1 /*
2 Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License, version 2.0,
6 as published by the Free Software Foundation.
7
8 This program is also distributed with certain software (including
9 but not limited to OpenSSL) that is licensed under separate terms,
10 as designated in a particular file or component or in included license
11 documentation. The authors of MySQL hereby grant you an additional
12 permission to link the program and your derivative works with the
13 separately licensed software that they have included with MySQL.
14
15 Without limiting anything contained in the foregoing, this file,
16 which is part of C Driver for MySQL (Connector/C), is also subject to the
17 Universal FOSS Exception, version 1.0, a copy of which can be found at
18 http://oss.oracle.com/licenses/universal-foss-exception.
19
20 This program is distributed in the hope that it will be useful,
21 but WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 GNU General Public License, version 2.0, for more details.
24
25 You should have received a copy of the GNU General Public License
26 along with this program; if not, write to the Free Software
27 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
28
29 #include <my_rnd.h>
30
31 #if defined(HAVE_OPENSSL)
32 #include <openssl/rand.h>
33 #include <openssl/err.h>
34 #endif /* HAVE_OPENSSL */
35
36
37 /*
38 A wrapper to use OpenSSL PRNGs.
39 */
40
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44
45 /**
46 Generate random number.
47
48 @param rand_st [INOUT] Structure used for number generation.
49
50 @retval Generated pseudo random number.
51 */
52
my_rnd(struct rand_struct * rand_st)53 double my_rnd(struct rand_struct *rand_st)
54 {
55 rand_st->seed1= (rand_st->seed1*3+rand_st->seed2) % rand_st->max_value;
56 rand_st->seed2= (rand_st->seed1+rand_st->seed2+33) % rand_st->max_value;
57 return (((double) rand_st->seed1) / rand_st->max_value_dbl);
58 }
59
60
61
62 /**
63 Fill a buffer with random bytes using the SSL library routines
64
65 @param buffer [OUT] Buffer to receive the random data
66 @param buffer_size [IN] sizeof the the buffer
67
68 @retval 1 error ocurred.
69 @retval 0 OK
70 */
71 int
my_rand_buffer(unsigned char * buffer,size_t buffer_size)72 my_rand_buffer(unsigned char *buffer, size_t buffer_size)
73 {
74 int rc;
75 #if defined(HAVE_OPENSSL)
76 rc= RAND_bytes(buffer, buffer_size);
77
78 if (!rc)
79 {
80 ERR_clear_error();
81 return 1;
82 }
83 #else /* no SSL */
84 #error not using an SSL library not supported
85 #endif
86 return 0;
87 }
88
89
90 /**
91 Generate a random number using the OpenSSL supplied
92 random number generator if available.
93
94 @param rand_st [INOUT] Structure used for number generation
95 only if none of the SSL libraries are
96 available.
97
98 @retval Generated random number.
99 */
100
my_rnd_ssl(struct rand_struct * rand_st)101 double my_rnd_ssl(struct rand_struct *rand_st)
102 {
103 unsigned int res;
104
105 if (my_rand_buffer((unsigned char *) &res, sizeof(res)))
106 return my_rnd(rand_st);
107
108 return (double)res / (double)UINT_MAX;
109 }
110
111
112 #ifdef __cplusplus
113 }
114 #endif
115