Re: [PATCH net-next v5 12/20] zinc: BLAKE2s generic C implementation and selftest
From: Eric Biggers <ebiggers@kernel.org>
Date: 2018-09-19 00:41:40
Also in:
linux-crypto, lkml
On Tue, Sep 18, 2018 at 06:16:38PM +0200, Jason A. Donenfeld wrote:
quoted hunk ↗ jump to hunk
The C implementation was originally based on Samuel Neves' public domain reference implementation but has since been heavily modified for the kernel. We're able to do compile-time optimizations by moving some scaffolding around the final function into the header file. Information: https://blake2.net/ Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Samuel Neves <redacted> Cc: Andy Lutomirski <luto@kernel.org> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jean-Philippe Aumasson <redacted> --- include/zinc/blake2s.h | 95 ++ lib/zinc/Kconfig | 3 + lib/zinc/Makefile | 3 + lib/zinc/blake2s/blake2s.c | 301 +++++ lib/zinc/selftest/blake2s.h | 2095 +++++++++++++++++++++++++++++++++++ 5 files changed, 2497 insertions(+) create mode 100644 include/zinc/blake2s.h create mode 100644 lib/zinc/blake2s/blake2s.c create mode 100644 lib/zinc/selftest/blake2s.hdiff --git a/include/zinc/blake2s.h b/include/zinc/blake2s.h new file mode 100644 index 000000000000..951281596274 --- /dev/null +++ b/include/zinc/blake2s.h@@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: MIT + * + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#ifndef _ZINC_BLAKE2S_H +#define _ZINC_BLAKE2S_H + +#include <linux/types.h> +#include <linux/kernel.h> +#include <crypto/algapi.h> + +enum blake2s_lengths { + BLAKE2S_BLOCKBYTES = 64, + BLAKE2S_OUTBYTES = 32, + BLAKE2S_KEYBYTES = 32 +}; + +struct blake2s_state { + u32 h[8]; + u32 t[2]; + u32 f[2]; + u8 buf[BLAKE2S_BLOCKBYTES]; + size_t buflen; + u8 last_node; +}; + +void blake2s_init(struct blake2s_state *state, const size_t outlen); +void blake2s_init_key(struct blake2s_state *state, const size_t outlen, + const void *key, const size_t keylen); +void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen); +void __blake2s_final(struct blake2s_state *state); +static inline void blake2s_final(struct blake2s_state *state, u8 *out, + const size_t outlen) +{ + int i; + +#ifdef DEBUG + BUG_ON(!out || !outlen || outlen > BLAKE2S_OUTBYTES); +#endif + __blake2s_final(state); + + if (__builtin_constant_p(outlen) && !(outlen % sizeof(u32))) { + if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || + IS_ALIGNED((unsigned long)out, __alignof__(u32))) { + __le32 *outwords = (__le32 *)out; + + for (i = 0; i < outlen / sizeof(u32); ++i) + outwords[i] = cpu_to_le32(state->h[i]); + } else { + __le32 buffer[BLAKE2S_OUTBYTES];
This buffer is 4 times too long.
+
+ for (i = 0; i < outlen / sizeof(u32); ++i)
+ buffer[i] = cpu_to_le32(state->h[i]);
+ memcpy(out, buffer, outlen);
+ memzero_explicit(buffer, sizeof(buffer));
+ }
+ } else {
+ u8 buffer[BLAKE2S_OUTBYTES] __aligned(__alignof__(u32));
+ __le32 *outwords = (__le32 *)buffer;
+
+ for (i = 0; i < 8; ++i)
+ outwords[i] = cpu_to_le32(state->h[i]);
+ memcpy(out, buffer, outlen);
+ memzero_explicit(buffer, sizeof(buffer));
+ }
+
+ memzero_explicit(state, sizeof(*state));
+}
Or how about something much simpler:
static inline void blake2s_final(struct blake2s_state *state, u8 *out,
const size_t outlen)
{
#ifdef DEBUG
BUG_ON(!out || !outlen || outlen > BLAKE2S_OUTBYTES);
#endif
__blake2s_final(state);
cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
memcpy(out, state->h, outlen);
memzero_explicit(state, sizeof(*state));
}