new upstream release (3.3.0); modify package compatibility for Stretch

[ossec-hids.git] / src / shared / randombytes.c

diff --git a/src/shared/randombytes.c b/src/shared/randombytes.c
new file mode 100644 (file)
index 0000000..2a72138
--- /dev/null
+++ b/src/shared/randombytes.c
@@ -0,0 +1,56 @@
+#ifndef WIN32
+#include <sys/stat.h>
+#include <fcntl.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "shared.h"
+
+
+void randombytes(void *ptr, size_t length)
+{
+    char failed = 0;
+
+#ifdef WIN32
+    static HCRYPTPROV prov = 0;
+    if (prov == 0) {
+        if (!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, 0)) {
+            failed = 1;
+        }
+    }
+    if (!failed && !CryptGenRandom(prov, length, ptr)) {
+        failed = 1;
+    }
+#else
+    static int fh = -1;
+
+    if (fh >= 0 || (fh = open("/dev/urandom", O_RDONLY)) >= 0 || (fh = open("/dev/random", O_RDONLY)) >= 0) {
+        const ssize_t ret = read(fh, ptr, length);
+        if (ret < 0 || (size_t) ret != length) {
+            failed = 1;
+        }
+    } else {
+        failed = 1;
+    }
+#endif
+
+    if (failed) {
+        ErrorExit("%s: ERROR: randombytes failed for all possible methods for accessing random data", __local_name);
+    }
+}
+
+void srandom_init(void)
+{
+#ifndef WIN32
+#ifdef __OpenBSD__
+    srandomdev();
+#else
+    unsigned int seed;
+    randombytes(&seed, sizeof seed);
+    srandom(seed);
+#endif /* !__OpenBSD__ */
+#endif /* !WIN32 */
+}
+