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Groups > linux.kernel > #1543330
| From | David Laight <David.Laight@ACULAB.COM> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | RE: [PATCH v5 3/4] secure_seq: use SipHash in place of MD5 |
| Date | 2016-12-16 11:10 +0100 |
| Message-ID | <sOXCF-29N-3@gated-at.bofh.it> (permalink) |
| References | <sOKYN-1X6-3@gated-at.bofh.it> <sOKYP-1X6-63@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Jason A. Donenfeld
> Sent: 15 December 2016 20:30
> This gives a clear speed and security improvement. Siphash is both
> faster and is more solid crypto than the aging MD5.
>
> Rather than manually filling MD5 buffers, for IPv6, we simply create
> a layout by a simple anonymous struct, for which gcc generates
> rather efficient code. For IPv4, we pass the values directly to the
> short input convenience functions.
...
> diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
> index 88a8e429fc3e..c80583bf3213 100644
...
> + const struct {
> + struct in6_addr saddr;
> + struct in6_addr daddr;
> + __be16 sport;
> + __be16 dport;
> + u32 padding;
> + } __aligned(SIPHASH_ALIGNMENT) combined = {
> + .saddr = *(struct in6_addr *)saddr,
> + .daddr = *(struct in6_addr *)daddr,
> + .sport = sport,
> + .dport = dport
> + };
I think you should explicitly initialise the 'padding'.
It can do no harm and makes it obvious that it is necessary.
You are still putting over-aligned data on stack.
You only need to align it to the alignment of u64 (not the size of u64).
If an on-stack item has a stronger alignment requirement than the stack
the gcc has to generate two stack frames for the function.
If you assign to each field (instead of using initialisers) then you
can get the alignment by making the first member an anonymous union
of in6_addr and u64.
Oh - and wait a bit longer between revisions.
David
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[PATCH v5 0/4] The SipHash Patchset "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-15 21:40 +0100
[PATCH v5 4/4] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-15 21:40 +0100
[PATCH v5 3/4] secure_seq: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-15 21:40 +0100
RE: [PATCH v5 3/4] secure_seq: use SipHash in place of MD5 David Laight <David.Laight@ACULAB.COM> - 2016-12-16 11:10 +0100
Re: [PATCH v5 3/4] secure_seq: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 17:00 +0100
[PATCH v5 2/4] siphash: add Nu{32,64} helpers "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-15 21:50 +0100
RE: [PATCH v5 2/4] siphash: add Nu{32,64} helpers David Laight <David.Laight@ACULAB.COM> - 2016-12-16 11:50 +0100
RE: [PATCH v5 2/4] siphash: add Nu{32,64} helpers "George Spelvin" <linux@sciencehorizons.net> - 2016-12-16 16:50 +0100
[PATCH v6 4/5] md5: remove from lib and only live in crypto "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
[PATCH v6 2/5] secure_seq: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
[PATCH v6 5/5] syncookies: use SipHash in place of SHA1 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
[PATCH v6 0/5] The SipHash Patchset "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
[PATCH v6 3/5] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
Re: [PATCH v6 3/5] random: use SipHash in place of MD5 Andy Lutomirski <luto@amacapital.net> - 2016-12-16 22:40 +0100
[PATCH v6 1/5] siphash: add cryptographically secure PRF "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 04:10 +0100
[PATCH v7 0/6] The SipHash Patchset "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
[PATCH v7 6/6] siphash: implement HalfSipHash1-3 for hash tables "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
Re: [PATCH v7 6/6] siphash: implement HalfSipHash1-3 for hash tables Andi Kleen <ak@linux.intel.com> - 2016-12-22 01:50 +0100
[PATCH v7 5/6] syncookies: use SipHash in place of SHA1 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
[PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:20 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Andy Lutomirski <luto@amacapital.net> - 2016-12-22 01:00 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 03:10 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Andy Lutomirski <luto@amacapital.net> - 2016-12-22 03:20 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 03:50 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 04:20 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Theodore Ts'o <tytso@mit.edu> - 2016-12-22 06:50 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 07:10 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Theodore Ts'o <tytso@mit.edu> - 2016-12-22 17:00 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 17:20 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Theodore Ts'o <tytso@mit.edu> - 2016-12-22 17:40 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 17:40 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 13:50 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 14:20 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 16:10 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 16:20 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 16:30 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 16:40 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 16:50 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 17:00 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 17:00 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Theodore Ts'o <tytso@mit.edu> - 2016-12-22 17:00 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-22 19:10 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 19:20 +0100
Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5 Theodore Ts'o <tytso@mit.edu> - 2016-12-22 21:00 +0100
Re: [PATCH v7 3/6] random: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 03:40 +0100
[PATCH v7 4/6] md5: remove from lib and only live in crypto "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
[PATCH v7 2/6] secure_seq: use SipHash in place of MD5 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
[PATCH v7 1/6] siphash: add cryptographically secure PRF "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-22 00:10 +0100
Re: [PATCH v7 1/6] siphash: add cryptographically secure PRF Stephen Hemminger <stephen@networkplumber.org> - 2016-12-22 02:50 +0100
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