Logo Search packages:      
Sourcecode: wdm version File versions  Download package

genauth.c

/* $Xorg: genauth.c,v 1.5 2001/02/09 02:05:40 xorgcvs Exp $ */
/*

Copyright 1988, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/
/* $XFree86: xc/programs/xdm/genauth.c,v 3.13 2001/12/14 20:01:22 dawes Exp $ */

/*
 * xdm - display manager daemon
 * Author:  Keith Packard, MIT X Consortium
 */

# include   <X11/Xauth.h>
# include   <X11/Xos.h>

# include   <dm.h>
# include   <dm_auth.h>

#include <errno.h>

#include <time.h>
#define Time_t time_t

#include <wdmlib.h>

static unsigned char    key[8];

#ifdef HASXDMAUTH

typedef unsigned char auth_cblock[8];     /* block size */

typedef struct auth_ks_struct { auth_cblock _; } auth_wrapper_schedule[16];

extern void _XdmcpWrapperToOddParity();

static void
longtochars (long l, unsigned char *c)
{
    c[0] = (l >> 24) & 0xff;
    c[1] = (l >> 16) & 0xff;
    c[2] = (l >> 8) & 0xff;
    c[3] = l & 0xff;
}

#endif

# define FILE_LIMIT     1024  /* no more than this many buffers */

#if !defined(ARC4_RANDOM) && !defined(DEV_RANDOM)
static int
sumFile (char *name, long sum[2])
{
    long    buf[1024*2];
    int         cnt;
    int         fd;
    int         loops;
    int         reads;
    int         i;
    int     ret_status = 0;

    fd = open (name, O_RDONLY);
    if (fd < 0) {
      WDMError("Cannot open randomFile \"%s\", errno = %d\n", name, errno);
      return 0;
    }
#ifdef FRAGILE_DEV_MEM
    if (strcmp(name, "/dev/mem") == 0) lseek (fd, (off_t) 0x100000, SEEK_SET);
#endif
    reads = FILE_LIMIT;
    sum[0] = 0;
    sum[1] = 0;
    while ((cnt = read (fd, (char *) buf, sizeof (buf))) > 0 && --reads > 0) {
      loops = cnt / (2 * sizeof (long));
      for (i = 0; i < loops; i+= 2) {
          sum[0] += buf[i];
          sum[1] += buf[i+1];
          ret_status = 1;
      }
    }
    if (cnt < 0)
      WDMError("Cannot read randomFile \"%s\", errno = %d\n", name, errno);
    close (fd);
    return ret_status;
}
#endif

#ifdef HASXDMAUTH
static void
InitXdmcpWrapper (void)
{

#ifdef      ARC4_RANDOM
    u_int32_t sum[2];

    sum[0] = arc4random();
    sum[1] = arc4random();
    *(u_char *)sum = 0;

    _XdmcpWrapperToOddParity(sum, key);

#elif DEV_RANDOM
    int fd;
    unsigned char   tmpkey[8];
    
    if ((fd = open(DEV_RANDOM, O_RDONLY)) >= 0) {
      if (read(fd, tmpkey, 8) == 8) {
          tmpkey[0] = 0;
          _XdmcpWrapperToOddParity(tmpkey, key);
          close(fd);
          return; 
      } else {
          close(fd);
      }
    }
#else    
    long        sum[2];
    unsigned char   tmpkey[8];

    if (!sumFile (randomFile, sum)) {
      sum[0] = time ((Time_t *) 0);
      sum[1] = time ((Time_t *) 0);
    }
    longtochars (sum[0], tmpkey+0);
    longtochars (sum[1], tmpkey+4);
    tmpkey[0] = 0;
    _XdmcpWrapperToOddParity (tmpkey, key);
#endif
}

#endif

#ifndef HASXDMAUTH
/* A random number generator that is more unpredictable
   than that shipped with some systems.
   This code is taken from the C standard. */

static unsigned long int next = 1;

static int
xdm_rand(void)
{
    next = next * 1103515245 + 12345;
    return (unsigned int)(next/65536) % 32768;
}

static void
xdm_srand(unsigned int seed)
{
    next = seed;
}
#endif /* no HASXDMAUTH */

void
GenerateAuthData (char *auth, int len)
{
    long        ldata[2];

#ifdef ITIMER_REAL
    {
      struct timeval  now;

      X_GETTIMEOFDAY (&now);
      ldata[0] = now.tv_usec;
      ldata[1] = now.tv_sec;
    }
#else
    {
#ifndef __EMX__
      long    time ();
#endif

      ldata[0] = time ((long *) 0);
      ldata[1] = getpid ();
    }
#endif
#ifdef HASXDMAUTH
    {
      int             bit;
      int             i;
      auth_wrapper_schedule    schedule;
      unsigned char         data[8];
      static int      xdmcpAuthInited;
    
      longtochars (ldata[0], data+0);
      longtochars (ldata[1], data+4);
      if (!xdmcpAuthInited)
      {
          InitXdmcpWrapper ();
          xdmcpAuthInited = 1;
      }
      _XdmcpAuthSetup (key, schedule);
      for (i = 0; i < len; i++) {
          auth[i] = 0;
          for (bit = 1; bit < 256; bit <<= 1) {
            _XdmcpAuthDoIt (data, data, schedule, 1);
            if ((data[0] + data[1]) & 0x4)
                auth[i] |= bit;
          }
      }
    }
#else
    {
      int       seed;
      int       value;
      int       i;
      static long localkey[2] = {0,0};
    
      if ( (localkey[0] == 0) && (localkey[1] == 0) ) {
#ifdef ARC4_RANDOM
          localkey[0] = arc4random();
          localkey[1] = arc4random();
#elif defined(DEV_RANDOM)
          int fd;
    
          if ((fd = open(DEV_RANDOM, O_RDONLY)) >= 0) {
            if (read(fd, (char *)localkey, 8) != 8) {
                localkey[0] = 1;
            }
            close(fd);
          } else {
            localkey[0] = 1;
          }
#else 
          if (!sumFile (randomFile, localkey)) {
            localkey[0] = 1; /* To keep from continually calling sumFile() */
          }
#endif
      }

      seed = (ldata[0]+localkey[0]) + ((ldata[1]+localkey[1]) << 16);
      xdm_srand (seed);
      for (i = 0; i < len; i++)
      {
          value = xdm_rand ();
          auth[i] = (value & 0xff00) >> 8;
      }
      value = len;
      if (value > sizeof (key))
          value = sizeof (key);
      memmove( (char *) key, auth, value);
    }
#endif
}

Generated by  Doxygen 1.6.0   Back to index