random: Use arch-specific RNG to initialize the entropy store
If there is an architecture-specific random number generator (such as
RDRAND for Intel architectures), use it to initialize /dev/random's
entropy stores. Even in the worst case, if RDRAND is something like
AES(NSA_KEY, counter++), it won't hurt, and it will definitely help
against any other adversaries.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 85da874..3079477 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -965,6 +965,7 @@
*/
static void init_std_data(struct entropy_store *r)
{
+ int i;
ktime_t now;
unsigned long flags;
@@ -974,6 +975,11 @@
now = ktime_get_real();
mix_pool_bytes(r, &now, sizeof(now));
+ for (i = r->poolinfo->poolwords; i; i--) {
+ if (!arch_get_random_long(&flags))
+ break;
+ mix_pool_bytes(r, &flags, sizeof(flags));
+ }
mix_pool_bytes(r, utsname(), sizeof(*(utsname())));
}