[Python-checkins] bpo-28503: Use crypt_r() when available instead of crypt() (GH-11373)
Gregory P. Smith
webhook-mailer at python.org
Sun Dec 30 18:42:35 EST 2018
https://github.com/python/cpython/commit/387512c7ecde6446f2e29408af2e16b9fc043807
commit: 387512c7ecde6446f2e29408af2e16b9fc043807
branch: master
author: Gregory P. Smith <greg at krypto.org>
committer: GitHub <noreply at github.com>
date: 2018-12-30T15:42:32-08:00
summary:
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.
files:
A Misc/NEWS.d/next/Library/2018-12-30-14-56-33.bpo-28503.V4kNN3.rst
M Include/Python.h
M Modules/_cryptmodule.c
M configure
M configure.ac
M pyconfig.h.in
diff --git a/Include/Python.h b/Include/Python.h
index cb24c8d33ee6..aa60175f5235 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -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? */
diff --git a/Misc/NEWS.d/next/Library/2018-12-30-14-56-33.bpo-28503.V4kNN3.rst b/Misc/NEWS.d/next/Library/2018-12-30-14-56-33.bpo-28503.V4kNN3.rst
new file mode 100644
index 000000000000..651fef1f0371
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-12-30-14-56-33.bpo-28503.V4kNN3.rst
@@ -0,0 +1,2 @@
+The `crypt` module now internally uses the `crypt_r()` library function
+instead of `crypt()` when available.
diff --git a/Modules/_cryptmodule.c b/Modules/_cryptmodule.c
index 58d179e6a3d2..5d03f45f6436 100644
--- a/Modules/_cryptmodule.c
+++ b/Modules/_cryptmodule.c
@@ -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);
}
diff --git a/configure b/configure
index edb85b524f54..13677b9d96b6 100755
--- a/configure
+++ b/configure
@@ -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 "$LINENO" "clock_gettime" "ac_cv_func_clock_gettime"
diff --git a/configure.ac b/configure.ac
index 349c927484cd..bd09a9c9e1e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3818,6 +3818,23 @@ AC_CHECK_FUNCS(gettimeofday,
])
)
+# We search for both crypt and crypt_r as one or the other may be defined
+# This gets us our -lcrypt in LIBS when required on the target platform.
+AC_SEARCH_LIBS(crypt, crypt)
+AC_SEARCH_LIBS(crypt_r, crypt)
+
+AC_CHECK_FUNC(crypt_r,
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#define _GNU_SOURCE /* Required for crypt_r()'s prototype in glibc. */
+#include <crypt.h>
+]], [[
+struct crypt_data d;
+char *r = crypt_r("", "", &d);
+]])],
+ [AC_DEFINE(HAVE_CRYPT_R, 1, [Define if you have the crypt_r() function.])],
+ [])
+)
+
AC_CHECK_FUNCS(clock_gettime, [], [
AC_CHECK_LIB(rt, clock_gettime, [
LIBS="$LIBS -lrt"
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 254a2dcab4da..f37ca3615025 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -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
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