/*
- * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * 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
* https://www.openssl.org/source/license.html
*/
+#define _GNU_SOURCE
#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>
+#include "internal/dso.h"
+#if defined(__linux)
+# include <sys/syscall.h>
+#endif
+#if defined(__FreeBSD__)
+# include <sys/types.h>
+# include <sys/sysctl.h>
+# include <sys/param.h>
+#endif
+#if defined(__OpenBSD__) || defined(__NetBSD__)
+# include <sys/param.h>
+#endif
+#ifdef OPENSSL_SYS_UNIX
+# include <sys/types.h>
+# include <unistd.h>
+# include <sys/time.h>
+
+static uint64_t get_time_stamp(void);
+static uint64_t get_timer_bits(void);
-#ifdef OPENSSL_RAND_SEED_GETRANDOM
-# include <linux/random.h>
+/* 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
+int syscall_random(void *buf, size_t buflen);
+
#if (defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) && \
!defined(OPENSSL_RAND_SEED_NONE)
# error "UEFI and VXWorks only support seeding NONE"
*
* As a precaution, we assume only 2 bits of entropy per byte.
*/
-size_t RAND_POOL_acquire_entropy(RAND_POOL *pool)
+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;
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*/);
+ bytes_needed = rand_pool_bytes_needed(pool, 4 /*entropy_factor*/);
for (i = 0; i < bytes_needed; i++) {
/*
/* 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);
+ rand_pool_add(pool, arg, &v, sizeof(v) , 2);
}
- return RAND_POOL_entropy_available(pool);
+ return rand_pool_entropy_available(pool);
}
# else
# error "Seeding uses urandom but DEVRANDOM is not configured"
# endif
+# if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
+# if __GLIBC_PREREQ(2, 25)
+# define OPENSSL_HAVE_GETRANDOM
+# endif
+# endif
+
+# if (defined(__FreeBSD__) && __FreeBSD_version >= 1200061)
+# define OPENSSL_HAVE_GETRANDOM
+# endif
+
+# if defined(OPENSSL_HAVE_GETRANDOM)
+# include <sys/random.h>
+# endif
+
# if defined(OPENSSL_RAND_SEED_OS)
-# if defined(DEVRANDOM)
-# define OPENSSL_RAND_SEED_DEVRANDOM
-# else
+# 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_RAND_SEED_LIBRANDOM)
# error "librandom not (yet) supported"
# endif
+# if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
+/*
+ * sysctl_random(): Use sysctl() to read a random number from the kernel
+ * Returns the size on success, 0 on failure.
+ */
+static size_t sysctl_random(char *buf, size_t buflen)
+{
+ int mib[2];
+ size_t done = 0;
+ size_t len;
+
+ /*
+ * 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 (!ossl_assert(buflen % sizeof(long) == 0))
+ return 0;
+
+ /*
+ * 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
+ return 0;
+#endif
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_ARND;
+
+ do {
+ len = buflen;
+ if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
+ return done;
+ done += len;
+ buf += len;
+ buflen -= len;
+ } while (buflen > 0);
+
+ return done;
+}
+# endif
+
+/*
+ * syscall_random(): Try to get random data using a system call
+ * returns the number of bytes returned in buf, or <= 0 on error.
+ */
+int syscall_random(void *buf, size_t buflen)
+{
+ union {
+ void *p;
+ int (*f)(void *buffer, size_t length);
+ } p_getentropy;
+
+ /*
+ * Do runtime detection to find getentropy().
+ *
+ * We could cache the result of the lookup, but we normally don't
+ * call this function often.
+ *
+ * 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)
+ */
+ p_getentropy.p = DSO_global_lookup("getentropy");
+ if (p_getentropy.p != NULL)
+ return p_getentropy.f(buf, buflen);
+
+# if defined(OPENSSL_HAVE_GETRANDOM)
+ return (int)getrandom(buf, buflen, 0);
+# endif
+
+ /* Linux supports this since version 3.17 */
+# if defined(__linux) && defined(SYS_getrandom)
+ return (int)syscall(SYS_getrandom, buf, buflen, 0);
+# endif
+
+# if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
+ return (int)sysctl_random(buf, buflen);
+# endif
+
+ return -1;
+}
+
/*
* Try the various seeding methods in turn, exit when successful.
*
* of input from the different entropy sources (trust, quality,
* possibility of blocking).
*/
-size_t RAND_POOL_acquire_entropy(RAND_POOL *pool)
+size_t rand_pool_acquire_entropy(RAND_POOL *pool)
{
# ifdef OPENSSL_RAND_SEED_NONE
- return RAND_POOL_entropy_available(pool);
+ 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);
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
+ buffer = rand_pool_add_begin(pool, bytes_needed);
if (buffer != NULL) {
size_t bytes = 0;
- if (getrandom(buffer, bytes_needed, 0) == (int)bytes_needed)
+ if (syscall_random(buffer, bytes_needed) == (int)bytes_needed)
bytes = bytes_needed;
- entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes);
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ entropy_available = rand_pool_entropy_available(pool);
}
if (entropy_available > 0)
return entropy_available;
# endif
# ifdef OPENSSL_RAND_SEED_DEVRANDOM
- bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
if (bytes_needed > 0) {
static const char *paths[] = { DEVRANDOM, NULL };
FILE *fp;
if ((fp = fopen(paths[i], "rb")) == NULL)
continue;
setbuf(fp, NULL);
- buffer = RAND_POOL_add_begin(pool, bytes_needed);
+ 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);
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ entropy_available = rand_pool_entropy_available(pool);
}
fclose(fp);
if (entropy_available > 0)
return entropy_available;
- bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
}
}
# endif
# endif
# ifdef OPENSSL_RAND_SEED_EGD
- bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+ bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
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);
+ buffer = rand_pool_add_begin(pool, bytes_needed);
if (buffer != NULL) {
size_t bytes = 0;
int num = RAND_query_egd_bytes(paths[i],
if (num == (int)bytes_needed)
bytes = bytes_needed;
- entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes);
+ rand_pool_add_end(pool, bytes, 8 * bytes);
+ entropy_available = rand_pool_entropy_available(pool);
}
if (entropy_available > 0)
return entropy_available;
}
# endif
- return RAND_POOL_entropy_available(pool);
+ return rand_pool_entropy_available(pool);
# endif
}
# endif
+#endif
+
+#ifdef OPENSSL_SYS_UNIX
+int rand_pool_add_nonce_data(RAND_POOL *pool)
+{
+ struct {
+ pid_t pid;
+ CRYPTO_THREAD_ID tid;
+ uint64_t time;
+ } data = { 0 };
+
+ /*
+ * Add process id, thread id, and a high resolution timestamp to
+ * ensure that the nonce is unique whith high probability for
+ * different process instances.
+ */
+ data.pid = getpid();
+ data.tid = CRYPTO_THREAD_get_current_id();
+ data.time = get_time_stamp();
+
+ return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
+}
+
+int rand_pool_add_additional_data(RAND_POOL *pool)
+{
+ struct {
+ CRYPTO_THREAD_ID tid;
+ uint64_t time;
+ } data = { 0 };
+
+ /*
+ * Add some noise from the thread id and a high resolution timer.
+ * The thread id adds a little randomness if the drbg is accessed
+ * concurrently (which is the case for the <master> drbg).
+ */
+ 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
+# if defined(__unix__) \
+ || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
+ {
+ struct timeval tv;
+
+ if (gettimeofday(&tv, NULL) == 0)
+ return TWO32TO64(tv.tv_sec, tv.tv_usec);
+ }
+# endif
+ return time(NULL);
+}
+
+/*
+ * 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();
+
+ if (res != 0)
+ return res;
+
+# 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
+# define CLOCK_TYPE CLOCK_REALTIME
+# endif
+
+ 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 (gettimeofday(&tv, NULL) == 0)
+ return TWO32TO64(tv.tv_sec, tv.tv_usec);
+ }
+# endif
+ return time(NULL);
+}
#endif
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