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-rw-r--r--src/pulsecore/random.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/src/pulsecore/random.c b/src/pulsecore/random.c
new file mode 100644
index 00000000..3d3357a5
--- /dev/null
+++ b/src/pulsecore/random.c
@@ -0,0 +1,108 @@
+/* $Id$ */
+
+/***
+ This file is part of PulseAudio.
+
+ PulseAudio is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ PulseAudio 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with PulseAudio; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <time.h>
+
+#include <pulsecore/core-util.h>
+#include <pulsecore/log.h>
+
+#include "random.h"
+
+static int has_whined = 0;
+
+static const char *devices[] = { "/dev/urandom", "/dev/random", NULL };
+
+static int random_proper(void *ret_data, size_t length) {
+#ifdef OS_IS_WIN32
+ assert(ret_data && length);
+
+ return -1;
+
+#else /* OS_IS_WIN32 */
+
+ int fd, ret = -1;
+ ssize_t r = 0;
+ const char **device;
+
+ assert(ret_data && length);
+
+ device = devices;
+
+ while (*device) {
+ ret = 0;
+
+ if ((fd = open(*device, O_RDONLY)) >= 0) {
+
+ if ((r = pa_loop_read(fd, ret_data, length)) < 0 || (size_t) r != length)
+ ret = -1;
+
+ close(fd);
+ } else
+ ret = -1;
+
+ if (ret == 0)
+ break;
+ }
+
+ return ret;
+#endif /* OS_IS_WIN32 */
+}
+
+void pa_random_seed(void) {
+ unsigned int seed;
+
+ if (random_proper(&seed, sizeof(unsigned int)) < 0) {
+ if (!has_whined)
+ pa_log_warn(__FILE__": failed to get proper entropy. Falling back to seeding with current time.");
+ has_whined = 1;
+
+ seed = (unsigned int) time(NULL);
+ }
+
+ srand(seed);
+}
+
+void pa_random(void *ret_data, size_t length) {
+ uint8_t *p;
+ size_t l;
+
+ assert(ret_data && length);
+
+ if (random_proper(ret_data, length) >= 0)
+ return;
+
+ if (!has_whined)
+ pa_log_warn(__FILE__": failed to get proper entropy. Falling back to unsecure pseudo RNG.");
+ has_whined = 1;
+
+ for (p = ret_data, l = length; l > 0; p++, l--)
+ *p = (uint8_t) rand();
+}