1 files changed, 137 insertions, 0 deletions
diff --git a/src/util-random.c b/src/util-random.c
new file mode 100644
index 0000000..0beee32
--- /dev/null
+++ b/src/util-random.c
@@ -0,0 +1,137 @@
+/* Copyright (C) 2007-2017 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ *
+ * Functions for getting a random value based on
+ * SEI CERT C Coding Standard MSC30-C
+ */
+
+#include "suricata-common.h"
+#include "suricata.h"
+#include "util-random.h"
+#include "util-debug.h"
+
+#if !(defined(HAVE_WINCRYPT_H) &&  defined(OS_WIN32))
+#if defined(HAVE_CLOCK_GETTIME)
+
+static long int RandomGetClock(void)
+{
+    struct timespec ts;
+    clock_gettime(CLOCK_REALTIME, &ts);
+
+    // coverity[dont_call : FALSE]
+    srandom(ts.tv_nsec ^ ts.tv_sec);
+    long int value = random();
+    return value;
+}
+
+#else
+
+static long int RandomGetPosix(void)
+{
+    struct timeval tv;
+    memset(&tv, 0, sizeof(tv));
+    gettimeofday(&tv, NULL);
+
+    // coverity[dont_call : FALSE]
+    srandom(tv.tv_usec ^ tv.tv_sec);
+    long int value = random();
+    return value;
+}
+
+#endif
+#endif /* !(defined(HAVE_WINCRYPT_H) &&  defined(OS_WIN32)) */
+
+#if defined(HAVE_WINCRYPT_H) && defined(OS_WIN32)
+#include <wincrypt.h>
+
+long int RandomGet(void)
+{
+    if (g_disable_randomness)
+        return 0;
+
+    HCRYPTPROV p;
+    if (!CryptAcquireContext(&p, NULL, NULL, PROV_RSA_FULL, 0)) {
+        DWORD err = GetLastError();
+        SCLogDebug("CryptAcquireContext error: %" PRIu32, (uint32_t)err);
+        if (err == (DWORD)NTE_BAD_KEYSET) {
+            /* The key doesn't exist yet, create it */
+            if (!CryptAcquireContext(&p, NULL, NULL, PROV_RSA_FULL,
+                                     CRYPT_NEWKEYSET)) {
+
+                SCLogDebug("CryptAcquireContext error: %" PRIu32,
+                           (uint32_t)err);
+                return -1;
+            }
+        } else {
+            return -1;
+        }
+    }
+
+    long int value = 0;
+    if (!CryptGenRandom(p, sizeof(value), (BYTE *)&value)) {
+        (void)CryptReleaseContext(p, 0);
+        return -1;
+    }
+
+    (void)CryptReleaseContext(p, 0);
+
+    return value;
+}
+#elif defined(HAVE_GETRANDOM)
+long int RandomGet(void)
+{
+    if (g_disable_randomness)
+        return 0;
+
+    long int value = 0;
+    int ret = getrandom(&value, sizeof(value), 0);
+    /* ret should be sizeof(value), but if it is > 0 and < sizeof(value)
+     * it's still better than nothing so we return what we have */
+    if (ret <= 0) {
+        if (ret == -1 && errno == ENOSYS) {
+#if defined(HAVE_CLOCK_GETTIME)
+            return RandomGetClock();
+#else
+            return RandomGetPosix();
+#endif
+        }
+        return -1;
+    }
+    return value;
+}
+#elif defined(HAVE_CLOCK_GETTIME)
+long int RandomGet(void)
+{
+    if (g_disable_randomness)
+        return 0;
+
+    return RandomGetClock();
+}
+#else
+long int RandomGet(void)
+{
+    if (g_disable_randomness)
+        return 0;
+
+    return RandomGetPosix();
+}
+#endif