rand_unix.c@ 86560

Last change on this file since 86560 was 86560, checked in by vboxsync, 5 years ago
openssl-1.1.1h: Applied our OpenSSL changes to 1.1.1h. Didn't check te build. bugref:9847
File size: 25.2 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(__NetBSD__)) && !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__)
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 defined(__FreeBSD__)
251	if (!ossl_assert(buflen % sizeof(long) == 0)) {
252	errno = EINVAL;
253	return -1;
254	}
255	#endif
256
257	/*
258	* On NetBSD before 4.0 KERN_ARND was an alias for KERN_URND, and only
259	* filled in an int, leaving the rest uninitialized. Since NetBSD 4.0
260	* it returns a variable number of bytes with the current version supporting
261	* up to 256 bytes.
262	* Just return an error on older NetBSD versions.
263	*/
264	#if defined(__NetBSD__) && __NetBSD_Version__ < 400000000
265	errno = ENOSYS;
266	return -1;
267	#endif
268
269	mib[0] = CTL_KERN;
270	mib[1] = KERN_ARND;
271
272	do {
273	len = buflen > 256 ? 256 : buflen;
274	if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
275	return done > 0 ? done : -1;
276	done += len;
277	buf += len;
278	buflen -= len;
279	} while (buflen > 0);
280
281	return done;
282	}
283	# endif
284
285	# if defined(OPENSSL_RAND_SEED_GETRANDOM)
286
287	# if defined(__linux) && !defined(__NR_getrandom)
288	# if defined(__arm__)
289	# define __NR_getrandom (__NR_SYSCALL_BASE+384)
290	# elif defined(__i386__)
291	# define __NR_getrandom 355
292	# elif defined(__x86_64__)
293	# if defined(__ILP32__)
294	# define __NR_getrandom (__X32_SYSCALL_BIT + 318)
295	# else
296	# define __NR_getrandom 318
297	# endif
298	# elif defined(__xtensa__)
299	# define __NR_getrandom 338
300	# elif defined(__s390__) \|\| defined(__s390x__)
301	# define __NR_getrandom 349
302	# elif defined(__bfin__)
303	# define __NR_getrandom 389
304	# elif defined(__powerpc__)
305	# define __NR_getrandom 359
306	# elif defined(__mips__) \|\| defined(__mips64)
307	# if _MIPS_SIM == _MIPS_SIM_ABI32
308	# define __NR_getrandom (__NR_Linux + 353)
309	# elif _MIPS_SIM == _MIPS_SIM_ABI64
310	# define __NR_getrandom (__NR_Linux + 313)
311	# elif _MIPS_SIM == _MIPS_SIM_NABI32
312	# define __NR_getrandom (__NR_Linux + 317)
313	# endif
314	# elif defined(__hppa__)
315	# define __NR_getrandom (__NR_Linux + 339)
316	# elif defined(__sparc__)
317	# define __NR_getrandom 347
318	# elif defined(__ia64__)
319	# define __NR_getrandom 1339
320	# elif defined(__alpha__)
321	# define __NR_getrandom 511
322	# elif defined(__sh__)
323	# if defined(__SH5__)
324	# define __NR_getrandom 373
325	# else
326	# define __NR_getrandom 384
327	# endif
328	# elif defined(__avr32__)
329	# define __NR_getrandom 317
330	# elif defined(__microblaze__)
331	# define __NR_getrandom 385
332	# elif defined(__m68k__)
333	# define __NR_getrandom 352
334	# elif defined(__cris__)
335	# define __NR_getrandom 356
336	# elif defined(__aarch64__)
337	# define __NR_getrandom 278
338	# else /* generic */
339	# define __NR_getrandom 278
340	# endif
341	# endif
342
343	/*
344	* syscall_random(): Try to get random data using a system call
345	* returns the number of bytes returned in buf, or < 0 on error.
346	*/
347	static ssize_t syscall_random(void *buf, size_t buflen)
348	{
349	/*
350	* Note: 'buflen' equals the size of the buffer which is used by the
351	* get_entropy() callback of the RAND_DRBG. It is roughly bounded by
352	*
353	* 2 * RAND_POOL_FACTOR * (RAND_DRBG_STRENGTH / 8) = 2^14
354	*
355	* which is way below the OSSL_SSIZE_MAX limit. Therefore sign conversion
356	* between size_t and ssize_t is safe even without a range check.
357	*/
358
359	/*
360	* Do runtime detection to find getentropy().
361	*
362	* Known OSs that should support this:
363	* - Darwin since 16 (OSX 10.12, IOS 10.0).
364	* - Solaris since 11.3
365	* - OpenBSD since 5.6
366	* - Linux since 3.17 with glibc 2.25
367	* - FreeBSD since 12.0 (1200061)
368	*/
369	# if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__) && !defined(__hpux)
370	extern int getentropy(void *buffer, size_t length) __attribute__((weak));
371
372	if (getentropy != NULL)
373	return getentropy(buf, buflen) == 0 ? (ssize_t)buflen : -1;
374	# else
375	union {
376	void *p;
377	int (f)(void buffer, size_t length);
378	} p_getentropy;
379
380	/*
381	* We could cache the result of the lookup, but we normally don't
382	* call this function often.
383	*/
384	ERR_set_mark();
385	p_getentropy.p = DSO_global_lookup("getentropy");
386	ERR_pop_to_mark();
387	if (p_getentropy.p != NULL)
388	return p_getentropy.f(buf, buflen) == 0 ? (ssize_t)buflen : -1;
389	# endif
390
391	/* Linux supports this since version 3.17 */
392	# if defined(__linux) && defined(__NR_getrandom)
393	return syscall(__NR_getrandom, buf, buflen, 0);
394	# elif (defined(__FreeBSD__) \|\| defined(__NetBSD__)) && defined(KERN_ARND)
395	return sysctl_random(buf, buflen);
396	# else
397	errno = ENOSYS;
398	return -1;
399	# endif
400	}
401	# endif /* defined(OPENSSL_RAND_SEED_GETRANDOM) */
402
403	# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
404	static const char *random_device_paths[] = { DEVRANDOM };
405	static struct random_device {
406	int fd;
407	dev_t dev;
408	ino_t ino;
409	mode_t mode;
410	dev_t rdev;
411	} random_devices[OSSL_NELEM(random_device_paths)];
412	static int keep_random_devices_open = 1;
413
414	# if defined(__linux) && defined(DEVRANDOM_WAIT) \
415	&& defined(OPENSSL_RAND_SEED_GETRANDOM)
416	static void *shm_addr;
417
418	static void cleanup_shm(void)
419	{
420	shmdt(shm_addr);
421	}
422
423	/*
424	* Ensure that the system randomness source has been adequately seeded.
425	* This is done by having the first start of libcrypto, wait until the device
426	* /dev/random becomes able to supply a byte of entropy. Subsequent starts
427	* of the library and later reseedings do not need to do this.
428	*/
429	static int wait_random_seeded(void)
430	{
431	static int seeded = OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID < 0;
432	static const int kernel_version[] = { DEVRANDOM_SAFE_KERNEL };
433	int kernel[2];
434	int shm_id, fd, r;
435	char c, *p;
436	struct utsname un;
437	fd_set fds;
438
439	if (!seeded) {
440	/* See if anything has created the global seeded indication */
441	if ((shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1, 0)) == -1) {
442	/*
443	* Check the kernel's version and fail if it is too recent.
444	*
445	* Linux kernels from 4.8 onwards do not guarantee that
446	* /dev/urandom is properly seeded when /dev/random becomes
447	* readable. However, such kernels support the getentropy(2)
448	* system call and this should always succeed which renders
449	* this alternative but essentially identical source moot.
450	*/
451	if (uname(&un) == 0) {
452	kernel[0] = atoi(un.release);
453	p = strchr(un.release, '.');
454	kernel[1] = p == NULL ? 0 : atoi(p + 1);
455	if (kernel[0] > kernel_version[0]
456	\|\| (kernel[0] == kernel_version[0]
457	&& kernel[1] >= kernel_version[1])) {
458	return 0;
459	}
460	}
461	/* Open /dev/random and wait for it to be readable */
462	if ((fd = open(DEVRANDOM_WAIT, O_RDONLY)) != -1) {
463	if (DEVRANDM_WAIT_USE_SELECT && fd < FD_SETSIZE) {
464	FD_ZERO(&fds);
465	FD_SET(fd, &fds);
466	while ((r = select(fd + 1, &fds, NULL, NULL, NULL)) < 0
467	&& errno == EINTR);
468	} else {
469	while ((r = read(fd, &c, 1)) < 0 && errno == EINTR);
470	}
471	close(fd);
472	if (r == 1) {
473	seeded = 1;
474	/* Create the shared memory indicator */
475	shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1,
476	IPC_CREAT \| S_IRUSR \| S_IRGRP \| S_IROTH);
477	}
478	}
479	}
480	if (shm_id != -1) {
481	seeded = 1;
482	/*
483	* Map the shared memory to prevent its premature destruction.
484	* If this call fails, it isn't a big problem.
485	*/
486	shm_addr = shmat(shm_id, NULL, SHM_RDONLY);
487	if (shm_addr != (void *)-1)
488	OPENSSL_atexit(&cleanup_shm);
489	}
490	}
491	return seeded;
492	}
493	# else /* defined __linux && DEVRANDOM_WAIT && OPENSSL_RAND_SEED_GETRANDOM */
494	static int wait_random_seeded(void)
495	{
496	return 1;
497	}
498	# endif
499
500	/*
501	* Verify that the file descriptor associated with the random source is
502	* still valid. The rationale for doing this is the fact that it is not
503	* uncommon for daemons to close all open file handles when daemonizing.
504	* So the handle might have been closed or even reused for opening
505	* another file.
506	*/
507	static int check_random_device(struct random_device * rd)
508	{
509	struct stat st;
510
511	return rd->fd != -1
512	&& fstat(rd->fd, &st) != -1
513	&& rd->dev == st.st_dev
514	&& rd->ino == st.st_ino
515	&& ((rd->mode ^ st.st_mode) & ~(S_IRWXU \| S_IRWXG \| S_IRWXO)) == 0
516	&& rd->rdev == st.st_rdev;
517	}
518
519	/*
520	* Open a random device if required and return its file descriptor or -1 on error
521	*/
522	static int get_random_device(size_t n)
523	{
524	struct stat st;
525	struct random_device * rd = &random_devices[n];
526
527	/* reuse existing file descriptor if it is (still) valid */
528	if (check_random_device(rd))
529	return rd->fd;
530
531	/* open the random device ... */
532	if ((rd->fd = open(random_device_paths[n], O_RDONLY)) == -1)
533	return rd->fd;
534
535	/* ... and cache its relevant stat(2) data */
536	if (fstat(rd->fd, &st) != -1) {
537	rd->dev = st.st_dev;
538	rd->ino = st.st_ino;
539	rd->mode = st.st_mode;
540	rd->rdev = st.st_rdev;
541	} else {
542	close(rd->fd);
543	rd->fd = -1;
544	}
545
546	return rd->fd;
547	}
548
549	/*
550	* Close a random device making sure it is a random device
551	*/
552	static void close_random_device(size_t n)
553	{
554	struct random_device * rd = &random_devices[n];
555
556	if (check_random_device(rd))
557	close(rd->fd);
558	rd->fd = -1;
559	}
560
561	int rand_pool_init(void)
562	{
563	size_t i;
564
565	for (i = 0; i < OSSL_NELEM(random_devices); i++)
566	random_devices[i].fd = -1;
567
568	return 1;
569	}
570
571	void rand_pool_cleanup(void)
572	{
573	size_t i;
574
575	for (i = 0; i < OSSL_NELEM(random_devices); i++)
576	close_random_device(i);
577	}
578
579	void rand_pool_keep_random_devices_open(int keep)
580	{
581	if (!keep)
582	rand_pool_cleanup();
583
584	keep_random_devices_open = keep;
585	}
586
587	# else /* !defined(OPENSSL_RAND_SEED_DEVRANDOM) */
588
589	int rand_pool_init(void)
590	{
591	return 1;
592	}
593
594	void rand_pool_cleanup(void)
595	{
596	}
597
598	void rand_pool_keep_random_devices_open(int keep)
599	{
600	}
601
602	# endif /* defined(OPENSSL_RAND_SEED_DEVRANDOM) */
603
604	/*
605	* Try the various seeding methods in turn, exit when successful.
606	*
607	* TODO(DRBG): If more than one entropy source is available, is it
608	* preferable to stop as soon as enough entropy has been collected
609	* (as favored by @rsalz) or should one rather be defensive and add
610	* more entropy than requested and/or from different sources?
611	*
612	* Currently, the user can select multiple entropy sources in the
613	* configure step, yet in practice only the first available source
614	* will be used. A more flexible solution has been requested, but
615	* currently it is not clear how this can be achieved without
616	* overengineering the problem. There are many parameters which
617	* could be taken into account when selecting the order and amount
618	* of input from the different entropy sources (trust, quality,
619	* possibility of blocking).
620	*/
621	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
622	{
623	# if defined(OPENSSL_RAND_SEED_NONE)
624	return rand_pool_entropy_available(pool);
625	# else
626	size_t entropy_available;
627
628	# if defined(OPENSSL_RAND_SEED_GETRANDOM)
629	{
630	size_t bytes_needed;
631	unsigned char *buffer;
632	ssize_t bytes;
633	/* Maximum allowed number of consecutive unsuccessful attempts */
634	int attempts = 3;
635
636	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
637	while (bytes_needed != 0 && attempts-- > 0) {
638	buffer = rand_pool_add_begin(pool, bytes_needed);
639	bytes = syscall_random(buffer, bytes_needed);
640	if (bytes > 0) {
641	rand_pool_add_end(pool, bytes, 8 * bytes);
642	bytes_needed -= bytes;
643	attempts = 3; /* reset counter after successful attempt */
644	} else if (bytes < 0 && errno != EINTR) {
645	break;
646	}
647	}
648	}
649	entropy_available = rand_pool_entropy_available(pool);
650	if (entropy_available > 0)
651	return entropy_available;
652	# endif
653
654	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
655	{
656	/* Not yet implemented. */
657	}
658	# endif
659
660	# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
661	if (wait_random_seeded()) {
662	size_t bytes_needed;
663	unsigned char *buffer;
664	size_t i;
665
666	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
667	for (i = 0; bytes_needed > 0 && i < OSSL_NELEM(random_device_paths);
668	i++) {
669	ssize_t bytes = 0;
670	/* Maximum number of consecutive unsuccessful attempts */
671	int attempts = 3;
672	const int fd = get_random_device(i);
673
674	if (fd == -1)
675	continue;
676
677	while (bytes_needed != 0 && attempts-- > 0) {
678	buffer = rand_pool_add_begin(pool, bytes_needed);
679	bytes = read(fd, buffer, bytes_needed);
680
681	if (bytes > 0) {
682	rand_pool_add_end(pool, bytes, 8 * bytes);
683	bytes_needed -= bytes;
684	attempts = 3; /* reset counter on successful attempt */
685	} else if (bytes < 0 && errno != EINTR) {
686	break;
687	}
688	}
689	if (bytes < 0 \|\| !keep_random_devices_open)
690	close_random_device(i);
691
692	bytes_needed = rand_pool_bytes_needed(pool, 1);
693	}
694	entropy_available = rand_pool_entropy_available(pool);
695	if (entropy_available > 0)
696	return entropy_available;
697	}
698	# endif
699
700	# if defined(OPENSSL_RAND_SEED_RDTSC)
701	entropy_available = rand_acquire_entropy_from_tsc(pool);
702	if (entropy_available > 0)
703	return entropy_available;
704	# endif
705
706	# if defined(OPENSSL_RAND_SEED_RDCPU)
707	entropy_available = rand_acquire_entropy_from_cpu(pool);
708	if (entropy_available > 0)
709	return entropy_available;
710	# endif
711
712	# if defined(OPENSSL_RAND_SEED_EGD)
713	{
714	static const char *paths[] = { DEVRANDOM_EGD, NULL };
715	size_t bytes_needed;
716	unsigned char *buffer;
717	int i;
718
719	bytes_needed = rand_pool_bytes_needed(pool, 1 /entropy_factor/);
720	for (i = 0; bytes_needed > 0 && paths[i] != NULL; i++) {
721	size_t bytes = 0;
722	int num;
723
724	buffer = rand_pool_add_begin(pool, bytes_needed);
725	num = RAND_query_egd_bytes(paths[i],
726	buffer, (int)bytes_needed);
727	if (num == (int)bytes_needed)
728	bytes = bytes_needed;
729
730	rand_pool_add_end(pool, bytes, 8 * bytes);
731	bytes_needed = rand_pool_bytes_needed(pool, 1);
732	}
733	entropy_available = rand_pool_entropy_available(pool);
734	if (entropy_available > 0)
735	return entropy_available;
736	}
737	# endif
738
739	return rand_pool_entropy_available(pool);
740	# endif
741	}
742	# endif
743	#endif
744
745	#if defined(OPENSSL_SYS_UNIX) \|\| defined(__DJGPP__)
746	int rand_pool_add_nonce_data(RAND_POOL *pool)
747	{
748	struct {
749	pid_t pid;
750	CRYPTO_THREAD_ID tid;
751	uint64_t time;
752	} data = { 0 };
753
754	/*
755	* Add process id, thread id, and a high resolution timestamp to
756	* ensure that the nonce is unique with high probability for
757	* different process instances.
758	*/
759	data.pid = getpid();
760	data.tid = CRYPTO_THREAD_get_current_id();
761	data.time = get_time_stamp();
762
763	return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
764	}
765
766	int rand_pool_add_additional_data(RAND_POOL *pool)
767	{
768	struct {
769	int fork_id;
770	CRYPTO_THREAD_ID tid;
771	uint64_t time;
772	} data = { 0 };
773
774	/*
775	* Add some noise from the thread id and a high resolution timer.
776	* The fork_id adds some extra fork-safety.
777	* The thread id adds a little randomness if the drbg is accessed
778	* concurrently (which is the case for the <master> drbg).
779	*/
780	data.fork_id = openssl_get_fork_id();
781	data.tid = CRYPTO_THREAD_get_current_id();
782	data.time = get_timer_bits();
783
784	return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
785	}
786
787
788	/*
789	* Get the current time with the highest possible resolution
790	*
791	* The time stamp is added to the nonce, so it is optimized for not repeating.
792	* The current time is ideal for this purpose, provided the computer's clock
793	* is synchronized.
794	*/
795	static uint64_t get_time_stamp(void)
796	{
797	# if defined(OSSL_POSIX_TIMER_OKAY)
798	{
799	struct timespec ts;
800
801	if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
802	return TWO32TO64(ts.tv_sec, ts.tv_nsec);
803	}
804	# endif
805	# if defined(__unix__) \
806	\|\| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
807	{
808	struct timeval tv;
809
810	if (gettimeofday(&tv, NULL) == 0)
811	return TWO32TO64(tv.tv_sec, tv.tv_usec);
812	}
813	# endif
814	return time(NULL);
815	}
816
817	/*
818	* Get an arbitrary timer value of the highest possible resolution
819	*
820	* The timer value is added as random noise to the additional data,
821	* which is not considered a trusted entropy sourec, so any result
822	* is acceptable.
823	*/
824	static uint64_t get_timer_bits(void)
825	{
826	uint64_t res = OPENSSL_rdtsc();
827
828	if (res != 0)
829	return res;
830
831	# if defined(__sun) \|\| defined(__hpux)
832	return gethrtime();
833	# elif defined(_AIX)
834	{
835	timebasestruct_t t;
836
837	read_wall_time(&t, TIMEBASE_SZ);
838	return TWO32TO64(t.tb_high, t.tb_low);
839	}
840	# elif defined(OSSL_POSIX_TIMER_OKAY)
841	{
842	struct timespec ts;
843
844	# ifdef CLOCK_BOOTTIME
845	# define CLOCK_TYPE CLOCK_BOOTTIME
846	# elif defined(_POSIX_MONOTONIC_CLOCK)
847	# define CLOCK_TYPE CLOCK_MONOTONIC
848	# else
849	# define CLOCK_TYPE CLOCK_REALTIME
850	# endif
851
852	if (clock_gettime(CLOCK_TYPE, &ts) == 0)
853	return TWO32TO64(ts.tv_sec, ts.tv_nsec);
854	}
855	# endif
856	# if defined(__unix__) \
857	\|\| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
858	{
859	struct timeval tv;
860
861	if (gettimeofday(&tv, NULL) == 0)
862	return TWO32TO64(tv.tv_sec, tv.tv_usec);
863	}
864	# endif
865	return time(NULL);
866	}
867	#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
868	\|\| defined(__DJGPP__) */

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source: vbox/trunk/src/libs/openssl-1.1.1h/crypto/rand/rand_unix.c@ 86560

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