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 (at) mbsi.ca> 29 * Ported to lwIP. 30 * 98-05-29 Guy Lancaster <glanca (at) 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 */ 82
