Commit Graph

450 Commits

Author SHA1 Message Date
Alejandro Colomar
1eaa30756e Assume <errno.h> exists
ISO C99 requires <errno.h>.

Many files in the project already include <errno.h> unconditionally,
so it's reasonable to assume that it is always available.

Link: <https://github.com/shadow-maint/shadow/pull/600>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-12-12 09:16:43 +01:00
Alejandro Colomar
c4d9dcacc9 Assume <stdbool.h> exists
ISO C99 requires <stdbool.h>.

Many files in the project already include <stdbool.h> unconditionally,
so it's reasonable to assume that it is always available.

Link: <https://github.com/shadow-maint/shadow/pull/600>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-12-12 09:16:43 +01:00
Alejandro Colomar
ab91ec10b4 Hide [[gnu::malloc(deallocator)]] in a macro
Clang doesn't implement this attribute and reports an error.  Work
around it by hiding it in a macro that will be empty in clang.

Reported-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-12-05 10:47:19 +01:00
Alex Colomar
155c9421b9 libmisc: agetpass(), erase_pass(): Add functions for getting passwords safely
There are several issues with getpass(3).

Many implementations of it share the same issues that the infamous
gets(3).  In glibc it's not so terrible, since it's a wrapper
around getline(3).  But it still has an important bug:

If the password is long enough, getline(3) will realloc(3) memory,
and prefixes of the password will be laying around in some
deallocated memory.

See the getpass(3) manual page for more details, and especially
the commit that marked it as deprecated, which links to a long
discussion in the linux-man@ mailing list.

So, readpassphrase(3bsd) is preferrable, which is provided by
libbsd on GNU systems.  However, using readpassphrase(3) directly
is a bit verbose, so we can write our own wrapper with a simpler
interface similar to that of getpass(3).

One of the benefits of writing our own interface around
readpassphrase(3) is that we can hide there any checks that should
be done always and which would be error-prone to repeat every
time.  For example, check that there was no truncation in the
password.

Also, use malloc(3) to get the buffer, instead of using a global
buffer.  We're not using a multithreaded program (and it wouldn't
make sense to do so), but it's nice to know that the visibility of
our passwords is as limited as possible.

erase_pass() is a clean-up function that handles all clean-up
correctly, including zeroing the entire buffer, and then
free(3)ing the memory.  By using [[gnu::malloc(erase_pass)]], we
make sure that we don't leak the buffers in any case, since the
compiler will be able to enforce clean up.

Link: <https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit?id=7ca189099d73bde954eed2d7fc21732bcc8ddc6b>
Reported-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-12-05 10:47:19 +01:00
Serge Hallyn
90424e7c20 Don't warn when failed to open /etc/nsswitch.conf
Maybe we should have a debug mode where it's still printed, but
we don't, so let's be quieter.

Closes #557
2022-11-08 10:18:17 -06:00
Iker Pedrosa
16afe18142 Raise limit for passwd and shadow entry length
Moreover, include checks to prevent writing entries longer than the
length limit.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1422497

Signed-off-by: Tomáš Mráz <tm@t8m.info>
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-10-14 10:41:40 +02:00
Alejandro Colomar
3dc1754e50 Use libc MAX() and MIN()
glibc, musl, FreeBSD, and OpenBSD define the MAX() and MIN()
macros in <sys/param.h> with the same definition that we use.
Let's not redefine it here and use the system one, as it's
effectively the same as we define (modulo whitespace).

See:

shadow (previously):

alx@asus5775:~/src/shadow/shadow$ grepc -ktm MAX
./lib/defines.h:318:#define MAX(x,y) (((x) > (y)) ? (x) : (y))

glibc:

alx@asus5775:~/src/gnu/glibc$ grepc -ktm -x 'sys/param.h$' MAX
./misc/sys/param.h:103:#define MAX(a,b) (((a)>(b))?(a):(b))

musl:

alx@asus5775:~/src/musl/musl$ grepc -ktm -x 'sys/param.h$' MAX
./include/sys/param.h:19:#define MAX(a,b) (((a)>(b))?(a):(b))

OpenBSD:

alx@asus5775:~/src/bsd/openbsd/src$ grepc -ktm -x 'sys/param.h$' MAX
./sys/sys/param.h:193:#define	MAX(a,b) (((a)>(b))?(a):(b))

FreeBSD:

alx@asus5775:~/src/bsd/freebsd/freebsd-src$ grepc -ktm -x 'sys/param.h$' MAX
./sys/sys/param.h:333:#define	MAX(a,b) (((a)>(b))?(a):(b))

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-09-30 16:13:36 -05:00
Alex Colomar
0d9799de04 Don't test for NULL before calling free(3)
free(3) accepts NULL, since the oldest ISO C.  I guess the
paranoid code was taking care of prehistoric implementations of
free(3).  I've never known of an implementation that doesn't
conform to this, so let's simplify this.

Remove xfree(3), which was effectively an equivalent of free(3).

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-09-29 16:03:53 +02:00
Christian Göttsche
e74bfe2c75 lib: use strzero where applicable
Replace `memzero (s, strlen(s))` with just the internal wrapper
`strzero (s)` where the underlying allocated size is not known.
2022-09-27 16:52:06 +02:00
Luca BRUNO
14e7caf6b2 lib/commonio: make lock failures more detailed
This tweaks the database locking logic so that failures in the
link-checking paths are more detailed.
The rationale for this is that I've experienced a non-deterministic
bug which seems to be coming from this logic, and I'd like to get
more details about the actual failing condition.
2022-09-15 10:31:13 -05:00
genBTC
23634d8de7 useradd: check MLS enablement before setting serange Resolves: https://github.com/shadow-maint/shadow/issues/552 2022-09-02 20:29:34 -05:00
Christian Göttsche
dab764d019 Require symlink support
Require lstat(2), lchown(2), S_IFLNK and S_ISLNK from POSIX.1-2001.

Already unconditionally used in lib/tcbfuncs.c and lib/run_part.c.
2022-08-17 12:34:01 -05:00
Christian Göttsche
c6c8130db4 Use function format attribute where applicable
Allow the compiler to verify the format string against the supplied
arguments.

    chage.c:239:51: warning: format not a string literal, format string not checked [-Wformat-nonliteral]
      239 |                 (void) strftime (buf, sizeof buf, format, tp);
          |                                                   ^~~~~~
2022-08-06 11:27:56 -05:00
Christian Göttsche
ce185b2b48 Drop obsolete prototype for log_dolog()
log_dolog() is neither implemented nor used.
2022-08-06 11:27:56 -05:00
Christian Göttsche
87d5a54ba0 Drop superfluous const from return type
salt.c:102:22: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
      102 | static /*@observer@*/const unsigned long SHA_get_salt_rounds (/*@null@*/int *prefered_rounds);
          |                      ^~~~~
    salt.c:110:22: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
      110 | static /*@observer@*/const unsigned long YESCRYPT_get_salt_cost (/*@null@*/int *prefered_cost);
          |                      ^~~~~

    subordinateio.c:160:8: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
      160 | static const bool range_exists(struct commonio_db *db, const char *owner)
          |        ^~~~~
2022-08-06 11:27:56 -05:00
Christian Göttsche
44917600b6 Drop register keyword
Compilers are free to ignore the indented hint and modern optimizations
should create good code by themself.

(As such it is for example deprecated in C++17.)
2022-08-06 11:27:56 -05:00
Christian Göttsche
c5090d91a1 Return void pointer from xmalloc
xmalloc is a wrapper around malloc(3), which bails out on OOM failures.
As such it returns raw memory and is used to allocated all kind of
types.
2022-08-06 11:27:56 -05:00
Christian Göttsche
e32b4a9a81 Declare read-only parameters const
Signal callers arguments are not going to be modified and allow passing
const pointers.
2022-08-06 11:27:56 -05:00
Iker Pedrosa
3ec32f9975 subordinateio: also compare the owner ID
IDs already populate /etc/subuid and /etc/subgid files so it's necessary
not only to check for the owner name but also for the owner ID of a
given range.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2093311

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-07-20 09:29:31 -05:00
Iker Pedrosa
3b89b71680 Initialize local variables
CWE-457 by CodeQL.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-24 07:49:11 -05:00
Iker Pedrosa
0c7ded471f Add header guards
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-24 07:49:11 -05:00
Iker Pedrosa
0b51cde162 Remove commented out code and FIXMEs
In order to remove some of the FIXMEs it was necessary to change the
code and call getulong() instead of getlong().

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-05-24 07:49:11 -05:00
Iker Pedrosa
e101219ad7 nss: get shadow_logfd with log_get_logfd()
If /etc/nsswitch.conf doesn't exist podman crashes because shadow_logfd
is NULL. In order to avoid that load the log file descriptor with the
log_get_logfd() helper function.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2038811

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2022-01-15 08:47:50 -06:00
Alejandro Colomar
1b96f6a9b3 Remove AC_HEADER_TIME and TIME_WITH_SYS_TIME checks
Systems on which <sys/time.h> conflicted with <time.h> are obsolete.

This macro has been marked as obsolete by autoconf documentation.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Alejandro Colomar
5538ecd7cc Remove AC_HEADER_STAT and STAT_MACROS_BROKEN
As autoconf documentation says, this macro is obsolescent, as no
current systems have the bug in S_ISDIR, S_ISREG, etc..
The affected systems were Tektronix UTekV, Amdahl UTS, and
Motorola System V/88.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Alejandro Colomar
9e788adf56 Remove AC_HEADER_SYS_WAIT
GNU autoconf documentation marks this macro as obsolescent, as
current systems are compatible with POSIX.

Simplify code to unconditionally include <sys/wait.h>, and don't
redefine WIFEXITSTATUS() and WIFEXITED(), since they are mandated
by POSIX.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Alejandro Colomar
5450f9a904 Remove old compatibility DIRECT macro.
Use struct dirent directly.  See parent commit.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Alejandro Colomar
79e28694ef Remove AC_HEADER_DIRENT
POSIX.1-2001 defines 'struct dirent' in <dirent.h>.  It replaces
the old 'struct direct' found in BSDs.  All of the systems that I
checked (including FreeBSD, NetBSD, and OpenBSD), now provide
<dirent.h> with 'struct dirent', as mandated by POSIX.

Since autoconf first checks <dirent.h> and only if it's missing it
checks other header files, it's clear that it will always find
<dirent.h>, so let's simplify.

GNU autoconf documentation declares this macro as obsolescent, and
acknowledges that all current systems with directory libraries
have <dirent.h>:
<https://www.gnu.org/software/autoconf/manual/autoconf-2.70/html_node/Particular-Headers.html>

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2022-01-15 08:25:53 -06:00
Serge Hallyn
39eea79d8d
Merge pull request #487 from cgzones/misc_warnings
Resolve several compiler warnings
2022-01-03 09:45:12 -06:00
Serge Hallyn
98f943f2a5
Merge pull request #481 from alejandro-colomar/STDC_HEADERS
Assume C89 is available
2022-01-03 09:37:06 -06:00
Christian Göttsche
7a799ebb2c Ensure memory cleaning
Compilers are allowed to and do optimize memset(3) calls away for
pointers not accessed in the future. Since the memzero wrappers purpose
is exactly to unconditionally override memory (e.g. for stored
passwords) do not implement via regular memset(3), but via either
memset_s(3), explicit_bzero(3) or a hand written implementation using
volatile pointers.

See https://wiki.sei.cmu.edu/confluence/display/c/MSC06-C.+Beware+of+compiler+optimizations
2022-01-03 15:09:39 +01:00
Christian Göttsche
b2bc1f6927 Do not return garbage in run_parts
If scandir(3) returns 0, the uninitialized value of execute_result will
be returned.
2022-01-03 15:09:17 +01:00
Christian Göttsche
a8166a86ed Declare read-only arguments of run_part(s) const
run_part() and run_parts() do not modify their directory, name and
action arguments.
Also include the header in the implementation to provide the prototypes.

useradd.c:2495:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
 2495 |         if (run_parts ("/etc/shadow-maint/useradd-pre.d", (char*)user_name,
      |                                                           ^
useradd.c:2495:24: warning: passing argument 1 of ‘run_parts’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
 2495 |         if (run_parts ("/etc/shadow-maint/useradd-pre.d", (char*)user_name,
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from useradd.c:45:
../lib/run_part.h:2:22: note: expected ‘char *’ but argument is of type ‘const char *’
    2 | int run_parts (char *directory, char *name, char *action);
      |                ~~~~~~^~~~~~~~~
useradd.c:2496:25: warning: passing argument 3 of ‘run_parts’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
 2496 |                         "useradd")) {
      |                         ^~~~~~~~~
2022-01-03 15:09:17 +01:00
Christian Göttsche
119cee142e Declare argument of nss_init const
nss_init() does not modify its path argument, thus declare it const.
Also drop superfluous prototype.

nss.c:54:31: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
   54 |                 nsswitch_path = NSSWITCH;
      |                               ^
2022-01-03 15:09:17 +01:00
Christian Göttsche
45bba0e190 Use strict prototypes
Function declarations with no argument declare functions taking an
arbitrary number of arguments. Use the special type void to declare
functions taking no argument.
2022-01-03 15:09:17 +01:00
Christian Göttsche
f84b8530c5 Declare file local functions static 2022-01-03 15:09:17 +01:00
Sam James
7ad96661ef build: include lib/shadowlog_internal.h in dist tarballs
Fixes: #485
Signed-off-by: Sam James <sam@gentoo.org>
2022-01-02 21:06:36 -06:00
Serge Hallyn
e8a2cfa7dc
Merge pull request #451 from hallyn/2021-12-05/license 2022-01-02 18:38:42 -06:00
Alejandro Colomar
44126d85ee Remove definition of ISDIGIT_LOCALE(c)
It wasn't being used at all.  Let's remove it.

Use isdigit(3) directly in comments that referenced it.

Also, in those comments, remove an outdated reference to the fact
that ISDIGIT_LOCALE(c) might evaluate its argument more than once,
which could be true a few commits ago, until
IN_CTYPE_DEFINITION(c) was removed.  Previously, the definition
for ISDIGIT_LOCALE(c) was:

 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
 # define IN_CTYPE_DOMAIN(c) 1
 #else
 # define IN_CTYPE_DOMAIN(c) isascii(c)
 #endif

 #define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))

Which could evaluate 'c' twice on pre-C89 systems (which I hope
don't exist nowadays).

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-29 02:41:09 +01:00
Alejandro Colomar
45d2e6dff0 Remove IN_CTYPE_DOMAIN, which was always true
The recent removal of STDC_HEADERS made IN_CTYPE_DOMAIN be defined
to 1 unconditionally.  Remove the now unnecessary definition, and
propagate its truthness to expressions where it was used.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-29 02:41:09 +01:00
Alejandro Colomar
4e1afcd662 Assume STDC_HEADERS will always be defined
We're in 2021.  C89 is everywhere; in fact, there are many other
assumptions in the code that wouldn't probably hold on
pre-standard C environments.  Let's simplify and assume that C89
is available.

The specific assumptions are that:
- <string.h>, and <stdlib.h> are available
- strchr(3), strrchr(3), and strtok(3) are available
- isalpha(3), isspace(3), isdigit(3), and isupper(3) are available

I think we can safely assume we have all of those.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-29 02:39:04 +01:00
Alejandro Colomar
b7e12ec04e Remove HAVE_MEMSET ifdefs
memset(3) has been in standard C since C89.  It is also in
POSIX.1-2001, in SVr4, and in 4.3BSD (see memset(3) and memset(3p)).
We can assume that this function is always available.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-27 21:52:00 +01:00
Alejandro Colomar
047bfc47c6 Remove HAVE_MEMCPY ifdefs
memcpy(3) has been in standard C since C89.  It is also in
POSIX.1-2001, in SVr4, and in 4.3BSD (see memcpy(3) and memcpy(3p)).
We can assume that this function is always available.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-27 21:38:47 +01:00
Adam Sampson
2b0bdef6f9 lib: provide default values for shadow_progname/shadow_logfd 2021-12-27 16:28:23 +00:00
Serge Hallyn
e1b1d187f4
Merge pull request #467 from alejandro-colomar/date_to_str
Have a single definition of date_to_str()
2021-12-27 09:53:00 -06:00
Alejandro Colomar
355ad6a9e0 Have a single definition of date_to_str()
PARAMETERS:

According to the C2x charter, I reordered the parameters 'size'
and 'buf' from previously existing date_to_str() definitions.

C2x charter:
> 15. Application Programming Interfaces (APIs) should be
> self-documenting when possible.  In particular, the order of
> parameters in function declarations should be arranged such that
> the size of an array appears before the array.  The purpose is to
> allow Variable-Length Array (VLA) notation to be used.  This not
> only makes the code's purpose clearer to human readers, but also
> makes static analysis easier.  Any new APIs added to the Standard
> should take this into consideration.

I used 'long' for the date parameter, as some uses of the function
need to pass a negative value meaning "never".

FUNCTION BODY:

I didn't check '#ifdef HAVE_STRFTIME', which old definitions did,
since strftime(3) is guaranteed by the C89 standard, and all of
the conversion specifiers that we use are also specified by that
standard, so we don't need any extensions at all.

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
2021-12-26 18:55:39 +01:00
Adam Sampson
0e6fe5e728 lib: rename Prog to shadow_progname, with only one definition
The build was failing with duplicate symbol errors with -fno-common.
This is the default in GCC 10 and later, and explicitly enabled in some
distributions to catch problems like this. There were two causes:

- Prog and shadow_logfd were defined in a header file that was included
  in multiple other files. Fix this by defining them once in
  shadowlog.c, and having extern declarations in the header.

- Most of the tools (except id/nologin) also define a Prog variable,
  which is not intended to alias the one in the library. Fix
  this by renaming Prog in the library to shadow_progname, which also
  matches the new accessor functions for it.
2021-12-25 22:41:58 +00:00
Serge Hallyn
f93cf255d4 Update licensing info
Closes #238

Update all files to list SPDX license shortname.  Most files are
BSD 3 clause license.

The exceptions are:

serge@sl ~/src/shadow$ git grep SPDX-License | grep -v BSD-3-Clause
contrib/atudel:# SPDX-License-Identifier: BSD-4-Clause
lib/tcbfuncs.c: * SPDX-License-Identifier: 0BSD
libmisc/salt.c: * SPDX-License-Identifier: Unlicense
src/login_nopam.c: * SPDX-License-Identifier: Unlicense
src/nologin.c: * SPDX-License-Identifier: BSD-2-Clause
src/vipw.c: * SPDX-License-Identifier: GPL-2.0-or-later

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-12-23 19:36:50 -06:00
Serge Hallyn
79157cbad8 Make shadow_logfd and Prog not extern
Closes #444
Closes #465

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-12-23 15:18:07 -06:00
Iker Pedrosa
d594243fbb lib: check NULL before freeing passwd data
Add an additional NULL check condition in spw_free() and pw_free() to
avoid freeing an already empty pointer.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
2021-11-19 12:09:59 +01:00