zfs-builds-mm/zfs-2.0.0-rc6/module/icp/algs/skein/skein_port.h
2020-11-15 11:35:49 +01:00

116 lines
3.4 KiB
C

/*
* Platform-specific definitions for Skein hash function.
*
* Source code author: Doug Whiting, 2008.
*
* This algorithm and source code is released to the public domain.
*
* Many thanks to Brian Gladman for his portable header files.
*
* To port Skein to an "unsupported" platform, change the definitions
* in this file appropriately.
*/
/* Copyright 2013 Doug Whiting. This code is released to the public domain. */
#ifndef _SKEIN_PORT_H_
#define _SKEIN_PORT_H_
#include <sys/types.h> /* get integer type definitions */
#ifndef RotL_64
#define RotL_64(x, N) (((x) << (N)) | ((x) >> (64 - (N))))
#endif
/*
* Skein is "natively" little-endian (unlike SHA-xxx), for optimal
* performance on x86 CPUs. The Skein code requires the following
* definitions for dealing with endianness:
*
* SKEIN_NEED_SWAP: 0 for little-endian, 1 for big-endian
* Skein_Put64_LSB_First
* Skein_Get64_LSB_First
* Skein_Swap64
*
* If SKEIN_NEED_SWAP is defined at compile time, it is used here
* along with the portable versions of Put64/Get64/Swap64, which
* are slow in general.
*
* Otherwise, an "auto-detect" of endianness is attempted below.
* If the default handling doesn't work well, the user may insert
* platform-specific code instead (e.g., for big-endian CPUs).
*
*/
#ifndef SKEIN_NEED_SWAP /* compile-time "override" for endianness? */
#include <sys/isa_defs.h> /* get endianness selection */
#if defined(_ZFS_BIG_ENDIAN)
/* here for big-endian CPUs */
#define SKEIN_NEED_SWAP (1)
#else
/* here for x86 and x86-64 CPUs (and other detected little-endian CPUs) */
#define SKEIN_NEED_SWAP (0)
#define Skein_Put64_LSB_First(dst08, src64, bCnt) bcopy(src64, dst08, bCnt)
#define Skein_Get64_LSB_First(dst64, src08, wCnt) \
bcopy(src08, dst64, 8 * (wCnt))
#endif
#endif /* ifndef SKEIN_NEED_SWAP */
/*
* Provide any definitions still needed.
*/
#ifndef Skein_Swap64 /* swap for big-endian, nop for little-endian */
#if SKEIN_NEED_SWAP
#define Skein_Swap64(w64) \
(((((uint64_t)(w64)) & 0xFF) << 56) | \
(((((uint64_t)(w64)) >> 8) & 0xFF) << 48) | \
(((((uint64_t)(w64)) >> 16) & 0xFF) << 40) | \
(((((uint64_t)(w64)) >> 24) & 0xFF) << 32) | \
(((((uint64_t)(w64)) >> 32) & 0xFF) << 24) | \
(((((uint64_t)(w64)) >> 40) & 0xFF) << 16) | \
(((((uint64_t)(w64)) >> 48) & 0xFF) << 8) | \
(((((uint64_t)(w64)) >> 56) & 0xFF)))
#else
#define Skein_Swap64(w64) (w64)
#endif
#endif /* ifndef Skein_Swap64 */
#ifndef Skein_Put64_LSB_First
static inline void
Skein_Put64_LSB_First(uint8_t *dst, const uint64_t *src, size_t bCnt)
{
/*
* this version is fully portable (big-endian or little-endian),
* but slow
*/
size_t n;
for (n = 0; n < bCnt; n++)
dst[n] = (uint8_t)(src[n >> 3] >> (8 * (n & 7)));
}
#endif /* ifndef Skein_Put64_LSB_First */
#ifndef Skein_Get64_LSB_First
static inline void
Skein_Get64_LSB_First(uint64_t *dst, const uint8_t *src, size_t wCnt)
{
/*
* this version is fully portable (big-endian or little-endian),
* but slow
*/
size_t n;
for (n = 0; n < 8 * wCnt; n += 8)
dst[n / 8] = (((uint64_t)src[n])) +
(((uint64_t)src[n + 1]) << 8) +
(((uint64_t)src[n + 2]) << 16) +
(((uint64_t)src[n + 3]) << 24) +
(((uint64_t)src[n + 4]) << 32) +
(((uint64_t)src[n + 5]) << 40) +
(((uint64_t)src[n + 6]) << 48) +
(((uint64_t)src[n + 7]) << 56);
}
#endif /* ifndef Skein_Get64_LSB_First */
#endif /* _SKEIN_PORT_H_ */