s4-tests: Moved some commonly redefined security descriptor methods to a utils class

These methods are used in more than one testsuite now so they are now in a utility class instead of being defined everywhere.

source4/scripting/python/samba/sd_utils.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python
+#
+# Utility methods for security descriptor manipulation
+#
+# Copyright Nadezhda Ivanova 2010 <nivanova@samba.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import samba
+from ldb import Message, MessageElement, Dn
+from ldb import FLAG_MOD_REPLACE, SCOPE_BASE
+from samba.ndr import ndr_pack, ndr_unpack
+from samba.dcerpc import security
+
+class SDUtils:
+    '''Some utilities for manipulation of security descriptors
+    on objects'''
+
+    def __init__(self, samdb):
+        self.ldb = samdb
+        self.domain_sid = security.dom_sid(self.ldb.get_domain_sid())
+
+    def modify_sd_on_dn(self, object_dn, sd, controls=None):
+        """ Modify security descriptor using either SDDL string
+            or security.descriptor object
+        """
+        m = Message()
+        m.dn = Dn(self.ldb, object_dn)
+        assert(isinstance(sd, str) or isinstance(sd, security.descriptor))
+        if isinstance(sd, str):
+            tmp_desc = security.descriptor.from_sddl(sd, self.domain_sid)
+        elif isinstance(sd, security.descriptor):
+            tmp_desc = sd
+
+        m["nTSecurityDescriptor"] = MessageElement(ndr_pack(tmp_desc),
+                                                       FLAG_MOD_REPLACE,
+                                                       "nTSecurityDescriptor")
+        self.ldb.modify(m, controls)
+
+    def read_sd_on_dn(self, object_dn, controls=None):
+        res = self.ldb.search(object_dn, SCOPE_BASE, None,
+                              ["nTSecurityDescriptor"], controls=controls)
+        desc = res[0]["nTSecurityDescriptor"][0]
+        return ndr_unpack(security.descriptor, desc)
+
+    def get_object_sid(self, object_dn):
+        res = self.ldb.search(object_dn)
+        return ndr_unpack(security.dom_sid, res[0]["objectSid"][0])
+
+    def dacl_add_ace(self, object_dn, ace):
+        """ Adds an ACE to an objects security descriptor
+        """
+        desc = self.read_sd_on_dn(object_dn)
+        desc_sddl = desc.as_sddl(self.domain_sid)
+        if ace in desc_sddl:
+            return
+        if desc_sddl.find("(") >= 0:
+            desc_sddl = desc_sddl[:desc_sddl.index("(")] + ace + desc_sddl[desc_sddl.index("("):]
+        else:
+            desc_sddl = desc_sddl + ace
+        self.modify_sd_on_dn(object_dn, desc_sddl)
+
+    def get_sd_as_sddl(self, object_dn, controls=None):
+        """ Return object nTSecutiryDescriptor in SDDL format
+        """
+        desc = self.read_sd_on_dn(object_dn, controls=controls)
+        return desc.as_sddl(self.domain_sid)