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diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
--- a/sys/dev/random/random_harvestq.c
+++ b/sys/dev/random/random_harvestq.c
@@ -478,6 +478,7 @@
struct health_test_softc *ht;
ht = &healthtest[source];
+ memset(ht, 0, sizeof(*ht));
KASSERT(ht->ht_state == INIT,
("%s: health test state is %d for source %d",
__func__, ht->ht_state, source));
@@ -532,12 +533,22 @@
};
const int error_rate = 34;
- if (min_entropy == 0)
- min_entropy = 1;
- else if (min_entropy < 0 || min_entropy >= nitems(apt_cutoffs)) {
+ if (min_entropy == 0) {
+ /*
+ * For environmental sources, the main source of entropy is the
+ * associated timecounter value. Since these sources can be
+ * influenced by unprivileged users, we conservatively use a
+ * min-entropy estimate of 1 bit per sample. For "pure"
+ * sources, we assume 8 bits per sample, as such sources provide
+ * a variable amount of data per read and in particular might
+ * only provide a single byte at a time.
+ */
+ min_entropy = source >= RANDOM_PURE_START ? 8 : 1;
+ } else if (min_entropy < 0 || min_entropy >= nitems(apt_cutoffs)) {
panic("invalid min_entropy %d for %s", min_entropy,
random_source_descr[source]);
}
+
ht->ht_rct_limit = 1 + howmany(error_rate, min_entropy);
ht->ht_apt_cutoff = apt_cutoffs[min_entropy];
}
@@ -707,7 +718,7 @@
RANDOM_HARVEST_INIT_LOCK();
harvest_context.hc_active_buf = 0;
- for (int i = 0; i < ENTROPYSOURCE; i++)
+ for (int i = RANDOM_START; i <= RANDOM_ENVIRONMENTAL_END; i++)
random_healthtest_init(i, 0);
}
SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_init, NULL);
@@ -901,6 +912,8 @@
printf("random: registering fast source %s\n", rsource->rs_ident);
+ random_healthtest_init(rsource->rs_source, rsource->rs_min_entropy);
+
RANDOM_HARVEST_LOCK();
hc_source_mask |= (1 << rsource->rs_source);
CK_LIST_INSERT_HEAD(&source_list, rrs, rrs_entries);
diff --git a/sys/dev/random/randomdev.h b/sys/dev/random/randomdev.h
--- a/sys/dev/random/randomdev.h
+++ b/sys/dev/random/randomdev.h
@@ -103,6 +103,7 @@
const char *rs_ident;
enum random_entropy_source rs_source;
random_source_read_t *rs_read;
+ int rs_min_entropy;
};
void random_source_register(const struct random_source *);

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