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 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 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