Before 3b7cc05387 ("lib: replace `USER_NAME_MAX_LENGTH` macro"), this
code did use a length. It used a utmp(5) fixed-width buffer, so the
length matches the buffer size (there was no terminating NUL byte).
However, sysconf(_SC_LOGIN_NAME_MAX) returns a buffer size that accounts
for the terminating null byte; see sysconf(3). Thus, the commit that
introduced the call to sysconf(3), should have taken that detail into
account.
403a2e3771 ("lib/chkname.c: Take NUL byte into account"), by Tobias,
caught that bug in <lib/chkname.c>, but missed that the same commit that
introduced that bug, introduced the same bug in two other places.
This fixes all remaining calls to sysconf(_SC_LOGIN_NAME_MAX).
I still observe some suspicious code after this fix:
if (do_rlogin(hostname, username, max_size - 1, term, sizeof(term)))
...
login_prompt(username, max_size - 1);
We're passing size-1 to functions that want a size. But since the fix
to those will be different, let's do that in the following commits.
Link: <https://github.com/shadow-maint/shadow/pull/935>
Link: <https://github.com/shadow-maint/shadow/issues/920#issuecomment-1926002209>
Link: <https://github.com/shadow-maint/shadow/pull/757>
Link: <https://github.com/shadow-maint/shadow/issues/674>
See-also: 403a2e3771 ("lib/chkname.c: Take NUL byte into account")
Fixes: 3b7cc05387 ("lib: replace `USER_NAME_MAX_LENGTH` macro")
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Tobias Stoeckmann <tobias@stoeckmann.org>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
It is slightly confusing to allow adding these only to later refuse them.
Here is a (lightly tested :) patch to also refuse them when adding.
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
The conversion from day to seconds can be done in print_date
(renamed to print_day_as_date for clarification). This has the nice
benefit that DAY multiplication and long to time_t conversion are done
at just one place.
Co-developed-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Co-developed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
The password returned by agetpass can be used directly without copying
it into a char array first.
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
Clarify how this endless while(true) loop can be stopped by using a
boolean variable as condition and turn it into a do-while loop.
Suggested-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
New option --stdin/-t is available for root user. It is useful
for automation/setup and it makes shadow utils passwd more versatile.
Signed-off-by: Tomas Halman <tomas@halman.net>
There is an inconsistent use of the MAYBE_UNUSED macro. Sometimes the
`int unused(x)` form is used form and others the `unused int x`. We'd
like to use the second form always.
Related-To: https://github.com/shadow-maint/shadow/issues/918
Suggested-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Pablo Saavedra <psaavedra@igalia.com>
argv is passed to execve(3), which for historic reasons is non-const,
but doesn't modify the strings.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
strtou[l]l(3) silently converts negative numbers into positive. This
behavior is wrong: a negative value should be parsed as a negative
value, which would underflow unsigned (long) long, and so would return
the smallest possible value, 0, and set errno to ERANGE to report an
error.
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
The sulogin program calls pw_entry in a loop while incorrect root
passwords are entered.
Free the previously allocated memory to avoid memory exhaustion.
Co-developed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
We don't need 'static', because it's in main(), which is only called
once. However, we will need initialization as if it were 'static', so
use ={} to initialize it. This will allow freeing the pointers before
they have been allocated.
Cc: Samanta Navarro <ferivoz@riseup.net>
Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Those variables are only used in main(). Restrict their scope.
Keep them static (.bss), as changing that may be dangerous.
Suggested-by: Samanta Navarro <ferivoz@riseup.net>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
The size of time_t varies across systems, but since data type long is
more than enough to calculate with days (precision of shadow file),
use it instead.
Just in case a shadow file contains huge values, check for a possible
signed integer overflow.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Link: <https://github.com/shadow-maint/shadow/pull/876>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
The variable declarations for the buffers have been aligned in this
commit, so that they appear in the diff, making it easier to review.
Some important but somewhat tangent changes included in this commit:
- lib/nss.c: The size was being defined as 65, but then used as 64.
That was a bug, although not an important one; we were just wasting
one byte. Fix that while we replace snprintf() by SNPRINTF(), which
will get the size from sizeof(), and thus will use the real size.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Check for close(2) failure at more places closing a file descriptor
written to.
Also ignore failures with errno set to EINTR (see man:close(2) for
details).
sprintf(3) does not take the destination buffer into account. Although
the destination in these case is large enough, sprintf(3) indicates a
code smell.
Use the xasprintf() wrapper.
Group them at the end of the list of variable definitions, and use
'#if defined()' instead of '#if[n]def'. Also indent nested ones.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
su.c:678:26: warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘const void *’ [-Wformat=]
su.c:681:44: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘const void *’ [-Wformat=]
su.c:683:46: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘const void *’ [-Wformat=]
Reported-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
We don't need to terminate them manually after the call. Remove all
that paranoid code, which in some cases was even wrong. While at it,
let's do a few more things:
- Use sizeof(buf) for the size of the buffer. I found that a few cases
were passing one less byte (probably because the last one was
manually zeroed later). This caused a double NUL. snprintf(3) wants
the size of the entire buffer to properly terminate it. Passing the
exact value hardcoded is brittle, so use sizeof().
- Align and improve style of variable declarations. This makes them
appear in this diff, which will help review the patch.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
- Set errno = 0 before the call. Otherwise, it may contain anything.
- ERANGE is not the only possible errno value of these functions. They
can also set it to EINVAL.
- Any errno value after these calls is bad; just compare against 0.
- Don't check for the return value; just errno. This function is
guaranteed to not modify errno on success (POSIX).
- Check endptr == str, which may or may not set EINVAL.
Suggested-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Since failure() is [[noreturn]], we can invert the conditional so that
we don't need an else. This silences a -Wunused-parameter warning.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
This simplifies the code a little bit, and prepares for the next
commits, which will clean up further.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
