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 #include <config.h>
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <rand.h>
39 #include <heim_threads.h>
40
41 #include <roken.h>
42
43 #include "randi.h"
44
45 /*
46 * Unix /dev/random
47 */
48
49 int
_hc_unix_device_fd(int flags,const char ** fn)50 _hc_unix_device_fd(int flags, const char **fn)
51 {
52 static const char *rnd_devices[] = {
53 "/dev/urandom",
54 "/dev/random",
55 "/dev/srandom",
56 "/dev/arandom",
57 NULL
58 };
59 const char **p;
60
61 for(p = rnd_devices; *p; p++) {
62 int fd = open(*p, flags | O_NDELAY);
63 if(fd >= 0) {
64 if (fn)
65 *fn = *p;
66 rk_cloexec(fd);
67 return fd;
68 }
69 }
70 return -1;
71 }
72
73 static void
unix_seed(const void * indata,int size)74 unix_seed(const void *indata, int size)
75 {
76 int fd;
77
78 if (size <= 0)
79 return;
80
81 fd = _hc_unix_device_fd(O_WRONLY, NULL);
82 if (fd < 0)
83 return;
84
85 write(fd, indata, size);
86 close(fd);
87
88 }
89
90
91 static int
unix_bytes(unsigned char * outdata,int size)92 unix_bytes(unsigned char *outdata, int size)
93 {
94 ssize_t count;
95 int fd;
96
97 if (size < 0)
98 return 0;
99 else if (size == 0)
100 return 1;
101
102 fd = _hc_unix_device_fd(O_RDONLY, NULL);
103 if (fd < 0)
104 return 0;
105
106 while (size > 0) {
107 count = read(fd, outdata, size);
108 if (count < 0 && errno == EINTR)
109 continue;
110 else if (count <= 0) {
111 close(fd);
112 return 0;
113 }
114 outdata += count;
115 size -= count;
116 }
117 close(fd);
118
119 return 1;
120 }
121
122 static void
unix_cleanup(void)123 unix_cleanup(void)
124 {
125 }
126
127 static void
unix_add(const void * indata,int size,double entropi)128 unix_add(const void *indata, int size, double entropi)
129 {
130 unix_seed(indata, size);
131 }
132
133 static int
unix_pseudorand(unsigned char * outdata,int size)134 unix_pseudorand(unsigned char *outdata, int size)
135 {
136 return unix_bytes(outdata, size);
137 }
138
139 static int
unix_status(void)140 unix_status(void)
141 {
142 int fd;
143
144 fd = _hc_unix_device_fd(O_RDONLY, NULL);
145 if (fd < 0)
146 return 0;
147 close(fd);
148
149 return 1;
150 }
151
152 const RAND_METHOD hc_rand_unix_method = {
153 unix_seed,
154 unix_bytes,
155 unix_cleanup,
156 unix_add,
157 unix_pseudorand,
158 unix_status
159 };
160
161 const RAND_METHOD *
RAND_unix_method(void)162 RAND_unix_method(void)
163 {
164 return &hc_rand_unix_method;
165 }
166