crypto/rand/rand_unix.c - third_party/openssl - Git at Google

 /*
  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 #include "e_os.h"
 #include <stdio.h>
 #include "internal/cryptlib.h"
 #include <openssl/rand.h>
 #include "rand_lcl.h"
 #include "internal/rand_int.h"
 #include <stdio.h>

 #if (defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) && \
         !defined(OPENSSL_RAND_SEED_NONE)
 # error "UEFI and VXWorks only support seeding NONE"
 #endif

 #if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) \
     || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) \
     || defined(OPENSSL_SYS_UEFI))

 # if defined(OPENSSL_SYS_VOS)

 #  ifndef OPENSSL_RAND_SEED_OS
 #   error "Unsupported seeding method configured; must be os"
 #  endif

 #  if defined(OPENSSL_SYS_VOS_HPPA) && defined(OPENSSL_SYS_VOS_IA32)
 #   error "Unsupported HP-PA and IA32 at the same time."
 #  endif
 #  if !defined(OPENSSL_SYS_VOS_HPPA) && !defined(OPENSSL_SYS_VOS_IA32)
 #   error "Must have one of HP-PA or IA32"
 #  endif

 /*
  * The following algorithm repeatedly samples the real-time clock (RTC) to
  * generate a sequence of unpredictable data.  The algorithm relies upon the
  * uneven execution speed of the code (due to factors such as cache misses,
  * interrupts, bus activity, and scheduling) and upon the rather large
  * relative difference between the speed of the clock and the rate at which
  * it can be read.  If it is ported to an environment where execution speed
  * is more constant or where the RTC ticks at a much slower rate, or the
  * clock can be read with fewer instructions, it is likely that the results
  * would be far more predictable.  This should only be used for legacy
  * platforms.
  *
  * As a precaution, we assume only 2 bits of entropy per byte.
  */
 size_t rand_pool_acquire_entropy(RAND_POOL *pool)
 {
     short int code;
     gid_t curr_gid;
     pid_t curr_pid;
     uid_t curr_uid;
     int i, k;
     size_t bytes_needed;
     struct timespec ts;
     unsigned char v;
 #  ifdef OPENSSL_SYS_VOS_HPPA
     long duration;
     extern void s$sleep(long *_duration, short int *_code);
 #  else
     long long duration;
     extern void s$sleep2(long long *_duration, short int *_code);
 #  endif

     /*
      * Seed with the gid, pid, and uid, to ensure *some* variation between
      * different processes.
      */
     curr_gid = getgid();
     rand_pool_add(pool, &curr_gid, sizeof(curr_gid), 0);
     curr_pid = getpid();
     rand_pool_add(pool, &curr_pid, sizeof(curr_pid), 0);
     curr_uid = getuid();
     rand_pool_add(pool, &curr_uid, sizeof(curr_uid), 0);

     bytes_needed = rand_pool_bytes_needed(pool, 2 /*entropy_per_byte*/);

     for (i = 0; i < bytes_needed; i++) {
         /*
          * burn some cpu; hope for interrupts, cache collisions, bus
          * interference, etc.
          */
         for (k = 0; k < 99; k++)
             ts.tv_nsec = random();

 #  ifdef OPENSSL_SYS_VOS_HPPA
         /* sleep for 1/1024 of a second (976 us).  */
         duration = 1;
         s$sleep(&duration, &code);
 #  else
         /* sleep for 1/65536 of a second (15 us).  */
         duration = 1;
         s$sleep2(&duration, &code);
 #  endif

         /* Get wall clock time, take 8 bits. */
         clock_gettime(CLOCK_REALTIME, &ts);
         v = (unsigned char)(ts.tv_nsec & 0xFF);
         rand_pool_add(pool, arg, &v, sizeof(v) , 2);
     }
     return rand_pool_entropy_available(pool);
 }

 # else

 #  if defined(OPENSSL_RAND_SEED_EGD) && \
         (defined(OPENSSL_NO_EGD) || !defined(DEVRANDOM_EGD))
 #   error "Seeding uses EGD but EGD is turned off or no device given"
 #  endif

 #  if defined(OPENSSL_RAND_SEED_DEVRANDOM) && !defined(DEVRANDOM)
 #   error "Seeding uses urandom but DEVRANDOM is not configured"
 #  endif

 #  if defined(OPENSSL_RAND_SEED_OS)
 #   if !defined(DEVRANDOM)
 #    error "OS seeding requires DEVRANDOM to be configured"
 #   endif
 #   define OPENSSL_RAND_SEED_DEVRANDOM
 #   if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
 #    if __GLIBC_PREREQ(2, 25)
 #     define OPENSSL_RAND_SEED_GETRANDOM
 #    endif
 #   endif
 #  endif

 #  ifdef OPENSSL_RAND_SEED_GETRANDOM
 #   include <sys/random.h>
 #  endif

 #  if defined(OPENSSL_RAND_SEED_LIBRANDOM)
 #   error "librandom not (yet) supported"
 #  endif

 /*
  * Try the various seeding methods in turn, exit when successful.
  *
  * TODO(DRBG): If more than one entropy source is available, is it
  * preferable to stop as soon as enough entropy has been collected
  * (as favored by @rsalz) or should one rather be defensive and add
  * more entropy than requested and/or from different sources?
  *
  * Currently, the user can select multiple entropy sources in the
  * configure step, yet in practice only the first available source
  * will be used. A more flexible solution has been requested, but
  * currently it is not clear how this can be achieved without
  * overengineering the problem. There are many parameters which
  * could be taken into account when selecting the order and amount
  * of input from the different entropy sources (trust, quality,
  * possibility of blocking).
  */
 size_t rand_pool_acquire_entropy(RAND_POOL *pool)
 {
 #  ifdef OPENSSL_RAND_SEED_NONE
     return rand_pool_entropy_available(pool);
 #  else
     size_t bytes_needed;
     size_t entropy_available = 0;
     unsigned char *buffer;

 #   ifdef OPENSSL_RAND_SEED_GETRANDOM
     bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/);
     buffer = rand_pool_add_begin(pool, bytes_needed);
     if (buffer != NULL) {
         size_t bytes = 0;

         if (getrandom(buffer, bytes_needed, 0) == (int)bytes_needed)
             bytes = bytes_needed;

         entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
     }
     if (entropy_available > 0)
         return entropy_available;
 #   endif

 #   if defined(OPENSSL_RAND_SEED_LIBRANDOM)
     {
         /* Not yet implemented. */
     }
 #   endif

 #   ifdef OPENSSL_RAND_SEED_DEVRANDOM
     bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/);
     if (bytes_needed > 0) {
         static const char *paths[] = { DEVRANDOM, NULL };
         FILE *fp;
         int i;

         for (i = 0; paths[i] != NULL; i++) {
             if ((fp = fopen(paths[i], "rb")) == NULL)
                 continue;
             setbuf(fp, NULL);
             buffer = rand_pool_add_begin(pool, bytes_needed);
             if (buffer != NULL) {
                 size_t bytes = 0;
                 if (fread(buffer, 1, bytes_needed, fp) == bytes_needed)
                     bytes = bytes_needed;

                 entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
             }
             fclose(fp);
             if (entropy_available > 0)
                 return entropy_available;

             bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/);
         }
     }
 #   endif

 #   ifdef OPENSSL_RAND_SEED_RDTSC
     entropy_available = rand_acquire_entropy_from_tsc(pool);
     if (entropy_available > 0)
         return entropy_available;
 #   endif

 #   ifdef OPENSSL_RAND_SEED_RDCPU
     entropy_available = rand_acquire_entropy_from_cpu(pool);
     if (entropy_available > 0)
         return entropy_available;
 #   endif

 #   ifdef OPENSSL_RAND_SEED_EGD
     bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/);
     if (bytes_needed > 0) {
         static const char *paths[] = { DEVRANDOM_EGD, NULL };
         int i;

         for (i = 0; paths[i] != NULL; i++) {
             buffer = rand_pool_add_begin(pool, bytes_needed);
             if (buffer != NULL) {
                 size_t bytes = 0;
                 int num = RAND_query_egd_bytes(paths[i],
                                                buffer, (int)bytes_needed);
                 if (num == (int)bytes_needed)
                     bytes = bytes_needed;

                 entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
             }
             if (entropy_available > 0)
                 return entropy_available;
         }
     }
 #   endif

     return rand_pool_entropy_available(pool);
 #  endif
 }
 # endif

 #endif
	/*
	* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the OpenSSL license (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	#include "e_os.h"
	#include <stdio.h>
	#include "internal/cryptlib.h"
	#include <openssl/rand.h>
	#include "rand_lcl.h"
	#include "internal/rand_int.h"
	#include <stdio.h>

	#if (defined(OPENSSL_SYS_VXWORKS) \|\| defined(OPENSSL_SYS_UEFI)) && \
	!defined(OPENSSL_RAND_SEED_NONE)
	# error "UEFI and VXWorks only support seeding NONE"
	#endif

	#if !(defined(OPENSSL_SYS_WINDOWS) \|\| defined(OPENSSL_SYS_WIN32) \
	\|\| defined(OPENSSL_SYS_VMS) \|\| defined(OPENSSL_SYS_VXWORKS) \
	\|\| defined(OPENSSL_SYS_UEFI))

	# if defined(OPENSSL_SYS_VOS)

	# ifndef OPENSSL_RAND_SEED_OS
	# error "Unsupported seeding method configured; must be os"
	# endif

	# if defined(OPENSSL_SYS_VOS_HPPA) && defined(OPENSSL_SYS_VOS_IA32)
	# error "Unsupported HP-PA and IA32 at the same time."
	# endif
	# if !defined(OPENSSL_SYS_VOS_HPPA) && !defined(OPENSSL_SYS_VOS_IA32)
	# error "Must have one of HP-PA or IA32"
	# endif

	/*
	* The following algorithm repeatedly samples the real-time clock (RTC) to
	* generate a sequence of unpredictable data. The algorithm relies upon the
	* uneven execution speed of the code (due to factors such as cache misses,
	* interrupts, bus activity, and scheduling) and upon the rather large
	* relative difference between the speed of the clock and the rate at which
	* it can be read. If it is ported to an environment where execution speed
	* is more constant or where the RTC ticks at a much slower rate, or the
	* clock can be read with fewer instructions, it is likely that the results
	* would be far more predictable. This should only be used for legacy
	* platforms.
	*
	* As a precaution, we assume only 2 bits of entropy per byte.
	*/
	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
	{
	short int code;
	gid_t curr_gid;
	pid_t curr_pid;
	uid_t curr_uid;
	int i, k;
	size_t bytes_needed;
	struct timespec ts;
	unsigned char v;
	# ifdef OPENSSL_SYS_VOS_HPPA
	long duration;
	extern void s$sleep(long _duration, short int _code);
	# else
	long long duration;
	extern void s$sleep2(long long _duration, short int _code);
	# endif

	/*
	* Seed with the gid, pid, and uid, to ensure some variation between
	* different processes.
	*/
	curr_gid = getgid();
	rand_pool_add(pool, &curr_gid, sizeof(curr_gid), 0);
	curr_pid = getpid();
	rand_pool_add(pool, &curr_pid, sizeof(curr_pid), 0);
	curr_uid = getuid();
	rand_pool_add(pool, &curr_uid, sizeof(curr_uid), 0);

	bytes_needed = rand_pool_bytes_needed(pool, 2 /entropy_per_byte/);

	for (i = 0; i < bytes_needed; i++) {
	/*
	* burn some cpu; hope for interrupts, cache collisions, bus
	* interference, etc.
	*/
	for (k = 0; k < 99; k++)
	ts.tv_nsec = random();

	# ifdef OPENSSL_SYS_VOS_HPPA
	/* sleep for 1/1024 of a second (976 us). */
	duration = 1;
	s$sleep(&duration, &code);
	# else
	/* sleep for 1/65536 of a second (15 us). */
	duration = 1;
	s$sleep2(&duration, &code);
	# endif

	/* Get wall clock time, take 8 bits. */
	clock_gettime(CLOCK_REALTIME, &ts);
	v = (unsigned char)(ts.tv_nsec & 0xFF);
	rand_pool_add(pool, arg, &v, sizeof(v) , 2);
	}
	return rand_pool_entropy_available(pool);
	}

	# else

	# if defined(OPENSSL_RAND_SEED_EGD) && \
	(defined(OPENSSL_NO_EGD) \|\| !defined(DEVRANDOM_EGD))
	# error "Seeding uses EGD but EGD is turned off or no device given"
	# endif

	# if defined(OPENSSL_RAND_SEED_DEVRANDOM) && !defined(DEVRANDOM)
	# error "Seeding uses urandom but DEVRANDOM is not configured"
	# endif

	# if defined(OPENSSL_RAND_SEED_OS)
	# if !defined(DEVRANDOM)
	# error "OS seeding requires DEVRANDOM to be configured"
	# endif
	# define OPENSSL_RAND_SEED_DEVRANDOM
	# if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
	# if __GLIBC_PREREQ(2, 25)
	# define OPENSSL_RAND_SEED_GETRANDOM
	# endif
	# endif
	# endif

	# ifdef OPENSSL_RAND_SEED_GETRANDOM
	# include <sys/random.h>
	# endif

	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
	# error "librandom not (yet) supported"
	# endif

	/*
	* Try the various seeding methods in turn, exit when successful.
	*
	* TODO(DRBG): If more than one entropy source is available, is it
	* preferable to stop as soon as enough entropy has been collected
	* (as favored by @rsalz) or should one rather be defensive and add
	* more entropy than requested and/or from different sources?
	*
	* Currently, the user can select multiple entropy sources in the
	* configure step, yet in practice only the first available source
	* will be used. A more flexible solution has been requested, but
	* currently it is not clear how this can be achieved without
	* overengineering the problem. There are many parameters which
	* could be taken into account when selecting the order and amount
	* of input from the different entropy sources (trust, quality,
	* possibility of blocking).
	*/
	size_t rand_pool_acquire_entropy(RAND_POOL *pool)
	{
	# ifdef OPENSSL_RAND_SEED_NONE
	return rand_pool_entropy_available(pool);
	# else
	size_t bytes_needed;
	size_t entropy_available = 0;
	unsigned char *buffer;

	# ifdef OPENSSL_RAND_SEED_GETRANDOM
	bytes_needed = rand_pool_bytes_needed(pool, 8 /entropy_per_byte/);
	buffer = rand_pool_add_begin(pool, bytes_needed);
	if (buffer != NULL) {
	size_t bytes = 0;

	if (getrandom(buffer, bytes_needed, 0) == (int)bytes_needed)
	bytes = bytes_needed;

	entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
	}
	if (entropy_available > 0)
	return entropy_available;
	# endif

	# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
	{
	/* Not yet implemented. */
	}
	# endif

	# ifdef OPENSSL_RAND_SEED_DEVRANDOM
	bytes_needed = rand_pool_bytes_needed(pool, 8 /entropy_per_byte/);
	if (bytes_needed > 0) {
	static const char *paths[] = { DEVRANDOM, NULL };
	FILE *fp;
	int i;

	for (i = 0; paths[i] != NULL; i++) {
	if ((fp = fopen(paths[i], "rb")) == NULL)
	continue;
	setbuf(fp, NULL);
	buffer = rand_pool_add_begin(pool, bytes_needed);
	if (buffer != NULL) {
	size_t bytes = 0;
	if (fread(buffer, 1, bytes_needed, fp) == bytes_needed)
	bytes = bytes_needed;

	entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
	}
	fclose(fp);
	if (entropy_available > 0)
	return entropy_available;

	bytes_needed = rand_pool_bytes_needed(pool, 8 /entropy_per_byte/);
	}
	}
	# endif

	# ifdef OPENSSL_RAND_SEED_RDTSC
	entropy_available = rand_acquire_entropy_from_tsc(pool);
	if (entropy_available > 0)
	return entropy_available;
	# endif

	# ifdef OPENSSL_RAND_SEED_RDCPU
	entropy_available = rand_acquire_entropy_from_cpu(pool);
	if (entropy_available > 0)
	return entropy_available;
	# endif

	# ifdef OPENSSL_RAND_SEED_EGD
	bytes_needed = rand_pool_bytes_needed(pool, 8 /entropy_per_byte/);
	if (bytes_needed > 0) {
	static const char *paths[] = { DEVRANDOM_EGD, NULL };
	int i;

	for (i = 0; paths[i] != NULL; i++) {
	buffer = rand_pool_add_begin(pool, bytes_needed);
	if (buffer != NULL) {
	size_t bytes = 0;
	int num = RAND_query_egd_bytes(paths[i],
	buffer, (int)bytes_needed);
	if (num == (int)bytes_needed)
	bytes = bytes_needed;

	entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes);
	}
	if (entropy_available > 0)
	return entropy_available;
	}
	}
	# endif

	return rand_pool_entropy_available(pool);
	# endif
	}
	# endif

	#endif