[RFC PATCH 2/3] newrole: cleanse shadow data hold by libc

["Christian Göttsche" <cgoettsche@seltendoof.de>]

From: Christian Göttsche <cgzones@googlemail.com>

Override the memory holding the retrieved password after usage to avoid
potential leaks.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
 policycoreutils/newrole/newrole.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/policycoreutils/newrole/newrole.c b/policycoreutils/newrole/newrole.c
index 1e01d2ef..59a5caa3 100644
--- a/policycoreutils/newrole/newrole.c
+++ b/policycoreutils/newrole/newrole.c
@@ -388,6 +388,7 @@ static int authenticate_via_shadow_passwd(const char *uname)
 	/* Ask user to input unencrypted password */
 	if (!(unencrypted_password_s = getpass(PASSWORD_PROMPT))) {
 		fprintf(stderr, _("getpass cannot open /dev/tty\n"));
+		memzero(p_shadow_line->sp_pwdp, strlen(p_shadow_line->sp_pwdp));
 		return 0;
 	}
 
@@ -398,11 +399,13 @@ static int authenticate_via_shadow_passwd(const char *uname)
 	memzero(unencrypted_password_s, strlen(unencrypted_password_s));
 	if (errno || !encrypted_password_s) {
 		fprintf(stderr, _("Cannot encrypt password.\n"));
+		memzero(p_shadow_line->sp_pwdp, strlen(p_shadow_line->sp_pwdp));
 		return 0;
 	}
 
 	ret = streq_constant(encrypted_password_s, p_shadow_line->sp_pwdp);
 	memzero(encrypted_password_s, strlen(encrypted_password_s));
+	memzero(p_shadow_line->sp_pwdp, strlen(p_shadow_line->sp_pwdp));
 	return ret;
 }
 #endif				/* if/else USE_PAM */
-- 
2.43.0