From 6b58c306f2b5b2dcef66386167df6c8703c397b2 Mon Sep 17 00:00:00 2001
From: matthew <>
Date: Thu, 12 Jun 2014 22:01:55 +0000
Subject: Add regress test for explicit_bzero.
---
src/regress/lib/libc/Makefile | 4 +-
src/regress/lib/libc/explicit_bzero/Makefile | 5 +
.../lib/libc/explicit_bzero/explicit_bzero.c | 138 +++++++++++++++++++++
3 files changed, 145 insertions(+), 2 deletions(-)
create mode 100644 src/regress/lib/libc/explicit_bzero/Makefile
create mode 100644 src/regress/lib/libc/explicit_bzero/explicit_bzero.c
(limited to 'src')
diff --git a/src/regress/lib/libc/Makefile b/src/regress/lib/libc/Makefile
index f138f16ffd..71eb6398a8 100644
--- a/src/regress/lib/libc/Makefile
+++ b/src/regress/lib/libc/Makefile
@@ -1,7 +1,7 @@
-# $OpenBSD: Makefile,v 1.39 2014/06/07 01:46:40 tobiasu Exp $
+# $OpenBSD: Makefile,v 1.40 2014/06/12 22:01:55 matthew Exp $
SUBDIR+= _setjmp alloca atexit basename cephes cxa-atexit db dirname env
-SUBDIR+= fmemopen fnmatch fpclassify getcap getopt_long glob
+SUBDIR+= explicit_bzero fmemopen fnmatch fpclassify getcap getopt_long glob
SUBDIR+= hsearch longjmp locale malloc mkstemp modf netdb open_memstream
SUBDIR+= orientation popen printf
SUBDIR+= regex setjmp setjmp-signal sigreturn sigsetjmp sprintf
diff --git a/src/regress/lib/libc/explicit_bzero/Makefile b/src/regress/lib/libc/explicit_bzero/Makefile
new file mode 100644
index 0000000000..cd514a43a1
--- /dev/null
+++ b/src/regress/lib/libc/explicit_bzero/Makefile
@@ -0,0 +1,5 @@
+# $OpenBSD: Makefile,v 1.1 2014/06/12 22:01:55 matthew Exp $
+
+PROG= explicit_bzero
+
+.include <bsd.regress.mk>
diff --git a/src/regress/lib/libc/explicit_bzero/explicit_bzero.c b/src/regress/lib/libc/explicit_bzero/explicit_bzero.c
new file mode 100644
index 0000000000..b4b6c9e559
--- /dev/null
+++ b/src/regress/lib/libc/explicit_bzero/explicit_bzero.c
@@ -0,0 +1,138 @@
+/* $OpenBSD: explicit_bzero.c,v 1.1 2014/06/12 22:01:55 matthew Exp $ */
+/*
+ * Copyright (c) 2014 Google Inc.
+ *
+ * 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.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+
+#define ASSERT_EQ(a, b) assert((a) == (b))
+#define ASSERT_NE(a, b) assert((a) != (b))
+#define ASSERT_GE(a, b) assert((a) >= (b))
+
+static void
+call_on_stack(void (*fn)(int), void *stack, size_t stacklen)
+{
+ /*
+ * This is a bit more complicated than strictly necessary, but
+ * it ensures we don't have any flaky test failures due to
+ * inherited signal masks/actions/etc.
+ *
+ * On systems where SA_ONSTACK is not supported, this could
+ * alternatively be implemented using makecontext() or
+ * pthread_attr_setstack().
+ */
+
+ const struct sigaction sigact = {
+ .sa_handler = fn,
+ .sa_flags = SA_ONSTACK,
+ };
+ const stack_t sigstk = {
+ .ss_sp = stack,
+ .ss_size = stacklen,
+ };
+ struct sigaction oldsigact;
+ stack_t oldsigstk;
+ sigset_t sigset, oldsigset;
+
+ /* First, block all signals. */
+ ASSERT_EQ(0, sigemptyset(&sigset));
+ ASSERT_EQ(0, sigfillset(&sigset));
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &sigset, &oldsigset));
+
+ /* Next setup the signal stack and handler for SIGUSR1. */
+ ASSERT_EQ(0, sigaltstack(&sigstk, &oldsigstk));
+ ASSERT_EQ(0, sigaction(SIGUSR1, &sigact, &oldsigact));
+
+ /* Raise SIGUSR1 and momentarily unblock it to run the handler. */
+ ASSERT_EQ(0, raise(SIGUSR1));
+ ASSERT_EQ(0, sigdelset(&sigset, SIGUSR1));
+ ASSERT_EQ(-1, sigsuspend(&sigset));
+ ASSERT_EQ(EINTR, errno);
+
+ /* Restore the original signal action, stack, and mask. */
+ ASSERT_EQ(0, sigaction(SIGUSR1, &oldsigact, NULL));
+ ASSERT_EQ(0, sigaltstack(&oldsigstk, NULL));
+ ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &oldsigset, NULL));
+}
+
+/* 128 bits of random data. */
+static const char secret[16] = {
+ 0xa0, 0x6c, 0x0c, 0x81, 0xba, 0xd8, 0x5b, 0x0c,
+ 0xb0, 0xd6, 0xd4, 0xe3, 0xeb, 0x52, 0x5f, 0x96,
+};
+
+enum {
+ SECRETCOUNT = 16,
+ SECRETBYTES = SECRETCOUNT * sizeof(secret)
+};
+
+static void
+populate_secret(char *buf, size_t len)
+{
+ int i, fds[2];
+ ASSERT_EQ(0, pipe(fds));
+
+ for (i = 0; i < SECRETCOUNT; i++)
+ ASSERT_EQ(sizeof(secret), write(fds[1], secret, sizeof(secret)));
+ ASSERT_EQ(0, close(fds[1]));
+
+ ASSERT_EQ(len, read(fds[0], buf, len));
+ ASSERT_EQ(0, close(fds[0]));
+}
+
+static void
+test_without_bzero(int signo)
+{
+ char buf[SECRETBYTES];
+ populate_secret(buf, sizeof(buf));
+}
+
+static void
+test_with_bzero(int signo)
+{
+ char buf[SECRETBYTES];
+ populate_secret(buf, sizeof(buf));
+ explicit_bzero(buf, sizeof(buf));
+}
+
+static char altstack[SIGSTKSZ];
+
+int
+main()
+{
+ /*
+ * First, test that if we *don't* call explicit_bzero, that we
+ * *are* able to find the secret data on the stack. This
+ * sanity checks that call_on_stack() and populare_secret()
+ * work as intended.
+ */
+ memset(altstack, 0, sizeof(altstack));
+ call_on_stack(test_without_bzero, altstack, sizeof(altstack));
+ ASSERT_NE(NULL, memmem(altstack, sizeof(altstack), secret, sizeof(secret)));
+
+ /*
+ * Now test with a call to explicit_bzero() and check that we
+ * *don't* find the secret data.
+ */
+ memset(altstack, 0, sizeof(altstack));
+ call_on_stack(test_with_bzero, altstack, sizeof(altstack));
+ ASSERT_EQ(NULL, memmem(altstack, sizeof(altstack), secret, sizeof(secret)));
+
+ return (0);
+}
--
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