From 4a3cbd75b57b2046721dd3f83b14c74f0644a13b Mon Sep 17 00:00:00 2001
From: gbrochar <gaetanbrochard@protonmail.com>
Date: Fri, 16 Feb 2024 17:33:46 +0100
Subject: [PATCH] fix: leaks

---
 rsa/bigint.c | 38 ++++++++++----------------------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/rsa/bigint.c b/rsa/bigint.c
index ab4d131..dda3504 100644
--- a/rsa/bigint.c
+++ b/rsa/bigint.c
@@ -82,35 +82,11 @@ int bigint_cmp(bigint_t a, bigint_t b) {
 	return 0;
 }
 
-// TODO check opti
-bigint_t assignable_bigint_substraction(bigint_t a, bigint_t b) {
-	if (a.len != b.len) {
-		printf("error: attempting to substract numbers of different length\n");
-		exit(1);
-	}
-
-	bigint_t result = bigint_clone(a);
-	bigint_t borrow = bigint_clone(b);
-	bigint_t y = bigint_clone(b);
-	bigint_t zero = bigint_zero(a.len);
-	while (bigint_cmp(borrow, zero)) {
-		for (size_t i = 0; i < a.len; i++) {
-			borrow.data[i] = ~result.data[i] & y.data[i];
-			result.data[i] = result.data[i] ^ y.data[i];
-		}
-		bigint_destroy(y);
-		y = assignable_bigint_bitwise_left_shift(borrow);
-	}
-	bigint_destroy(y);
-	bigint_destroy(borrow);
-	bigint_destroy(zero);
-	return result;
-}
-
 // TODO check opti
 void bigint_substraction(bigint_t a, bigint_t bb) {
 	bigint_t b = bigint_clone(bb);
 	if (a.len > bb.len) {
+		bigint_destroy(b);
 		b = bigint_zero(a.len);
 		memcpy(b.data, bb.data, b.len * sizeof(uint32_t));
 	}
@@ -130,6 +106,7 @@ void bigint_substraction(bigint_t a, bigint_t bb) {
 		bigint_destroy(y);
 		y = assignable_bigint_bitwise_left_shift(borrow);
 	}
+	bigint_destroy(b);
 	bigint_destroy(y);
 	bigint_destroy(borrow);
 	bigint_destroy(zero);
@@ -141,6 +118,7 @@ void custom_bigint_modulo(bigint_t a, bigint_t b, bigint_t result) {
 	memcpy(result.data, a.data, a.len * sizeof(uint32_t));
 	bigint_t mod = bigint_clone(b);
 	if (a.len > b.len) {
+		bigint_destroy(mod);
 		mod = bigint_zero(a.len);
 		memcpy(mod.data, b.data, b.len * sizeof(uint32_t));
 	}
@@ -211,9 +189,7 @@ void bigint_add(bigint_t a, bigint_t b) {
 		result.data[cursor / size] |= (a_bit ^ b_bit ^ carriage) << (cursor % size);
 		carriage = (a_bit & b_bit) | ((a_bit ^ b_bit) & carriage);
 	}
-//	memcpy(a.data, result.data, a.len * sizeof(uint32_t));
-	bigint_destroy(a);
-	a = bigint_clone(result);
+	memcpy(a.data, result.data, a.len * sizeof(uint32_t));
 	bigint_destroy(result);
 }
 
@@ -330,6 +306,8 @@ bigint_t bigint_prime(size_t len) {
 			custom_bigint_pow_mod(x, two, n, y, custom, custom2);
 			if (bigint_cmp(y, one) == 0 && bigint_cmp(x, one) != 0 && bigint_cmp(x, n_minus_one) != 0) {
 				bulk_destroy(x, y, n, d, two, one, n_minus_two, n_minus_one);
+				bigint_destroy(custom);
+				bigint_destroy(custom2);
 				bigint_destroy(a);
 				return bigint_prime(len);
 			}
@@ -338,10 +316,14 @@ bigint_t bigint_prime(size_t len) {
 		}
 		if (bigint_cmp(y, one) != 0) {
 			bulk_destroy(x, y, n, d, two, one, n_minus_two, n_minus_one);
+			bigint_destroy(custom);
+			bigint_destroy(custom2);
 			bigint_destroy(a);
 			return bigint_prime(len);
 		}
 	}
+	bulk_destroy(x, y, custom, d, two, one, n_minus_two, n_minus_one);
+	bigint_destroy(custom2);
 	bigint_destroy(a);
 	return n;
 }