From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Eric Biggers <ebiggers@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Netdev <netdev@vger.kernel.org>,
Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Samuel Neves <sneves@dei.uc.pt>,
Andrew Lutomirski <luto@kernel.org>,
Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Subject: Re: [PATCH net-next v5 03/20] zinc: ChaCha20 generic C implementation and selftest
Date: Wed, 19 Sep 2018 04:02:51 +0200 [thread overview]
Message-ID: <CAHmME9qOZEBNr0yndDWmfGMwuFSsN16n4KCDUSdHCPtCVe+Afw@mail.gmail.com> (raw)
In-Reply-To: <20180919010816.GD74746@gmail.com>
On Wed, Sep 19, 2018 at 3:08 AM Eric Biggers <ebiggers@kernel.org> wrote:
> Does this consistently perform as well as an implementation that organizes the
> operations such that the quarterrounds for all columns/diagonals are
> interleaved? As-is, there are tight dependencies in QUARTER_ROUND() (as well as
> in the existing chacha20_block() in lib/chacha20.c, for that matter), so we're
> heavily depending on the compiler to do the needed interleaving so as to not get
> potentially disastrous performance. Making it explicit could be a good idea.
It does perform as well, and the compiler outputs good code, even on
older compilers. Notably that's all a single statement (via the comma
operator).
> > +}
> > +
> > +static void chacha20_generic(u8 *out, const u8 *in, u32 len, const u32 key[8],
> > + const u32 counter[4])
> > +{
> > + __le32 buf[CHACHA20_BLOCK_WORDS];
> > + u32 x[] = {
> > + EXPAND_32_BYTE_K,
> > + key[0], key[1], key[2], key[3],
> > + key[4], key[5], key[6], key[7],
> > + counter[0], counter[1], counter[2], counter[3]
> > + };
> > +
> > + if (out != in)
> > + memmove(out, in, len);
> > +
> > + while (len >= CHACHA20_BLOCK_SIZE) {
> > + chacha20_block_generic(buf, x);
> > + crypto_xor(out, (u8 *)buf, CHACHA20_BLOCK_SIZE);
> > + len -= CHACHA20_BLOCK_SIZE;
> > + out += CHACHA20_BLOCK_SIZE;
> > + }
> > + if (len) {
> > + chacha20_block_generic(buf, x);
> > + crypto_xor(out, (u8 *)buf, len);
> > + }
> > +}
>
> If crypto_xor_cpy() is used instead of crypto_xor(), and 'in' is incremented
> along with 'out', then the memmove() is not needed.
Nice idea, thanks. Implemented.
Jason
next prev parent reply other threads:[~2018-09-19 2:03 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-18 16:16 [PATCH net-next v5 00/20] WireGuard: Secure Network Tunnel Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 01/20] asm: simd context helper API Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 02/20] zinc: introduce minimal cryptography library Jason A. Donenfeld
2018-09-20 15:41 ` Ard Biesheuvel
2018-09-20 16:01 ` Andy Lutomirski
2018-09-20 16:02 ` Arnd Bergmann
2018-09-21 0:11 ` Jason A. Donenfeld
2018-09-21 3:12 ` Andrew Lunn
2018-09-21 3:16 ` Jason A. Donenfeld
2018-09-21 3:23 ` Andy Lutomirski
2018-09-21 4:15 ` Jason A. Donenfeld
2018-09-21 4:30 ` Ard Biesheuvel
2018-09-21 4:32 ` Jason A. Donenfeld
2018-09-21 4:52 ` Andy Lutomirski
2018-09-22 16:11 ` Arnd Bergmann
2018-09-25 7:18 ` Arnd Bergmann
2018-09-25 14:29 ` Jason A. Donenfeld
2018-09-21 0:17 ` Jason A. Donenfeld
2018-09-25 10:25 ` Ard Biesheuvel
2018-09-25 14:44 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 03/20] zinc: ChaCha20 generic C implementation and selftest Jason A. Donenfeld
2018-09-19 1:08 ` Eric Biggers
2018-09-19 2:02 ` Jason A. Donenfeld [this message]
2018-09-18 16:16 ` [PATCH net-next v5 04/20] zinc: ChaCha20 x86_64 implementation Jason A. Donenfeld
2018-09-18 22:29 ` Thomas Gleixner
2018-09-19 2:14 ` Jason A. Donenfeld
2018-09-19 6:13 ` Thomas Gleixner
2018-09-19 11:33 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 05/20] zinc: ChaCha20 ARM and ARM64 implementations Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 06/20] zinc: ChaCha20 MIPS32r2 implementation Jason A. Donenfeld
2018-09-18 20:25 ` Paul Burton
2018-09-20 13:19 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 07/20] zinc: Poly1305 generic C implementations and selftest Jason A. Donenfeld
2018-09-19 0:50 ` Eric Biggers
2018-09-19 1:35 ` Jason A. Donenfeld
2018-09-19 4:13 ` Andy Lutomirski
2018-09-19 11:50 ` Jason A. Donenfeld
2018-09-19 12:26 ` Jason A. Donenfeld
2018-09-19 1:39 ` Jason A. Donenfeld
2018-09-19 1:41 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 08/20] zinc: Poly1305 x86_64 implementation Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 09/20] zinc: Poly1305 ARM and ARM64 implementations Jason A. Donenfeld
2018-09-18 22:55 ` Eric Biggers
2018-09-19 0:17 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 10/20] zinc: Poly1305 MIPS32r2 and MIPS64 implementations Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 11/20] zinc: ChaCha20Poly1305 construction and selftest Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 12/20] zinc: BLAKE2s generic C implementation " Jason A. Donenfeld
2018-09-19 0:41 ` Eric Biggers
2018-09-19 0:45 ` Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 13/20] zinc: BLAKE2s x86_64 implementation Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 14/20] zinc: Curve25519 generic C implementations and selftest Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 15/20] zinc: Curve25519 x86_64 implementation Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 16/20] zinc: Curve25519 ARM implementation Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 17/20] crypto: port Poly1305 to Zinc Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 18/20] crypto: port ChaCha20 " Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 19/20] security/keys: rewrite big_key crypto to use Zinc Jason A. Donenfeld
2018-09-18 16:16 ` [PATCH net-next v5 20/20] net: WireGuard secure network tunnel Jason A. Donenfeld
2018-09-18 23:34 ` Andrew Lunn
2018-09-19 2:04 ` Jason A. Donenfeld
2018-09-19 12:38 ` Andrew Lunn
2018-09-18 17:01 ` [PATCH net-next v5 19/20] security/keys: rewrite big_key crypto to use Zinc David Howells
2018-09-18 17:12 ` Jason A. Donenfeld
2018-09-18 18:28 ` [PATCH net-next v5 00/20] WireGuard: Secure Network Tunnel Ard Biesheuvel
2018-09-18 21:01 ` Jason A. Donenfeld
2018-09-19 17:21 ` Ard Biesheuvel
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