| /* |
| * Copyright (c) 1999,2000,2004 Damien Miller <djm@mindrot.org> |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| */ |
| |
| #include "includes.h" |
| #include "log.h" |
| |
| RCSID("$Id: bsd-arc4random.c,v 1.8 2004/02/17 05:49:55 djm Exp $"); |
| |
| #ifndef HAVE_ARC4RANDOM |
| |
| #include <openssl/rand.h> |
| #include <openssl/rc4.h> |
| #include <openssl/err.h> |
| |
| /* Size of key to use */ |
| #define SEED_SIZE 20 |
| |
| /* Number of bytes to reseed after */ |
| #define REKEY_BYTES (1 << 24) |
| |
| static int rc4_ready = 0; |
| static RC4_KEY rc4; |
| |
| unsigned int arc4random(void) |
| { |
| unsigned int r = 0; |
| static int first_time = 1; |
| |
| if (rc4_ready <= 0) { |
| if (first_time) |
| seed_rng(); |
| first_time = 0; |
| arc4random_stir(); |
| } |
| |
| RC4(&rc4, sizeof(r), (unsigned char *)&r, (unsigned char *)&r); |
| |
| rc4_ready -= sizeof(r); |
| |
| return(r); |
| } |
| |
| void arc4random_stir(void) |
| { |
| unsigned char rand_buf[SEED_SIZE]; |
| |
| memset(&rc4, 0, sizeof(rc4)); |
| if (RAND_bytes(rand_buf, sizeof(rand_buf)) <= 0) |
| fatal("Couldn't obtain random bytes (error %ld)", |
| ERR_get_error()); |
| RC4_set_key(&rc4, sizeof(rand_buf), rand_buf); |
| RC4(&rc4, sizeof(rand_buf), rand_buf, rand_buf); |
| memset(rand_buf, 0, sizeof(rand_buf)); |
| |
| rc4_ready = REKEY_BYTES; |
| } |
| #endif /* !HAVE_ARC4RANDOM */ |