Messages in this thread Patch in this message | | | Date | Tue, 07 Aug 2012 04:28:07 +0100 | From | Ben Hutchings <> | Subject | [ 12/70] random: Use arch-specific RNG to initialize the entropy store |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Theodore Ts'o <tytso@mit.edu>
commit 3e88bdff1c65145f7ba297ccec69c774afe4c785 upstream.
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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/char/random.c | 6 ++++++ 1 file changed, 6 insertions(+)
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 @@ 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()))); }
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