1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 3.01 of the PHP license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | https://www.php.net/license/3_01.txt |
9 | If you did not receive a copy of the PHP license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@php.net so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Authors: Sascha Schumann <sascha@schumann.cx> |
14 | Go Kudo <zeriyoshi@php.net> |
15 +----------------------------------------------------------------------+
16 */
17
18 #ifdef HAVE_CONFIG_H
19 # include "config.h"
20 #endif
21
22 #include "php.h"
23 #include "php_random.h"
24
25 #include "Zend/zend_exceptions.h"
26
27 /*
28 * combinedLCG() returns a pseudo random number in the range of (0, 1).
29 * The function combines two CGs with periods of
30 * 2^31 - 85 and 2^31 - 249. The period of this function
31 * is equal to the product of both primes.
32 */
33 #define MODMULT(a, b, c, m, s) q = s / a; s = b * (s - a * q) - c * q; if (s < 0) s += m
34
seed(php_random_status * status,uint64_t seed)35 static void seed(php_random_status *status, uint64_t seed)
36 {
37 php_random_status_state_combinedlcg *s = status->state;
38
39 s->state[0] = seed & 0xffffffffU;
40 s->state[1] = seed >> 32;
41 }
42
generate(php_random_status * status)43 static php_random_result generate(php_random_status *status)
44 {
45 php_random_status_state_combinedlcg *s = status->state;
46 int32_t q, z;
47
48 MODMULT(53668, 40014, 12211, 2147483563L, s->state[0]);
49 MODMULT(52774, 40692, 3791, 2147483399L, s->state[1]);
50
51 z = s->state[0] - s->state[1];
52 if (z < 1) {
53 z += 2147483562;
54 }
55
56 return (php_random_result){
57 .size = sizeof(uint32_t),
58 .result = (uint64_t) z,
59 };
60 }
61
range(php_random_status * status,zend_long min,zend_long max)62 static zend_long range(php_random_status *status, zend_long min, zend_long max)
63 {
64 return php_random_range(&php_random_algo_combinedlcg, status, min, max);
65 }
66
serialize(php_random_status * status,HashTable * data)67 static bool serialize(php_random_status *status, HashTable *data)
68 {
69 php_random_status_state_combinedlcg *s = status->state;
70 zval t;
71
72 for (uint32_t i = 0; i < 2; i++) {
73 ZVAL_STR(&t, php_random_bin2hex_le(&s->state[i], sizeof(uint32_t)));
74 zend_hash_next_index_insert(data, &t);
75 }
76
77 return true;
78 }
79
unserialize(php_random_status * status,HashTable * data)80 static bool unserialize(php_random_status *status, HashTable *data)
81 {
82 php_random_status_state_combinedlcg *s = status->state;
83 zval *t;
84
85 for (uint32_t i = 0; i < 2; i++) {
86 t = zend_hash_index_find(data, i);
87 if (!t || Z_TYPE_P(t) != IS_STRING || Z_STRLEN_P(t) != (2 * sizeof(uint32_t))) {
88 return false;
89 }
90 if (!php_random_hex2bin_le(Z_STR_P(t), &s->state[i])) {
91 return false;
92 }
93 }
94
95 return true;
96 }
97
98 const php_random_algo php_random_algo_combinedlcg = {
99 sizeof(php_random_status_state_combinedlcg),
100 seed,
101 generate,
102 range,
103 serialize,
104 unserialize
105 };
106
107 /* {{{ php_random_combinedlcg_seed_default */
php_random_combinedlcg_seed_default(php_random_status_state_combinedlcg * state)108 PHPAPI void php_random_combinedlcg_seed_default(php_random_status_state_combinedlcg *state)
109 {
110 struct timeval tv;
111
112 if (gettimeofday(&tv, NULL) == 0) {
113 state->state[0] = tv.tv_usec ^ (tv.tv_usec << 11);
114 } else {
115 state->state[0] = 1;
116 }
117
118 #ifdef ZTS
119 state->state[1] = (zend_long) tsrm_thread_id();
120 #else
121 state->state[1] = (zend_long) getpid();
122 #endif
123
124 /* Add entropy to s2 by calling gettimeofday() again */
125 if (gettimeofday(&tv, NULL) == 0) {
126 state->state[1] ^= (tv.tv_usec << 11);
127 }
128 }
129 /* }}} */
130
