+#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;