bpo-28503: Use crypt_r() when available instead of crypt() (GH-11373)

Use crypt_r() when available instead of crypt() in the crypt module.

As a nice side effect: This also avoids a memory sanitizer flake as clang msan doesn't know about crypt's internal libc allocated buffer.
This commit is contained in:
Gregory P. Smith 2018-12-30 15:42:32 -08:00 committed by GitHub
parent 1b29c03c95
commit 387512c7ec
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 185 additions and 1 deletions

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@ -36,7 +36,17 @@
#include <unistd.h>
#endif
#ifdef HAVE_CRYPT_H
#if defined(HAVE_CRYPT_R) && !defined(_GNU_SOURCE)
/* Required for glibc to expose the crypt_r() function prototype. */
# define _GNU_SOURCE
# define _Py_GNU_SOURCE_FOR_CRYPT
#endif
#include <crypt.h>
#ifdef _Py_GNU_SOURCE_FOR_CRYPT
/* Don't leak the _GNU_SOURCE define to other headers. */
# undef _GNU_SOURCE
# undef _Py_GNU_SOURCE_FOR_CRYPT
#endif
#endif
/* For size_t? */

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@ -0,0 +1,2 @@
The `crypt` module now internally uses the `crypt_r()` library function
instead of `crypt()` when available.

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@ -34,7 +34,15 @@ static PyObject *
crypt_crypt_impl(PyObject *module, const char *word, const char *salt)
/*[clinic end generated code: output=0512284a03d2803c input=0e8edec9c364352b]*/
{
return Py_BuildValue("s", crypt(word, salt));
char *crypt_result;
#ifdef HAVE_CRYPT_R
struct crypt_data data;
memset(&data, 0, sizeof(data));
crypt_result = crypt_r(word, salt, &data);
#else
crypt_result = crypt(word, salt);
#endif
return Py_BuildValue("s", crypt_result);
}

144
configure vendored
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@ -12677,6 +12677,150 @@ fi
done
# We search for both crypt and crypt_r as one or the other may be defined
# This gets us our -lcrypt in LIBS when required on the target platform.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing crypt" >&5
$as_echo_n "checking for library containing crypt... " >&6; }
if ${ac_cv_search_crypt+:} false; then :
$as_echo_n "(cached) " >&6
else
ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char crypt ();
int
main ()
{
return crypt ();
;
return 0;
}
_ACEOF
for ac_lib in '' crypt; do
if test -z "$ac_lib"; then
ac_res="none required"
else
ac_res=-l$ac_lib
LIBS="-l$ac_lib $ac_func_search_save_LIBS"
fi
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_search_crypt=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext
if ${ac_cv_search_crypt+:} false; then :
break
fi
done
if ${ac_cv_search_crypt+:} false; then :
else
ac_cv_search_crypt=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_crypt" >&5
$as_echo "$ac_cv_search_crypt" >&6; }
ac_res=$ac_cv_search_crypt
if test "$ac_res" != no; then :
test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing crypt_r" >&5
$as_echo_n "checking for library containing crypt_r... " >&6; }
if ${ac_cv_search_crypt_r+:} false; then :
$as_echo_n "(cached) " >&6
else
ac_func_search_save_LIBS=$LIBS
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char crypt_r ();
int
main ()
{
return crypt_r ();
;
return 0;
}
_ACEOF
for ac_lib in '' crypt; do
if test -z "$ac_lib"; then
ac_res="none required"
else
ac_res=-l$ac_lib
LIBS="-l$ac_lib $ac_func_search_save_LIBS"
fi
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_search_crypt_r=$ac_res
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext
if ${ac_cv_search_crypt_r+:} false; then :
break
fi
done
if ${ac_cv_search_crypt_r+:} false; then :
else
ac_cv_search_crypt_r=no
fi
rm conftest.$ac_ext
LIBS=$ac_func_search_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_crypt_r" >&5
$as_echo "$ac_cv_search_crypt_r" >&6; }
ac_res=$ac_cv_search_crypt_r
if test "$ac_res" != no; then :
test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
fi
ac_fn_c_check_func "$LINENO" "crypt_r" "ac_cv_func_crypt_r"
if test "x$ac_cv_func_crypt_r" = xyes; then :
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#define _GNU_SOURCE /* Required for crypt_r()'s prototype in glibc. */
#include <crypt.h>
int
main ()
{
struct crypt_data d;
char *r = crypt_r("", "", &d);
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
$as_echo "#define HAVE_CRYPT_R 1" >>confdefs.h
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
fi
for ac_func in clock_gettime
do :
ac_fn_c_check_func "$LINENO" "clock_gettime" "ac_cv_func_clock_gettime"

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@ -3818,6 +3818,23 @@ AC_CHECK_FUNCS(gettimeofday,
])
)
# We search for both crypt and crypt_r as one or the other may be defined
# This gets us our -lcrypt in LIBS when required on the target platform.
AC_SEARCH_LIBS(crypt, crypt)
AC_SEARCH_LIBS(crypt_r, crypt)
AC_CHECK_FUNC(crypt_r,
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#define _GNU_SOURCE /* Required for crypt_r()'s prototype in glibc. */
#include <crypt.h>
]], [[
struct crypt_data d;
char *r = crypt_r("", "", &d);
]])],
[AC_DEFINE(HAVE_CRYPT_R, 1, [Define if you have the crypt_r() function.])],
[])
)
AC_CHECK_FUNCS(clock_gettime, [], [
AC_CHECK_LIB(rt, clock_gettime, [
LIBS="$LIBS -lrt"

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@ -147,6 +147,9 @@
/* Define to 1 if you have the <crypt.h> header file. */
#undef HAVE_CRYPT_H
/* Define if you have the crypt_r() function. */
#undef HAVE_CRYPT_R
/* Define to 1 if you have the `ctermid' function. */
#undef HAVE_CTERMID