Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1999-2000 Damien Miller. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 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. |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 12 | * |
| 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. |
| 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 26 | |
| 27 | #ifndef HAVE_ARC4RANDOM |
| 28 | |
Damien Miller | 72c9a7e | 2000-09-24 11:10:13 +1100 | [diff] [blame] | 29 | #include <openssl/rand.h> |
| 30 | #include <openssl/rc4.h> |
| 31 | |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 32 | /* Size of key to use */ |
| 33 | #define SEED_SIZE 20 |
| 34 | |
| 35 | /* Number of bytes to reseed after */ |
Damien Miller | 250ee8b | 2000-08-30 14:06:35 +1100 | [diff] [blame] | 36 | #define REKEY_BYTES (1 << 18) |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 37 | |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 38 | static int rc4_ready = 0; |
| 39 | static RC4_KEY rc4; |
| 40 | |
| 41 | unsigned int arc4random(void) |
| 42 | { |
| 43 | unsigned int r = 0; |
| 44 | |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 45 | if (rc4_ready <= 0) |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 46 | arc4random_stir(); |
| 47 | |
| 48 | RC4(&rc4, sizeof(r), (unsigned char *)&r, (unsigned char *)&r); |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 49 | |
| 50 | rc4_ready -= sizeof(r); |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 51 | |
| 52 | return(r); |
| 53 | } |
| 54 | |
| 55 | void arc4random_stir(void) |
| 56 | { |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 57 | unsigned char rand_buf[SEED_SIZE]; |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 58 | |
| 59 | memset(&rc4, 0, sizeof(rc4)); |
| 60 | |
| 61 | seed_rng(); |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 62 | |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 63 | RAND_bytes(rand_buf, sizeof(rand_buf)); |
| 64 | |
| 65 | RC4_set_key(&rc4, sizeof(rand_buf), rand_buf); |
| 66 | |
| 67 | memset(rand_buf, 0, sizeof(rand_buf)); |
Damien Miller | f3df052 | 2000-08-23 15:31:41 +1000 | [diff] [blame] | 68 | |
Damien Miller | c30d35c | 2000-08-30 09:40:09 +1100 | [diff] [blame] | 69 | rc4_ready = REKEY_BYTES; |
Damien Miller | 11fa2cc | 2000-08-16 10:35:58 +1000 | [diff] [blame] | 70 | } |
| 71 | #endif /* !HAVE_ARC4RANDOM */ |