Add regress coverage for BN_num_bits_word()

1 files changed, 25 insertions, 1 deletions

diff --git a/src/regress/lib/libcrypto/bn/bn_unit.c b/src/regress/lib/libcrypto/bn/bn_unit.c
index 1af3e8868d..6c5b210739 100644
--- a/src/regress/lib/libcrypto/bn/bn_unit.c
+++ b/src/regress/lib/libcrypto/bn/bn_unit.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bn_unit.c,v 1.2 2022/12/06 18:23:29 tb Exp $ */
+/*      $OpenBSD: bn_unit.c,v 1.3 2023/02/14 15:08:15 tb Exp $ */
 
 /*
  * Copyright (c) 2022 Theo Buehler <tb@openbsd.org>
@@ -69,12 +69,36 @@ test_bn_print_null_derefs(void)
         return failed;
 }
 
+static int
+test_bn_num_bits_word(void)
+{
+        BN_ULONG w = 1;
+        int i, num_bits;
+        int failed = 0;
+
+        if ((num_bits = BN_num_bits_word(0)) != 0) {
+                warnx("BN_num_bits_word(0): want 0, got %d", num_bits);
+                failed |= 1;
+        }
+
+        for (i = 0; i < BN_BITS2; i++) {
+                if ((num_bits = BN_num_bits_word(w << i)) != i + 1) {
+                        warnx("BN_num_bits_word(0x%llx): want %d, got %d",
+                            (unsigned long long)(w << i), i + 1, num_bits);
+                        failed |= 1;
+                }
+        }
+
+        return failed;
+}
+
 int
 main(void)
 {
         int failed = 0;
 
         failed |= test_bn_print_null_derefs();
+        failed |= test_bn_num_bits_word();
 
         return failed;
 }