ab69c4858c
Chacha20 with a 256 bit key and 128 bit counter size is a good match for an AES256-ICM replacement. In userspace, Chacha20 is typically marginally slower than AES-ICM on machines with AESNI intrinsics, but typically much faster than AES on machines without special intrinsics. ChaCha20 does well on typical modern architectures with SIMD instructions, which includes most types of machines FreeBSD runs on. In the kernel, we can't (or don't) make use of AESNI intrinsics for random(4) anyway. So even on amd64, using Chacha provides a modest performance improvement in random device throughput today. This change makes the stream cipher used by random(4) configurable at boot time with the 'kern.random.use_chacha20_cipher' tunable. Very rough, non-scientific measurements at the /dev/random device, on a GENERIC-NODEBUG amd64 VM with 'pv', show a factor of 2.2x higher throughput for Chacha20 over the existing AES-ICM mode. Reviewed by: delphij, markm Approved by: secteam (delphij) Differential Revision: https://reviews.freebsd.org/D19475
68 lines
2.6 KiB
C
68 lines
2.6 KiB
C
/*-
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* Copyright (c) 2000-2015 Mark R V Murray
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef SYS_DEV_RANDOM_HASH_H_INCLUDED
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#define SYS_DEV_RANDOM_HASH_H_INCLUDED
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#include <crypto/chacha20/_chacha.h>
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#include <dev/random/uint128.h>
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/* Keys are formed from cipher blocks */
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#define RANDOM_KEYSIZE 32 /* (in bytes) == 256 bits */
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#define RANDOM_KEYSIZE_WORDS (RANDOM_KEYSIZE/sizeof(uint32_t))
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#define RANDOM_BLOCKSIZE 16 /* (in bytes) == 128 bits */
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#define RANDOM_BLOCKSIZE_WORDS (RANDOM_BLOCKSIZE/sizeof(uint32_t))
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#define RANDOM_KEYS_PER_BLOCK (RANDOM_KEYSIZE/RANDOM_BLOCKSIZE)
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/* The size of the zero block portion used to form H_d(m) */
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#define RANDOM_ZERO_BLOCKSIZE 64 /* (in bytes) == 512 zero bits */
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struct randomdev_hash {
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SHA256_CTX sha;
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};
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union randomdev_key {
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struct {
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keyInstance key; /* Key schedule */
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cipherInstance cipher; /* Rijndael internal */
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};
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struct chacha_ctx chacha;
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};
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extern bool fortuna_chachamode;
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void randomdev_hash_init(struct randomdev_hash *);
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void randomdev_hash_iterate(struct randomdev_hash *, const void *, size_t);
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void randomdev_hash_finish(struct randomdev_hash *, void *);
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void randomdev_encrypt_init(union randomdev_key *, const void *);
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void randomdev_keystream(union randomdev_key *context, uint128_t *, void *, u_int);
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void randomdev_getkey(union randomdev_key *, const void **, size_t *);
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#endif /* SYS_DEV_RANDOM_HASH_H_INCLUDED */
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