From 9a975f634241ffe54dc33bc6c157002d105e44b4 Mon Sep 17 00:00:00 2001
From: mii8080 <39086319+morioka22@users.noreply.github.com>
Date: Thu, 9 Jun 2022 08:33:44 +0000
Subject: [PATCH] =?UTF-8?q?=E6=95=B0=E5=AD=A6=E6=BA=96=E5=82=99?=
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---
 src/common/math.rs                   | 49 ++++++++++++++++++++++++++++
 src/elliptic_curve/elliptic_curve.rs |  1 +
 src/main.rs                          |  7 ++--
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/src/common/math.rs b/src/common/math.rs
index 74553a0..a1c7054 100644
--- a/src/common/math.rs
+++ b/src/common/math.rs
@@ -1,9 +1,58 @@
 use bigdecimal::{num_bigint::BigInt, Zero, One};
+use primitive_types::U512;
+
+use super::finite_field::FiniteFieldElement;
+use bigdecimal::Num;
 
 pub fn plus_mod(a: BigInt, m: BigInt) -> BigInt {
     (a.clone() % m.clone() + m.clone()) % m
 }
 
+pub fn u512_to_bigint(i: U512) -> BigInt {
+    BigInt::from_str_radix(&format!("{}", i), 10).unwrap()
+}
+
+pub fn bigint_to_u512(i: BigInt) -> U512 {
+    U512::from_str_radix(&format!("{}", i), 10).unwrap()
+}
+
+pub fn abs(a: BigInt, p: BigInt) -> BigInt {
+    if a >= BigInt::zero() {
+        a % p
+    } else {
+        (p.clone()-(-a)%p.clone())%p
+    }
+}
+
+pub fn pow_mod(a: BigInt, n: BigInt, p: BigInt) -> BigInt {
+    let mut r = BigInt::one();
+    let mut db = a.clone();
+    let mut n = n;
+
+    while n > BigInt::zero() {
+        if (n.clone() & BigInt::one()) == BigInt::one() {
+            r = (r.clone() * db.clone()) % p.clone();
+        }
+        db = (db.clone() * db.clone()) % p.clone();
+        n = n >> 1;
+    }
+
+    abs(r, p)
+}
+
+pub fn random_n_q(p: BigInt) -> BigInt {
+    let mut i = BigInt::one();
+    let k = (p.clone() - BigInt::one()) >> 1i32;
+    while i < p {
+        println!("pm {:?}", FiniteFieldElement::new(bigint_to_u512(i.clone()), bigint_to_u512(p.clone())).pow(bigint_to_u512(k.clone())).value);
+        if bigint_to_u512(pow_mod(i.clone(),k.clone(),p.clone())) != U512::one() {
+            break;
+        }
+        i += BigInt::one();
+    }
+    i
+}
+
 pub fn mod_inv(a: BigInt, m: BigInt) -> BigInt {
     let mut a = a;
     if a < BigInt::zero() {
diff --git a/src/elliptic_curve/elliptic_curve.rs b/src/elliptic_curve/elliptic_curve.rs
index 0e25497..c60d4f6 100644
--- a/src/elliptic_curve/elliptic_curve.rs
+++ b/src/elliptic_curve/elliptic_curve.rs
@@ -46,6 +46,7 @@ impl EllipticCurvePoint {
             EllipticCurvePoint::Infinity => true,
         }
     }
+
 }
 
 impl Neg for EllipticCurvePoint {
diff --git a/src/main.rs b/src/main.rs
index ce8b4db..fddf71e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,12 @@
-use encrypt::{elliptic_curve::{elliptic_curve::EllipticCurve, encryption::Encryption}, common::finite_field::FiniteFieldElement};
+use bigdecimal::num_bigint::BigInt;
+use encrypt::{elliptic_curve::{elliptic_curve::EllipticCurve, encryption::Encryption}, common::{finite_field::FiniteFieldElement, math::random_n_q}};
 use primitive_types::U512;
 
 fn main() {
     println!("Encryption Library");
 
+    println!("{}", random_n_q(BigInt::from(23)));
+
     let p = U512::from_str_radix("115792089237316195423570985008687907853269984665640564039457584007908834671663", 10).unwrap();
 
     let secp256_k1_a = FiniteFieldElement::new(U512::from(0u8), p);
@@ -41,7 +44,7 @@ fn main() {
     let public_key = encryption.get_public_key(private_key);
     println!("public_key: {}", public_key);
 
-    for x in 0..100 {
+    for x in 0..10 {
         let ten = encryption.plain_to_ec_point(U512::from(10u32));
         let e_ten = encryption.encrypt(ten, public_key, None);
         println!("10 -> {}", e_ten.data);