e += 1;
+    }
+
+    if c != one_element {
+        let r = sff(c.sqrt());
+        for (f_star, e_star) in r {
+            z.push((f_star, 2 * e_star));
+        }
+    }
+
+    z
+}
+
+#[cfg(test)]
+mod tests {
+
+    use serde_json::json;
+    // Note this useful idiom: importing names from outer (for mod tests) scope.
+    use super::*;
+
+    #[test]
+    fn byte_indices_0x01() {
+        let json_f = json!([
+            "vL77UwAAAAAAAAAAAAAAAA==",
+            "mEHchYAAAAAAAAAAAAAAAA==",
+            "9WJa0MAAAAAAAAAAAAAAAA==",
+            "akHfwWAAAAAAAAAAAAAAAA==",
+            "E12o/QAAAAAAAAAAAAAAAA==",
+            "vKJ/FgAAAAAAAAAAAAAAAA==",
+            "yctWwAAAAAAAAAAAAAAAAA==",
+            "c1BXYAAAAAAAAAAAAAAAAA==",
+            "o0AtAAAAAAAAAAAAAAAAAA==",
+            "AbP2AAAAAAAAAAAAAAAAAA==",
+            "k2YAAAAAAAAAAAAAAAAAAA==",
+            "vBYAAAAAAAAAAAAAAAAAAA==",
+            "dSAAAAAAAAAAAAAAAAAAAA==",
+            "69gAAAAAAAAAAAAAAAAAAA==",
+            "VkAAAAAAAAAAAAAAAAAAAA==",
+            "a4AAAAAAAAAAAAAAAAAAAA==",
+            "gAAAAAAAAAAAAAAAAAAAAA=="
+        ]);
+        let poly_f = Polynomial::from_c_array(&json_f);
+
+        let factors = sff(poly_f);
+        let mut result: Vec<Factors> = vec![];
+
+        for (factor, exponent) in factors {
+            result.push(Factors {
+                factor: factor.to_c_array(),
+                exponent,
+            });
+        }
+
+        println!("{:?}", result.sort());
+        let bit_indices: Vec<u8> = vec![0];
+        assert!(false)
+    }
+}