/* * $Id: mt19937db.c,v 12.9 2008/03/12 19:23:38 mbrey Exp $ */ #include "db_config.h" #include "db_int.h" #include "dbinc/crypto.h" #include "dbinc/hmac.h" /* A C-program for MT19937: Integer version (1999/10/28) */ /* genrand() generates one pseudorandom unsigned integer (32bit) */ /* which is uniformly distributed among 0 to 2^32-1 for each */ /* call. sgenrand(seed) sets initial values to the working area */ /* of 624 words. Before genrand(), sgenrand(seed) must be */ /* called once. (seed is any 32-bit integer.) */ /* Coded by Takuji Nishimura, considering the suggestions by */ /* Topher Cooper and Marc Rieffel in July-Aug. 1997. */ /* This library is free software under the Artistic license: */ /* see the file COPYING distributed together with this code. */ /* For the verification of the code, its output sequence file */ /* mt19937int.out is attached (2001/4/2) */ /* Copyright (C) 1997, 1999 Makoto Matsumoto and Takuji Nishimura. */ /* Any feedback is very welcome. For any question, comments, */ /* see http://www.math.keio.ac.jp/matumoto/emt.html or email */ /* matumoto@math.keio.ac.jp */ /* REFERENCE */ /* M. Matsumoto and T. Nishimura, */ /* "Mersenne Twister: A 623-Dimensionally Equidistributed Uniform */ /* Pseudo-Random Number Generator", */ /* ACM Transactions on Modeling and Computer Simulation, */ /* Vol. 8, No. 1, January 1998, pp 3--30. */ /* Period parameters */ #define N 624 #define M 397 #define MATRIX_A 0x9908b0df /* constant vector a */ #define UPPER_MASK 0x80000000 /* most significant w-r bits */ #define LOWER_MASK 0x7fffffff /* least significant r bits */ /* Tempering parameters */ #define TEMPERING_MASK_B 0x9d2c5680 #define TEMPERING_MASK_C 0xefc60000 #define TEMPERING_SHIFT_U(y) (y >> 11) #define TEMPERING_SHIFT_S(y) (y << 7) #define TEMPERING_SHIFT_T(y) (y << 15) #define TEMPERING_SHIFT_L(y) (y >> 18) static void __db_sgenrand __P((unsigned long, unsigned long *, int *)); #ifdef NOT_USED static void __db_lsgenrand __P((unsigned long *, unsigned long *, int *)); #endif static unsigned long __db_genrand __P((ENV *)); /* * __db_generate_iv -- * Generate an initialization vector (IV) * * PUBLIC: int __db_generate_iv __P((ENV *, u_int32_t *)); */ int __db_generate_iv(env, iv) ENV *env; u_int32_t *iv; { int i, n, ret; ret = 0; n = DB_IV_BYTES / sizeof(u_int32_t); MUTEX_LOCK(env, env->mtx_mt); if (env->mt == NULL) { if ((ret = __os_calloc(env, 1, N*sizeof(unsigned long), &env->mt)) != 0) return (ret); /* mti==N+1 means mt[N] is not initialized */ env->mti = N + 1; } for (i = 0; i < n; i++) { /* * We do not allow 0. If we get one just try again. */ do { iv[i] = (u_int32_t)__db_genrand(env); } while (iv[i] == 0); } MUTEX_UNLOCK(env, env->mtx_mt); return (0); } /* Initializing the array with a seed */ static void __db_sgenrand(seed, mt, mtip) unsigned long seed; unsigned long mt[]; int *mtip; { int i; DB_ASSERT(NULL, seed != 0); for (i=0;i<N;i++) { mt[i] = seed & 0xffff0000; seed = 69069 * seed + 1; mt[i] |= (seed & 0xffff0000) >> 16; seed = 69069 * seed + 1; } *mtip = N; } #ifdef NOT_USED /* Initialization by "sgenrand()" is an example. Theoretically, */ /* there are 2^19937-1 possible states as an intial state. */ /* This function allows to choose any of 2^19937-1 ones. */ /* Essential bits in "seed_array[]" is following 19937 bits: */ /* (seed_array[0]&UPPER_MASK), seed_array[1], ..., seed_array[N-1]. */ /* (seed_array[0]&LOWER_MASK) is discarded. */ /* Theoretically, */ /* (seed_array[0]&UPPER_MASK), seed_array[1], ..., seed_array[N-1] */ /* can take any values except all zeros. */ static void __db_lsgenrand(seed_array, mt, mtip) unsigned long seed_array[]; unsigned long mt[]; int *mtip; /* the length of seed_array[] must be at least N */ { int i; for (i=0;i<N;i++) mt[i] = seed_array[i]; *mtip=N; } #endif static unsigned long __db_genrand(env) ENV *env; { db_timespec ts; unsigned long y; static unsigned long mag01[2]={0x0, MATRIX_A}; /* mag01[x] = x * MATRIX_A for x=0,1 */ u_int32_t seed; /* * We are called with ENV->mtx_mt locked. */ if (env->mti >= N) { /* generate N words at one time */ int kk; if (env->mti == N+1) { /* if sgenrand() has not been called, */ /* * Seed the generator with the hashed time. The __db_mac * function will return 4 bytes if we don't send in a key. */ do { __os_gettime(env, &ts, 1); __db_chksum(NULL, (u_int8_t *)&ts.tv_sec, sizeof(ts.tv_sec), NULL, (u_int8_t *)&seed); } while (seed == 0); __db_sgenrand((unsigned long)seed, env->mt, &env->mti); } for (kk=0;kk<N-M;kk++) { y = (env->mt[kk]&UPPER_MASK)|(env->mt[kk+1]&LOWER_MASK); env->mt[kk] = env->mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1]; } for (;kk<N-1;kk++) { y = (env->mt[kk]&UPPER_MASK)|(env->mt[kk+1]&LOWER_MASK); env->mt[kk] = env->mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1]; } y = (env->mt[N-1]&UPPER_MASK)|(env->mt[0]&LOWER_MASK); env->mt[N-1] = env->mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1]; env->mti = 0; } y = env->mt[env->mti++]; y ^= TEMPERING_SHIFT_U(y); y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B; y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C; y ^= TEMPERING_SHIFT_L(y); return y; }