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/* sysutils.c - system helpers
* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#ifdef HAVE_STAT
#include <sys/stat.h>
#endif
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
#include <asm/sysinfo.h>
#include <asm/unistd.h>
#endif
#ifdef HAVE_SETRLIMIT
#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>
#endif
#include "util.h"
#include "i18n.h"
#include "sysutils.h"
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
#warning using trap_unaligned
static int
setsysinfo(unsigned long op, void *buffer, unsigned long size,
int *start, void *arg, unsigned long flag)
{
return syscall(__NR_osf_setsysinfo, op, buffer, size, start, arg, flag);
}
void
trap_unaligned(void)
{
unsigned int buf[2];
buf[0] = SSIN_UACPROC;
buf[1] = UAC_SIGBUS | UAC_NOPRINT;
setsysinfo(SSI_NVPAIRS, buf, 1, 0, 0, 0);
}
#else
void
trap_unaligned(void)
{ /* dummy */
}
#endif
int
disable_core_dumps (void)
{
#ifdef HAVE_DOSISH_SYSTEM
return 0;
#else
# ifdef HAVE_SETRLIMIT
struct rlimit limit;
/* We only set the current limit unless we were not able to
retrieve the old value. */
if (getrlimit (RLIMIT_CORE, &limit))
limit.rlim_max = 0;
limit.rlim_cur = 0;
if( !setrlimit (RLIMIT_CORE, &limit) )
return 0;
if( errno != EINVAL && errno != ENOSYS )
log_fatal (_("can't disable core dumps: %s\n"), strerror(errno) );
#endif
return 1;
#endif
}
int
enable_core_dumps (void)
{
#ifdef HAVE_DOSISH_SYSTEM
return 0;
#else
# ifdef HAVE_SETRLIMIT
struct rlimit limit;
if (getrlimit (RLIMIT_CORE, &limit))
return 1;
limit.rlim_cur = limit.rlim_max;
setrlimit (RLIMIT_CORE, &limit);
return 1; /* We always return true because trhis function is
merely a debugging aid. */
# endif
return 1;
#endif
}
/* Return a string which is used as a kind of process ID */
const byte *
get_session_marker( size_t *rlen )
{
static byte marker[SIZEOF_UNSIGNED_LONG*2];
static int initialized;
if ( !initialized ) {
volatile ulong aa, bb; /* we really want the uninitialized value */
ulong a, b;
initialized = 1;
/* also this marker is guessable it is not easy to use this
* for a faked control packet because an attacker does not
* have enough control about the time the verification does
* take place. Of course, we can add just more random but
* than we need the random generator even for verification
* tasks - which does not make sense. */
a = aa ^ (ulong)getpid();
b = bb ^ (ulong)time(NULL);
memcpy( marker, &a, SIZEOF_UNSIGNED_LONG );
memcpy( marker+SIZEOF_UNSIGNED_LONG, &b, SIZEOF_UNSIGNED_LONG );
}
*rlen = sizeof(marker);
return marker;
}
#if 0 /* not yet needed - Note that this will require inclusion of
cmacros.am in Makefile.am */
int
check_permissions(const char *path,int extension,int checkonly)
{
#if defined(HAVE_STAT) && !defined(HAVE_DOSISH_SYSTEM)
char *tmppath;
struct stat statbuf;
int ret=1;
int isdir=0;
if(opt.no_perm_warn)
return 0;
if(extension && path[0]!=DIRSEP_C)
{
if(strchr(path,DIRSEP_C))
tmppath=make_filename(path,NULL);
else
tmppath=make_filename(GNUPG_LIBDIR,path,NULL);
}
else
tmppath=m_strdup(path);
/* It's okay if the file doesn't exist */
if(stat(tmppath,&statbuf)!=0)
{
ret=0;
goto end;
}
isdir=S_ISDIR(statbuf.st_mode);
/* Per-user files must be owned by the user. Extensions must be
owned by the user or root. */
if((!extension && statbuf.st_uid != getuid()) ||
(extension && statbuf.st_uid!=0 && statbuf.st_uid!=getuid()))
{
if(!checkonly)
log_info(_("Warning: unsafe ownership on %s \"%s\"\n"),
isdir?"directory":extension?"extension":"file",path);
goto end;
}
/* This works for both directories and files - basically, we don't
care what the owner permissions are, so long as the group and
other permissions are 0 for per-user files, and non-writable for
extensions. */
if((extension && (statbuf.st_mode & (S_IWGRP|S_IWOTH)) !=0) ||
(!extension && (statbuf.st_mode & (S_IRWXG|S_IRWXO)) != 0))
{
char *dir;
/* However, if the directory the directory/file is in is owned
by the user and is 700, then this is not a problem.
Theoretically, we could walk this test up to the root
directory /, but for the sake of sanity, I'm stopping at one
level down. */
dir= make_dirname (tmppath);
if(stat(dir,&statbuf)==0 && statbuf.st_uid==getuid() &&
S_ISDIR(statbuf.st_mode) && (statbuf.st_mode & (S_IRWXG|S_IRWXO))==0)
{
xfree (dir);
ret=0;
goto end;
}
m_free(dir);
if(!checkonly)
log_info(_("Warning: unsafe permissions on %s \"%s\"\n"),
isdir?"directory":extension?"extension":"file",path);
goto end;
}
ret=0;
end:
m_free(tmppath);
return ret;
#endif /* HAVE_STAT && !HAVE_DOSISH_SYSTEM */
return 0;
}
#endif
|
