All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Theodore Ts'o" <tytso@mit.edu>
To: Linux Kernel Developers List <linux-kernel@vger.kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Subject: [PATCH] random: use arch-specific RNG to initialize the entropy store
Date: Thu, 22 Dec 2011 16:28:01 -0500	[thread overview]
Message-ID: <1324589281-31931-1-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <20111222210522.GG5041@thunk.org>

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>
---
 drivers/char/random.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 6035ab8..f10780a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -961,6 +961,7 @@ EXPORT_SYMBOL(get_random_bytes);
  */
 static void init_std_data(struct entropy_store *r)
 {
+	int i;
 	ktime_t now;
 	unsigned long flags;
 
@@ -970,6 +971,11 @@ 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())));
 }
 
-- 
1.7.8.11.gefc1f.dirty


           reply	other threads:[~2011-12-22 21:28 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20111222210522.GG5041@thunk.org>]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1324589281-31931-1-git-send-email-tytso@mit.edu \
    --to=tytso@mit.edu \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [PATCH] random: use arch-specific RNG to initialize the entropy store' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.