summaryrefslogtreecommitdiff
path: root/source4/heimdal/lib/hcrypto/rand.c
blob: d5c1f687b910d2848eda53d5dfd9b781f34acad4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/*
 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <rand.h>
#include <randi.h>

#include <roken.h>

#ifndef O_BINARY
#define O_BINARY 0
#endif

#ifdef _WIN32
#include<shlobj.h>
#endif

/**
 * @page page_rand RAND - random number
 *
 * See the library functions here: @ref hcrypto_rand
 */

const static RAND_METHOD *selected_meth = NULL;
static ENGINE *selected_engine = NULL;

static void
init_method(void)
{
    if (selected_meth != NULL)
	return;
#if defined(_WIN32)
    selected_meth = &hc_rand_w32crypto_method;
#elif defined(__APPLE__)
    selected_meth = &hc_rand_unix_method;
#else
    selected_meth = &hc_rand_fortuna_method;
#endif
}

/**
 * Seed that random number generator. Secret material can securely be
 * feed into the function, they will never be returned.
 *
 * @param indata seed data
 * @param size length seed data
 *
 * @ingroup hcrypto_rand
 */

void
RAND_seed(const void *indata, size_t size)
{
    init_method();
    (*selected_meth->seed)(indata, size);
}

/**
 * Get a random block from the random generator, can be used for key material.
 *
 * @param outdata random data
 * @param size length random data
 *
 * @return 1 on success, 0 on failure.
 *
 * @ingroup hcrypto_rand
 */
int
RAND_bytes(void *outdata, size_t size)
{
    if (size == 0)
	return 1;
    init_method();
    return (*selected_meth->bytes)(outdata, size);
}

/**
 * Reset and free memory used by the random generator.
 *
 * @ingroup hcrypto_rand
 */

void
RAND_cleanup(void)
{
    const RAND_METHOD *meth = selected_meth;
    ENGINE *engine = selected_engine;

    selected_meth = NULL;
    selected_engine = NULL;

    if (meth)
	(*meth->cleanup)();
    if (engine)
	ENGINE_finish(engine);
}

/**
 * Seed that random number generator. Secret material can securely be
 * feed into the function, they will never be returned.
 *
 * @param indata the input data.
 * @param size size of in data.
 * @param entropi entropi in data.
 *
 *
 * @ingroup hcrypto_rand
 */

void
RAND_add(const void *indata, size_t size, double entropi)
{
    init_method();
    (*selected_meth->add)(indata, size, entropi);
}

/**
 * Get a random block from the random generator, should NOT be used for key material.
 *
 * @param outdata random data
 * @param size length random data
 *
 * @return 1 on success, 0 on failure.
 *
 * @ingroup hcrypto_rand
 */

int
RAND_pseudo_bytes(void *outdata, size_t size)
{
    init_method();
    return (*selected_meth->pseudorand)(outdata, size);
}

/**
 * Return status of the random generator
 *
 * @return 1 if the random generator can deliver random data.
 *
 * @ingroup hcrypto_rand
 */

int
RAND_status(void)
{
    init_method();
    return (*selected_meth->status)();
}

/**
 * Set the default random method.
 *
 * @param meth set the new default method.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_rand
 */

int
RAND_set_rand_method(const RAND_METHOD *meth)
{
    const RAND_METHOD *old = selected_meth;
    selected_meth = meth;
    if (old)
	(*old->cleanup)();
    if (selected_engine) {
	ENGINE_finish(selected_engine);
	selected_engine = NULL;
    }
    return 1;
}

/**
 * Get the default random method.
 *
 * @ingroup hcrypto_rand
 */

const RAND_METHOD *
RAND_get_rand_method(void)
{
    init_method();
    return selected_meth;
}

/**
 * Set the default random method from engine.
 *
 * @param engine use engine, if NULL is passed it, old method and engine is cleared.
 *
 * @return 1 on success, 0 on failure.
 *
 * @ingroup hcrypto_rand
 */

int
RAND_set_rand_engine(ENGINE *engine)
{
    const RAND_METHOD *meth, *old = selected_meth;

    if (engine) {
	ENGINE_up_ref(engine);
	meth = ENGINE_get_RAND(engine);
	if (meth == NULL) {
	    ENGINE_finish(engine);
	    return 0;
	}
    } else {
	meth = NULL;
    }

    if (old)
	(*old->cleanup)();

    if (selected_engine)
	ENGINE_finish(selected_engine);

    selected_engine = engine;
    selected_meth = meth;

    return 1;
}

#define RAND_FILE_SIZE 1024

/**
 * Load a a file and feed it into RAND_seed().
 *
 * @param filename name of file to read.
 * @param size minimum size to read.
 *
 * @ingroup hcrypto_rand
 */

int
RAND_load_file(const char *filename, size_t size)
{
    unsigned char buf[128];
    size_t len;
    ssize_t slen;
    int fd;

    fd = open(filename, O_RDONLY | O_BINARY, 0600);
    if (fd < 0)
	return 0;
    rk_cloexec(fd);
    len = 0;
    while(len < size) {
	slen = read(fd, buf, sizeof(buf));
	if (slen <= 0)
	    break;
	RAND_seed(buf, slen);
	len += slen;
    }
    close(fd);

    return len ? 1 : 0;
}

/**
 * Write of random numbers to a file to store for later initiation with RAND_load_file().
 *
 * @param filename name of file to write.
 *
 * @return 1 on success and non-one on failure.
 * @ingroup hcrypto_rand
 */

int
RAND_write_file(const char *filename)
{
    unsigned char buf[128];
    size_t len;
    int res = 0, fd;

    fd = open(filename, O_WRONLY | O_CREAT | O_BINARY, 0600);
    if (fd < 0)
	return 0;
    rk_cloexec(fd);

    len = 0;
    while(len < RAND_FILE_SIZE) {
	res = RAND_bytes(buf, sizeof(buf));
	if (res != 1)
	    break;
	if (write(fd, buf, sizeof(buf)) != sizeof(buf)) {
	    res = 0;
	    break;
	}
	len += sizeof(buf);
    }

    close(fd);

    return res;
}

/**
 * Return the default random state filename for a user to use for
 * RAND_load_file(), and RAND_write_file().
 *
 * @param filename buffer to hold file name.
 * @param size size of buffer filename.
 *
 * @return the buffer filename or NULL on failure.
 *
 * @ingroup hcrypto_rand
 */

const char *
RAND_file_name(char *filename, size_t size)
{
    const char *e = NULL;
    int pathp = 0, ret;

    if (!issuid()) {
	e = getenv("RANDFILE");
	if (e == NULL)
	    e = getenv("HOME");
	if (e)
	    pathp = 1;
    }

#ifndef _WIN32
    /*
     * Here we really want to call getpwuid(getuid()) but this will
     * cause recursive lookups if the nss library uses
     * gssapi/krb5/hcrypto to authenticate to the ldap servers.
     *
     * So at least return the unix /dev/random if we have one
     */
    if (e == NULL) {
	int fd;

	fd = _hc_unix_device_fd(O_RDONLY, &e);
	if (fd >= 0)
	    close(fd);
    }
#else  /* Win32 */

    if (e == NULL) {
	char profile[MAX_PATH];

	if (SHGetFolderPath(NULL, CSIDL_LOCAL_APPDATA, NULL,
			    SHGFP_TYPE_CURRENT, profile) == S_OK) {
	    ret = snprintf(filename, size, "%s\\.rnd", profile);

	    if (ret > 0 && ret < size)
		return filename;
	}
    }

#endif

    if (e == NULL)
	return NULL;

    if (pathp)
	ret = snprintf(filename, size, "%s/.rnd", e);
    else
	ret = snprintf(filename, size, "%s", e);

    if (ret <= 0 || ret >= size)
	return NULL;

    return filename;
}