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DEFINITIONS
This source file includes following definitions.
- init_method
- RAND_seed
- RAND_bytes
- RAND_cleanup
- RAND_add
- RAND_pseudo_bytes
- RAND_status
- RAND_set_rand_method
- RAND_get_rand_method
- RAND_set_rand_engine
- RAND_load_file
- RAND_write_file
- RAND_file_name
1 /*
2 * Copyright (c) 2006 - 2007 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 #include <randi.h>
44
45 #include <roken.h>
46
47 #ifndef O_BINARY
48 #define O_BINARY 0
49 #endif
50
51 /**
52 * @page page_rand RAND - random number
53 *
54 * See the library functions here: @ref hcrypto_rand
55 */
56
57 const static RAND_METHOD *selected_meth = NULL;
58 static ENGINE *selected_engine = NULL;
59
60 static void
61 init_method(void)
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62 {
63 if (selected_meth != NULL)
64 return;
65 selected_meth = &hc_rand_fortuna_method;
66 }
67
68 /**
69 * Seed that random number generator. Secret material can securely be
70 * feed into the function, they will never be returned.
71 *
72 * @param indata seed data
73 * @param size length seed data
74 *
75 * @ingroup hcrypto_rand
76 */
77
78 void
79 RAND_seed(const void *indata, size_t size)
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80 {
81 init_method();
82 (*selected_meth->seed)(indata, size);
83 }
84
85 /**
86 * Get a random block from the random generator, can be used for key material.
87 *
88 * @param outdata random data
89 * @param size length random data
90 *
91 * @return 1 on success, 0 on failure.
92 *
93 * @ingroup hcrypto_rand
94 */
95 int
96 RAND_bytes(void *outdata, size_t size)
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97 {
98 init_method();
99 return (*selected_meth->bytes)(outdata, size);
100 }
101
102 /**
103 * Reset and free memory used by the random generator.
104 *
105 * @ingroup hcrypto_rand
106 */
107
108 void
109 RAND_cleanup(void)
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110 {
111 const RAND_METHOD *meth = selected_meth;
112 ENGINE *engine = selected_engine;
113
114 selected_meth = NULL;
115 selected_engine = NULL;
116
117 if (meth)
118 (*meth->cleanup)();
119 if (engine)
120 ENGINE_finish(engine);
121 }
122
123 /**
124 * Seed that random number generator. Secret material can securely be
125 * feed into the function, they will never be returned.
126 *
127 * @param indata the input data.
128 * @param size size of in data.
129 * @param entropi entropi in data.
130 *
131 *
132 * @ingroup hcrypto_rand
133 */
134
135 void
136 RAND_add(const void *indata, size_t size, double entropi)
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137 {
138 init_method();
139 (*selected_meth->add)(indata, size, entropi);
140 }
141
142 /**
143 * Get a random block from the random generator, should NOT be used for key material.
144 *
145 * @param outdata random data
146 * @param size length random data
147 *
148 * @return 1 on success, 0 on failure.
149 *
150 * @ingroup hcrypto_rand
151 */
152
153 int
154 RAND_pseudo_bytes(void *outdata, size_t size)
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155 {
156 init_method();
157 return (*selected_meth->pseudorand)(outdata, size);
158 }
159
160 /**
161 * Return status of the random generator
162 *
163 * @return 1 if the random generator can deliver random data.
164 *
165 * @ingroup hcrypto_rand
166 */
167
168 int
169 RAND_status(void)
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170 {
171 init_method();
172 return (*selected_meth->status)();
173 }
174
175 /**
176 * Set the default random method.
177 *
178 * @param meth set the new default method.
179 *
180 * @return 1 on success.
181 *
182 * @ingroup hcrypto_rand
183 */
184
185 int
186 RAND_set_rand_method(const RAND_METHOD *meth)
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187 {
188 const RAND_METHOD *old = selected_meth;
189 selected_meth = meth;
190 if (old)
191 (*old->cleanup)();
192 if (selected_engine) {
193 ENGINE_finish(selected_engine);
194 selected_engine = NULL;
195 }
196 return 1;
197 }
198
199 /**
200 * Get the default random method.
201 *
202 * @ingroup hcrypto_rand
203 */
204
205 const RAND_METHOD *
206 RAND_get_rand_method(void)
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207 {
208 init_method();
209 return selected_meth;
210 }
211
212 /**
213 * Set the default random method from engine.
214 *
215 * @param engine use engine, if NULL is passed it, old method and engine is cleared.
216 *
217 * @return 1 on success, 0 on failure.
218 *
219 * @ingroup hcrypto_rand
220 */
221
222 int
223 RAND_set_rand_engine(ENGINE *engine)
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224 {
225 const RAND_METHOD *meth, *old = selected_meth;
226
227 if (engine) {
228 ENGINE_up_ref(engine);
229 meth = ENGINE_get_RAND(engine);
230 if (meth == NULL) {
231 ENGINE_finish(engine);
232 return 0;
233 }
234 } else {
235 meth = NULL;
236 }
237
238 if (old)
239 (*old->cleanup)();
240
241 if (selected_engine)
242 ENGINE_finish(selected_engine);
243
244 selected_engine = engine;
245 selected_meth = meth;
246
247 return 1;
248 }
249
250 #define RAND_FILE_SIZE 1024
251
252 /**
253 * Load a a file and feed it into RAND_seed().
254 *
255 * @param filename name of file to read.
256 * @param size minimum size to read.
257 *
258 * @ingroup hcrypto_rand
259 */
260
261 int
262 RAND_load_file(const char *filename, size_t size)
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263 {
264 unsigned char buf[128];
265 size_t len;
266 ssize_t slen;
267 int fd;
268
269 fd = open(filename, O_RDONLY | O_BINARY, 0600);
270 if (fd < 0)
271 return 0;
272 rk_cloexec(fd);
273 len = 0;
274 while(len < size) {
275 slen = read(fd, buf, sizeof(buf));
276 if (slen <= 0)
277 break;
278 RAND_seed(buf, slen);
279 len += slen;
280 }
281 close(fd);
282
283 return len ? 1 : 0;
284 }
285
286 /**
287 * Write of random numbers to a file to store for later initiation with RAND_load_file().
288 *
289 * @param filename name of file to write.
290 *
291 * @return 1 on success and non-one on failure.
292 * @ingroup hcrypto_rand
293 */
294
295 int
296 RAND_write_file(const char *filename)
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297 {
298 unsigned char buf[128];
299 size_t len;
300 int res = 0, fd;
301
302 fd = open(filename, O_WRONLY | O_CREAT | O_BINARY, 0600);
303 if (fd < 0)
304 return 0;
305 rk_cloexec(fd);
306
307 len = 0;
308 while(len < RAND_FILE_SIZE) {
309 res = RAND_bytes(buf, sizeof(buf));
310 if (res != 1)
311 break;
312 if (write(fd, buf, sizeof(buf)) != sizeof(buf)) {
313 res = 0;
314 break;
315 }
316 len += sizeof(buf);
317 }
318
319 close(fd);
320
321 return res;
322 }
323
324 /**
325 * Return the default random state filename for a user to use for
326 * RAND_load_file(), and RAND_write_file().
327 *
328 * @param filename buffer to hold file name.
329 * @param size size of buffer filename.
330 *
331 * @return the buffer filename or NULL on failure.
332 *
333 * @ingroup hcrypto_rand
334 */
335
336 const char *
337 RAND_file_name(char *filename, size_t size)
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338 {
339 const char *e = NULL;
340 int pathp = 0, ret;
341
342 if (!issuid()) {
343 e = getenv("RANDFILE");
344 if (e == NULL) {
345 e = getenv("HOME");
346 if (e)
347 pathp = 1;
348 }
349 }
350 /*
351 * Here we really want to call getpwuid(getuid()) but this will
352 * cause recursive lookups if the nss library uses
353 * gssapi/krb5/hcrypto to authenticate to the ldap servers.
354 */
355
356 if (e == NULL)
357 return NULL;
358
359 if (pathp)
360 ret = snprintf(filename, size, "%s/.rnd", e);
361 else
362 ret = snprintf(filename, size, "%s", e);
363
364 if (ret <= 0 || ret >= size)
365 return NULL;
366
367 return filename;
368 }