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>
This commit is contained in:
Matt Mackall 2007-06-16 10:16:11 -07:00 committed by Linus Torvalds
parent 39a2790266
commit 679ce0ace6
1 changed files with 1 additions and 1 deletions

View File

@ -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));
}