userok: Allow NULL components in kerberosSuperUser

Modify kerberosSuperUser so that it can support callers passing NULL,
rather than just empty, instance and cell strings

Change-Id: Ifc21eb0c4f562d65519e31db32723c3a2d19b363
Reviewed-on: http://gerrit.openafs.org/3351
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/auth/userok.c b/src/auth/userok.c
index 36260e55f5ffc946388b80444884f897ab8567a2..a8cb274297294b3ec3f558ba3d4919d8884745e8 100644 (file)
--- a/src/auth/userok.c
+++ b/src/auth/userok.c
@@ -340,7 +340,7 @@ static int
 kerberosSuperUser(struct afsconf_dir *adir, char *tname, char *tinst,
                  char *tcell, char *namep)
 {
-    char tcell_l[MAXKTCREALMLEN];
+    char tcell_l[MAXKTCREALMLEN] = "";
     char *tmp;
 
     /* keep track of which one actually authorized request */
@@ -353,11 +353,13 @@ kerberosSuperUser(struct afsconf_dir *adir, char *tname, char *tinst,
     int flag;
 
     /* generate lowercased version of cell name */
-    strcpy(tcell_l, tcell);
-    tmp = tcell_l;
-    while (*tmp) {
-       *tmp = tolower(*tmp);
-       tmp++;
+    if (tcell) {
+       strcpy(tcell_l, tcell);
+       tmp = tcell_l;
+       while (*tmp) {
+           *tmp = tolower(*tmp);
+           tmp++;
+       }
     }
 
     /* determine local cell name. It's static, so will only get
@@ -394,7 +396,7 @@ kerberosSuperUser(struct afsconf_dir *adir, char *tname, char *tinst,
     /* If yes, then make sure that the name is not present in
      * an exclusion list */
     if (lrealm_match) {
-       if (tinst[0])
+       if (tinst && tinst[0])
            snprintf(uname,sizeof(uname),"%s.%s@%s",tname,tinst,tcell);
        else
            snprintf(uname,sizeof(uname),"%s@%s",tname,tcell);
@@ -408,7 +410,8 @@ kerberosSuperUser(struct afsconf_dir *adir, char *tname, char *tinst,
     flag = 0;
 
     /* localauth special case */
-    if (strlen(tinst) == 0 && strlen(tcell) == 0
+    if ((tinst == NULL || strlen(tinst) == 0) &&
+       (tcell == NULL || strlen(tcell) == 0)
        && !strcmp(tname, AUTH_SUPERUSER)) {
        strcpy(uname, "<LocalAuth>");
        flag = 1;