rand_unix.c@ 83531

Last change on this file since 83531 was 83531, checked in by vboxsync, 5 years ago
setting svn:sync-process=export for openssl-1.1.1f, all files except tests
File size: 25.0 KB

Line
1	/*
2	* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3	*
4	* Licensed under the OpenSSL license (the "License"). You may not use
5	* this file except in compliance with the License. You can obtain a copy
6	* in the file LICENSE in the source distribution or at
7	* https://www.openssl.org/source/license.html
8	*/
9
10	#ifndef _GNU_SOURCE
11	# define _GNU_SOURCE
12	#endif
13	#include "e_os.h"
14	#include <stdio.h>
15	#include "internal/cryptlib.h"
16	#include <openssl/rand.h>
17	#include <openssl/crypto.h>
18	#include "rand_local.h"
19	#include "crypto/rand.h"
20	#include <stdio.h>
21	#include "internal/dso.h"
22	#ifdef __linux
23	# include <sys/syscall.h>
24	# ifdef DEVRANDOM_WAIT
25	# include <sys/shm.h>
26	# include <sys/utsname.h>
27	# endif
28	#endif
29	#if defined(__FreeBSD__) && !defined(OPENSSL_SYS_UEFI)
30	# include <sys/types.h>
31	# include <sys/sysctl.h>
32	# include <sys/param.h>
33	#endif
34	#if defined(__OpenBSD__) \|\| defined(__NetBSD__)
35	# include <sys/param.h>
36	#endif
37
38	#if defined(OPENSSL_SYS_UNIX) \|\| defined(__DJGPP__)
39	# include <sys/types.h>
40	# include <sys/stat.h>
41	# include <fcntl.h>
42	# include <unistd.h>
43	# include <sys/time.h>
44
45	static uint64_t get_time_stamp(void);
46	static uint64_t get_timer_bits(void);
47
48	/* Macro to convert two thirty two bit values into a sixty four bit one */
49	# define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b))
50
51	/*
52	* Check for the existence and support of POSIX timers. The standard
53	* says that the _POSIX_TIMERS macro will have a positive value if they
54	* are available.
55	*
56	* However, we want an additional constraint: that the timer support does
57	* not require an extra library dependency. Early versions of glibc
58	* require -lrt to be specified on the link line to access the timers,
59	* so this needs to be checked for.
60	*
61	* It is worse because some libraries define __GLIBC__ but don't
62	* support the version testing macro (e.g. uClibc). This means
63	* an extra check is needed.
64	*
65	* The final condition is:
66	* "have posix timers and either not glibc or glibc without -lrt"
67	*
68	* The nested #if sequences are required to avoid using a parameterised
69	* macro that might be undefined.
70	*/
71	# undef OSSL_POSIX_TIMER_OKAY
72	# if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0
73	# if defined(__GLIBC__)
74	# if defined(__GLIBC_PREREQ)
75	# if __GLIBC_PREREQ(2, 17)
76	# define OSSL_POSIX_TIMER_OKAY
77	# endif
78	# endif
79	# else
80	# define OSSL_POSIX_TIMER_OKAY
81	# endif
82	# endif
83	#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
84	\|\| defined(__DJGPP__) */
85
86	#if defined(OPENSSL_RAND_SEED_NONE)
87	/* none means none. this simplifies the following logic */
88	# undef OPENSSL_RAND_SEED_OS
89	# undef OPENSSL_RAND_SEED_GETRANDOM
90	# undef OPENSSL_RAND_SEED_LIBRANDOM
91	# undef OPENSSL_RAND_SEED_DEVRANDOM
92	# undef OPENSSL_RAND_SEED_RDTSC
93	# undef OPENSSL_RAND_SEED_RDCPU
94	# undef OPENSSL_RAND_SEED_EGD
95	#endif
96
97	#if (defined(OPENSSL_SYS_VXWORKS) \|\| defined(OPENSSL_SYS_UEFI)) && \
98	!defined(OPENSSL_RAND_SEED_NONE)
99	# error "UEFI and VXWorks only support seeding NONE"
100	#endif
101
102	#if defined(OPENSSL_SYS_VXWORKS)
103	/* empty implementation */
104	int rand_pool_init(void)
105	{
106	return 1;
107	}
108
109	void rand_pool_cleanup(void)
110	{
111	}
112
113	void rand_pool_keep_random_devices_open(int keep)
114	{
115	}
116
117	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
118	{
119	return rand_pool_entropy_available(pool);
120	}
121	#endif
122
123	#if !(defined(OPENSSL_SYS_WINDOWS) \|\| defined(OPENSSL_SYS_WIN32) \
124	\|\| defined(OPENSSL_SYS_VMS) \|\| defined(OPENSSL_SYS_VXWORKS) \
125	\|\| defined(OPENSSL_SYS_UEFI))
126
127	# if defined(OPENSSL_SYS_VOS)
128
129	# ifndef OPENSSL_RAND_SEED_OS
130	# error "Unsupported seeding method configured; must be os"
131	# endif
132
133	# if defined(OPENSSL_SYS_VOS_HPPA) && defined(OPENSSL_SYS_VOS_IA32)
134	# error "Unsupported HP-PA and IA32 at the same time."
135	# endif
136	# if !defined(OPENSSL_SYS_VOS_HPPA) && !defined(OPENSSL_SYS_VOS_IA32)
137	# error "Must have one of HP-PA or IA32"
138	# endif
139
140	/*
141	* The following algorithm repeatedly samples the real-time clock (RTC) to
142	* generate a sequence of unpredictable data. The algorithm relies upon the
143	* uneven execution speed of the code (due to factors such as cache misses,
144	* interrupts, bus activity, and scheduling) and upon the rather large
145	* relative difference between the speed of the clock and the rate at which
146	* it can be read. If it is ported to an environment where execution speed
147	* is more constant or where the RTC ticks at a much slower rate, or the
148	* clock can be read with fewer instructions, it is likely that the results
149	* would be far more predictable. This should only be used for legacy
150	* platforms.
151	*
152	* As a precaution, we assume only 2 bits of entropy per byte.
153	*/
154	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
155	{
156	short int code;
157	int i, k;
158	size_t bytes_needed;
159	struct timespec ts;
160	unsigned char v;
161	# ifdef OPENSSL_SYS_VOS_HPPA
162	long duration;
163	extern void s$sleep(long _duration, short int _code);
164	# else
165	long long duration;
166	extern void s$sleep2(long long _duration, short int _code);
167	# endif
168
169	bytes_needed = rand_pool_bytes_needed(pool, 4 /entropy_factor/);
170
171	for (i = 0; i < bytes_needed; i++) {
172	/*
173	* burn some cpu; hope for interrupts, cache collisions, bus
174	* interference, etc.
175	*/
176	for (k = 0; k < 99; k++)
177	ts.tv_nsec = random();
178
179	# ifdef OPENSSL_SYS_VOS_HPPA
180	/* sleep for 1/1024 of a second (976 us). */
181	duration = 1;
182	s$sleep(&duration, &code);
183	# else
184	/* sleep for 1/65536 of a second (15 us). */
185	duration = 1;
186	s$sleep2(&duration, &code);
187	# endif
188
189	/* Get wall clock time, take 8 bits. */
190	clock_gettime(CLOCK_REALTIME, &ts);
191	v = (unsigned char)(ts.tv_nsec & 0xFF);
192	rand_pool_add(pool, arg, &v, sizeof(v) , 2);
193	}
194	return rand_pool_entropy_available(pool);
195	}
196
197	void rand_pool_cleanup(void)
198	{
199	}
200
201	void rand_pool_keep_random_devices_open(int keep)
202	{
203	}
204
205	# else
206
207	# if defined(OPENSSL_RAND_SEED_EGD) && \
208	(defined(OPENSSL_NO_EGD) \|\| !defined(DEVRANDOM_EGD))
209	# error "Seeding uses EGD but EGD is turned off or no device given"
210	# endif
211
212	# if defined(OPENSSL_RAND_SEED_DEVRANDOM) && !defined(DEVRANDOM)
213	# error "Seeding uses urandom but DEVRANDOM is not configured"
214	# endif
215
216	# if defined(OPENSSL_RAND_SEED_OS)
217	# if !defined(DEVRANDOM)
218	# error "OS seeding requires DEVRANDOM to be configured"
219	# endif
220	# define OPENSSL_RAND_SEED_GETRANDOM
221	# define OPENSSL_RAND_SEED_DEVRANDOM
222	# endif
223
224	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
225	# error "librandom not (yet) supported"
226	# endif
227
228	# if (defined(__FreeBSD__) \|\| defined(__NetBSD__)) && defined(KERN_ARND)
229	/*
230	* sysctl_random(): Use sysctl() to read a random number from the kernel
231	* Returns the number of bytes returned in buf on success, -1 on failure.
232	*/
233	static ssize_t sysctl_random(char *buf, size_t buflen)
234	{
235	int mib[2];
236	size_t done = 0;
237	size_t len;
238
239	/*
240	* Note: sign conversion between size_t and ssize_t is safe even
241	* without a range check, see comment in syscall_random()
242	*/
243
244	/*
245	* On FreeBSD old implementations returned longs, newer versions support
246	* variable sizes up to 256 byte. The code below would not work properly
247	* when the sysctl returns long and we want to request something not a
248	* multiple of longs, which should never be the case.
249	*/
250	if (!ossl_assert(buflen % sizeof(long) == 0)) {
251	errno = EINVAL;
252	return -1;
253	}
254
255	/*
256	* On NetBSD before 4.0 KERN_ARND was an alias for KERN_URND, and only
257	* filled in an int, leaving the rest uninitialized. Since NetBSD 4.0
258	* it returns a variable number of bytes with the current version supporting
259	* up to 256 bytes.
260	* Just return an error on older NetBSD versions.
261	*/
262	#if defined(__NetBSD__) && __NetBSD_Version__ < 400000000
263	errno = ENOSYS;
264	return -1;
265	#endif
266
267	mib[0] = CTL_KERN;
268	mib[1] = KERN_ARND;
269
270	do {
271	len = buflen;
272	if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
273	return done > 0 ? done : -1;
274	done += len;
275	buf += len;
276	buflen -= len;
277	} while (buflen > 0);
278
279	return done;
280	}
281	# endif
282
283	# if defined(OPENSSL_RAND_SEED_GETRANDOM)
284
285	# if defined(__linux) && !defined(__NR_getrandom)
286	# if defined(__arm__)
287	# define __NR_getrandom (__NR_SYSCALL_BASE+384)
288	# elif defined(__i386__)
289	# define __NR_getrandom 355
290	# elif defined(__x86_64__)
291	# if defined(__ILP32__)
292	# define __NR_getrandom (__X32_SYSCALL_BIT + 318)
293	# else
294	# define __NR_getrandom 318
295	# endif
296	# elif defined(__xtensa__)
297	# define __NR_getrandom 338
298	# elif defined(__s390__) \|\| defined(__s390x__)
299	# define __NR_getrandom 349
300	# elif defined(__bfin__)
301	# define __NR_getrandom 389
302	# elif defined(__powerpc__)
303	# define __NR_getrandom 359
304	# elif defined(__mips__) \|\| defined(__mips64)
305	# if _MIPS_SIM == _MIPS_SIM_ABI32
306	# define __NR_getrandom (__NR_Linux + 353)
307	# elif _MIPS_SIM == _MIPS_SIM_ABI64
308	# define __NR_getrandom (__NR_Linux + 313)
309	# elif _MIPS_SIM == _MIPS_SIM_NABI32
310	# define __NR_getrandom (__NR_Linux + 317)
311	# endif
312	# elif defined(__hppa__)
313	# define __NR_getrandom (__NR_Linux + 339)
314	# elif defined(__sparc__)
315	# define __NR_getrandom 347
316	# elif defined(__ia64__)
317	# define __NR_getrandom 1339
318	# elif defined(__alpha__)
319	# define __NR_getrandom 511
320	# elif defined(__sh__)
321	# if defined(__SH5__)
322	# define __NR_getrandom 373
323	# else
324	# define __NR_getrandom 384
325	# endif
326	# elif defined(__avr32__)
327	# define __NR_getrandom 317
328	# elif defined(__microblaze__)
329	# define __NR_getrandom 385
330	# elif defined(__m68k__)
331	# define __NR_getrandom 352
332	# elif defined(__cris__)
333	# define __NR_getrandom 356
334	# elif defined(__aarch64__)
335	# define __NR_getrandom 278
336	# else /* generic */
337	# define __NR_getrandom 278
338	# endif
339	# endif
340
341	/*
342	* syscall_random(): Try to get random data using a system call
343	* returns the number of bytes returned in buf, or < 0 on error.
344	*/
345	static ssize_t syscall_random(void *buf, size_t buflen)
346	{
347	/*
348	* Note: 'buflen' equals the size of the buffer which is used by the
349	* get_entropy() callback of the RAND_DRBG. It is roughly bounded by
350	*
351	* 2 * RAND_POOL_FACTOR * (RAND_DRBG_STRENGTH / 8) = 2^14
352	*
353	* which is way below the OSSL_SSIZE_MAX limit. Therefore sign conversion
354	* between size_t and ssize_t is safe even without a range check.
355	*/
356
357	/*
358	* Do runtime detection to find getentropy().
359	*
360	* Known OSs that should support this:
361	* - Darwin since 16 (OSX 10.12, IOS 10.0).
362	* - Solaris since 11.3
363	* - OpenBSD since 5.6
364	* - Linux since 3.17 with glibc 2.25
365	* - FreeBSD since 12.0 (1200061)
366	*/
367	# if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__) && !defined(__hpux)
368	extern int getentropy(void *buffer, size_t length) __attribute__((weak));
369
370	if (getentropy != NULL)
371	return getentropy(buf, buflen) == 0 ? (ssize_t)buflen : -1;
372	# else
373	union {
374	void *p;
375	int (f)(void buffer, size_t length);
376	} p_getentropy;
377
378	/*
379	* We could cache the result of the lookup, but we normally don't
380	* call this function often.
381	*/
382	ERR_set_mark();
383	p_getentropy.p = DSO_global_lookup("getentropy");
384	ERR_pop_to_mark();
385	if (p_getentropy.p != NULL)
386	return p_getentropy.f(buf, buflen) == 0 ? (ssize_t)buflen : -1;
387	# endif
388
389	/* Linux supports this since version 3.17 */
390	# if defined(__linux) && defined(__NR_getrandom)
391	return syscall(__NR_getrandom, buf, buflen, 0);
392	# elif (defined(__FreeBSD__) \|\| defined(__NetBSD__)) && defined(KERN_ARND)
393	return sysctl_random(buf, buflen);
394	# else
395	errno = ENOSYS;
396	return -1;
397	# endif
398	}
399	# endif /* defined(OPENSSL_RAND_SEED_GETRANDOM) */
400
401	# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
402	static const char *random_device_paths[] = { DEVRANDOM };
403	static struct random_device {
404	int fd;
405	dev_t dev;
406	ino_t ino;
407	mode_t mode;
408	dev_t rdev;
409	} random_devices[OSSL_NELEM(random_device_paths)];
410	static int keep_random_devices_open = 1;
411
412	# if defined(__linux) && defined(DEVRANDOM_WAIT)
413	static void *shm_addr;
414
415	static void cleanup_shm(void)
416	{
417	shmdt(shm_addr);
418	}
419
420	/*
421	* Ensure that the system randomness source has been adequately seeded.
422	* This is done by having the first start of libcrypto, wait until the device
423	* /dev/random becomes able to supply a byte of entropy. Subsequent starts
424	* of the library and later reseedings do not need to do this.
425	*/
426	static int wait_random_seeded(void)
427	{
428	static int seeded = OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID < 0;
429	static const int kernel_version[] = { DEVRANDOM_SAFE_KERNEL };
430	int kernel[2];
431	int shm_id, fd, r;
432	char c, *p;
433	struct utsname un;
434	fd_set fds;
435
436	if (!seeded) {
437	/* See if anything has created the global seeded indication */
438	if ((shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1, 0)) == -1) {
439	/*
440	* Check the kernel's version and fail if it is too recent.
441	*
442	* Linux kernels from 4.8 onwards do not guarantee that
443	* /dev/urandom is properly seeded when /dev/random becomes
444	* readable. However, such kernels support the getentropy(2)
445	* system call and this should always succeed which renders
446	* this alternative but essentially identical source moot.
447	*/
448	if (uname(&un) == 0) {
449	kernel[0] = atoi(un.release);
450	p = strchr(un.release, '.');
451	kernel[1] = p == NULL ? 0 : atoi(p + 1);
452	if (kernel[0] > kernel_version[0]
453	\|\| (kernel[0] == kernel_version[0]
454	&& kernel[1] >= kernel_version[1])) {
455	return 0;
456	}
457	}
458	/* Open /dev/random and wait for it to be readable */
459	if ((fd = open(DEVRANDOM_WAIT, O_RDONLY)) != -1) {
460	if (DEVRANDM_WAIT_USE_SELECT && fd < FD_SETSIZE) {
461	FD_ZERO(&fds);
462	FD_SET(fd, &fds);
463	while ((r = select(fd + 1, &fds, NULL, NULL, NULL)) < 0
464	&& errno == EINTR);
465	} else {
466	while ((r = read(fd, &c, 1)) < 0 && errno == EINTR);
467	}
468	close(fd);
469	if (r == 1) {
470	seeded = 1;
471	/* Create the shared memory indicator */
472	shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1,
473	IPC_CREAT \| S_IRUSR \| S_IRGRP \| S_IROTH);
474	}
475	}
476	}
477	if (shm_id != -1) {
478	seeded = 1;
479	/*
480	* Map the shared memory to prevent its premature destruction.
481	* If this call fails, it isn't a big problem.
482	*/
483	shm_addr = shmat(shm_id, NULL, SHM_RDONLY);
484	if (shm_addr != (void *)-1)
485	OPENSSL_atexit(&cleanup_shm);
486	}
487	}
488	return seeded;
489	}
490	# else /* defined __linux */
491	static int wait_random_seeded(void)
492	{
493	return 1;
494	}
495	# endif
496
497	/*
498	* Verify that the file descriptor associated with the random source is
499	* still valid. The rationale for doing this is the fact that it is not
500	* uncommon for daemons to close all open file handles when daemonizing.
501	* So the handle might have been closed or even reused for opening
502	* another file.
503	*/
504	static int check_random_device(struct random_device * rd)
505	{
506	struct stat st;
507
508	return rd->fd != -1
509	&& fstat(rd->fd, &st) != -1
510	&& rd->dev == st.st_dev
511	&& rd->ino == st.st_ino
512	&& ((rd->mode ^ st.st_mode) & ~(S_IRWXU \| S_IRWXG \| S_IRWXO)) == 0
513	&& rd->rdev == st.st_rdev;
514	}
515
516	/*
517	* Open a random device if required and return its file descriptor or -1 on error
518	*/
519	static int get_random_device(size_t n)
520	{
521	struct stat st;
522	struct random_device * rd = &random_devices[n];
523
524	/* reuse existing file descriptor if it is (still) valid */
525	if (check_random_device(rd))
526	return rd->fd;
527
528	/* open the random device ... */
529	if ((rd->fd = open(random_device_paths[n], O_RDONLY)) == -1)
530	return rd->fd;
531
532	/* ... and cache its relevant stat(2) data */
533	if (fstat(rd->fd, &st) != -1) {
534	rd->dev = st.st_dev;
535	rd->ino = st.st_ino;
536	rd->mode = st.st_mode;
537	rd->rdev = st.st_rdev;
538	} else {
539	close(rd->fd);
540	rd->fd = -1;
541	}
542
543	return rd->fd;
544	}
545
546	/*
547	* Close a random device making sure it is a random device
548	*/
549	static void close_random_device(size_t n)
550	{
551	struct random_device * rd = &random_devices[n];
552
553	if (check_random_device(rd))
554	close(rd->fd);
555	rd->fd = -1;
556	}
557
558	int rand_pool_init(void)
559	{
560	size_t i;
561
562	for (i = 0; i < OSSL_NELEM(random_devices); i++)
563	random_devices[i].fd = -1;
564
565	return 1;
566	}
567
568	void rand_pool_cleanup(void)
569	{
570	size_t i;
571
572	for (i = 0; i < OSSL_NELEM(random_devices); i++)
573	close_random_device(i);
574	}
575
576	void rand_pool_keep_random_devices_open(int keep)
577	{
578	if (!keep)
579	rand_pool_cleanup();
580
581	keep_random_devices_open = keep;
582	}
583
584	# else /* !defined(OPENSSL_RAND_SEED_DEVRANDOM) */
585
586	int rand_pool_init(void)
587	{
588	return 1;
589	}
590
591	void rand_pool_cleanup(void)
592	{
593	}
594
595	void rand_pool_keep_random_devices_open(int keep)
596	{
597	}
598
599	# endif /* defined(OPENSSL_RAND_SEED_DEVRANDOM) */
600
601	/*
602	* Try the various seeding methods in turn, exit when successful.
603	*
604	* TODO(DRBG): If more than one entropy source is available, is it
605	* preferable to stop as soon as enough entropy has been collected
606	* (as favored by @rsalz) or should one rather be defensive and add
607	* more entropy than requested and/or from different sources?
608	*
609	* Currently, the user can select multiple entropy sources in the
610	* configure step, yet in practice only the first available source
611	* will be used. A more flexible solution has been requested, but
612	* currently it is not clear how this can be achieved without
613	* overengineering the problem. There are many parameters which
614	* could be taken into account when selecting the order and amount
615	* of input from the different entropy sources (trust, quality,
616	* possibility of blocking).
617	*/
618	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
619	{
620	# if defined(OPENSSL_RAND_SEED_NONE)
621	return rand_pool_entropy_available(pool);
622	# else
623	size_t entropy_available;
624
625	# if defined(OPENSSL_RAND_SEED_GETRANDOM)
626	{
627	size_t bytes_needed;
628	unsigned char *buffer;
629	ssize_t bytes;
630	/* Maximum allowed number of consecutive unsuccessful attempts */
631	int attempts = 3;
632
633	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
634	while (bytes_needed != 0 && attempts-- > 0) {
635	buffer = rand_pool_add_begin(pool, bytes_needed);
636	bytes = syscall_random(buffer, bytes_needed);
637	if (bytes > 0) {
638	rand_pool_add_end(pool, bytes, 8 * bytes);
639	bytes_needed -= bytes;
640	attempts = 3; /* reset counter after successful attempt */
641	} else if (bytes < 0 && errno != EINTR) {
642	break;
643	}
644	}
645	}
646	entropy_available = rand_pool_entropy_available(pool);
647	if (entropy_available > 0)
648	return entropy_available;
649	# endif
650
651	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
652	{
653	/* Not yet implemented. */
654	}
655	# endif
656
657	# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
658	if (wait_random_seeded()) {
659	size_t bytes_needed;
660	unsigned char *buffer;
661	size_t i;
662
663	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
664	for (i = 0; bytes_needed > 0 && i < OSSL_NELEM(random_device_paths);
665	i++) {
666	ssize_t bytes = 0;
667	/* Maximum number of consecutive unsuccessful attempts */
668	int attempts = 3;
669	const int fd = get_random_device(i);
670
671	if (fd == -1)
672	continue;
673
674	while (bytes_needed != 0 && attempts-- > 0) {
675	buffer = rand_pool_add_begin(pool, bytes_needed);
676	bytes = read(fd, buffer, bytes_needed);
677
678	if (bytes > 0) {
679	rand_pool_add_end(pool, bytes, 8 * bytes);
680	bytes_needed -= bytes;
681	attempts = 3; /* reset counter on successful attempt */
682	} else if (bytes < 0 && errno != EINTR) {
683	break;
684	}
685	}
686	if (bytes < 0 \|\| !keep_random_devices_open)
687	close_random_device(i);
688
689	bytes_needed = rand_pool_bytes_needed(pool, 1);
690	}
691	entropy_available = rand_pool_entropy_available(pool);
692	if (entropy_available > 0)
693	return entropy_available;
694	}
695	# endif
696
697	# if defined(OPENSSL_RAND_SEED_RDTSC)
698	entropy_available = rand_acquire_entropy_from_tsc(pool);
699	if (entropy_available > 0)
700	return entropy_available;
701	# endif
702
703	# if defined(OPENSSL_RAND_SEED_RDCPU)
704	entropy_available = rand_acquire_entropy_from_cpu(pool);
705	if (entropy_available > 0)
706	return entropy_available;
707	# endif
708
709	# if defined(OPENSSL_RAND_SEED_EGD)
710	{
711	static const char *paths[] = { DEVRANDOM_EGD, NULL };
712	size_t bytes_needed;
713	unsigned char *buffer;
714	int i;
715
716	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
717	for (i = 0; bytes_needed > 0 && paths[i] != NULL; i++) {
718	size_t bytes = 0;
719	int num;
720
721	buffer = rand_pool_add_begin(pool, bytes_needed);
722	num = RAND_query_egd_bytes(paths[i],
723	buffer, (int)bytes_needed);
724	if (num == (int)bytes_needed)
725	bytes = bytes_needed;
726
727	rand_pool_add_end(pool, bytes, 8 * bytes);
728	bytes_needed = rand_pool_bytes_needed(pool, 1);
729	}
730	entropy_available = rand_pool_entropy_available(pool);
731	if (entropy_available > 0)
732	return entropy_available;
733	}
734	# endif
735
736	return rand_pool_entropy_available(pool);
737	# endif
738	}
739	# endif
740	#endif
741
742	#if defined(OPENSSL_SYS_UNIX) \|\| defined(__DJGPP__)
743	int rand_pool_add_nonce_data(RAND_POOL *pool)
744	{
745	struct {
746	pid_t pid;
747	CRYPTO_THREAD_ID tid;
748	uint64_t time;
749	} data = { 0 };
750
751	/*
752	* Add process id, thread id, and a high resolution timestamp to
753	* ensure that the nonce is unique with high probability for
754	* different process instances.
755	*/
756	data.pid = getpid();
757	data.tid = CRYPTO_THREAD_get_current_id();
758	data.time = get_time_stamp();
759
760	return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
761	}
762
763	int rand_pool_add_additional_data(RAND_POOL *pool)
764	{
765	struct {
766	int fork_id;
767	CRYPTO_THREAD_ID tid;
768	uint64_t time;
769	} data = { 0 };
770
771	/*
772	* Add some noise from the thread id and a high resolution timer.
773	* The fork_id adds some extra fork-safety.
774	* The thread id adds a little randomness if the drbg is accessed
775	* concurrently (which is the case for the <master> drbg).
776	*/
777	data.fork_id = openssl_get_fork_id();
778	data.tid = CRYPTO_THREAD_get_current_id();
779	data.time = get_timer_bits();
780
781	return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
782	}
783
784
785	/*
786	* Get the current time with the highest possible resolution
787	*
788	* The time stamp is added to the nonce, so it is optimized for not repeating.
789	* The current time is ideal for this purpose, provided the computer's clock
790	* is synchronized.
791	*/
792	static uint64_t get_time_stamp(void)
793	{
794	# if defined(OSSL_POSIX_TIMER_OKAY)
795	{
796	struct timespec ts;
797
798	if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
799	return TWO32TO64(ts.tv_sec, ts.tv_nsec);
800	}
801	# endif
802	# if defined(__unix__) \
803	\|\| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
804	{
805	struct timeval tv;
806
807	if (gettimeofday(&tv, NULL) == 0)
808	return TWO32TO64(tv.tv_sec, tv.tv_usec);
809	}
810	# endif
811	return time(NULL);
812	}
813
814	/*
815	* Get an arbitrary timer value of the highest possible resolution
816	*
817	* The timer value is added as random noise to the additional data,
818	* which is not considered a trusted entropy sourec, so any result
819	* is acceptable.
820	*/
821	static uint64_t get_timer_bits(void)
822	{
823	uint64_t res = OPENSSL_rdtsc();
824
825	if (res != 0)
826	return res;
827
828	# if defined(__sun) \|\| defined(__hpux)
829	return gethrtime();
830	# elif defined(_AIX)
831	{
832	timebasestruct_t t;
833
834	read_wall_time(&t, TIMEBASE_SZ);
835	return TWO32TO64(t.tb_high, t.tb_low);
836	}
837	# elif defined(OSSL_POSIX_TIMER_OKAY)
838	{
839	struct timespec ts;
840
841	# ifdef CLOCK_BOOTTIME
842	# define CLOCK_TYPE CLOCK_BOOTTIME
843	# elif defined(_POSIX_MONOTONIC_CLOCK)
844	# define CLOCK_TYPE CLOCK_MONOTONIC
845	# else
846	# define CLOCK_TYPE CLOCK_REALTIME
847	# endif
848
849	if (clock_gettime(CLOCK_TYPE, &ts) == 0)
850	return TWO32TO64(ts.tv_sec, ts.tv_nsec);
851	}
852	# endif
853	# if defined(__unix__) \
854	\|\| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
855	{
856	struct timeval tv;
857
858	if (gettimeofday(&tv, NULL) == 0)
859	return TWO32TO64(tv.tv_sec, tv.tv_usec);
860	}
861	# endif
862	return time(NULL);
863	}
864	#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
865	\|\| defined(__DJGPP__) */

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source: vbox/trunk/src/libs/openssl-1.1.1f/crypto/rand/rand_unix.c@ 83531

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