2 * Copyright (c) 1999-2000 Damien Miller. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #ifndef HAVE_ARC4RANDOM
31 #include <openssl/rand.h>
32 #include <openssl/rc4.h>
34 /* Size of key to use */
37 /* Number of bytes to reseed after */
38 #define REKEY_BYTES (1 << 24)
40 static int rc4_ready = 0;
43 unsigned int arc4random(void)
46 static int first_time = 1;
55 RC4(&rc4, sizeof(r), (unsigned char *)&r, (unsigned char *)&r);
57 rc4_ready -= sizeof(r);
62 void arc4random_stir(void)
64 unsigned char rand_buf[SEED_SIZE];
66 memset(&rc4, 0, sizeof(rc4));
67 if (!RAND_bytes(rand_buf, sizeof(rand_buf)))
68 fatal("Couldn't obtain random bytes (error %ld)",
70 RC4_set_key(&rc4, sizeof(rand_buf), rand_buf);
71 memset(rand_buf, 0, sizeof(rand_buf));
73 rc4_ready = REKEY_BYTES;
75 #endif /* !HAVE_ARC4RANDOM */