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passt/siphash.h
David Gibson 020ff7a40e siphash: Remove stale prototypes
In fc8f0f8c ("siphash: Use incremental rather than all-at-once siphash
functions") we removed the older interface to the SipHash implementation,
which took fixed sized blocks of data.  However, we forgot to remove the
prototypes for those functions, so do that now.

Fixes: fc8f0f8c48 ("siphash: Use incremental rather than all-at-once siphash functions")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-06-19 14:55:42 +02:00

119 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: Stefano Brivio <sbrivio@redhat.com>
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* This is an implementation of the SipHash-2-4-64 functions needed for TCP
* initial sequence numbers and socket lookup table hash for IPv4 and IPv6, see:
*
* Aumasson, J.P. and Bernstein, D.J., 2012, December. SipHash: a fast
* short-input PRF. In International Conference on Cryptology in India
* (pp. 489-508). Springer, Berlin, Heidelberg.
*
* http://cr.yp.to/siphash/siphash-20120918.pdf
*
* This includes code from the reference SipHash implementation at
* https://github.com/veorq/SipHash/ originally licensed as follows:
*
* --
* SipHash reference C implementation
*
* Copyright (c) 2012-2021 Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
* Copyright (c) 2012-2014 Daniel J. Bernstein <djb@cr.yp.to>
*
* To the extent possible under law, the author(s) have dedicated all copyright
* and related and neighboring rights to this software to the public domain
* worldwide. This software is distributed without any warranty.
*
* You should have received a copy of the CC0 Public Domain Dedication along
* with this software. If not, see
* <http://creativecommons.org/publicdomain/zero/1.0/>.
* --
*
* and from the Linux kernel implementation (lib/siphash.c), originally licensed
* as follows:
*
* --
* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This file is provided under a dual BSD/GPLv2 license.
* --
*
*/
#ifndef SIPHASH_H
#define SIPHASH_H
/**
* struct siphash_state - Internal state of siphash calculation
*/
struct siphash_state {
uint64_t v[4];
};
#define SIPHASH_INIT(k) { { \
0x736f6d6570736575ULL ^ (k)[0], \
0x646f72616e646f6dULL ^ (k)[1], \
0x6c7967656e657261ULL ^ (k)[0], \
0x7465646279746573ULL ^ (k)[1] \
} }
/**
* sipround() - Perform rounds of SipHash scrambling
* @v: siphash state (4 x 64-bit integers)
* @n: Number of rounds to apply
*/
static inline void sipround(struct siphash_state *state, int n)
{
int i;
#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
for (i = 0; i < n; i++) {
state->v[0] += state->v[1];
state->v[1] = ROTL(state->v[1], 13) ^ state->v[0];
state->v[0] = ROTL(state->v[0], 32);
state->v[2] += state->v[3];
state->v[3] = ROTL(state->v[3], 16) ^ state->v[2];
state->v[0] += state->v[3];
state->v[3] = ROTL(state->v[3], 21) ^ state->v[0];
state->v[2] += state->v[1];
state->v[1] = ROTL(state->v[1], 17) ^ state->v[2];
state->v[2] = ROTL(state->v[2], 32);
}
#undef ROTL
}
/**
* siphash_feed() - Fold 64-bits of data into the hash state
* @v: siphash state (4 x 64-bit integers)
* @in: New value to fold into hash
*/
static inline void siphash_feed(struct siphash_state *state, uint64_t in)
{
state->v[3] ^= in;
sipround(state, 2);
state->v[0] ^= in;
}
/**
* siphash_final - Finalize SipHash calculations
* @v: siphash state (4 x 64-bit integers)
* @len: Total length of input data
* @tail: Final data for the hash (<= 7 bytes)
*/
static inline uint64_t siphash_final(struct siphash_state *state,
size_t len, uint64_t tail)
{
uint64_t b = (uint64_t)(len) << 56 | tail;
siphash_feed(state, b);
state->v[2] ^= 0xff;
sipround(state, 4);
return state->v[0] ^ state->v[1] ^ state->v[2] ^ state->v[3];
}
#endif /* SIPHASH_H */