random123

Counter-based Random Number Generators
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ars.h (7067B)


      1 /*
      2 Copyright 2010-2011, D. E. Shaw Research.
      3 All rights reserved.
      4 
      5 Redistribution and use in source and binary forms, with or without
      6 modification, are permitted provided that the following conditions are
      7 met:
      8 
      9 * Redistributions of source code must retain the above copyright
     10   notice, this list of conditions, and the following disclaimer.
     11 
     12 * Redistributions in binary form must reproduce the above copyright
     13   notice, this list of conditions, and the following disclaimer in the
     14   documentation and/or other materials provided with the distribution.
     15 
     16 * Neither the name of D. E. Shaw Research nor the names of its
     17   contributors may be used to endorse or promote products derived from
     18   this software without specific prior written permission.
     19 
     20 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     22 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     23 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     24 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     25 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     26 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     30 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31 */
     32 #ifndef __Random123_ars_dot_hpp__
     33 #define __Random123_ars_dot_hpp__
     34 
     35 #include "features/compilerfeatures.h"
     36 #include "array.h"
     37 
     38 #if R123_USE_AES_NI
     39 
     40 #ifndef ARS1xm128i_DEFAULT_ROUNDS
     41 #define ARS1xm128i_DEFAULT_ROUNDS 7
     42 #endif
     43 
     44 /** @ingroup AESNI */
     45 enum r123_enum_ars1xm128i {ars1xm128i_rounds = ARS1xm128i_DEFAULT_ROUNDS};
     46 
     47 /* ARS1xm128i with Weyl keys.  Fast, and Crush-resistant, but NOT CRYPTO. */
     48 /** @ingroup AESNI */
     49 typedef struct r123array1xm128i ars1xm128i_ctr_t;
     50 /** @ingroup AESNI */
     51 typedef struct r123array1xm128i ars1xm128i_key_t;
     52 /** @ingroup AESNI */
     53 typedef struct r123array1xm128i ars1xm128i_ukey_t;
     54 /** @ingroup AESNI */
     55 R123_STATIC_INLINE ars1xm128i_key_t ars1xm128ikeyinit(ars1xm128i_ukey_t uk) { return uk; }
     56 /** @ingroup AESNI */
     57 R123_STATIC_INLINE ars1xm128i_ctr_t ars1xm128i_R(unsigned int Nrounds, ars1xm128i_ctr_t in, ars1xm128i_key_t k){
     58     __m128i kweyl = _mm_set_epi64x(R123_64BIT(0xBB67AE8584CAA73B), /* sqrt(3) - 1.0 */
     59                                    R123_64BIT(0x9E3779B97F4A7C15)); /* golden ratio */
     60     /* N.B.  the aesenc instructions do the xor *after*
     61     // so if we want to follow the AES pattern, we
     62     // have to do the initial xor explicitly */
     63     __m128i kk = k.v[0].m;
     64     __m128i v = _mm_xor_si128(in.v[0].m, kk);
     65     ars1xm128i_ctr_t ret;
     66     R123_ASSERT(Nrounds<=10);
     67     if( Nrounds>1 ){
     68         kk = _mm_add_epi64(kk, kweyl);
     69         v = _mm_aesenc_si128(v, kk);
     70     }
     71     if( Nrounds>2 ){
     72         kk = _mm_add_epi64(kk, kweyl);
     73         v = _mm_aesenc_si128(v, kk);
     74     }
     75     if( Nrounds>3 ){
     76         kk = _mm_add_epi64(kk, kweyl);
     77         v = _mm_aesenc_si128(v, kk);
     78     }
     79     if( Nrounds>4 ){
     80         kk = _mm_add_epi64(kk, kweyl);
     81         v = _mm_aesenc_si128(v, kk);
     82     }
     83     if( Nrounds>5 ){
     84         kk = _mm_add_epi64(kk, kweyl);
     85         v = _mm_aesenc_si128(v, kk);
     86     }
     87     if( Nrounds>6 ){
     88         kk = _mm_add_epi64(kk, kweyl);
     89         v = _mm_aesenc_si128(v, kk);
     90     }
     91     if( Nrounds>7 ){
     92         kk = _mm_add_epi64(kk, kweyl);
     93         v = _mm_aesenc_si128(v, kk);
     94     }
     95     if( Nrounds>8 ){
     96         kk = _mm_add_epi64(kk, kweyl);
     97         v = _mm_aesenc_si128(v, kk);
     98     }
     99     if( Nrounds>9 ){
    100         kk = _mm_add_epi64(kk, kweyl);
    101         v = _mm_aesenc_si128(v, kk);
    102     }
    103     kk = _mm_add_epi64(kk, kweyl);
    104     v = _mm_aesenclast_si128(v, kk);
    105     ret.v[0].m = v;
    106     return ret;
    107 }
    108 
    109 /** @def ars1xm128i
    110 @ingroup AESNI
    111 The ars1mx128i macro provides a C API interface to the @ref AESNI "ARS" CBRNG with the default number of rounds i.e. \c ars1xm128i_rounds **/
    112 #define ars1xm128i(c,k) ars1xm128i_R(ars1xm128i_rounds, c, k)
    113 
    114 /** @ingroup AESNI */
    115 typedef struct r123array4x32 ars4x32_ctr_t;
    116 /** @ingroup AESNI */
    117 typedef struct r123array4x32 ars4x32_key_t;
    118 /** @ingroup AESNI */
    119 typedef struct r123array4x32 ars4x32_ukey_t;
    120 /** @ingroup AESNI */
    121 enum r123_enum_ars4x32 {ars4x32_rounds = ARS1xm128i_DEFAULT_ROUNDS};
    122 /** @ingroup AESNI */
    123 R123_STATIC_INLINE ars4x32_key_t ars4x32keyinit(ars4x32_ukey_t uk) { return uk; }
    124 /** @ingroup AESNI */
    125 R123_STATIC_INLINE ars4x32_ctr_t ars4x32_R(unsigned int Nrounds, ars4x32_ctr_t c, ars4x32_key_t k){
    126     ars1xm128i_ctr_t c128;
    127     ars1xm128i_key_t k128;
    128     c128.v[0].m = _mm_set_epi32(c.v[3], c.v[2], c.v[1], c.v[0]);
    129     k128.v[0].m = _mm_set_epi32(k.v[3], k.v[2], k.v[1], k.v[0]);
    130     c128 = ars1xm128i_R(Nrounds, c128, k128);
    131     _mm_storeu_si128((__m128i*)&c.v[0], c128.v[0].m);
    132     return c;
    133 }
    134 
    135 /** @def ars4x32
    136 @ingroup AESNI
    137 The ars4x32 macro provides a C API interface to the @ref AESNI "ARS" CBRNG with the default number of rounds i.e. \c ars4x32_rounds **/
    138 #define ars4x32(c,k) ars4x32_R(ars4x32_rounds, c, k)
    139 
    140 #ifdef __cplusplus
    141 namespace r123{
    142 /** 
    143 @ingroup AESNI
    144 
    145 ARS1xm128i_R exports the member functions, typedefs and operator overloads required by a @ref CBRNG class.
    146 
    147 ARS1xm128i uses the crypotgraphic AES round function, but a @b non-cryptographc key schedule
    148 to save time and space.
    149 
    150 ARS1xm128i is only available when the feature-test macro R123_USE_AES_NI is true, which
    151 should occur only when the compiler is configured to generate AES-NI instructions (or
    152 when defaults are overridden by compile-time, compiler-command-line options).
    153 
    154 The template argument, ROUNDS, is the number of times the ARS round
    155 functions will be applied.
    156 
    157 As of September 2011, the authors know of no statistical flaws with
    158 ROUNDS=5 or more.
    159 
    160 @class ARS1xm128i_R
    161 
    162 */
    163 template<unsigned int ROUNDS>
    164 struct ARS1xm128i_R{
    165     typedef ars1xm128i_ctr_t ctr_type;
    166     typedef ars1xm128i_key_t key_type;
    167     typedef ars1xm128i_key_t ukey_type;
    168     static const unsigned int rounds=ROUNDS;
    169     R123_FORCE_INLINE(ctr_type operator()(ctr_type ctr, key_type key) const){
    170         return ars1xm128i_R(ROUNDS, ctr, key);
    171     }
    172 };
    173 
    174 /** @class ARS4x32_R
    175     @ingroup AESNI
    176 */
    177 
    178 template<unsigned int ROUNDS>
    179 struct ARS4x32_R{
    180     typedef ars4x32_ctr_t ctr_type;
    181     typedef ars4x32_key_t key_type;
    182     typedef ars4x32_key_t ukey_type;
    183     static const unsigned int rounds=ROUNDS;
    184     R123_FORCE_INLINE(ctr_type operator()(ctr_type ctr, key_type key) const){
    185         return ars4x32_R(ROUNDS, ctr, key);
    186     }
    187 };
    188 /**
    189 @ingroup AESNI
    190 
    191 @class ARS1xm128i_R
    192   ARS1xm128i is equivalent to ARS1xm128i_R<7>.    With 7 rounds,
    193   the ARS1xm128i CBRNG  has a considerable safety margin over the minimum number
    194   of rounds with no known statistical flaws, but still has excellent
    195   performance. */
    196 typedef ARS1xm128i_R<ars1xm128i_rounds> ARS1xm128i;
    197 typedef ARS4x32_R<ars4x32_rounds> ARS4x32;
    198 } // namespace r123
    199 
    200 #endif /* __cplusplus */
    201 
    202 #endif /* R123_USE_AES_NI */
    203 
    204 #endif