adduser/addgroup: check username for invalid chars

(by Tito <farmatito AT tiscali.it>). +129 bytes when enabled.

3 files changed, 16 insertions, 0 deletions

diff --git a/loginutils/Config.in b/loginutils/Config.in
index 81d05ef89..c57d9976e 100644
--- a/loginutils/Config.in
+++ b/loginutils/Config.in
@@ -82,6 +82,18 @@ config FEATURE_DEL_USER_FROM_GROUP
           If called with two non-option arguments, deluser
           or delgroup will remove an user from a specified group.
 
+config FEATURE_CHECK_NAMES
+        bool "Enable sanity check on user/group names in adduser and addgroup"
+        default n
+        depends on ADDUSER || ADDGROUP
+        help
+          Enable sanity check on user and group names in adduser and addgroup.
+          To avoid problems, the user or group name should consist only of
+          letters, digits, underscores, periods, at signs and dashes,
+          and not start with a dash (as defined by IEEE Std 1003.1-2001).
+          For compatibility with Samba machine accounts "$" is also supported
+          at the end of the user or group name.
+
 config ADDUSER
         bool "adduser"
         default n
diff --git a/loginutils/addgroup.c b/loginutils/addgroup.c
index b25f8171d..367c6b9f0 100644
--- a/loginutils/addgroup.c
+++ b/loginutils/addgroup.c
@@ -173,8 +173,11 @@ int addgroup_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #endif
         } else
 #endif /* ENABLE_FEATURE_ADDUSER_TO_GROUP */
+        {
+                die_if_bad_username(argv[0]);
                 new_group(argv[0], gid);
 
+        }
         /* Reached only on success */
         return EXIT_SUCCESS;
 }
diff --git a/loginutils/adduser.c b/loginutils/adduser.c
index d409eabb9..cd68015d1 100644
--- a/loginutils/adduser.c
+++ b/loginutils/adduser.c
@@ -111,6 +111,7 @@ int adduser_main(int argc ATTRIBUTE_UNUSED, char **argv)
 
         /* fill in the passwd struct */
         pw.pw_name = argv[0];
+        die_if_bad_username(pw.pw_name);
         if (!pw.pw_dir) {
                 /* create string for $HOME if not specified already */
                 pw.pw_dir = xasprintf("/home/%s", argv[0]);