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 #include <sys/systm.h> /* for bcopy() */ 20 21 #ifndef RotL_64 22 #define RotL_64(x, N) (((x) << (N)) | ((x) >> (64 - (N)))) 23 #endif 24 25 /* 26 * Skein is "natively" little-endian (unlike SHA-xxx), for optimal 27 * performance on x86 CPUs. The Skein code requires the following 28 * definitions for dealing with endianness: 29 * 30 * SKEIN_NEED_SWAP: 0 for little-endian, 1 for big-endian 31 * Skein_Put64_LSB_First 32 * Skein_Get64_LSB_First 33 * Skein_Swap64 34 * 35 * If SKEIN_NEED_SWAP is defined at compile time, it is used here 36 * along with the portable versions of Put64/Get64/Swap64, which 37 * are slow in general. 38 * 39 * Otherwise, an "auto-detect" of endianness is attempted below. 40 * If the default handling doesn't work well, the user may insert 41 * platform-specific code instead (e.g., for big-endian CPUs). 42 * 43 */ 44 #ifndef SKEIN_NEED_SWAP /* compile-time "override" for endianness? */ 45 46 #include <sys/isa_defs.h> /* get endianness selection */ 47 48 #define PLATFORM_MUST_ALIGN _ALIGNMENT_REQUIRED 49 #if defined(_BIG_ENDIAN) 50 /* here for big-endian CPUs */ 51 #define SKEIN_NEED_SWAP (1) 52 #else 53 /* here for x86 and x86-64 CPUs (and other detected little-endian CPUs) */ 54 #define SKEIN_NEED_SWAP (0) 55 #if PLATFORM_MUST_ALIGN == 0 /* ok to use "fast" versions? */ 56 #define Skein_Put64_LSB_First(dst08, src64, bCnt) bcopy(src64, dst08, bCnt) 57 #define Skein_Get64_LSB_First(dst64, src08, wCnt) \ 58 bcopy(src08, dst64, 8 * (wCnt)) 59 #endif 60 #endif 61 62 #endif /* ifndef SKEIN_NEED_SWAP */ 63 64 /* 65 * Provide any definitions still needed. 66 */ 67 #ifndef Skein_Swap64 /* swap for big-endian, nop for little-endian */ 68 #if SKEIN_NEED_SWAP 69 #define Skein_Swap64(w64) \ 70 (((((uint64_t)(w64)) & 0xFF) << 56) | \ 71 (((((uint64_t)(w64)) >> 8) & 0xFF) << 48) | \ 72 (((((uint64_t)(w64)) >> 16) & 0xFF) << 40) | \ 73 (((((uint64_t)(w64)) >> 24) & 0xFF) << 32) | \ 74 (((((uint64_t)(w64)) >> 32) & 0xFF) << 24) | \ 75 (((((uint64_t)(w64)) >> 40) & 0xFF) << 16) | \ 76 (((((uint64_t)(w64)) >> 48) & 0xFF) << 8) | \ 77 (((((uint64_t)(w64)) >> 56) & 0xFF))) 78 #else 79 #define Skein_Swap64(w64) (w64) 80 #endif 81 #endif /* ifndef Skein_Swap64 */ 82 83 #ifndef Skein_Put64_LSB_First 84 void 85 Skein_Put64_LSB_First(uint8_t *dst, const uint64_t *src, size_t bCnt) 86 #ifdef SKEIN_PORT_CODE /* instantiate the function code here? */ 87 { 88 /* 89 * this version is fully portable (big-endian or little-endian), 90 * but slow 91 */ 92 size_t n; 93 94 for (n = 0; n < bCnt; n++) 95 dst[n] = (uint8_t)(src[n >> 3] >> (8 * (n & 7))); 96 } 97 #else 98 ; /* output only the function prototype */ 99 #endif 100 #endif /* ifndef Skein_Put64_LSB_First */ 101 102 #ifndef Skein_Get64_LSB_First 103 void 104 Skein_Get64_LSB_First(uint64_t *dst, const uint8_t *src, size_t wCnt) 105 #ifdef SKEIN_PORT_CODE /* instantiate the function code here? */ 106 { 107 /* 108 * this version is fully portable (big-endian or little-endian), 109 * but slow 110 */ 111 size_t n; 112 113 for (n = 0; n < 8 * wCnt; n += 8) 114 dst[n / 8] = (((uint64_t)src[n])) + 115 (((uint64_t)src[n + 1]) << 8) + 116 (((uint64_t)src[n + 2]) << 16) + 117 (((uint64_t)src[n + 3]) << 24) + 118 (((uint64_t)src[n + 4]) << 32) + 119 (((uint64_t)src[n + 5]) << 40) + 120 (((uint64_t)src[n + 6]) << 48) + 121 (((uint64_t)src[n + 7]) << 56); 122 } 123 #else 124 ; /* output only the function prototype */ 125 #endif 126 #endif /* ifndef Skein_Get64_LSB_First */ 127 128 #endif /* _SKEIN_PORT_H_ */ 129