As-gui Sources / file comparison
comparison: as_rand.cpp
as_rand.cpp
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- c1941114ca88
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| 1 // | |
| 2 // OSSP asgui - Accounting system graphical user interface | |
| 3 // Copyright (c) 2002-2004 The OSSP Project (http://www.ossp.org/) | |
| 4 // Copyright (c) 2002-2004 Ralf S. Engelschall <rse@engelschall.com> | |
| 5 // Copyright (c) 2002-2004 Michael Schloh von Bennewitz <michael@schloh.com> | |
| 6 // Copyright (c) 2002-2004 Cable & Wireless Telecommunications Services GmbH | |
| 7 // | |
| 8 // This file is part of OSSP asgui, an accounting system graphical user | |
| 9 // interface which can be found at http://www.ossp.org/pkg/tool/asgui/. | |
| 10 // | |
| 11 // Permission to use, copy, modify, and distribute this software for | |
| 12 // any purpose with or without fee is hereby granted, provided that | |
| 13 // the above copyright notice and this permission notice appear in all | |
| 14 // copies. | |
| 15 // | |
| 16 // THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED | |
| 17 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
| 18 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 19 // IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR | |
| 20 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | |
| 23 // USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
| 24 // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
| 25 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |
| 26 // OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 27 // SUCH DAMAGE. | |
| 28 // | |
| 29 // as_rand.cpp: ISO C++ implementation | |
| 30 // | |
| 31 | |
| 32 #include <fcntl.h> | |
| 33 #include <cerrno> | |
| 34 | |
| 35 #include "as_rand.h" | |
| 36 | |
| 37 #if HAVE_UNISTD_H | |
| 38 #include <unistd.h> | |
| 39 #endif // HAVE_UNISTD_H | |
| 40 #if HAVE_STDLIB_H | |
| 41 #include <stdlib.h> | |
| 42 #endif // HAVE_STDLIB_H | |
| 43 | |
| 44 #if TIME_WITH_SYS_TIME | |
| 45 #include <sys/time.h> | |
| 46 #include <time.h> | |
| 47 #else | |
| 48 #if HAVE_SYS_TIME_H | |
| 49 #include <sys/time.h> | |
| 50 #else | |
| 51 #include <time.h> | |
| 52 #endif // HAVE_SYS_TIME_H | |
| 53 #endif // TIME_WITH_SYS_TIME | |
| 54 | |
| 55 | |
| 56 namespace AS { | |
| 57 | |
| 58 // Constructor | |
| 59 Rand::Rand(void) | |
| 60 { | |
| 61 this->nFd = -4; // Object fresh status | |
| 62 this->openDevice(); // Open the random device | |
| 63 // if (this->nFd < 0) | |
| 64 // throw Genexcept("Could not open /dev/urandom or /dev/random."); | |
| 65 } | |
| 66 | |
| 67 // Destructor | |
| 68 Rand::~Rand(void) | |
| 69 { | |
| 70 this->closeDevice(); // Close the random device | |
| 71 this->nFd = -4; // Return this object to its fresh status | |
| 72 } | |
| 73 | |
| 74 // | |
| 75 // Rand::openDevice(void) | |
| 76 // Open the random device associated with this object | |
| 77 // | |
| 78 void Rand::openDevice(void) | |
| 79 { | |
| 80 struct timeval Time; | |
| 81 | |
| 82 if (this->nFd == -4) { // -4 indicates a fresh object | |
| 83 gettimeofday(&Time, 0); | |
| 84 this->nFd = open("/dev/urandom", O_RDONLY); | |
| 85 if (this->nFd == -1) | |
| 86 this->nFd = open("/dev/random", O_RDONLY | O_NONBLOCK); | |
| 87 srand((getpid() << 16) ^ getuid() ^ Time.tv_sec ^ Time.tv_usec); // Seed | |
| 88 } | |
| 89 | |
| 90 // Improve randomness by stirring in entropy | |
| 91 gettimeofday(&Time, 0); | |
| 92 for (int nIter = (Time.tv_sec ^ Time.tv_usec) & 0x1F; nIter > 0; nIter--) | |
| 93 rand(); | |
| 94 } | |
| 95 | |
| 96 // | |
| 97 // Rand::closeDevice(void) | |
| 98 // Close the random device associated with this object | |
| 99 // | |
| 100 void Rand::closeDevice(void) | |
| 101 { | |
| 102 if (this->nFd >= 0) | |
| 103 close(this->nFd); | |
| 104 } | |
| 105 | |
| 106 // | |
| 107 // Rand::genData(void *pvBuf, int nBytes) | |
| 108 // Generate a series of random data from the system | |
| 109 // standard random devices /dev/[u|s]random | |
| 110 // | |
| 111 void Rand::genData(void *pBuf, int nBytes) | |
| 112 { | |
| 113 int nRead = 0; | |
| 114 int nLost = 0; | |
| 115 char *szOut = (char *)pBuf; | |
| 116 | |
| 117 if (this->nFd >= 0) { | |
| 118 while (nBytes > 0) { | |
| 119 nRead = read(this->nFd, szOut, nBytes); | |
| 120 if ((nRead < 0) && ((errno == EINTR) || (errno == EAGAIN))) | |
| 121 continue; | |
| 122 if (nRead <= 0) { | |
| 123 if (nLost++ == 8) | |
| 124 break; | |
| 125 continue; | |
| 126 } | |
| 127 nBytes -= nRead; | |
| 128 szOut += nRead; | |
| 129 nLost = 0; | |
| 130 } | |
| 131 } | |
| 132 | |
| 133 // For systems with no /dev/random, we do the next best thing | |
| 134 for (int nIter = 0; nIter< nBytes; nIter++) | |
| 135 *szOut++ = rand() & 0xFF; | |
| 136 } | |
| 137 } // namespace AS |
