From adebb6e733c59da7c75051f27c47f38337d387ae Mon Sep 17 00:00:00 2001
From: Georg Koppen <gk@torproject.org>
Date: Tue, 10 Feb 2015 01:44:08 +0000
Subject: [PATCH] ssp.c (__guard_setup): For Windows...
* ssp.c (__guard_setup): For Windows, use approved
methods to get a suitable random number for the stack
check guard rather than reading /dev/random.
From-SVN: r220559
---
libssp/ChangeLog | 7 +++++++
libssp/ssp.c | 16 ++++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/libssp/ChangeLog b/libssp/ChangeLog
index d1580a37e986..843992ebdb89 100644
--- a/libssp/ChangeLog
+++ b/libssp/ChangeLog
@@ -1,3 +1,10 @@
+2015-02-09 Georg Koppen <gk@torproject.org>
+
+ * ssp.c: Conditionally include <windows.h>
+ (__guard_setup): For Windows, use approved methods to get
+ a suitable random number for the stack check guard rather
+ than reading /dev/random.
+
2015-01-22 Matthias Klose <doko@ubuntu.com>
* gets-chk.c: Declare prototype for gets in C11 mode.
diff --git a/libssp/ssp.c b/libssp/ssp.c
index 96adf17ce3fe..38e3ec83f6b5 100644
--- a/libssp/ssp.c
+++ b/libssp/ssp.c
@@ -55,6 +55,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
/* Native win32 apps don't know about /dev/tty but can print directly
to the console using "CONOUT$" */
#if defined (_WIN32) && !defined (__CYGWIN__)
+#include <windows.h>
# define _PATH_TTY "CONOUT$"
#else
# define _PATH_TTY "/dev/tty"
@@ -75,6 +76,20 @@ __guard_setup (void)
if (__stack_chk_guard != 0)
return;
+#if defined (_WIN32) && !defined (__CYGWIN__)
+ HCRYPTPROV hprovider = 0;
+ if (CryptAcquireContext(&hprovider, NULL, NULL, PROV_RSA_FULL,
+ CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
+ {
+ if (CryptGenRandom(hprovider, sizeof (__stack_chk_guard),
+ (BYTE *)&__stack_chk_guard) && __stack_chk_guard != 0)
+ {
+ CryptReleaseContext(hprovider, 0);
+ return;
+ }
+ CryptReleaseContext(hprovider, 0);
+ }
+#else
fd = open ("/dev/urandom", O_RDONLY);
if (fd != -1)
{
@@ -85,6 +100,7 @@ __guard_setup (void)
return;
}
+#endif
/* If a random generator can't be used, the protector switches the guard
to the "terminator canary". */
p = (unsigned char *) &__stack_chk_guard;
--
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