Commit 679ce0ac authored Jun 16, 2007 by Matt Mackall Committed by Linus Torvalds Jun 16, 2007

random: fix output buffer folding



(As reported by linux@horizon.com)

Folding is done to minimize the theoretical possibility of systematic
weakness in the particular bits of the SHA1 hash output.  The result of
this bug is that 16 out of 80 bits are un-folded.  Without a major new
vulnerability being found in SHA1, this is harmless, but still worth
fixing.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: <linux@horizon.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 39a27902

drivers/char/random.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -794,7 +794,7 @@ static void extract_buf(struct entropy_store r, __u8 out)

		buf[0] ^= buf[3];
		buf[1] ^= buf[4];
		buf[0] ^= rol32(buf[3], 16);
		buf[2] ^= rol32(buf[2], 16);
		memcpy(out, buf, EXTRACT_SIZE);
		memset(buf, 0, sizeof(buf));
		}

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