From 2a9db307d9f79c480bef7885bacf38f18659bd54 Mon Sep 17 00:00:00 2001
From: alivecow <mail@ta-lotz.de>
Date: Fri, 15 Nov 2024 10:26:38 +0100
Subject: [PATCH] fix: Add handling of pow with 0

---
 src/utils/field.rs | 67 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 59 insertions(+), 8 deletions(-)

diff --git a/src/utils/field.rs b/src/utils/field.rs
index 758ea75..5f47fce 100644
--- a/src/utils/field.rs
+++ b/src/utils/field.rs
@@ -54,7 +54,9 @@ impl Polynomial {
 
     pub fn pow(&self, mut exponent: u128) -> Polynomial {
         if exponent == 0 {
-            return Polynomial::new(vec![FieldElement::new(vec![0])]);
+            return Polynomial::new(vec![FieldElement::new(
+                polynomial_2_block(vec![0], "gcm").unwrap(),
+            )]);
         }
 
         let base = self.clone();
@@ -69,6 +71,12 @@ impl Polynomial {
     }
 
     pub fn pow_mod(mut self, mut exponent: u128, modulus: Polynomial) -> Polynomial {
+        if exponent == 0 {
+            return Polynomial::new(vec![FieldElement::new(
+                polynomial_2_block(vec![0], "gcm").unwrap(),
+            )]);
+        }
+
         let mut result: Polynomial = Polynomial::new(vec![FieldElement::new(
             polynomial_2_block(vec![0], "gcm").unwrap(),
         )]);
@@ -536,15 +544,13 @@ impl ByteArray {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use base64::prelude::*;
     use serde_json::json;
-    use std::fs;
 
     #[test]
     fn test_byte_array_shift1() {
         let mut byte_array: ByteArray = ByteArray(vec![0x00, 0x01]);
         let shifted_array: ByteArray = ByteArray(vec![0x00, 0x02]);
-        byte_array.left_shift("xex");
+        byte_array.left_shift("xex").unwrap();
 
         assert_eq!(byte_array.0, shifted_array.0);
     }
@@ -553,7 +559,7 @@ mod tests {
     fn test_byte_array_shift2() {
         let mut byte_array: ByteArray = ByteArray(vec![0xFF, 0x00]);
         let shifted_array: ByteArray = ByteArray(vec![0xFE, 0x01]);
-        byte_array.left_shift("xex");
+        byte_array.left_shift("xex").unwrap();
 
         assert_eq!(
             byte_array.0, shifted_array.0,
@@ -566,7 +572,7 @@ mod tests {
     fn test_byte_array_shift1_gcm() {
         let mut byte_array: ByteArray = ByteArray(vec![0xFF, 0x00]);
         let shifted_array: ByteArray = ByteArray(vec![0x7F, 0x80]);
-        byte_array.left_shift("gcm");
+        byte_array.left_shift("gcm").unwrap();
 
         assert_eq!(
             byte_array.0, shifted_array.0,
@@ -579,7 +585,7 @@ mod tests {
     fn test_byte_array_shift1_right_gcm() {
         let mut byte_array: ByteArray = ByteArray(vec![0xFF, 0x00]);
         let shifted_array: ByteArray = ByteArray(vec![0xFE, 0x00]);
-        byte_array.right_shift("gcm");
+        byte_array.right_shift("gcm").unwrap();
 
         assert_eq!(
             byte_array.0, shifted_array.0,
@@ -592,7 +598,7 @@ mod tests {
     fn test_byte_array_shift_right() {
         let mut byte_array: ByteArray = ByteArray(vec![0x02]);
         let shifted_array: ByteArray = ByteArray(vec![0x01]);
-        byte_array.right_shift("xex");
+        byte_array.right_shift("xex").unwrap();
 
         assert_eq!(
             byte_array.0, shifted_array.0,
@@ -814,6 +820,21 @@ mod tests {
         //assert_eq!(BASE64_STANDARD.encode(product), "MoAAAAAAAAAAAAAAAAAAAA==");
     }
 
+    #[test]
+    fn test_poly_pow_with_zero() {
+        let json1 = json!([
+            "JAAAAAAAAAAAAAAAAAAAAA==",
+            "wAAAAAAAAAAAAAAAAAAAAA==",
+            "ACAAAAAAAAAAAAAAAAAAAA=="
+        ]);
+        let element1: Polynomial = Polynomial::from_c_array(&json1);
+
+        let result = element1.pow(0);
+
+        assert_eq!(result.to_c_array(), vec!["gAAAAAAAAAAAAAAAAAAAAA=="]);
+        //assert_eq!(BASE64_STANDARD.encode(product), "MoAAAAAAAAAAAAAAAAAAAA==");
+    }
+
     #[test]
     fn test_field_pow_mod_01() {
         let json1 = json!([
@@ -840,6 +861,36 @@ mod tests {
         //assert_eq!(BASE64_STANDARD.encode(product), "MoAAAAAAAAAAAAAAAAAAAA==");
     }
 
+    #[test]
+    fn test_field_pow_mod_with_zero() {
+        let json1 = json!([
+            "JAAAAAAAAAAAAAAAAAAAAA==",
+            "wAAAAAAAAAAAAAAAAAAAAA==",
+            "ACAAAAAAAAAAAAAAAAAAAA=="
+        ]);
+        let element1: Polynomial = Polynomial::from_c_array(&json1);
+
+        let result = element1.pow(0);
+
+        assert_eq!(result.to_c_array(), vec!["gAAAAAAAAAAAAAAAAAAAAA=="]);
+        //assert_eq!(BASE64_STANDARD.encode(product), "MoAAAAAAAAAAAAAAAAAAAA==");
+    }
+
+    #[test]
+    fn test_field_pow_mod_10mill() {
+        let json1 = json!([
+            "JAAAAAAAAAAAAAAAAAAAAA==",
+            "wAAAAAAAAAAAAAAAAAAAAA==",
+            "ACAAAAAAAAAAAAAAAAAAAA=="
+        ]);
+        let element1: Polynomial = Polynomial::from_c_array(&json1);
+
+        let result = element1.pow(10000000);
+
+        assert_eq!(result.to_c_array(), vec!["gAAAAAAAAAAAAAAAAAAAAA=="]);
+        //assert_eq!(BASE64_STANDARD.encode(product), "MoAAAAAAAAAAAAAAAAAAAA==");
+    }
+
     #[test]
     fn test_poly_div_01() {
         let element1 =