1 /*
2 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5 /*
6 * Copyright (c) 1999-2000 Damien Miller. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "includes.h"
30 #include "log.h"
31
32 RCSID("$Id: bsd-arc4random.c,v 1.5 2002/05/08 22:57:18 tim Exp $");
33
34 #pragma ident "%Z%%M% %I% %E% SMI"
35
36 #ifndef HAVE_ARC4RANDOM
37
38 #include <openssl/rand.h>
39 #include <openssl/rc4.h>
40 #include <openssl/err.h>
41
42 /* Size of key to use */
43 #define SEED_SIZE 20
44
45 /* Number of bytes to reseed after */
46 #define REKEY_BYTES (1 << 24)
47
48 static int rc4_ready = 0;
49 static RC4_KEY rc4;
50
arc4random(void)51 unsigned int arc4random(void)
52 {
53 unsigned int r = 0;
54 static int first_time = 1;
55
56 if (rc4_ready <= 0) {
57 if (first_time)
58 seed_rng();
59 first_time = 0;
60 arc4random_stir();
61 }
62
63 RC4(&rc4, sizeof(r), (unsigned char *)&r, (unsigned char *)&r);
64
65 rc4_ready -= sizeof(r);
66
67 return(r);
68 }
69
arc4random_stir(void)70 void arc4random_stir(void)
71 {
72 unsigned char rand_buf[SEED_SIZE];
73
74 memset(&rc4, 0, sizeof(rc4));
75 if (!RAND_bytes(rand_buf, sizeof(rand_buf)))
76 fatal("Couldn't obtain random bytes (error %ld)",
77 ERR_get_error());
78 RC4_set_key(&rc4, sizeof(rand_buf), rand_buf);
79 memset(rand_buf, 0, sizeof(rand_buf));
80
81 rc4_ready = REKEY_BYTES;
82 }
83 #endif /* !HAVE_ARC4RANDOM */
84