lib/liblwip/netif/ppp/randm.h

   1 /*****************************************************************************
   2 * randm.h - Random number generator header file.
   3 *
   4 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
   5 * Copyright (c) 1998 Global Election Systems Inc.
   6 *
   7 * The authors hereby grant permission to use, copy, modify, distribute,
   8 * and license this software and its documentation for any purpose, provided
   9 * that existing copyright notices are retained in all copies and that this
  10 * notice and the following disclaimer are included verbatim in any
  11 * distributions. No written agreement, license, or royalty fee is required
  12 * for any of the authorized uses.
  13 *
  14 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
  15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24 *
  25 ******************************************************************************
  26 * REVISION HISTORY
  27 *
  28 * 03-01-01 Marc Boucher <marc@mbsi.ca>
  29 *   Ported to lwIP.
  30 * 98-05-29 Guy Lancaster <glanca@gesn.com>, Global Election Systems Inc.
  31 *   Extracted from avos.
  32 *****************************************************************************/
  33
  34 #ifndef RANDM_H
  35 #define RANDM_H
  36
  37 /***********************
  38 *** PUBLIC FUNCTIONS ***
  39 ***********************/
  40 /*
  41  * Initialize the random number generator.
  42  */
  43 void avRandomInit(void);
  44
  45 /*
  46  * Churn the randomness pool on a random event.  Call this early and often
  47  * on random and semi-random system events to build randomness in time for
  48  * usage.  For randomly timed events, pass a null pointer and a zero length
  49  * and this will use the system timer and other sources to add randomness.
  50  * If new random data is available, pass a pointer to that and it will be
  51  * included.
  52  */
  53 void avChurnRand(char *randData, u32_t randLen);
  54
  55 /*
  56  * Randomize our random seed value.  To be called for truely random events
  57  * such as user operations and network traffic.
  58  */
  59 #if MD5_SUPPORT
  60 #define avRandomize() avChurnRand(NULL, 0)
  61 #else  /* MD5_SUPPORT */
  62 void avRandomize(void);
  63 #endif /* MD5_SUPPORT */
  64
  65 /*
  66  * Use the random pool to generate random data.  This degrades to pseudo
  67  * random when used faster than randomness is supplied using churnRand().
  68  * Thus it's important to make sure that the results of this are not
  69  * published directly because one could predict the next result to at
  70  * least some degree.  Also, it's important to get a good seed before
  71  * the first use.
  72  */
  73 void avGenRand(char *buf, u32_t bufLen);
  74
  75 /*
  76  * Return a new random number.
  77  */
  78 u32_t avRandom(void);
  79
  80
  81 #endif /* RANDM_H */