netcmd: Improve error handling of gpo aclcheck as non-admin

Reading the nTSecurityDescriptor attribute over LDAP requires admin
creds. However, if you don't specify admin creds, then you get an error
like this:

bin/samba-tool gpo aclcheck
ERROR(<class 'KeyError'>): uncaught exception - 'No such element'
  File "bin/python/samba/netcmd/__init__.py", line 184, in _run
    return self.run(*args, **kwargs)
  File "bin/python/samba/netcmd/gpo.py", line 1536, in run
    ds_sd_ndr = m['nTSecurityDescriptor'][0]

This patch adds an explicit check/error message to make the problem
clearer.

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/python/samba/netcmd/gpo.py b/python/samba/netcmd/gpo.py
index 1b5e927f633dc4bbf743b2cd8ac4db861c18cec8..95fe5d6d439b9b5b167a543c22cc4812ad2cdfc5 100644 (file)
--- a/python/samba/netcmd/gpo.py
+++ b/python/samba/netcmd/gpo.py
@@ -1533,6 +1533,10 @@ class cmd_aclcheck(GPOCommand):
 
             fs_sd = conn.get_acl(sharepath, security.SECINFO_OWNER | security.SECINFO_GROUP | security.SECINFO_DACL, security.SEC_FLAG_MAXIMUM_ALLOWED)
 
+            if 'nTSecurityDescriptor' not in m:
+                raise CommandError("Could not read nTSecurityDescriptor. "
+                                   "This requires an Administrator account")
+
             ds_sd_ndr = m['nTSecurityDescriptor'][0]
             ds_sd = ndr_unpack(security.descriptor, ds_sd_ndr).as_sddl()