Re: [PATCH, RFC 08/12] random: mix in architectural randomness earlier in extract_buf()

2013-09-22 Thread Theodore Ts'o
On Sun, Sep 22, 2013 at 09:11:58PM -0700, H. Peter Anvin wrote: > > This doesn't mix in across the entire width of the hash (my original > motivation for putting this at the end was to do it after the hash is > folded in half -- which is still believe is cryptographically dubious, > but please don

Re: [PATCH, RFC 08/12] random: mix in architectural randomness earlier in extract_buf()

2013-09-22 Thread H. Peter Anvin
On 09/22/2013 01:38 PM, Theodore Ts'o wrote: > Previously if CPU chip had a built-in random number generator (i.e., > RDRAND on newer x86 chips), we mixed it in at the very end of > extract_buf() using an XOR operation. > > We now mix it in right after the calculate a hash across the entire > pool

[PATCH, RFC 08/12] random: mix in architectural randomness earlier in extract_buf()

2013-09-22 Thread Theodore Ts'o
Previously if CPU chip had a built-in random number generator (i.e., RDRAND on newer x86 chips), we mixed it in at the very end of extract_buf() using an XOR operation. We now mix it in right after the calculate a hash across the entire pool. This has the advantage that any contribution of entrop