shadow/libmisc/failure.c

344 lines
8.9 KiB
C
Raw Normal View History

/*
* Copyright (c) 1989 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 1998, Marek Michałkiewicz
* Copyright (c) 2002 - 2005, Tomasz Kłoczko
2010-08-22 18:34:54 +05:30
* Copyright (c) 2008 - 2010, Nicolas François
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 COPYRIGHT
* HOLDERS OR 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.
*/
#include <config.h>
#ident "$Id$"
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include "defines.h"
#include "faillog.h"
#include "getdef.h"
#include "failure.h"
#define YEAR (365L*DAY)
/*
* failure - make failure entry
*
* failure() creates a new (struct faillog) entry or updates an
* existing one with the current failed login information.
*/
void failure (uid_t uid, const char *tty, struct faillog *fl)
{
int fd;
off_t offset_uid = (off_t) (sizeof *fl) * uid;
/*
* Don't do anything if failure logging isn't set up.
*/
if (access (FAILLOG_FILE, F_OK) != 0) {
return;
}
fd = open (FAILLOG_FILE, O_RDWR);
if (fd < 0) {
SYSLOG ((LOG_WARN,
"Can't write faillog entry for UID %lu in %s.",
(unsigned long) uid, FAILLOG_FILE));
return;
}
/*
* The file is indexed by UID value meaning that shared UID's
* share failure log records. That's OK since they really
* share just about everything else ...
*/
if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
|| (read (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
/* This is not necessarily a failure. The file is
* initially zero length.
*
* If lseek() or read() failed for any other reason, this
* might reset the counter. But the new failure will be
* logged.
*/
memzero (fl, sizeof *fl);
}
/*
* Update the record. We increment the failure count to log the
* latest failure. The only concern here is overflow, and we'll
* check for that. The line name and time of day are both
* updated as well.
*/
if (fl->fail_cnt + 1 > 0) {
fl->fail_cnt++;
}
Fix covscan BUFFER_SIZE Error: BUFFER_SIZE (CWE-170): [#def6] shadow-4.8.1/libmisc/failure.c:101: buffer_size_warning: Calling "strncpy" with a maximum size argument of 12 bytes on destination array "fl->fail_line" of size 12 bytes might leave the destination string unterminated. 99| } 100| 101|-> strncpy (fl->fail_line, tty, sizeof fl->fail_line); 102| (void) time (&fl->fail_time); 103| Error: BUFFER_SIZE (CWE-170): [#def9] shadow-4.8.1/libmisc/log.c:103: buffer_size_warning: Calling "strncpy" with a maximum size argument of 32 bytes on destination array "newlog.ll_line" of size 32 bytes might leave the destination string unterminated. 101| (void) time (&ll_time); 102| newlog.ll_time = ll_time; 103|-> strncpy (newlog.ll_line, line, sizeof newlog.ll_line); 104| #if HAVE_LL_HOST 105| strncpy (newlog.ll_host, host, sizeof newlog.ll_host); Error: BUFFER_SIZE (CWE-170): [#def10] shadow-4.8.1/libmisc/log.c:105: buffer_size_warning: Calling "strncpy" with a maximum size argument of 256 bytes on destination array "newlog.ll_host" of size 256 bytes might leave the destination string unterminated. 103| strncpy (newlog.ll_line, line, sizeof newlog.ll_line); 104| #if HAVE_LL_HOST 105|-> strncpy (newlog.ll_host, host, sizeof newlog.ll_host); 106| #endif 107| if ( (lseek (fd, offset, SEEK_SET) != offset) Error: BUFFER_SIZE (CWE-170): [#def13] shadow-4.8.1/libmisc/utmp.c:260: buffer_size_warning: Calling "strncpy" with a maximum size argument of 32 bytes on destination array "utent->ut_line" of size 32 bytes might leave the destination string unterminated. 258| #endif /* HAVE_STRUCT_UTMP_UT_TYPE */ 259| utent->ut_pid = getpid (); 260|-> strncpy (utent->ut_line, line, sizeof (utent->ut_line)); 261| #ifdef HAVE_STRUCT_UTMP_UT_ID 262| if (NULL != ut) { Error: BUFFER_SIZE (CWE-170): [#def14] shadow-4.8.1/libmisc/utmp.c:266: buffer_size_warning: Calling "strncpy" with a maximum size argument of 4 bytes on destination array "utent->ut_id" of size 4 bytes might leave the destination string unterminated. 264| } else { 265| /* XXX - assumes /dev/tty?? */ 266|-> strncpy (utent->ut_id, line + 3, sizeof (utent->ut_id)); 267| } 268| #endif /* HAVE_STRUCT_UTMP_UT_ID */ Error: BUFFER_SIZE (CWE-170): [#def15] shadow-4.8.1/libmisc/utmp.c:273: buffer_size_warning: Calling "strncpy" with a maximum size argument of 32 bytes on destination array "utent->ut_user" of size 32 bytes might leave the destination string unterminated. 271| #endif /* HAVE_STRUCT_UTMP_UT_NAME */ 272| #ifdef HAVE_STRUCT_UTMP_UT_USER 273|-> strncpy (utent->ut_user, name, sizeof (utent->ut_user)); 274| #endif /* HAVE_STRUCT_UTMP_UT_USER */ 275| if (NULL != hostname) { Error: BUFFER_SIZE (CWE-170): [#def16] shadow-4.8.1/libmisc/utmp.c:278: buffer_size_warning: Calling "strncpy" with a maximum size argument of 256 bytes on destination array "utent->ut_host" of size 256 bytes might leave the destination string unterminated. 276| struct addrinfo *info = NULL; 277| #ifdef HAVE_STRUCT_UTMP_UT_HOST 278|-> strncpy (utent->ut_host, hostname, sizeof (utent->ut_host)); 279| #endif /* HAVE_STRUCT_UTMP_UT_HOST */ 280| #ifdef HAVE_STRUCT_UTMP_UT_SYSLEN Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-06-16 13:20:53 +05:30
strncpy (fl->fail_line, tty, sizeof (fl->fail_line) - 1);
(void) time (&fl->fail_time);
/*
* Seek back to the correct position in the file and write the
* record out. Ideally we should lock the file in case the same
* account is being logged simultaneously. But the risk doesn't
* seem that great.
*/
if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
|| (write (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)
|| (close (fd) != 0)) {
SYSLOG ((LOG_WARN,
"Can't write faillog entry for UID %lu in %s.",
(unsigned long) uid, FAILLOG_FILE));
(void) close (fd);
}
}
static bool too_many_failures (const struct faillog *fl)
{
time_t now;
if ((0 == fl->fail_max) || (fl->fail_cnt < fl->fail_max)) {
return false;
}
if (0 == fl->fail_locktime) {
return true; /* locked until reset manually */
}
(void) time (&now);
if ((fl->fail_time + fl->fail_locktime) < now) {
return false; /* enough time since last failure */
}
return true;
}
/*
* failcheck - check for failures > allowable
*
* failcheck() is called AFTER the password has been validated. If the
* account has been "attacked" with too many login failures, failcheck()
* returns 0 to indicate that the login should be denied even though
* the password is valid.
*
* failed indicates if the login failed AFTER the password has been
* validated.
*/
int failcheck (uid_t uid, struct faillog *fl, bool failed)
{
int fd;
struct faillog fail;
off_t offset_uid = (off_t) (sizeof *fl) * uid;
/*
* Suppress the check if the log file isn't there.
*/
if (access (FAILLOG_FILE, F_OK) != 0) {
return 1;
}
fd = open (FAILLOG_FILE, failed?O_RDONLY:O_RDWR);
if (fd < 0) {
SYSLOG ((LOG_WARN,
"Can't open the faillog file (%s) to check UID %lu. "
"User access authorized.",
FAILLOG_FILE, (unsigned long) uid));
return 1;
}
/*
* Get the record from the file and determine if the user has
* exceeded the failure limit. If "max" is zero, any number
* of failures are permitted. Only when "max" is non-zero and
* "cnt" is greater than or equal to "max" is the account
* considered to be locked.
*
* If read fails, there is no record for this user yet (the
* file is initially zero length and extended by writes), so
* no need to reset the count.
*/
if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
|| (read (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
(void) close (fd);
return 1;
}
if (too_many_failures (fl)) {
(void) close (fd);
return 0;
}
/*
* The record is updated if this is not a failure. The count will
* be reset to zero, but the rest of the information will be left
* in the record in case someone wants to see where the failed
* login originated.
*/
if (!failed) {
fail = *fl;
fail.fail_cnt = 0;
if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
|| (write (fd, (const void *) &fail, sizeof fail) != (ssize_t) sizeof fail)
|| (close (fd) != 0)) {
SYSLOG ((LOG_WARN,
"Can't reset faillog entry for UID %lu in %s.",
(unsigned long) uid, FAILLOG_FILE));
(void) close (fd);
}
} else {
(void) close (fd);
}
return 1;
}
/*
* failprint - print line of failure information
*
* failprint takes a (struct faillog) entry and formats it into a
* message which is displayed at login time.
*/
void failprint (const struct faillog *fail)
{
struct tm *tp;
#if HAVE_STRFTIME
char lasttimeb[256];
char *lasttime = lasttimeb;
#else
char *lasttime;
#endif
time_t NOW;
if (0 == fail->fail_cnt) {
return;
}
tp = localtime (&(fail->fail_time));
(void) time (&NOW);
#if HAVE_STRFTIME
/*
* Print all information we have.
*/
(void) strftime (lasttimeb, sizeof lasttimeb, "%c", tp);
#else
/*
* Do the same thing, but don't use strftime since it
* probably doesn't exist on this system
*/
lasttime = asctime (tp);
lasttime[24] = '\0';
if ((NOW - fail->fail_time) < YEAR) {
lasttime[19] = '\0';
}
if ((NOW - fail->fail_time) < DAY) {
lasttime = lasttime + 11;
}
if (' ' == *lasttime) {
lasttime++;
}
#endif
* libmisc/limits.c: Avoid implicit conversion of integer to boolean. * libmisc/basename.c: Avoid implicit conversion of pointer to boolean. * libmisc/basename.c, lib/prototypes.h (Basename): Return a constant string. * libmisc/basename.c, libmisc/obscure.c, lib/prototypes.h, libmisc/xmalloc.c, libmisc/getdate.h, libmisc/system.c, libmisc/getgr_nam_gid.c, libmisc/failure.c, libmisc/valid.c: Add splint annotations. * libmisc/chowndir.c: Avoid memory leak. * libmisc/chowndir.c: Do not check *printf/*puts return value. * libmisc/chowntty.c: Avoid implicit conversion between integer types. * libmisc/obscure.c: Return a bool when possible instead of int. * libmisc/shell.c: Do not check *printf/*puts return value. * libmisc/shell.c: Do not check execle return value. * libmisc/setupenv.c: Avoid implicit conversion between integer types. * libmisc/xmalloc.c: size should not be zero to avoid returning NULL pointers. * libmisc/hushed.c: Do not check *printf/*puts return value. * libmisc/system.c: Avoid implicit conversion of integer to boolean. safe_system last argument is a boolean. * libmisc/system.c: Check return value of dup2. * libmisc/system.c: Do not check *printf/*puts return value. * libmisc/system.c: Do not check execve return value. * libmisc/salt.c: Do not check *printf/*puts return value. * libmisc/loginprompt.c: Do not check gethostname return value. * libmisc/find_new_gid.c, libmisc/find_new_uid.c: Do not check gr_rewind/pw_rewind return value. * libmisc/ttytype.c: Limit the number of parsed characters in the sscanf format. * libmisc/ttytype.c: Test if a type was really read. * libmisc/sub.c: Do not check *printf/*puts return value. * libmisc/sub.c: Avoid implicit conversion of integer to boolean. * src/userdel.c: Fix typo in comment. * src/userdel.c: Avoid implicit conversion of boolean to integer. * src/userdel.c: safe_system last argument is a boolean. * src/newusers.c: Avoid implicit conversion of boolean to integer. * src/newusers.c: Avoid implicit conversion of integer to boolean. * src/usermod.c: Add brackets. * src/usermod.c: Avoid implicit conversion of characters or integers to booleans. * src/vipw.c: Avoid implicit conversion of integer to boolean. * src/su.c: Avoid implicit conversion of integer to boolean. * src/su.c: Add brackets. * src/useradd.c: Avoid implicit conversion of characters or integers to booleans.
2010-08-23 00:43:53 +05:30
/*@-formatconst@*/
(void) printf (ngettext ("%d failure since last login.\n"
"Last was %s on %s.\n",
"%d failures since last login.\n"
"Last was %s on %s.\n",
(unsigned long) fail->fail_cnt),
fail->fail_cnt, lasttime, fail->fail_line);
* libmisc/limits.c: Avoid implicit conversion of integer to boolean. * libmisc/basename.c: Avoid implicit conversion of pointer to boolean. * libmisc/basename.c, lib/prototypes.h (Basename): Return a constant string. * libmisc/basename.c, libmisc/obscure.c, lib/prototypes.h, libmisc/xmalloc.c, libmisc/getdate.h, libmisc/system.c, libmisc/getgr_nam_gid.c, libmisc/failure.c, libmisc/valid.c: Add splint annotations. * libmisc/chowndir.c: Avoid memory leak. * libmisc/chowndir.c: Do not check *printf/*puts return value. * libmisc/chowntty.c: Avoid implicit conversion between integer types. * libmisc/obscure.c: Return a bool when possible instead of int. * libmisc/shell.c: Do not check *printf/*puts return value. * libmisc/shell.c: Do not check execle return value. * libmisc/setupenv.c: Avoid implicit conversion between integer types. * libmisc/xmalloc.c: size should not be zero to avoid returning NULL pointers. * libmisc/hushed.c: Do not check *printf/*puts return value. * libmisc/system.c: Avoid implicit conversion of integer to boolean. safe_system last argument is a boolean. * libmisc/system.c: Check return value of dup2. * libmisc/system.c: Do not check *printf/*puts return value. * libmisc/system.c: Do not check execve return value. * libmisc/salt.c: Do not check *printf/*puts return value. * libmisc/loginprompt.c: Do not check gethostname return value. * libmisc/find_new_gid.c, libmisc/find_new_uid.c: Do not check gr_rewind/pw_rewind return value. * libmisc/ttytype.c: Limit the number of parsed characters in the sscanf format. * libmisc/ttytype.c: Test if a type was really read. * libmisc/sub.c: Do not check *printf/*puts return value. * libmisc/sub.c: Avoid implicit conversion of integer to boolean. * src/userdel.c: Fix typo in comment. * src/userdel.c: Avoid implicit conversion of boolean to integer. * src/userdel.c: safe_system last argument is a boolean. * src/newusers.c: Avoid implicit conversion of boolean to integer. * src/newusers.c: Avoid implicit conversion of integer to boolean. * src/usermod.c: Add brackets. * src/usermod.c: Avoid implicit conversion of characters or integers to booleans. * src/vipw.c: Avoid implicit conversion of integer to boolean. * src/su.c: Avoid implicit conversion of integer to boolean. * src/su.c: Add brackets. * src/useradd.c: Avoid implicit conversion of characters or integers to booleans.
2010-08-23 00:43:53 +05:30
/*@=formatconst@*/
}
/*
2009-04-22 03:32:37 +05:30
* failtmp - update the cumulative failure log
*
* failtmp updates the (struct utmp) formatted failure log which
* maintains a record of all login failures.
*/
void failtmp (const char *username,
#ifdef USE_UTMPX
const struct utmpx *failent
#else /* !USE_UTMPX */
const struct utmp *failent
#endif /* !USE_UTMPX */
)
{
const char *ftmp;
int fd;
/*
* Get the name of the failure file. If no file has been defined
* in login.defs, don't do this.
*/
ftmp = getdef_str ("FTMP_FILE");
if (NULL == ftmp) {
return;
}
/*
* Open the file for append. It must already exist for this
* feature to be used.
*/
if (access (ftmp, F_OK) != 0) {
return;
}
fd = open (ftmp, O_WRONLY | O_APPEND);
if (-1 == fd) {
SYSLOG ((LOG_WARN,
"Can't append failure of user %s to %s.",
username, ftmp));
return;
}
/*
* Append the new failure record and close the log file.
*/
if ( (write (fd, (const void *) failent, sizeof *failent) != (ssize_t) sizeof *failent)
|| (close (fd) != 0)) {
SYSLOG ((LOG_WARN,
"Can't append failure of user %s to %s.",
username, ftmp));
(void) close (fd);
}
}