| 1 | /*␊ |
| 2 | * gen_uuid.c --- generate a DCE-compatible uuid␊ |
| 3 | *␊ |
| 4 | * Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.␊ |
| 5 | *␊ |
| 6 | * %Begin-Header%␊ |
| 7 | * Redistribution and use in source and binary forms, with or without␊ |
| 8 | * modification, are permitted provided that the following conditions␊ |
| 9 | * are met:␊ |
| 10 | * 1. Redistributions of source code must retain the above copyright␊ |
| 11 | * notice, and the entire permission notice in its entirety,␊ |
| 12 | * including the disclaimer of warranties.␊ |
| 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 | * 3. The name of the author may not be used to endorse or promote␊ |
| 17 | * products derived from this software without specific prior␊ |
| 18 | * written permission.␊ |
| 19 | * ␊ |
| 20 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED␊ |
| 21 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES␊ |
| 22 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF␊ |
| 23 | * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE␊ |
| 24 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR␊ |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT␊ |
| 26 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR␊ |
| 27 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF␊ |
| 28 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT␊ |
| 29 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE␊ |
| 30 | * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH␊ |
| 31 | * DAMAGE.␊ |
| 32 | * %End-Header%␊ |
| 33 | */␊ |
| 34 | ␊ |
| 35 | /*␊ |
| 36 | * Force inclusion of SVID stuff since we need it if we're compiling in␊ |
| 37 | * gcc-wall wall mode␊ |
| 38 | */␊ |
| 39 | #define _SVID_SOURCE␊ |
| 40 | ␊ |
| 41 | #include "libsaio.h"␊ |
| 42 | #include "uuid.h"␊ |
| 43 | ␊ |
| 44 | static void get_random_bytes(void *buf, int nbytes);␊ |
| 45 | ␊ |
| 46 | /*␊ |
| 47 | * Generate a series of random bytes, using arc4random␊ |
| 48 | */␊ |
| 49 | static void get_random_bytes(void *buf, int nbytes)␊ |
| 50 | {␊ |
| 51 | ␉unsigned char *cp = (unsigned char *) buf;␊ |
| 52 | ␉u_int32_t u;␊ |
| 53 | ␉int n = nbytes / sizeof(u);␊ |
| 54 | ␊ |
| 55 | ␉while (n-- > 0) {␊ |
| 56 | ␉␉u = arc4random();␊ |
| 57 | ␉␉memcpy(cp, &u, sizeof(u));␊ |
| 58 | ␉␉cp += sizeof(u);␊ |
| 59 | ␉}␊ |
| 60 | ␉if ((n = nbytes % sizeof(u)) > 0) {␊ |
| 61 | ␉␉u = arc4random();␊ |
| 62 | ␉␉memcpy(cp, &u, n);␊ |
| 63 | ␉}␊ |
| 64 | ␉return;␊ |
| 65 | }␊ |
| 66 | ␊ |
| 67 | void uuid_generate_random(uuid_t out)␊ |
| 68 | {␊ |
| 69 | ␉uuid_t␉buf;␊ |
| 70 | ␉struct uuid uu;␊ |
| 71 | ␊ |
| 72 | ␉get_random_bytes(buf, sizeof(buf));␊ |
| 73 | ␉uuid_unpack(buf, &uu);␊ |
| 74 | ␊ |
| 75 | ␉uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;␊ |
| 76 | ␉uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x4000;␊ |
| 77 | ␉uuid_pack(&uu, out);␊ |
| 78 | }␊ |
| 79 | ␊ |
| 80 | /*␊ |
| 81 | * This is the generic front-end␊ |
| 82 | */␊ |
| 83 | void uuid_generate(uuid_t out)␊ |
| 84 | {␊ |
| 85 | ␉uuid_generate_random(out);␊ |
| 86 | }␊ |
| 87 | |
