Back to index

lightning-sunbird  0.9+nobinonly
w32rng.c
Go to the documentation of this file.
00001 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
00002 /* ***** BEGIN LICENSE BLOCK *****
00003  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00004  *
00005  * The contents of this file are subject to the Mozilla Public License Version
00006  * 1.1 (the "License"); you may not use this file except in compliance with
00007  * the License. You may obtain a copy of the License at
00008  * http://www.mozilla.org/MPL/
00009  *
00010  * Software distributed under the License is distributed on an "AS IS" basis,
00011  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00012  * for the specific language governing rights and limitations under the
00013  * License.
00014  *
00015  * The Original Code is the Netscape Portable Runtime (NSPR).
00016  *
00017  * The Initial Developer of the Original Code is
00018  * Netscape Communications Corporation.
00019  * Portions created by the Initial Developer are Copyright (C) 1999-2000
00020  * the Initial Developer. All Rights Reserved.
00021  *
00022  * Contributor(s):
00023  *
00024  * Alternatively, the contents of this file may be used under the terms of
00025  * either the GNU General Public License Version 2 or later (the "GPL"), or
00026  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00027  * in which case the provisions of the GPL or the LGPL are applicable instead
00028  * of those above. If you wish to allow use of your version of this file only
00029  * under the terms of either the GPL or the LGPL, and not to allow others to
00030  * use your version of this file under the terms of the MPL, indicate your
00031  * decision by deleting the provisions above and replace them with the notice
00032  * and other provisions required by the GPL or the LGPL. If you do not delete
00033  * the provisions above, a recipient may use your version of this file under
00034  * the terms of any one of the MPL, the GPL or the LGPL.
00035  *
00036  * ***** END LICENSE BLOCK ***** */
00037 
00038 #include <windows.h>
00039 #include <time.h>
00040 #include <io.h>
00041 #include <sys/types.h>
00042 #include <sys/stat.h>
00043 #include <stdio.h>
00044 #include <primpl.h>
00045 
00046 static BOOL
00047 CurrentClockTickTime(LPDWORD lpdwHigh, LPDWORD lpdwLow)
00048 {
00049     LARGE_INTEGER   liCount;
00050 
00051     if (!QueryPerformanceCounter(&liCount))
00052         return FALSE;
00053 
00054     *lpdwHigh = liCount.u.HighPart;
00055     *lpdwLow = liCount.u.LowPart;
00056     return TRUE;
00057 }
00058 
00059 extern PRSize _PR_MD_GetRandomNoise( void *buf, PRSize size )
00060 {
00061     DWORD   dwHigh, dwLow, dwVal;
00062     int     n = 0;
00063     int     nBytes;
00064     time_t  sTime;
00065 
00066     if (size <= 0)
00067         return 0;
00068 
00069     CurrentClockTickTime(&dwHigh, &dwLow);
00070 
00071     // get the maximally changing bits first
00072     nBytes = sizeof(dwLow) > size ? size : sizeof(dwLow);
00073     memcpy((char *)buf, &dwLow, nBytes);
00074     n += nBytes;
00075     size -= nBytes;
00076 
00077     if (size <= 0)
00078         return n;
00079 
00080     nBytes = sizeof(dwHigh) > size ? size : sizeof(dwHigh);
00081     memcpy(((char *)buf) + n, &dwHigh, nBytes);
00082     n += nBytes;
00083     size -= nBytes;
00084 
00085     if (size <= 0)
00086         return n;
00087 
00088     // get the number of milliseconds that have elapsed since Windows started
00089     dwVal = GetTickCount();
00090 
00091     nBytes = sizeof(dwVal) > size ? size : sizeof(dwVal);
00092     memcpy(((char *)buf) + n, &dwVal, nBytes);
00093     n += nBytes;
00094     size -= nBytes;
00095 
00096     if (size <= 0)
00097         return n;
00098 
00099     // get the time in seconds since midnight Jan 1, 1970
00100     time(&sTime);
00101     nBytes = sizeof(sTime) > size ? size : sizeof(sTime);
00102     memcpy(((char *)buf) + n, &sTime, nBytes);
00103     n += nBytes;
00104 
00105     return n;
00106 }
00107