[incubator-nuttx] branch master updated: libc:add timingsafe_bcmp to libc

[xi...@apache.org]

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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 1a5351edac libc:add timingsafe_bcmp to libc
1a5351edac is described below

commit 1a5351edaccc14e75c317481e14d843990db342d
Author: anjiahao <an...@xiaomi.com>
AuthorDate: Sat Aug 27 12:22:29 2022 +0800

    libc:add timingsafe_bcmp to libc
    
    Signed-off-by: anjiahao <an...@xiaomi.com>
---
 include/string.h                       |  1 +
 libs/libc/string/Make.defs             |  2 +-
 libs/libc/string/lib_timingsafe_bcmp.c | 43 ++++++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/include/string.h b/include/string.h
index 8d82b6b7a0..7e449fe6ed 100644
--- a/include/string.h
+++ b/include/string.h
@@ -93,6 +93,7 @@ FAR void  *memmem(FAR const void *haystack, size_t haystacklen,
                   FAR const void *needle, size_t needlelen);
 
 void explicit_bzero(FAR void *s, size_t n);
+int timingsafe_bcmp(FAR const void *b1, FAR const void *b2, size_t n);
 
 #undef EXTERN
 #if defined(__cplusplus)
diff --git a/libs/libc/string/Make.defs b/libs/libc/string/Make.defs
index 6284d1fe74..1208246e97 100644
--- a/libs/libc/string/Make.defs
+++ b/libs/libc/string/Make.defs
@@ -29,7 +29,7 @@ CSRCS += lib_strerror.c lib_strncasecmp.c lib_strncat.c lib_strncmp.c
 CSRCS += lib_strndup.c lib_strcasestr.c lib_strpbrk.c lib_strrchr.c
 CSRCS += lib_strspn.c lib_strstr.c lib_strtok.c lib_strtokr.c
 CSRCS += lib_strsep.c lib_strerrorr.c lib_explicit_bzero.c lib_strsignal.c
-CSRCS += lib_index.c lib_rindex.c
+CSRCS += lib_index.c lib_rindex.c lib_timingsafe_bcmp.c
 
 ifneq ($(CONFIG_LIBC_ARCH_MEMCHR),y)
 CSRCS += lib_memchr.c
diff --git a/libs/libc/string/lib_timingsafe_bcmp.c b/libs/libc/string/lib_timingsafe_bcmp.c
new file mode 100644
index 0000000000..8473b61249
--- /dev/null
+++ b/libs/libc/string/lib_timingsafe_bcmp.c
@@ -0,0 +1,43 @@
+/****************************************************************************
+ * libs/libc/string/lib_timingsafe_bcmp.c
+ * $OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $
+ *
+ * Copyright (c) 2010 Damien Miller.  All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <string.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int timingsafe_bcmp(FAR const void *b1, FAR const void *b2, size_t n)
+{
+  FAR const unsigned char *p1 = b1;
+  FAR const unsigned char *p2 = b2;
+  int ret = 0;
+
+  for (; n > 0; n--)
+    {
+      ret |= *p1++ ^ *p2++;
+    }
+
+  return (ret != 0);
+}