2 * Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/random.h>
36 #include <sys/systm.h>
38 #include <dev/random/live_entropy_sources.h>
39 #include <dev/random/random_adaptors.h>
40 #include <dev/random/randomdev.h>
42 static int random_example_read(void *, int);
44 struct random_adaptor random_example = {
45 .ident = "Example RNG",
46 .source = RANDOM_PURE_BOGUS, /* Make sure this is in
47 * sys/random.h and is unique */
48 .read = random_example_read,
52 * Used under the license provided @ http://xkcd.com/221/
53 * http://creativecommons.org/licenses/by-nc/2.5/
58 return 4; /* chosen by fair dice roll, guaranteed to be random */
62 random_example_read(void *buf, int c)
69 for (count = 0; count < c; count++)
70 b[count] = getRandomNumber();
72 printf("returning %d bytes of pure randomness\n", c);
77 random_example_modevent(module_t mod, int type, void *unused)
83 live_entropy_source_register(&random_example);
87 live_entropy_source_deregister(&random_example);
101 LIVE_ENTROPY_SRC_MODULE(live_entropy_source_example, random_example_modevent, 1);