From: Loup Vaillant <loup@loup-vaillant.fr>
Date: Thu, 23 Mar 2023 11:02:57 +0000 (+0100)
Subject: Fixed NULL += 0 undefined behaviour
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=57bacd2c38456a8d517484c652280f6eda14b2e3;p=Monocypher.git

Fixed NULL += 0 undefined behaviour
---

diff --git a/src/monocypher.c b/src/monocypher.c
index 0257fb5..7fdebb0 100644
--- a/src/monocypher.c
+++ b/src/monocypher.c
@@ -377,6 +377,11 @@ void crypto_poly1305_init(crypto_poly1305_ctx *ctx, const u8 key[32])
 void crypto_poly1305_update(crypto_poly1305_ctx *ctx,
                             const u8 *message, size_t message_size)
 {
+	// Avoid undefined NULL pointer increments with empty messages
+	if (message_size == 0) {
+		return;
+	}
+
 	// Align ourselves with block boundaries
 	size_t aligned = MIN(gap(ctx->c_idx, 16), message_size);
 	FOR (i, 0, aligned) {