module/icp/algs/skein/skein_port.h

   1 /*
   2  * Platform-specific definitions for Skein hash function.
   3  *
   4  * Source code author: Doug Whiting, 2008.
   5  *
   6  * This algorithm and source code is released to the public domain.
   7  *
   8  * Many thanks to Brian Gladman for his portable header files.
   9  *
  10  * To port Skein to an "unsupported" platform, change the definitions
  11  * in this file appropriately.
  12  */
  13 /* Copyright 2013 Doug Whiting. This code is released to the public domain. */
  14
  15 #ifndef _SKEIN_PORT_H_
  16 #define _SKEIN_PORT_H_
  17
  18 #include <sys/types.h>  /* get integer type definitions */
  19
  20 #ifndef RotL_64
  21 #define RotL_64(x, N)   (((x) << (N)) | ((x) >> (64 - (N))))
  22 #endif
  23
  24 /*
  25  * Skein is "natively" little-endian (unlike SHA-xxx), for optimal
  26  * performance on x86 CPUs. The Skein code requires the following
  27  * definitions for dealing with endianness:
  28  *
  29  *    SKEIN_NEED_SWAP:  0 for little-endian, 1 for big-endian
  30  *    Skein_Put64_LSB_First
  31  *    Skein_Get64_LSB_First
  32  *    Skein_Swap64
  33  *
  34  * If SKEIN_NEED_SWAP is defined at compile time, it is used here
  35  * along with the portable versions of Put64/Get64/Swap64, which
  36  * are slow in general.
  37  *
  38  * Otherwise, an "auto-detect" of endianness is attempted below.
  39  * If the default handling doesn't work well, the user may insert
  40  * platform-specific code instead (e.g., for big-endian CPUs).
  41  *
  42  */
  43 #ifndef SKEIN_NEED_SWAP         /* compile-time "override" for endianness? */
  44
  45 #include <sys/isa_defs.h>       /* get endianness selection */
  46
  47 #if     defined(_ZFS_BIG_ENDIAN)
  48 /* here for big-endian CPUs */
  49 #define SKEIN_NEED_SWAP   (1)
  50 #else
  51 /* here for x86 and x86-64 CPUs (and other detected little-endian CPUs) */
  52 #define SKEIN_NEED_SWAP   (0)
  53 #define Skein_Put64_LSB_First(dst08, src64, bCnt) memcpy(dst08, src64, bCnt)
  54 #define Skein_Get64_LSB_First(dst64, src08, wCnt) \
  55         memcpy(dst64, src08, 8 * (wCnt))
  56 #endif
  57
  58 #endif                          /* ifndef SKEIN_NEED_SWAP */
  59
  60 /*
  61  * Provide any definitions still needed.
  62  */
  63 #ifndef Skein_Swap64    /* swap for big-endian, nop for little-endian */
  64 #if     SKEIN_NEED_SWAP
  65 #define Skein_Swap64(w64)                               \
  66         (((((uint64_t)(w64)) & 0xFF) << 56) |           \
  67         (((((uint64_t)(w64)) >> 8) & 0xFF) << 48) |     \
  68         (((((uint64_t)(w64)) >> 16) & 0xFF) << 40) |    \
  69         (((((uint64_t)(w64)) >> 24) & 0xFF) << 32) |    \
  70         (((((uint64_t)(w64)) >> 32) & 0xFF) << 24) |    \
  71         (((((uint64_t)(w64)) >> 40) & 0xFF) << 16) |    \
  72         (((((uint64_t)(w64)) >> 48) & 0xFF) << 8) |     \
  73         (((((uint64_t)(w64)) >> 56) & 0xFF)))
  74 #else
  75 #define Skein_Swap64(w64)  (w64)
  76 #endif
  77 #endif                          /* ifndef Skein_Swap64 */
  78
  79 #ifndef Skein_Put64_LSB_First
  80 static inline void
  81 Skein_Put64_LSB_First(uint8_t *dst, const uint64_t *src, size_t bCnt)
  82 {
  83         /*
  84          * this version is fully portable (big-endian or little-endian),
  85          * but slow
  86          */
  87         size_t n;
  88
  89         for (n = 0; n < bCnt; n++)
  90                 dst[n] = (uint8_t)(src[n >> 3] >> (8 * (n & 7)));
  91 }
  92 #endif                          /* ifndef Skein_Put64_LSB_First */
  93
  94 #ifndef Skein_Get64_LSB_First
  95 static inline void
  96 Skein_Get64_LSB_First(uint64_t *dst, const uint8_t *src, size_t wCnt)
  97 {
  98         /*
  99          * this version is fully portable (big-endian or little-endian),
 100          * but slow
 101          */
 102         size_t n;
 103
 104         for (n = 0; n < 8 * wCnt; n += 8)
 105                 dst[n / 8] = (((uint64_t)src[n])) +
 106                     (((uint64_t)src[n + 1]) << 8) +
 107                     (((uint64_t)src[n + 2]) << 16) +
 108                     (((uint64_t)src[n + 3]) << 24) +
 109                     (((uint64_t)src[n + 4]) << 32) +
 110                     (((uint64_t)src[n + 5]) << 40) +
 111                     (((uint64_t)src[n + 6]) << 48) +
 112                     (((uint64_t)src[n + 7]) << 56);
 113 }
 114 #endif                          /* ifndef Skein_Get64_LSB_First */
 115
 116 #endif  /* _SKEIN_PORT_H_ */