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Annotation of embedaddon/libnet/src/libnet_prand.c, revision 1.1.1.3

1.1       misho       1: /*
                      2:  *  libnet
                      3:  *  libnet_prand.c - pseudo-random number generation
                      4:  *
                      5:  *  Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
                      6:  *  All rights reserved.
                      7:  *
                      8:  * Redistribution and use in source and binary forms, with or without
                      9:  * modification, are permitted provided that the following conditions
                     10:  * are met:
                     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. Redistributions in binary form must reproduce the above copyright
                     14:  *    notice, this list of conditions and the following disclaimer in the
                     15:  *    documentation and/or other materials provided with the distribution.
                     16:  *
                     17:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
                     18:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     19:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
                     21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     27:  * SUCH DAMAGE.
                     28:  *
                     29:  */
1.1.1.3 ! misho      30: 
        !            31: #include "common.h"
        !            32: 
        !            33: #ifdef _WIN32
        !            34: #include <wincrypt.h>
        !            35: #include <time.h>
        !            36: 
1.1       misho      37: #else
1.1.1.3 ! misho      38: #include <sys/time.h> /* gettimeofday() */
1.1       misho      39: #endif
1.1.1.3 ! misho      40: 
        !            41: 
1.1       misho      42: int
                     43: libnet_seed_prand(libnet_t *l)
                     44: {
1.1.1.3 ! misho      45: #ifndef WIN32
1.1       misho      46:     struct timeval seed;
1.1.1.3 ! misho      47: #endif
1.1       misho      48: 
                     49:     if (l == NULL)
1.1.1.3 ! misho      50:     {
1.1       misho      51:         return (-1);
1.1.1.3 ! misho      52:     }
1.1       misho      53: 
1.1.1.3 ! misho      54: #ifdef WIN32
1.1       misho      55:     srand((unsigned)time(NULL));
1.1.1.3 ! misho      56: #else
1.1       misho      57:     if (gettimeofday(&seed, NULL) == -1)
                     58:     {
                     59:         snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
1.1.1.3 ! misho      60:                 "%s(): cannot gettimeofday", __func__);
1.1       misho      61:         return (-1);
                     62:     }
                     63: 
                     64:     /*
                     65:      *  More entropy then just seeding with time(2).
                     66:      */
                     67:     srandom((unsigned)(seed.tv_sec ^ seed.tv_usec));
1.1.1.3 ! misho      68: #endif
1.1       misho      69:     return (1);
                     70: }
                     71: 
1.1.1.3 ! misho      72: /* FIXME this code makes no sense. On unix we use random(), which
        !            73:  * is intended to have no security, and under win32 we use cryptographically
        !            74:  * strong entropy source? If necessary, why aren't we using /dev/random
        !            75:  * on unix? What's going on here?
        !            76:  */
1.1.1.2   misho      77: uint32_t
1.1       misho      78: libnet_get_prand(int mod)
                     79: {
1.1.1.2   misho      80:     uint32_t n;  /* 0 to 4,294,967,295 */
1.1.1.3 ! misho      81: #ifndef WIN32
1.1       misho      82:     n = random();
                     83: #else
1.1.1.3 ! misho      84:     HCRYPTPROV hProv = 0;
        !            85: 
        !            86:     CryptAcquireContext(&hProv,
        !            87:                         0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
        !            88: 
        !            89:     CryptGenRandom(hProv, sizeof(n), (BYTE*)&n);
        !            90:     CryptReleaseContext(hProv, 0);
1.1       misho      91: #endif
                     92:     switch (mod)
                     93:     {
                     94:         case LIBNET_PR2:
1.1.1.3 ! misho      95:             return (n & 0x1);           /* 0 - 1 */
1.1       misho      96:         case LIBNET_PR8:
1.1.1.3 ! misho      97:             return (n & 0xff);          /* 0 - 255 */
1.1       misho      98:         case LIBNET_PR16:
1.1.1.3 ! misho      99:             return (n & 0x7fff);        /* 0 - 32767 */
1.1       misho     100:         case LIBNET_PRu16:
1.1.1.3 ! misho     101:             return (n & 0xffff);        /* 0 - 65535 */
1.1       misho     102:         case LIBNET_PR32:
1.1.1.3 ! misho     103:             return (n & 0x7fffffff);    /* 0 - 2147483647 */
1.1       misho     104:         case LIBNET_PRu32:
                    105:             return (n);                 /* 0 - 4294967295 */
                    106:     }
                    107:     return (0);                         /* NOTTREACHED */
                    108: }
                    109: 
1.1.1.3 ! misho     110: /**
        !           111:  * Local Variables:
        !           112:  *  indent-tabs-mode: nil
        !           113:  *  c-file-style: "stroustrup"
        !           114:  * End:
        !           115:  */