From: jsing <jsing@openbsd.org>
Date: Fri, 23 Dec 2022 02:13:15 +0000 (+0000)
Subject: Add regress coverage for shifts of zero bits.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=0c6046f558d8122f7bcc7681fc52b8e74c1880eb;p=openbsd

Add regress coverage for shifts of zero bits.
---

diff --git a/regress/lib/libcrypto/bn/bn_shift.c b/regress/lib/libcrypto/bn/bn_shift.c
index fd5184523bd..743a911cbee 100644
--- a/regress/lib/libcrypto/bn/bn_shift.c
+++ b/regress/lib/libcrypto/bn/bn_shift.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bn_shift.c,v 1.4 2022/12/23 02:12:11 jsing Exp $ */
+/*	$OpenBSD: bn_shift.c,v 1.5 2022/12/23 02:13:15 jsing Exp $ */
 /*
  * Copyright (c) 2022 Joel Sing <jsing@openbsd.org>
  *
@@ -233,6 +233,43 @@ test_bn_shift(void)
 	if (!check_shift_result(bn1))
 		goto failure;
 
+	/*
+	 * Shift of zero (equivalent to a copy).
+	 */
+	BN_zero(bn2);
+	if (!BN_lshift(bn2, bn1, 0)) {
+		fprintf(stderr, "FAIL: failed to BN_lshift()\n");
+		goto failure;
+	}
+
+	if (!check_shift_result(bn2))
+		goto failure;
+
+	if (!BN_lshift(bn2, bn2, 0)) {
+		fprintf(stderr, "FAIL: failed to BN_lshift()\n");
+		goto failure;
+	}
+
+	if (!check_shift_result(bn2))
+		goto failure;
+
+	BN_zero(bn2);
+	if (!BN_rshift(bn2, bn1, 0)) {
+		fprintf(stderr, "FAIL: failed to BN_rshift()\n");
+		goto failure;
+	}
+
+	if (!check_shift_result(bn2))
+		goto failure;
+
+	if (!BN_rshift(bn2, bn2, 0)) {
+		fprintf(stderr, "FAIL: failed to BN_rshift()\n");
+		goto failure;
+	}
+
+	if (!check_shift_result(bn2))
+		goto failure;
+
 	failed = 0;
 
  failure: