1 /* $NetBSD: rand-unix.c,v 1.1.1.1 2011/04/13 18:14:50 elric Exp $ */
2
3 /*
4 * Copyright (c) 2006 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * 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 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <rand.h>
41 #include <heim_threads.h>
42
43 #include <krb5/roken.h>
44
45 #include "randi.h"
46
47 /*
48 * Unix /dev/random
49 */
50
51 int
_hc_unix_device_fd(int flags,const char ** fn)52 _hc_unix_device_fd(int flags, const char **fn)
53 {
54 static const char *rnd_devices[] = {
55 "/dev/urandom",
56 "/dev/random",
57 "/dev/srandom",
58 "/dev/arandom",
59 NULL
60 };
61 const char **p;
62
63 for(p = rnd_devices; *p; p++) {
64 int fd = open(*p, flags | O_NDELAY);
65 if(fd >= 0) {
66 if (fn)
67 *fn = *p;
68 rk_cloexec(fd);
69 return fd;
70 }
71 }
72 return -1;
73 }
74
75 static void
unix_seed(const void * indata,int size)76 unix_seed(const void *indata, int size)
77 {
78 int fd;
79
80 if (size <= 0)
81 return;
82
83 fd = _hc_unix_device_fd(O_WRONLY, NULL);
84 if (fd < 0)
85 return;
86
87 write(fd, indata, size);
88 close(fd);
89
90 }
91
92
93 static int
unix_bytes(unsigned char * outdata,int size)94 unix_bytes(unsigned char *outdata, int size)
95 {
96 ssize_t count;
97 int fd;
98
99 if (size < 0)
100 return 0;
101 else if (size == 0)
102 return 1;
103
104 fd = _hc_unix_device_fd(O_RDONLY, NULL);
105 if (fd < 0)
106 return 0;
107
108 while (size > 0) {
109 count = read(fd, outdata, size);
110 if (count < 0 && errno == EINTR)
111 continue;
112 else if (count <= 0) {
113 close(fd);
114 return 0;
115 }
116 outdata += count;
117 size -= count;
118 }
119 close(fd);
120
121 return 1;
122 }
123
124 static void
unix_cleanup(void)125 unix_cleanup(void)
126 {
127 }
128
129 static void
unix_add(const void * indata,int size,double entropi)130 unix_add(const void *indata, int size, double entropi)
131 {
132 unix_seed(indata, size);
133 }
134
135 static int
unix_pseudorand(unsigned char * outdata,int size)136 unix_pseudorand(unsigned char *outdata, int size)
137 {
138 return unix_bytes(outdata, size);
139 }
140
141 static int
unix_status(void)142 unix_status(void)
143 {
144 int fd;
145
146 fd = _hc_unix_device_fd(O_RDONLY, NULL);
147 if (fd < 0)
148 return 0;
149 close(fd);
150
151 return 1;
152 }
153
154 const RAND_METHOD hc_rand_unix_method = {
155 unix_seed,
156 unix_bytes,
157 unix_cleanup,
158 unix_add,
159 unix_pseudorand,
160 unix_status
161 };
162
163 const RAND_METHOD *
RAND_unix_method(void)164 RAND_unix_method(void)
165 {
166 return &hc_rand_unix_method;
167 }
168