1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/as_rand.cpp Fri Nov 28 11:21:08 2008 +0100
1.3 @@ -0,0 +1,137 @@
1.4 +//
1.5 +// OSSP asgui - Accounting system graphical user interface
1.6 +// Copyright (c) 2002-2004 The OSSP Project (http://www.ossp.org/)
1.7 +// Copyright (c) 2002-2004 Ralf S. Engelschall <rse@engelschall.com>
1.8 +// Copyright (c) 2002-2004 Michael Schloh von Bennewitz <michael@schloh.com>
1.9 +// Copyright (c) 2002-2004 Cable & Wireless Telecommunications Services GmbH
1.10 +//
1.11 +// This file is part of OSSP asgui, an accounting system graphical user
1.12 +// interface which can be found at http://www.ossp.org/pkg/tool/asgui/.
1.13 +//
1.14 +// Permission to use, copy, modify, and distribute this software for
1.15 +// any purpose with or without fee is hereby granted, provided that
1.16 +// the above copyright notice and this permission notice appear in all
1.17 +// copies.
1.18 +//
1.19 +// THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
1.20 +// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
1.21 +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1.22 +// IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR
1.23 +// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.24 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.25 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
1.26 +// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
1.27 +// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
1.28 +// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
1.29 +// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
1.30 +// SUCH DAMAGE.
1.31 +//
1.32 +// as_rand.cpp: ISO C++ implementation
1.33 +//
1.34 +
1.35 +#include <fcntl.h>
1.36 +#include <cerrno>
1.37 +
1.38 +#include "as_rand.h"
1.39 +
1.40 +#if HAVE_UNISTD_H
1.41 +#include <unistd.h>
1.42 +#endif // HAVE_UNISTD_H
1.43 +#if HAVE_STDLIB_H
1.44 +#include <stdlib.h>
1.45 +#endif // HAVE_STDLIB_H
1.46 +
1.47 +#if TIME_WITH_SYS_TIME
1.48 +#include <sys/time.h>
1.49 +#include <time.h>
1.50 +#else
1.51 +#if HAVE_SYS_TIME_H
1.52 +#include <sys/time.h>
1.53 +#else
1.54 +#include <time.h>
1.55 +#endif // HAVE_SYS_TIME_H
1.56 +#endif // TIME_WITH_SYS_TIME
1.57 +
1.58 +
1.59 +namespace AS {
1.60 +
1.61 +// Constructor
1.62 +Rand::Rand(void)
1.63 +{
1.64 + this->nFd = -4; // Object fresh status
1.65 + this->openDevice(); // Open the random device
1.66 +// if (this->nFd < 0)
1.67 +// throw Genexcept("Could not open /dev/urandom or /dev/random.");
1.68 +}
1.69 +
1.70 +// Destructor
1.71 +Rand::~Rand(void)
1.72 +{
1.73 + this->closeDevice(); // Close the random device
1.74 + this->nFd = -4; // Return this object to its fresh status
1.75 +}
1.76 +
1.77 +//
1.78 +// Rand::openDevice(void)
1.79 +// Open the random device associated with this object
1.80 +//
1.81 +void Rand::openDevice(void)
1.82 +{
1.83 + struct timeval Time;
1.84 +
1.85 + if (this->nFd == -4) { // -4 indicates a fresh object
1.86 + gettimeofday(&Time, 0);
1.87 + this->nFd = open("/dev/urandom", O_RDONLY);
1.88 + if (this->nFd == -1)
1.89 + this->nFd = open("/dev/random", O_RDONLY | O_NONBLOCK);
1.90 + srand((getpid() << 16) ^ getuid() ^ Time.tv_sec ^ Time.tv_usec); // Seed
1.91 + }
1.92 +
1.93 + // Improve randomness by stirring in entropy
1.94 + gettimeofday(&Time, 0);
1.95 + for (int nIter = (Time.tv_sec ^ Time.tv_usec) & 0x1F; nIter > 0; nIter--)
1.96 + rand();
1.97 +}
1.98 +
1.99 +//
1.100 +// Rand::closeDevice(void)
1.101 +// Close the random device associated with this object
1.102 +//
1.103 +void Rand::closeDevice(void)
1.104 +{
1.105 + if (this->nFd >= 0)
1.106 + close(this->nFd);
1.107 +}
1.108 +
1.109 +//
1.110 +// Rand::genData(void *pvBuf, int nBytes)
1.111 +// Generate a series of random data from the system
1.112 +// standard random devices /dev/[u|s]random
1.113 +//
1.114 +void Rand::genData(void *pBuf, int nBytes)
1.115 +{
1.116 + int nRead = 0;
1.117 + int nLost = 0;
1.118 + char *szOut = (char *)pBuf;
1.119 +
1.120 + if (this->nFd >= 0) {
1.121 + while (nBytes > 0) {
1.122 + nRead = read(this->nFd, szOut, nBytes);
1.123 + if ((nRead < 0) && ((errno == EINTR) || (errno == EAGAIN)))
1.124 + continue;
1.125 + if (nRead <= 0) {
1.126 + if (nLost++ == 8)
1.127 + break;
1.128 + continue;
1.129 + }
1.130 + nBytes -= nRead;
1.131 + szOut += nRead;
1.132 + nLost = 0;
1.133 + }
1.134 + }
1.135 +
1.136 + // For systems with no /dev/random, we do the next best thing
1.137 + for (int nIter = 0; nIter< nBytes; nIter++)
1.138 + *szOut++ = rand() & 0xFF;
1.139 +}
1.140 +} // namespace AS
