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DEFINITIONS
This source file includes following definitions.
- get_device_fd
- unix_seed
- unix_bytes
- unix_cleanup
- unix_add
- unix_pseudorand
- unix_status
- RAND_unix_method
1 /*
2 * Copyright (c) 2006 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
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 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #ifdef HAVE_CONFIG_H
35 #include <config.h>
36 #endif
37
38 RCSID("$Id$");
39
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <rand.h>
43
44 #include <roken.h>
45
46 #include "randi.h"
47
48 /*
49 * Unix /dev/random
50 */
51
52 static int
53 get_device_fd(int flags)
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54 {
55 static const char *rnd_devices[] = {
56 "/dev/urandom",
57 "/dev/random",
58 "/dev/srandom",
59 "/dev/arandom",
60 NULL
61 };
62 const char **p;
63
64 for(p = rnd_devices; *p; p++) {
65 int fd = open(*p, flags | O_NDELAY);
66 if(fd >= 0) {
67 rk_cloexec(fd);
68 return fd;
69 }
70 }
71 return -1;
72 }
73
74 static void
75 unix_seed(const void *indata, int size)
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76 {
77 int fd;
78
79 if (size <= 0)
80 return;
81
82 fd = get_device_fd(O_WRONLY);
83 if (fd < 0)
84 return;
85
86 write(fd, indata, size);
87 close(fd);
88
89 }
90
91 static int
92 unix_bytes(unsigned char *outdata, int size)
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93 {
94 ssize_t count;
95 int fd;
96
97 if (size <= 0)
98 return 0;
99
100 fd = get_device_fd(O_RDONLY);
101 if (fd < 0)
102 return 0;
103
104 while (size > 0) {
105 count = read (fd, outdata, size);
106 if (count < 0 && errno == EINTR)
107 continue;
108 else if (count <= 0) {
109 close(fd);
110 return 0;
111 }
112 outdata += count;
113 size -= count;
114 }
115 close(fd);
116
117 return 1;
118 }
119
120 static void
121 unix_cleanup(void)
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122 {
123 }
124
125 static void
126 unix_add(const void *indata, int size, double entropi)
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127 {
128 unix_seed(indata, size);
129 }
130
131 static int
132 unix_pseudorand(unsigned char *outdata, int size)
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133 {
134 return unix_bytes(outdata, size);
135 }
136
137 static int
138 unix_status(void)
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139 {
140 int fd;
141
142 fd = get_device_fd(O_RDONLY);
143 if (fd < 0)
144 return 0;
145 close(fd);
146
147 return 1;
148 }
149
150 const RAND_METHOD hc_rand_unix_method = {
151 unix_seed,
152 unix_bytes,
153 unix_cleanup,
154 unix_add,
155 unix_pseudorand,
156 unix_status
157 };
158
159 const RAND_METHOD *
160 RAND_unix_method(void)
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161 {
162 return &hc_rand_unix_method;
163 }