/*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
- * Licensed under the OpenSSL license (the "License"). You may not use
+ * Licensed under the Apache License 2.0 (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
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
#include "e_os.h"
+#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/rand.h>
-#include "rand_lcl.h"
+#include <openssl/crypto.h>
+#include "rand_local.h"
+#include "crypto/rand.h"
+#include <stdio.h>
+#include "internal/dso.h"
-#if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI))
+#ifdef __linux
+# include <sys/syscall.h>
+# ifdef DEVRANDOM_WAIT
+# include <sys/shm.h>
+# include <sys/utsname.h>
+# endif
+#endif
+#if (defined(__FreeBSD__) || defined(__NetBSD__)) && !defined(OPENSSL_SYS_UEFI)
+# include <sys/types.h>
+# include <sys/sysctl.h>
+# include <sys/param.h>
+#endif
+#if defined(__OpenBSD__)
+# include <sys/param.h>
+#endif
+#if (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) \
+ || defined(__DJGPP__)
# 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))
+# include <sys/time.h>
+
+static uint64_t get_time_stamp(void);
+static uint64_t get_timer_bits(void);
+
+/* Macro to convert two thirty two bit values into a sixty four bit one */
+# define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b))
+
+/*
+ * Check for the existence and support of POSIX timers. The standard
+ * says that the _POSIX_TIMERS macro will have a positive value if they
+ * are available.
+ *
+ * However, we want an additional constraint: that the timer support does
+ * not require an extra library dependency. Early versions of glibc
+ * require -lrt to be specified on the link line to access the timers,
+ * so this needs to be checked for.
+ *
+ * It is worse because some libraries define __GLIBC__ but don't
+ * support the version testing macro (e.g. uClibc). This means
+ * an extra check is needed.
+ *
+ * The final condition is:
+ * "have posix timers and either not glibc or glibc without -lrt"
+ *
+ * The nested #if sequences are required to avoid using a parameterised
+ * macro that might be undefined.
+ */
+# undef OSSL_POSIX_TIMER_OKAY
+# if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0
+# if defined(__GLIBC__)
+# if defined(__GLIBC_PREREQ)
+# if __GLIBC_PREREQ(2, 17)
+# define OSSL_POSIX_TIMER_OKAY
+# endif
+# endif
+# else
+# define OSSL_POSIX_TIMER_OKAY
+# endif
# endif
+#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
+ || defined(__DJGPP__) */
+
+#if defined(OPENSSL_RAND_SEED_NONE)
+/* none means none. this simplifies the following logic */
+# undef OPENSSL_RAND_SEED_OS
+# undef OPENSSL_RAND_SEED_GETRANDOM
+# undef OPENSSL_RAND_SEED_LIBRANDOM
+# undef OPENSSL_RAND_SEED_DEVRANDOM
+# undef OPENSSL_RAND_SEED_RDTSC
+# undef OPENSSL_RAND_SEED_RDCPU
+# undef OPENSSL_RAND_SEED_EGD
+#endif
+
+#if defined(OPENSSL_SYS_UEFI) && !defined(OPENSSL_RAND_SEED_NONE)
+# error "UEFI only supports 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 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.
+ * 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 generate 4 times the minimum required amount of seed
- * data.
+ * As a precaution, we assume only 2 bits of entropy per byte.
*/
-
-int RAND_poll(void)
+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$sleep(long *_duration, short int *_code);
# else
-# ifdef OPENSSL_SYS_VOS_IA32
long long duration;
extern void s$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;
+# endif
- curr_uid = getuid();
- RAND_add(&curr_uid, sizeof curr_uid, 1);
- curr_uid = 0;
+ bytes_needed = rand_pool_bytes_needed(pool, 4 /*entropy_factor*/);
- for (i = 0; i < (ENTROPY_NEEDED * 4); i++) {
+ for (i = 0; i < bytes_needed; i++) {
/*
* burn some cpu; hope for interrupts, cache collisions, bus
* interference, etc.
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 */
+# endif
- /* get wall clock time. */
+ /* Get wall clock time, take 8 bits. */
clock_gettime(CLOCK_REALTIME, &ts);
-
- /* take 8 bits */
- v = (unsigned char)(ts.tv_nsec % 256);
- RAND_add(&v, sizeof v, 1);
- v = 0;
+ v = (unsigned char)(ts.tv_nsec & 0xFF);
+ rand_pool_add(pool, arg, &v, sizeof(v) , 2);
}
- return 1;
+ return rand_pool_entropy_available(pool);
}
-# 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;
+void rand_pool_cleanup(void)
+{
}
-# else /* !defined(__OpenBSD__) */
-int RAND_poll(void)
+
+void rand_pool_keep_random_devices_open(int keep)
{
- 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;
+}
+
+# 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
-# ifdef DEVRANDOM
- static const char *randomfiles[] = { DEVRANDOM };
- struct stat randomstats[OSSL_NELEM(randomfiles)];
- int fd;
- unsigned int i;
+
+# 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_GETRANDOM
+# define OPENSSL_RAND_SEED_DEVRANDOM
# endif
-# if !defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD)
- static const char *egdsockets[] = { DEVRANDOM_EGD, NULL };
- const char **egdsocket = NULL;
+
+# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
+# error "librandom not (yet) supported"
# endif
-# ifdef DEVRANDOM
- memset(randomstats, 0, sizeof(randomstats));
+# if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
+/*
+ * sysctl_random(): Use sysctl() to read a random number from the kernel
+ * Returns the number of bytes returned in buf on success, -1 on failure.
+ */
+static ssize_t sysctl_random(char *buf, size_t buflen)
+{
+ int mib[2];
+ size_t done = 0;
+ size_t len;
+
/*
- * 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.
+ * Note: sign conversion between size_t and ssize_t is safe even
+ * without a range check, see comment in syscall_random()
*/
- 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
+ /*
+ * On FreeBSD old implementations returned longs, newer versions support
+ * variable sizes up to 256 byte. The code below would not work properly
+ * when the sysctl returns long and we want to request something not a
+ * multiple of longs, which should never be the case.
+ */
+#if defined(__FreeBSD__)
+ if (!ossl_assert(buflen % sizeof(long) == 0)) {
+ errno = EINVAL;
+ return -1;
+ }
+#endif
+
+ /*
+ * On NetBSD before 4.0 KERN_ARND was an alias for KERN_URND, and only
+ * filled in an int, leaving the rest uninitialized. Since NetBSD 4.0
+ * it returns a variable number of bytes with the current version supporting
+ * up to 256 bytes.
+ * Just return an error on older NetBSD versions.
+ */
+#if defined(__NetBSD__) && __NetBSD_Version__ < 400000000
+ errno = ENOSYS;
+ return -1;
+#endif
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_ARND;
+
+ do {
+ len = buflen > 256 ? 256 : buflen;
+ if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
+ return done > 0 ? done : -1;
+ done += len;
+ buf += len;
+ buflen -= len;
+ } while (buflen > 0);
+
+ return done;
+}
+# endif
+
+# if defined(OPENSSL_RAND_SEED_GETRANDOM)
+
+# if defined(__linux) && !defined(__NR_getrandom)
+# if defined(__arm__)
+# define __NR_getrandom (__NR_SYSCALL_BASE+384)
+# elif defined(__i386__)
+# define __NR_getrandom 355
+# elif defined(__x86_64__)
+# if defined(__ILP32__)
+# define __NR_getrandom (__X32_SYSCALL_BIT + 318)
+# else
+# define __NR_getrandom 318
+# endif
+# elif defined(__xtensa__)
+# define __NR_getrandom 338
+# elif defined(__s390__) || defined(__s390x__)
+# define __NR_getrandom 349
+# elif defined(__bfin__)
+# define __NR_getrandom 389
+# elif defined(__powerpc__)
+# define __NR_getrandom 359
+# elif defined(__mips__) || defined(__mips64)
+# if _MIPS_SIM == _MIPS_SIM_ABI32
+# define __NR_getrandom (__NR_Linux + 353)
+# elif _MIPS_SIM == _MIPS_SIM_ABI64
+# define __NR_getrandom (__NR_Linux + 313)
+# elif _MIPS_SIM == _MIPS_SIM_NABI32
+# define __NR_getrandom (__NR_Linux + 317)
+# endif
+# elif defined(__hppa__)
+# define __NR_getrandom (__NR_Linux + 339)
+# elif defined(__sparc__)
+# define __NR_getrandom 347
+# elif defined(__ia64__)
+# define __NR_getrandom 1339
+# elif defined(__alpha__)
+# define __NR_getrandom 511
+# elif defined(__sh__)
+# if defined(__SH5__)
+# define __NR_getrandom 373
+# else
+# define __NR_getrandom 384
+# endif
+# elif defined(__avr32__)
+# define __NR_getrandom 317
+# elif defined(__microblaze__)
+# define __NR_getrandom 385
+# elif defined(__m68k__)
+# define __NR_getrandom 352
+# elif defined(__cris__)
+# define __NR_getrandom 356
+# elif defined(__aarch64__)
+# define __NR_getrandom 278
+# else /* generic */
+# define __NR_getrandom 278
+# endif
# endif
- )) >= 0) {
- int usec = 10 * 1000; /* spend 10ms on each file */
- int r;
- unsigned int j;
- struct stat *st = &randomstats[i];
+/*
+ * syscall_random(): Try to get random data using a system call
+ * returns the number of bytes returned in buf, or < 0 on error.
+ */
+static ssize_t syscall_random(void *buf, size_t buflen)
+{
+ /*
+ * Note: 'buflen' equals the size of the buffer which is used by the
+ * get_entropy() callback of the RAND_DRBG. It is roughly bounded by
+ *
+ * 2 * RAND_POOL_FACTOR * (RAND_DRBG_STRENGTH / 8) = 2^14
+ *
+ * which is way below the OSSL_SSIZE_MAX limit. Therefore sign conversion
+ * between size_t and ssize_t is safe even without a range check.
+ */
+
+ /*
+ * Do runtime detection to find getentropy().
+ *
+ * Known OSs that should support this:
+ * - Darwin since 16 (OSX 10.12, IOS 10.0).
+ * - Solaris since 11.3
+ * - OpenBSD since 5.6
+ * - Linux since 3.17 with glibc 2.25
+ * - FreeBSD since 12.0 (1200061)
+ */
+# if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__) && !defined(__hpux)
+ extern int getentropy(void *buffer, size_t length) __attribute__((weak));
+
+ if (getentropy != NULL)
+ return getentropy(buf, buflen) == 0 ? (ssize_t)buflen : -1;
+# elif !defined(FIPS_MODULE)
+ union {
+ void *p;
+ int (*f)(void *buffer, size_t length);
+ } p_getentropy;
+
+ /*
+ * We could cache the result of the lookup, but we normally don't
+ * call this function often.
+ */
+ ERR_set_mark();
+ p_getentropy.p = DSO_global_lookup("getentropy");
+ ERR_pop_to_mark();
+ if (p_getentropy.p != NULL)
+ return p_getentropy.f(buf, buflen) == 0 ? (ssize_t)buflen : -1;
+# endif
+
+ /* Linux supports this since version 3.17 */
+# if defined(__linux) && defined(__NR_getrandom)
+ return syscall(__NR_getrandom, buf, buflen, 0);
+# elif (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
+ return sysctl_random(buf, buflen);
+# else
+ errno = ENOSYS;
+ return -1;
+# endif
+}
+# endif /* defined(OPENSSL_RAND_SEED_GETRANDOM) */
+
+# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
+static const char *random_device_paths[] = { DEVRANDOM };
+static struct random_device {
+ int fd;
+ dev_t dev;
+ ino_t ino;
+ mode_t mode;
+ dev_t rdev;
+} random_devices[OSSL_NELEM(random_device_paths)];
+static int keep_random_devices_open = 1;
+
+# if defined(__linux) && defined(DEVRANDOM_WAIT) \
+ && defined(OPENSSL_RAND_SEED_GETRANDOM)
+static void *shm_addr;
+
+# if !defined(FIPS_MODULE)
+static void cleanup_shm(void)
+{
+ shmdt(shm_addr);
+}
+# endif
+
+/*
+ * Ensure that the system randomness source has been adequately seeded.
+ * This is done by having the first start of libcrypto, wait until the device
+ * /dev/random becomes able to supply a byte of entropy. Subsequent starts
+ * of the library and later reseedings do not need to do this.
+ */
+static int wait_random_seeded(void)
+{
+ static int seeded = OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID < 0;
+ static const int kernel_version[] = { DEVRANDOM_SAFE_KERNEL };
+ int kernel[2];
+ int shm_id, fd, r;
+ char c, *p;
+ struct utsname un;
+ fd_set fds;
+
+ if (!seeded) {
+ /* See if anything has created the global seeded indication */
+ if ((shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1, 0)) == -1) {
/*
- * Avoid using same input... Used to be O_NOFOLLOW above, but
- * it's not universally appropriate...
+ * Check the kernel's version and fail if it is too recent.
+ *
+ * Linux kernels from 4.8 onwards do not guarantee that
+ * /dev/urandom is properly seeded when /dev/random becomes
+ * readable. However, such kernels support the getentropy(2)
+ * system call and this should always succeed which renders
+ * this alternative but essentially identical source moot.
*/
- 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 (uname(&un) == 0) {
+ kernel[0] = atoi(un.release);
+ p = strchr(un.release, '.');
+ kernel[1] = p == NULL ? 0 : atoi(p + 1);
+ if (kernel[0] > kernel_version[0]
+ || (kernel[0] == kernel_version[0]
+ && kernel[1] >= kernel_version[1])) {
+ return 0;
+ }
}
- if (j < i) {
+ /* Open /dev/random and wait for it to be readable */
+ if ((fd = open(DEVRANDOM_WAIT, O_RDONLY)) != -1) {
+ if (DEVRANDM_WAIT_USE_SELECT && fd < FD_SETSIZE) {
+ FD_ZERO(&fds);
+ FD_SET(fd, &fds);
+ while ((r = select(fd + 1, &fds, NULL, NULL, NULL)) < 0
+ && errno == EINTR);
+ } else {
+ while ((r = read(fd, &c, 1)) < 0 && errno == EINTR);
+ }
close(fd);
- continue;
+ if (r == 1) {
+ seeded = 1;
+ /* Create the shared memory indicator */
+ shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1,
+ IPC_CREAT | S_IRUSR | S_IRGRP | S_IROTH);
+ }
}
+ }
+ if (shm_id != -1) {
+ seeded = 1;
+ /*
+ * Map the shared memory to prevent its premature destruction.
+ * If this call fails, it isn't a big problem.
+ */
+ shm_addr = shmat(shm_id, NULL, SHM_RDONLY);
+# ifndef FIPS_MODULE
+ /* TODO 3.0: The FIPS provider doesn't have OPENSSL_atexit */
+ if (shm_addr != (void *)-1)
+ OPENSSL_atexit(&cleanup_shm);
+# endif
+ }
+ }
+ return seeded;
+}
+# else /* defined __linux && DEVRANDOM_WAIT && OPENSSL_RAND_SEED_GETRANDOM */
+static int wait_random_seeded(void)
+{
+ return 1;
+}
+# endif
- do {
- int try_read = 0;
+/*
+ * Verify that the file descriptor associated with the random source is
+ * still valid. The rationale for doing this is the fact that it is not
+ * uncommon for daemons to close all open file handles when daemonizing.
+ * So the handle might have been closed or even reused for opening
+ * another file.
+ */
+static int check_random_device(struct random_device * rd)
+{
+ struct stat st;
+
+ return rd->fd != -1
+ && fstat(rd->fd, &st) != -1
+ && rd->dev == st.st_dev
+ && rd->ino == st.st_ino
+ && ((rd->mode ^ st.st_mode) & ~(S_IRWXU | S_IRWXG | S_IRWXO)) == 0
+ && rd->rdev == st.st_rdev;
+}
-# if defined(OPENSSL_SYS_LINUX)
- /* use poll() */
- struct pollfd pset;
+/*
+ * Open a random device if required and return its file descriptor or -1 on error
+ */
+static int get_random_device(size_t n)
+{
+ struct stat st;
+ struct random_device * rd = &random_devices[n];
+
+ /* reuse existing file descriptor if it is (still) valid */
+ if (check_random_device(rd))
+ return rd->fd;
+
+ /* open the random device ... */
+ if ((rd->fd = open(random_device_paths[n], O_RDONLY)) == -1)
+ return rd->fd;
+
+ /* ... and cache its relevant stat(2) data */
+ if (fstat(rd->fd, &st) != -1) {
+ rd->dev = st.st_dev;
+ rd->ino = st.st_ino;
+ rd->mode = st.st_mode;
+ rd->rdev = st.st_rdev;
+ } else {
+ close(rd->fd);
+ rd->fd = -1;
+ }
+
+ return rd->fd;
+}
+
+/*
+ * Close a random device making sure it is a random device
+ */
+static void close_random_device(size_t n)
+{
+ struct random_device * rd = &random_devices[n];
- pset.fd = fd;
- pset.events = POLLIN;
- pset.revents = 0;
+ if (check_random_device(rd))
+ close(rd->fd);
+ rd->fd = -1;
+}
- if (poll(&pset, 1, usec / 1000) < 0)
- usec = 0;
- else
- try_read = (pset.revents & POLLIN) != 0;
+int rand_pool_init(void)
+{
+ size_t i;
-# else
- /* use select() */
- fd_set fset;
- struct timeval t;
+ for (i = 0; i < OSSL_NELEM(random_devices); i++)
+ random_devices[i].fd = -1;
- t.tv_sec = 0;
- t.tv_usec = usec;
+ return 1;
+}
- 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;
- }
+void rand_pool_cleanup(void)
+{
+ size_t i;
+
+ for (i = 0; i < OSSL_NELEM(random_devices); i++)
+ close_random_device(i);
+}
+
+void rand_pool_keep_random_devices_open(int keep)
+{
+ if (!keep)
+ rand_pool_cleanup();
+
+ keep_random_devices_open = keep;
+}
+
+# else /* !defined(OPENSSL_RAND_SEED_DEVRANDOM) */
+
+int rand_pool_init(void)
+{
+ return 1;
+}
+
+void rand_pool_cleanup(void)
+{
+}
+
+void rand_pool_keep_random_devices_open(int keep)
+{
+}
+
+# endif /* defined(OPENSSL_RAND_SEED_DEVRANDOM) */
+
+/*
+ * 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)
+{
+# if defined(OPENSSL_RAND_SEED_NONE)
+ return rand_pool_entropy_available(pool);
+# else
+ size_t entropy_available;
+
+# if defined(OPENSSL_RAND_SEED_GETRANDOM)
+ {
+ size_t bytes_needed;
+ unsigned char *buffer;
+ ssize_t bytes;
+ /* Maximum allowed number of consecutive unsuccessful attempts */
+ int attempts = 3;
+
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ while (bytes_needed != 0 && attempts-- > 0) {
+ buffer = rand_pool_add_begin(pool, bytes_needed);
+ bytes = syscall_random(buffer, bytes_needed);
+ if (bytes > 0) {
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ bytes_needed -= bytes;
+ attempts = 3; /* reset counter after successful attempt */
+ } else if (bytes < 0 && errno != EINTR) {
+ break;
+ }
+ }
+ }
+ entropy_available = rand_pool_entropy_available(pool);
+ if (entropy_available > 0)
+ return entropy_available;
# 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;
+# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
+ {
+ /* Not yet implemented. */
+ }
+# endif
+
+# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
+ if (wait_random_seeded()) {
+ size_t bytes_needed;
+ unsigned char *buffer;
+ size_t i;
+
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ for (i = 0; bytes_needed > 0 && i < OSSL_NELEM(random_device_paths);
+ i++) {
+ ssize_t bytes = 0;
+ /* Maximum number of consecutive unsuccessful attempts */
+ int attempts = 3;
+ const int fd = get_random_device(i);
+
+ if (fd == -1)
+ continue;
+
+ while (bytes_needed != 0 && attempts-- > 0) {
+ buffer = rand_pool_add_begin(pool, bytes_needed);
+ bytes = read(fd, buffer, bytes_needed);
+
+ if (bytes > 0) {
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ bytes_needed -= bytes;
+ attempts = 3; /* reset counter on successful attempt */
+ } else if (bytes < 0 && errno != EINTR) {
+ break;
+ }
}
- while ((r > 0 ||
- (errno == EINTR || errno == EAGAIN)) && usec != 0
- && n < ENTROPY_NEEDED);
+ if (bytes < 0 || !keep_random_devices_open)
+ close_random_device(i);
- close(fd);
+ bytes_needed = rand_pool_bytes_needed(pool, 1);
}
+ entropy_available = rand_pool_entropy_available(pool);
+ if (entropy_available > 0)
+ return entropy_available;
}
-# endif /* defined(DEVRANDOM) */
+# endif
+
+# if defined(OPENSSL_RAND_SEED_RDTSC)
+ entropy_available = rand_acquire_entropy_from_tsc(pool);
+ if (entropy_available > 0)
+ return entropy_available;
+# endif
+
+# if defined(OPENSSL_RAND_SEED_RDCPU)
+ entropy_available = rand_acquire_entropy_from_cpu(pool);
+ if (entropy_available > 0)
+ return entropy_available;
+# endif
+
+# if defined(OPENSSL_RAND_SEED_EGD)
+ {
+ static const char *paths[] = { DEVRANDOM_EGD, NULL };
+ size_t bytes_needed;
+ unsigned char *buffer;
+ int i;
+
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ for (i = 0; bytes_needed > 0 && paths[i] != NULL; i++) {
+ size_t bytes = 0;
+ int num;
+
+ buffer = rand_pool_add_begin(pool, bytes_needed);
+ num = RAND_query_egd_bytes(paths[i],
+ buffer, (int)bytes_needed);
+ if (num == (int)bytes_needed)
+ bytes = bytes_needed;
+
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ bytes_needed = rand_pool_bytes_needed(pool, 1);
+ }
+ entropy_available = rand_pool_entropy_available(pool);
+ if (entropy_available > 0)
+ return entropy_available;
+ }
+# endif
+
+ return rand_pool_entropy_available(pool);
+# endif
+}
+# endif
+#endif
+
+#if (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) \
+ || defined(__DJGPP__)
+int rand_pool_add_nonce_data(RAND_POOL *pool)
+{
+ struct {
+ pid_t pid;
+ CRYPTO_THREAD_ID tid;
+ uint64_t time;
+ } data;
+
+ /* Erase the entire structure including any padding */
+ memset(&data, 0, sizeof(data));
-# if !defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD)
/*
- * Use an EGD socket to read entropy from an EGD or PRNGD entropy
- * collecting daemon.
+ * Add process id, thread id, and a high resolution timestamp to
+ * ensure that the nonce is unique with high probability for
+ * different process instances.
*/
+ data.pid = getpid();
+ data.tid = CRYPTO_THREAD_get_current_id();
+ data.time = get_time_stamp();
- for (egdsocket = egdsockets; *egdsocket && n < ENTROPY_NEEDED;
- egdsocket++) {
- int r;
+ return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
+}
- r = RAND_query_egd_bytes(*egdsocket, (unsigned char *)tmpbuf + n,
- ENTROPY_NEEDED - n);
- if (r > 0)
- n += r;
+int rand_pool_add_additional_data(RAND_POOL *pool)
+{
+ struct {
+ int fork_id;
+ CRYPTO_THREAD_ID tid;
+ uint64_t time;
+ } data;
+
+ /* Erase the entire structure including any padding */
+ memset(&data, 0, sizeof(data));
+
+ /*
+ * Add some noise from the thread id and a high resolution timer.
+ * The fork_id adds some extra fork-safety.
+ * The thread id adds a little randomness if the drbg is accessed
+ * concurrently (which is the case for the <master> drbg).
+ */
+ data.fork_id = openssl_get_fork_id();
+ data.tid = CRYPTO_THREAD_get_current_id();
+ data.time = get_timer_bits();
+
+ return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
+}
+
+
+/*
+ * Get the current time with the highest possible resolution
+ *
+ * The time stamp is added to the nonce, so it is optimized for not repeating.
+ * The current time is ideal for this purpose, provided the computer's clock
+ * is synchronized.
+ */
+static uint64_t get_time_stamp(void)
+{
+# if defined(OSSL_POSIX_TIMER_OKAY)
+ {
+ struct timespec ts;
+
+ if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
+ return TWO32TO64(ts.tv_sec, ts.tv_nsec);
}
-# endif /* defined(DEVRANDOM_EGD) */
+# endif
+# if defined(__unix__) \
+ || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
+ {
+ struct timeval tv;
-# if defined(DEVRANDOM) || (!defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD))
- if (n > 0) {
- RAND_add(tmpbuf, sizeof tmpbuf, (double)n);
- OPENSSL_cleanse(tmpbuf, n);
+ if (gettimeofday(&tv, NULL) == 0)
+ return TWO32TO64(tv.tv_sec, tv.tv_usec);
}
-# endif
+# endif
+ return time(NULL);
+}
- /* 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);
+/*
+ * Get an arbitrary timer value of the highest possible resolution
+ *
+ * The timer value is added as random noise to the additional data,
+ * which is not considered a trusted entropy sourec, so any result
+ * is acceptable.
+ */
+static uint64_t get_timer_bits(void)
+{
+ uint64_t res = OPENSSL_rdtsc();
- l = time(NULL);
- RAND_add(&l, sizeof(l), 0.0);
+ if (res != 0)
+ return res;
-# if defined(DEVRANDOM) || (!defined(OPENSSL_NO_EGD) && defined(DEVRANDOM_EGD))
- return 1;
+# if defined(__sun) || defined(__hpux)
+ return gethrtime();
+# elif defined(_AIX)
+ {
+ timebasestruct_t t;
+
+ read_wall_time(&t, TIMEBASE_SZ);
+ return TWO32TO64(t.tb_high, t.tb_low);
+ }
+# elif defined(OSSL_POSIX_TIMER_OKAY)
+ {
+ struct timespec ts;
+
+# ifdef CLOCK_BOOTTIME
+# define CLOCK_TYPE CLOCK_BOOTTIME
+# elif defined(_POSIX_MONOTONIC_CLOCK)
+# define CLOCK_TYPE CLOCK_MONOTONIC
# else
- return 0;
+# define CLOCK_TYPE CLOCK_REALTIME
# endif
-}
-# endif /* defined(__OpenBSD__) */
-#endif /* !(defined(OPENSSL_SYS_WINDOWS) ||
- * defined(OPENSSL_SYS_WIN32) ||
- * defined(OPENSSL_SYS_VMS) ||
- * defined(OPENSSL_SYS_VXWORKS) */
+ if (clock_gettime(CLOCK_TYPE, &ts) == 0)
+ return TWO32TO64(ts.tv_sec, ts.tv_nsec);
+ }
+# endif
+# if defined(__unix__) \
+ || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
+ {
+ struct timeval tv;
-#if defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)
-int RAND_poll(void)
-{
- return 0;
+ if (gettimeofday(&tv, NULL) == 0)
+ return TWO32TO64(tv.tv_sec, tv.tv_usec);
+ }
+# endif
+ return time(NULL);
}
-#endif
+#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
+ || defined(__DJGPP__) */
projects / openssl.git / blobdiff