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authorTheodore Ts'o <tytso@mit.edu>2011-12-22 22:28:01 +0100
committerH. Peter Anvin <hpa@linux.intel.com>2012-01-16 20:18:21 +0100
commit3e88bdff1c65145f7ba297ccec69c774afe4c785 (patch)
tree2d01752cdd8a5b3f1cbcad3e0ef55d6f02696efd /drivers/char/random.c
parentrandom: Use arch_get_random_int instead of cycle counter if avail (diff)
downloadlinux-3e88bdff1c65145f7ba297ccec69c774afe4c785.tar.xz
linux-3e88bdff1c65145f7ba297ccec69c774afe4c785.zip
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>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 85da8740586b..30794779c523 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -965,6 +965,7 @@ EXPORT_SYMBOL(get_random_bytes);
*/
static void init_std_data(struct entropy_store *r)
{
+ int i;
ktime_t now;
unsigned long flags;
@@ -974,6 +975,11 @@ static void init_std_data(struct entropy_store *r)
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())));
}