/*
* Copyright 1995-2016 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 <stdio.h>
#define USE_SOCKETS
#include "e_os.h"
#include "internal/cryptlib.h"
#include <openssl/rand.h>
#include "rand_lcl.h"
#if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI))
# include <sys/types.h>
# include <sys/time.h>
# include <sys/times.h>
# include <sys/stat.h>
# include <fcntl.h>
# include <unistd.h>
# include <time.h>
# if defined(OPENSSL_SYS_LINUX) /* should actually be available virtually
* everywhere */
# include <poll.h>
# endif
# include <limits.h>
# ifndef FD_SETSIZE
# define FD_SETSIZE (8*sizeof(fd_set))
# endif
# if defined(OPENSSL_SYS_VOS)
/*
* 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 this code 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.
*
* As a precaution, we generate 4 times the minimum required amount of seed
* data.
*/
int RAND_poll(void)
{
short int code;
gid_t curr_gid;
pid_t curr_pid;
uid_t curr_uid;
int i, k;
struct timespec ts;
unsigned char v;
# ifdef OPENSSL_SYS_VOS_HPPA
long duration;
extern void s$sleep(long *_duration, short int *_code);
# else
# ifdef OPENSSL_SYS_VOS_IA32
long long duration;
extern void s$sleep2(long long *_duration, short int *_code);
# else
# error "Unsupported Platform."
# endif /* OPENSSL_SYS_VOS_IA32 */
# endif /* OPENSSL_SYS_VOS_HPPA */
/*
* Seed with the gid, pid, and uid, to ensure *some* variation between
* different processes.
*/
curr_gid = getgid();
RAND_add(&curr_gid, sizeof(curr_gid), 1);
curr_gid = 0;
curr_pid = getpid();
RAND_add(&curr_pid, sizeof(curr_pid), 1);
curr_pid = 0;
curr_uid = getuid();
RAND_add(&curr_uid, sizeof(curr_uid), 1);
curr_uid = 0;
for (i = 0; i < (ENTROPY_NEEDED * 4); 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$sleep(&duration, &code);
# else
# ifdef OPENSSL_SYS_VOS_IA32
/* sleep for 1/65536 of a second (15 us). */
duration = 1;
s$sleep2(&duration, &code);
# endif /* OPENSSL_SYS_VOS_IA32 */
# endif /* OPENSSL_SYS_VOS_HPPA */
/* get wall clock time. */
clock_gettime(CLOCK_REALTIME, &ts);
/* take 8 bits */
v = (unsigned char)(ts.tv_nsec % 256);
RAND_add(&v, sizeof(v), 1);
v = 0;
}
return 1;
}
# elif defined __OpenBSD__
int RAND_poll(void)
{
u_int32_t rnd = 0, i;
unsigned char buf[ENTROPY_NEEDED];
for (i = 0; i < sizeof(buf); i++) {
if (i % 4 == 0)
rnd = arc4random();
buf[i] = rnd;
rnd >>= 8;
}
RAND_add(buf, sizeof(buf), ENTROPY_NEEDED);
OPENSSL_cleanse(buf, sizeof(buf));
return 1;
}
# else /* !defined(__OpenBSD__) */
int RAND_poll(void)
{
unsigned long l;
pid_t curr_pid = getpid();
# if defined(DEVRANDOM) || (!defined(OPENSS_NO_EGD) && defined(DEVRANDOM_EGD))
unsigned char tmpbuf[ENTROPY_NEEDED];
int n = 0;
# endif
# ifdef DEVRANDOM
static const char *randomfiles[] = { DEVRANDOM };
struct stat randomstats[OSSL_NELEM(randomfiles)];
int fd;
unsigned int i;
# endif
# if !defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD)
static const char *egdsockets[] = { DEVRANDOM_EGD, NULL };
const char **egdsocket = NULL;
# endif
# ifdef DEVRANDOM
memset(randomstats, 0, sizeof(randomstats));
/*
* Use a random entropy pool device. Linux, FreeBSD and OpenBSD have
* this. Use /dev/urandom if you can as /dev/random may block if it runs
* out of random entries.
*/
for (i = 0; (i < OSSL_NELEM(randomfiles)) && (n < ENTROPY_NEEDED); i++) {
if ((fd = open(randomfiles[i], O_RDONLY
# ifdef O_NONBLOCK
| O_NONBLOCK
# endif
# ifdef O_BINARY
| O_BINARY
# endif
# ifdef O_NOCTTY /* If it happens to be a TTY (god forbid), do
* not make it our controlling tty */
| O_NOCTTY
# endif
)) >= 0) {
int usec = 10 * 1000; /* spend 10ms on each file */
int r;
unsigned int j;
struct stat *st = &randomstats[i];
/*
* Avoid using same input... Used to be O_NOFOLLOW above, but
* it's not universally appropriate...
*/
if (fstat(fd, st) != 0) {
close(fd);
continue;
}
for (j = 0; j < i; j++) {
if (randomstats[j].st_ino == st->st_ino &&
randomstats[j].st_dev == st->st_dev)
break;
}
if (j < i) {
close(fd);
continue;
}
do {
int try_read = 0;
# if defined(OPENSSL_SYS_LINUX)
/* use poll() */
struct pollfd pset;
pset.fd = fd;
pset.events = POLLIN;
pset.revents = 0;
if (poll(&pset, 1, usec / 1000) < 0)
usec = 0;
else
try_read = (pset.revents & POLLIN) != 0;
# else
/* use select() */
fd_set fset;
struct timeval t;
t.tv_sec = 0;
t.tv_usec = usec;
if (FD_SETSIZE > 0 && (unsigned)fd >= FD_SETSIZE) {
/*
* can't use select, so just try to read once anyway
*/
try_read = 1;
} else {
FD_ZERO(&fset);
FD_SET(fd, &fset);
if (select(fd + 1, &fset, NULL, NULL, &t) >= 0) {
usec = t.tv_usec;
if (FD_ISSET(fd, &fset))
try_read = 1;
} else
usec = 0;
}
# endif
if (try_read) {
r = read(fd, (unsigned char *)tmpbuf + n,
ENTROPY_NEEDED - n);
if (r > 0)
n += r;
} else
r = -1;
/*
* Some Unixen will update t in select(), some won't. For
* those who won't, or if we didn't use select() in the first
* place, give up here, otherwise, we will do this once again
* for the remaining time.
*/
if (usec == 10 * 1000)
usec = 0;
}
while ((r > 0 ||
(errno == EINTR || errno == EAGAIN)) && usec != 0
&& n < ENTROPY_NEEDED);
close(fd);
}
}
# endif /* defined(DEVRANDOM) */
# if !defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD)
/*
* Use an EGD socket to read entropy from an EGD or PRNGD entropy
* collecting daemon.
*/
for (egdsocket = egdsockets; *egdsocket && n < ENTROPY_NEEDED;
egdsocket++) {
int r;
r = RAND_query_egd_bytes(*egdsocket, (unsigned char *)tmpbuf + n,
ENTROPY_NEEDED - n);
if (r > 0)
n += r;
}
# endif /* defined(DEVRANDOM_EGD) */
# if defined(DEVRANDOM) || (!defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD))
if (n > 0) {
RAND_add(tmpbuf, sizeof(tmpbuf), (double)n);
OPENSSL_cleanse(tmpbuf, n);
}
# endif
/* put in some default random data, we need more than just this */
l = curr_pid;
RAND_add(&l, sizeof(l), 0.0);
l = getuid();
RAND_add(&l, sizeof(l), 0.0);
l = time(NULL);
RAND_add(&l, sizeof(l), 0.0);
# if defined(DEVRANDOM) || (!defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD))
return 1;
# else
return 0;
# endif
}
# endif /* defined(__OpenBSD__) */
#endif /* !(defined(OPENSSL_SYS_WINDOWS) ||
* defined(OPENSSL_SYS_WIN32) ||
* defined(OPENSSL_SYS_VMS) ||
* defined(OPENSSL_SYS_VXWORKS) */
#if defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)
int RAND_poll(void)
{
return 0;
}
#endif
