1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape Portable Runtime (NSPR).
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1999-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
** prrng.h -- NSPR Random Number Generator
**
**
** lth. 29-Oct-1999.
*/
#ifndef prrng_h___
#define prrng_h___
#include "prtypes.h"
#ifdef VBOX_WITH_XPCOM_NAMESPACE_CLEANUP
#define PR_GetRandomNoise VBoxNsprPR_GetRandomNoise
#endif /* VBOX_WITH_XPCOM_NAMESPACE_CLEANUP */
PR_BEGIN_EXTERN_C
/*
** PR_GetRandomNoise() -- Get random noise from the host platform
**
** Description:
** PR_GetRandomNoise() provides, depending on platform, a random value.
** The length of the random value is dependent on platform and the
** platform's ability to provide a random value at that moment.
**
** The intent of PR_GetRandomNoise() is to provide a "seed" value for a
** another random number generator that may be suitable for
** cryptographic operations. This implies that the random value
** provided may not be, by itself, cryptographically secure. The value
** generated by PR_GetRandomNoise() is at best, extremely difficult to
** predict and is as non-deterministic as the underlying platfrom can
** provide.
**
** Inputs:
** buf -- pointer to a caller supplied buffer to contain the
** generated random number. buf must be at least as large as
** is specified in the 'size' argument.
**
** size -- the requested size of the generated random number
**
** Outputs:
** a random number provided in 'buf'.
**
** Returns:
** PRSize value equal to the size of the random number actually
** generated, or zero. The generated size may be less than the size
** requested. A return value of zero means that PR_GetRandomNoise() is
** not implemented on this platform, or there is no available noise
** available to be returned at the time of the call.
**
** Restrictions:
** Calls to PR_GetRandomNoise() may use a lot of CPU on some platforms.
** Some platforms may block for up to a few seconds while they
** accumulate some noise. Busy machines generate lots of noise, but
** care is advised when using PR_GetRandomNoise() frequently in your
** application.
**
** History:
** Parts of the model dependent implementation for PR_GetRandomNoise()
** were taken in whole or part from code previously in Netscape's NSS
** component.
**
*/
NSPR_API(PRSize) PR_GetRandomNoise(
void *buf,
PRSize size
);
PR_END_EXTERN_C
#endif /* prrng_h___ */
/* end prrng.h */
|
