Add OpenSSH's timingsafe_bcmp() to libkern.

ok djm@, deraadt@

diff --git a/sys/conf/files b/sys/conf/files
index 6187472..4f5e41e 100644 (file)
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#      $OpenBSD: files,v 1.497 2010/07/13 16:47:03 deraadt Exp $
+#      $OpenBSD: files,v 1.498 2010/07/20 15:28:43 matthew Exp $
 #      $NetBSD: files,v 1.87 1996/05/19 17:17:50 jonathan Exp $
 
 #      @(#)files.newconf       7.5 (Berkeley) 5/10/93
@@ -1089,6 +1089,7 @@ file dev/x86emu/x86emu_util.c             x86emu
 file lib/libkern/mcount.c              gprof
 file lib/libkern/getsn.c
 file lib/libkern/random.c
+file lib/libkern/timingsafe_bcmp.c
 file lib/libkern/arch/${MACHINE_ARCH}/strchr.S | lib/libkern/strchr.c
 file lib/libkern/arch/${MACHINE_ARCH}/strrchr.S | lib/libkern/strrchr.c
 file lib/libkern/arch/${MACHINE_ARCH}/__main.S | lib/libkern/__main.c

diff --git a/sys/lib/libkern/libkern.h b/sys/lib/libkern/libkern.h
index 36655ea..6fd6671 100644 (file)
--- a/sys/lib/libkern/libkern.h
+++ b/sys/lib/libkern/libkern.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: libkern.h,v 1.26 2009/05/24 10:50:34 jsg Exp $        */
+/*     $OpenBSD: libkern.h,v 1.27 2010/07/20 15:28:44 matthew Exp $    */
 /*     $NetBSD: libkern.h,v 1.7 1996/03/14 18:52:08 christos Exp $     */
 
 /*-
@@ -163,5 +163,6 @@ int  strncasecmp(const char *, const char *, size_t);
 int     getsn(char *, int);
 char   *strchr(const char *, int);
 char   *strrchr(const char *, int);
+int     timingsafe_bcmp(const void *, const void *, size_t);
 
 #endif /* __LIBKERN_H__ */

diff --git a/sys/lib/libkern/timingsafe_bcmp.c b/sys/lib/libkern/timingsafe_bcmp.c
new file mode 100644 (file)
index 0000000..8e25a23
--- /dev/null
+++ b/sys/lib/libkern/timingsafe_bcmp.c
@@ -0,0 +1,33 @@
+/*     $OpenBSD: timingsafe_bcmp.c,v 1.1 2010/07/20 15:28:44 matthew 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.
+ */
+
+#if !defined(_KERNEL) && !defined(_STANDALONE)
+#include <string.h>
+#else
+#include <lib/libkern/libkern.h>
+#endif
+
+int
+timingsafe_bcmp(const void *b1, const void *b2, size_t n)
+{
+       const unsigned char *p1 = b1, *p2 = b2;
+       int ret = 0;
+
+       for (; n > 0; n--)
+               ret |= *p1++ ^ *p2++;
+       return (ret != 0);
+}