diff --git a/src/netif/ppp/magic.c b/src/netif/ppp/magic.c index 7e0a8ce0..38b80696 100644 --- a/src/netif/ppp/magic.c +++ b/src/netif/ppp/magic.c @@ -39,24 +39,48 @@ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ +/***************************************************************************** +* randm.c - Random number generator program file. +* +* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc. +* Copyright (c) 1998 by Global Election Systems Inc. +* +* The authors hereby grant permission to use, copy, modify, distribute, +* and license this software and its documentation for any purpose, provided +* that existing copyright notices are retained in all copies and that this +* notice and the following disclaimer are included verbatim in any +* distributions. No written agreement, license, or royalty fee is required +* for any of the authorized uses. +* +* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR +* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +* +****************************************************************************** +* REVISION HISTORY +* +* 03-01-01 Marc Boucher +* Ported to lwIP. +* 98-06-03 Guy Lancaster , Global Election Systems Inc. +* Extracted from avos. +*****************************************************************************/ #include "lwip/opt.h" -#define RCSID "$Id: magic.c,v 1.11 2003/06/11 23:56:26 paulus Exp $" +#define PPP_SUPPORT 1 +#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */ -#include -#include -#include -#include -#include - -#include "pppd.h" +#include "md5.h" #include "magic.h" - -static const char rcsid[] = RCSID; - -extern long mrand48 __P((void)); -extern void srand48 __P((long)); +#include "pppd.h" +#include "pppmy.h" /* * magic_init - Initialize the magic number generator. @@ -65,24 +89,124 @@ extern void srand48 __P((long)); * The current method uses the current hostid, current process ID * and current time, currently. */ -void -magic_init() -{ - long seed; - struct timeval t; - - gettimeofday(&t, NULL); - seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid(); - srand48(seed); +void magic_init() { + avRandomInit(); } /* * magic - Returns the next magic number. */ -u_int32_t -magic() +u_int32_t magic() { + return (u_int32_t)avRandom(); +} + +#if MD5_SUPPORT /* this module depends on MD5 */ +#define RANDPOOLSZ 16 /* Bytes stored in the pool of randomness. */ + +/*****************************/ +/*** LOCAL DATA STRUCTURES ***/ +/*****************************/ +static char randPool[RANDPOOLSZ]; /* Pool of randomness. */ +static long randCount = 0; /* Pseudo-random incrementer */ + + +/***********************************/ +/*** PUBLIC FUNCTION DEFINITIONS ***/ +/***********************************/ +/* + * Initialize the random number generator. + * + * Since this is to be called on power up, we don't have much + * system randomess to work with. Here all we use is the + * real-time clock. We'll accumulate more randomness as soon + * as things start happening. + */ +void +avRandomInit() { - return (u_int32_t) mrand48(); + avChurnRand(NULL, 0); +} + +/* + * Churn the randomness pool on a random event. Call this early and often + * on random and semi-random system events to build randomness in time for + * usage. For randomly timed events, pass a null pointer and a zero length + * and this will use the system timer and other sources to add randomness. + * If new random data is available, pass a pointer to that and it will be + * included. + * + * Ref: Applied Cryptography 2nd Ed. by Bruce Schneier p. 427 + */ +void +avChurnRand(char *randData, u32_t randLen) +{ + MD5_CTX md5; + + /* LWIP_DEBUGF(LOG_INFO, ("churnRand: %u@%P\n", randLen, randData)); */ + MD5_Init(&md5); + MD5_Update(&md5, (u_char *)randPool, sizeof(randPool)); + if (randData) { + MD5_Update(&md5, (u_char *)randData, randLen); + } else { + struct { + /* INCLUDE fields for any system sources of randomness */ + char foobar; + } sysData; + + /* Load sysData fields here. */ + MD5_Update(&md5, (u_char *)&sysData, sizeof(sysData)); + } + MD5_Final((u_char *)randPool, &md5); +/* LWIP_DEBUGF(LOG_INFO, ("churnRand: -> 0\n")); */ +} + +/* + * Use the random pool to generate random data. This degrades to pseudo + * random when used faster than randomness is supplied using churnRand(). + * Note: It's important that there be sufficient randomness in randPool + * before this is called for otherwise the range of the result may be + * narrow enough to make a search feasible. + * + * Ref: Applied Cryptography 2nd Ed. by Bruce Schneier p. 427 + * + * XXX Why does he not just call churnRand() for each block? Probably + * so that you don't ever publish the seed which could possibly help + * predict future values. + * XXX Why don't we preserve md5 between blocks and just update it with + * randCount each time? Probably there is a weakness but I wish that + * it was documented. + */ +void +avGenRand(char *buf, u32_t bufLen) +{ + MD5_CTX md5; + u_char tmp[16]; + u32_t n; + + while (bufLen > 0) { + n = LWIP_MIN(bufLen, RANDPOOLSZ); + MD5_Init(&md5); + MD5_Update(&md5, (u_char *)randPool, sizeof(randPool)); + MD5_Update(&md5, (u_char *)&randCount, sizeof(randCount)); + MD5_Final(tmp, &md5); + randCount++; + MEMCPY(buf, tmp, n); + buf += n; + bufLen -= n; + } +} + +/* + * Return a new random number. + */ +u32_t +avRandom() +{ + u32_t newRand; + + avGenRand((char *)&newRand, sizeof(newRand)); + + return newRand; } /* @@ -91,35 +215,101 @@ magic() void random_bytes(unsigned char *buf, int len) { - int i; - - for (i = 0; i < len; ++i) - buf[i] = mrand48() >> 24; + avGenRand(buf, len); } -#ifdef NO_DRAND48 +#else /* MD5_SUPPORT */ + +/*****************************/ +/*** LOCAL DATA STRUCTURES ***/ +/*****************************/ +static int avRandomized = 0; /* Set when truely randomized. */ +static u32_t avRandomSeed = 0; /* Seed used for random number generation. */ + + +/***********************************/ +/*** PUBLIC FUNCTION DEFINITIONS ***/ +/***********************************/ /* - * Substitute procedures for those systems which don't have - * drand48 et al. + * Initialize the random number generator. + * + * Here we attempt to compute a random number seed but even if + * it isn't random, we'll randomize it later. + * + * The current method uses the fields from the real time clock, + * the idle process counter, the millisecond counter, and the + * hardware timer tick counter. When this is invoked + * in startup(), then the idle counter and timer values may + * repeat after each boot and the real time clock may not be + * operational. Thus we call it again on the first random + * event. */ - -double -drand48() -{ - return (double)random() / (double)0x7fffffffL; /* 2**31-1 */ -} - -long -mrand48() -{ - return random(); -} - void -srand48(seedval) -long seedval; +avRandomInit() { - srandom((int)seedval); +#if 0 + /* Get a pointer into the last 4 bytes of clockBuf. */ + u32_t *lptr1 = (u32_t *)((char *)&clockBuf[3]); + + /* + * Initialize our seed using the real-time clock, the idle + * counter, the millisecond timer, and the hardware timer + * tick counter. The real-time clock and the hardware + * tick counter are the best sources of randomness but + * since the tick counter is only 16 bit (and truncated + * at that), the idle counter and millisecond timer + * (which may be small values) are added to help + * randomize the lower 16 bits of the seed. + */ + readClk(); + avRandomSeed += *(u32_t *)clockBuf + *lptr1 + OSIdleCtr + + ppp_mtime() + ((u32_t)TM1 << 16) + TM1; +#else + avRandomSeed += sys_jiffies(); /* XXX */ +#endif + + /* Initialize the Borland random number generator. */ + srand((unsigned)avRandomSeed); } -#endif +/* + * Randomize our random seed value. Here we use the fact that + * this function is called at *truely random* times by the polling + * and network functions. Here we only get 16 bits of new random + * value but we use the previous value to randomize the other 16 + * bits. + */ +void +avRandomize(void) +{ + static u32_t last_jiffies; + + if (!avRandomized) { + avRandomized = !0; + avRandomInit(); + /* The initialization function also updates the seed. */ + } else { + /* avRandomSeed += (avRandomSeed << 16) + TM1; */ + avRandomSeed += (sys_jiffies() - last_jiffies); /* XXX */ + } + last_jiffies = sys_jiffies(); +} + +/* + * Return a new random number. + * Here we use the Borland rand() function to supply a pseudo random + * number which we make truely random by combining it with our own + * seed which is randomized by truely random events. + * Thus the numbers will be truely random unless there have been no + * operator or network events in which case it will be pseudo random + * seeded by the real time clock. + */ +u32_t +avRandom() +{ + return ((((u32_t)rand() << 16) + rand()) + avRandomSeed); +} + +#endif /* MD5_SUPPORT */ + +#endif /* PPP_SUPPORT */ diff --git a/src/netif/ppp/magic.h b/src/netif/ppp/magic.h index c81213b4..9aaf1b1f 100644 --- a/src/netif/ppp/magic.h +++ b/src/netif/ppp/magic.h @@ -41,6 +41,87 @@ * * $Id: magic.h,v 1.5 2003/06/11 23:56:26 paulus Exp $ */ +/***************************************************************************** +* randm.h - Random number generator header file. +* +* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc. +* Copyright (c) 1998 Global Election Systems Inc. +* +* The authors hereby grant permission to use, copy, modify, distribute, +* and license this software and its documentation for any purpose, provided +* that existing copyright notices are retained in all copies and that this +* notice and the following disclaimer are included verbatim in any +* distributions. No written agreement, license, or royalty fee is required +* for any of the authorized uses. +* +* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR +* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +* +****************************************************************************** +* REVISION HISTORY +* +* 03-01-01 Marc Boucher +* Ported to lwIP. +* 98-05-29 Guy Lancaster , Global Election Systems Inc. +* Extracted from avos. +*****************************************************************************/ + +#ifndef RANDM_H +#define RANDM_H + +/*********************** +*** PUBLIC FUNCTIONS *** +***********************/ +/* + * Initialize the random number generator. + */ +void avRandomInit(void); + +/* + * Churn the randomness pool on a random event. Call this early and often + * on random and semi-random system events to build randomness in time for + * usage. For randomly timed events, pass a null pointer and a zero length + * and this will use the system timer and other sources to add randomness. + * If new random data is available, pass a pointer to that and it will be + * included. + */ +void avChurnRand(char *randData, u32_t randLen); + +/* + * Randomize our random seed value. To be called for truely random events + * such as user operations and network traffic. + */ +#if MD5_SUPPORT +#define avRandomize() avChurnRand(NULL, 0) +#else /* MD5_SUPPORT */ +void avRandomize(void); +#endif /* MD5_SUPPORT */ + +/* + * Use the random pool to generate random data. This degrades to pseudo + * random when used faster than randomness is supplied using churnRand(). + * Thus it's important to make sure that the results of this are not + * published directly because one could predict the next result to at + * least some degree. Also, it's important to get a good seed before + * the first use. + */ +void avGenRand(char *buf, u32_t bufLen); + +/* + * Return a new random number. + */ +u32_t avRandom(void); + + +#endif /* RANDM_H */ void magic_init __P((void)); /* Initialize the magic number generator */ u_int32_t magic __P((void)); /* Returns the next magic number */ diff --git a/src/netif/ppp/pppmy.h b/src/netif/ppp/pppmy.h index 632521f4..e79f43fa 100644 --- a/src/netif/ppp/pppmy.h +++ b/src/netif/ppp/pppmy.h @@ -11,6 +11,7 @@ #include /* FIXME: temporary */ #include "lwip/netif.h" +#include "lwip/def.h" /************************* *** PUBLIC DEFINITIONS ***