pam_get_authtok*: disallow setting pamh to NULL

This also prevents a potential NULL pointer dereference in
pam_get_authtok_internal and pam_get_authtok_verify when
the pamh argument they access is set to NULL.

3 files changed, 53 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index d7462dea..7fb662e5 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -13,7 +13,7 @@ TESTS = tst-pam_start tst-pam_end tst-pam_fail_delay tst-pam_open_session \
 	tst-pam_close_session tst-pam_acct_mgmt tst-pam_authenticate \
 	tst-pam_chauthtok tst-pam_setcred tst-pam_get_item tst-pam_set_item \
 	tst-pam_getenvlist tst-pam_get_user tst-pam_get_data tst-pam_set_data \
-	tst-pam_mkargv tst-pam_start_confdir
+	tst-pam_mkargv tst-pam_start_confdir tst-pam_get_authtok
 
 EXTRA_DIST = confdir
 
diff --git a/tests/meson.build b/tests/meson.build
index 4d37e450..21811b1f 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -8,6 +8,7 @@ foreach name: ['dlopen',
                'pam_authenticate',
                'pam_chauthtok',
                'pam_setcred',
+               'pam_get_authtok',
                'pam_get_item',
                'pam_set_item',
                'pam_getenvlist',
diff --git a/tests/tst-pam_get_authtok.c b/tests/tst-pam_get_authtok.c
new file mode 100644
index 00000000..ffda5968
--- /dev/null
+++ b/tests/tst-pam_get_authtok.c
@@ -0,0 +1,51 @@
+/*
+ * 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, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 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 author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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 "test_assert.h"
+#include <stdio.h>
+#include <security/pam_ext.h>
+
+int
+main (void)
+{
+  const char *authtok = "test";
+  const char *prompt = "test";
+
+  /* 1: Call pam_get_authtok_verify with NULL as pam handle */
+  ASSERT_EQ(PAM_SYSTEM_ERR, pam_get_authtok_verify (NULL, &authtok, prompt));
+
+  /* 2: Call pam_get_authtok with NULL as pam handle */
+  ASSERT_EQ(PAM_SYSTEM_ERR, pam_get_authtok (NULL, 0, &authtok, prompt));
+
+  return 0;
+}