account: Add tests for invalid system files

Each test creates an instance it LMI_Account, then intentionally
cripples one of system files related to users/groups, and performs
a simple sanity test that checks if instance properties are readable.

2 files changed, 570 insertions, 1 deletions

diff --git a/src/account/test/TestAccountInvalidEtc.py b/src/account/test/TestAccountInvalidEtc.py
new file mode 100644
index 0000000..7ed77c3
--- /dev/null
+++ b/src/account/test/TestAccountInvalidEtc.py
@@ -0,0 +1,452 @@
+# -*- encoding: utf-8 -*-
+# Copyright(C) 2012-2013 Red Hat, Inc.  All rights reserved.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or(at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+#
+# Authors: Alois Mahdal <amahdal@redhat.com>
+
+import sys
+
+from common import AccountBase, BackupStorage, BaseCrippler
+from lmi.shell import LMIInstance
+
+
+## ......................................................................... ##
+## Helper functions
+## ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ##
+
+def gen_cripple(*args):
+    """
+    Generator of test methods. Each call to this function adds
+    one test method to TestAccountInvalidEtc.
+
+    All arguments are passed to PasswdCrippler.cripple.
+    """
+
+    def _new_cripple_test(self):
+        self.crippler.cripple(*args)
+        self.assertSane()
+
+    meth_name = "test%s_%s_%s" % (path.replace("/", "_"), op, case)
+    _new_cripple_test.__name__ = meth_name
+    setattr(TestAccountInvalidEtc, meth_name, _new_cripple_test)
+
+
+## ......................................................................... ##
+## Test data (later "converted" to test methods)
+## ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ##
+
+class PasswdCrippler(BaseCrippler):
+    """
+    Cripple files related to user management
+    """
+
+    def _define_cases(self):
+
+        data = {
+            'ep': '$6$S2M8XGNtfRj/7mnX$Sn8XPyzOFYKSqSYLRlII4wYQc2A'
+                  '.R6gQxh19Oz9e6KHLcCsvLK7ePJWLbZInWktI8/ZaiT/fFA'
+                  'Tjx6c3Q1A.Y1',
+            'o15': 32769,               # over 15-bit uint
+            'o32': 4294967297,          # over 32-bit uint
+            'mi': sys.maxint,
+            'omi': sys.maxint + 1,
+        }
+
+        cases = {}
+        cases['/etc/passwd'] = {
+
+            # syntax traps
+            'empty_fields': "::::::",
+            'one_field': "user1\n",
+            'less_fields': "user1:x:2000:2000:U1:/home/user1",
+            'more_fields': "user1:x:2000:2000:U1:/home/user1:/bin/bash:hm",
+
+            # funny
+            'pegasus': "pegasus:x:66:65"
+                       ":tog-pegasus OpenPegasus WBEM/CIM services"
+                       ":/var/lib/Pegasus:/sbin/nologin",
+            'root': "root:x:0:0:root:/root:/bin/bash",
+
+            # field: name
+            'name_empty': ":x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_null': "\x00:x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_tab': "\x09:x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_space': " :x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_semicol': ";:x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_comma': ",:x:2000:2000:U1:/home/user1:/bin/bash",
+            'name_duplicate': "user1:x:2000:2000:U1:/home/user1:/bin/bash\n"
+                              "user1:x:2001:2001:User 2:/home/user2:/bin/bash",
+
+            # field: password
+            'password_empty': "user1::2000:2000:U1:/home/user1:/bin/bash",
+            'password_null': "user1:\x00:2000:2000:U1:/home/user1:/bin/bash",
+            'password_tab': "user1:\x09:2000:2000:U1:/home/user1:/bin/bash",
+            'password_space': "user1: :2000:2000:U1:/home/user1:/bin/bash",
+            'password_semicol': "user1:;:2000:2000:U1:/home/user1:/bin/bash",
+            'password_comma': "user1:,:2000:2000:U1:/home/user1:/bin/bash",
+            'password_2aster': "user1:**:2000:2000:U1:/home/user1:/bin/bash",
+            'password_2x': "user1:xx:2000:2000:U1:/home/user1:/bin/bash",
+            'password_asterx': "user1:*x:2000:2000:U1:/home/user1:/bin/bash",
+            'password_xaster': "user1:x*:2000:2000:U1:/home/user1:/bin/bash",
+
+            # field: uid
+            'uid_empty': "user1:x::2000:U1:/home/user1:/bin/bash",
+            'uid_null': "user1:x:\x00:2000:U1:/home/user1:/bin/bash",
+            'uid_tab': "user1:x:\x09:2000:U1:/home/user1:/bin/bash",
+            'uid_space': "user1:x: :2000:U1:/home/user1:/bin/bash",
+            'uid_semicol': "user1:x:;:2000:U1:/home/user1:/bin/bash",
+            'uid_comma': "user1:x:,:2000:U1:/home/user1:/bin/bash",
+            'uid_string': "user1:x:hey:2000:U1:/home/user1:/bin/bash",
+            'uid_negative': "user1:x:-2000:2000:U1:/home/user1:/bin/bash",
+            'uid_over15': "user1:x:%(o15)d:2000:U1:/home/user1:/bin/bash",
+            'uid_over32': "user1:x:%(o32)d:2000:U1:/home/user1:/bin/bash",
+            'uid_over_maxint': "user1:x:%(omi)d:2000:U1:/home/user1:/bin/sh",
+            'uid_maxint': "user1:x:%(mi)d:2000:U1:/home/user1:/bin/bash",
+            'uid_duplicate': "user1:x:2000:2000:U1:/home/user1:/bin/bash\n"
+                             "user2:x:2000:2001:User 2:/home/user2:/bin/bash",
+
+            # field: gid
+            'gid_empty': "user1:x:2000::U1:/home/user1:/bin/bash",
+            'gid_null': "user1:x:2000:\x00:U1:/home/user1:/bin/bash",
+            'gid_tab': "user1:x:2000:\x09:U1:/home/user1:/bin/bash",
+            'gid_space': "user1:x:2000: :U1:/home/user1:/bin/bash",
+            'gid_semicol': "user1:x:2000:;:U1:/home/user1:/bin/bash",
+            'gid_comma': "user1:x:2000:,:U1:/home/user1:/bin/bash",
+            'gid_string': "user1:x:2000:hey:U1:/home/user1:/bin/bash",
+            'gid_negative': "user1:x:2000:-2000:U1:/home/user1:/bin/bash",
+            'gid_over15': "user1:x:2000:%(o15)d:U1:/home/user1:/bin/bash",
+            'gid_over32': "user1:x:2000:%(o32)d:U1:/home/user1:/bin/bash",
+            'gid_over_maxint': "user1:x:2000:%(omi)d:U1:/home/user1:/bin/sh",
+            'gid_maxint': "user1:x:2000:%(mi)d:U1:/home/user1:/bin/bash",
+            'gid_duplicate': "user1:x:2000:2000:U1:/home/user1:/bin/bash\n"
+                             "user2:x:2001:2000:User 2:/home/user2:/bin/bash",
+
+            # field: directory
+            'directory_empty': "user1:x:2000:2000:U1::/bin/bash",
+            'directory_null': "user1:x:2000:2000:U1:\x00:/bin/bash",
+            'directory_tab': "user1:x:2000:2000:U1:\x09:/bin/bash",
+
+        }
+
+        cases['/etc/group'] = {
+
+            # a valid line as a template
+            'valid': "group1:x:2000:user1,user2,user3",
+
+            # syntax traps
+            'empty_fields': ":::",
+            'one_field': "group1\n",
+            'less_fields': "group1:x:user1,user2,user3",
+            'more_fields': "group1:x:2000:user1,user2,user3:hey",
+
+            # funny
+            'pegasus': "pegasus:x:65:",
+            'root': "root:x:0:",
+
+            # field: name
+            'name_empty': ":x:2000:user1,user2,user3",
+            'name_null': "\x00:x:2000:user1,user2,user3",
+            'name_tab': "\x09:x:2000:user1,user2,user3",
+            'name_space': " :x:2000:user1,user2,user3",
+            'name_semicol': ";:x:2000:user1,user2,user3",
+            'name_comma': ",:x:2000:user1,user2,user3",
+            'name_duplicate': "group1:x:2000:user1,user2,user3\n"
+                              "group1:x:2001:user1,user2,user3",
+
+            # field: password
+            'password_empty': "group1::2000:user1,user2,user3",
+            'password_null': "group1:\x00:2000:user1,user2,user3",
+            'password_tab': "group1:\x09:2000:user1,user2,user3",
+            'password_space': "group1: :2000:user1,user2,user3",
+            'password_semicol': "group1:;:2000:user1,user2,user3",
+            'password_comma': "group1:,:2000:user1,user2,user3",
+            'password_2aster': "group1:**:2000:user1,user2,user3",
+            'password_2x': "group1:xx:2000:user1,user2,user3",
+            'password_asterx': "group1:*x:2000:user1,user2,user3",
+            'password_xaster': "group1:x*:2000:user1,user2,user3",
+
+            # field: gid
+            'gid_empty': "group1:x::user1,user2,user3",
+            'gid_null': "group1:x:\x00:user1,user2,user3",
+            'gid_tab': "group1:x:\x09:user1,user2,user3",
+            'gid_space': "group1:x: :user1,user2,user3",
+            'gid_semicol': "group1:x:;:user1,user2,user3",
+            'gid_comma': "group1:x:,:user1,user2,user3",
+            'gid_string': "group1:x:hey:user1,user2,user3",
+            'gid_negative': "group1:x:-2000:user1,user2,user3",
+            'gid_over15': "group1:x:%(o15)d:user1,user2,user3",
+            'gid_over32': "group1:x:%(o32)d:user1,user2,user3",
+            'gid_over_maxint': "group1:x:%(omi)d:user1.user2,user3",
+            'gid_maxint': "group1:x:%(mi)d:user1,user2,user3",
+            'gid_duplicate': "group1:x:2000:user1,user2,user3"
+                             "user2:x:2000:user1,user2,user3",
+
+            # field: ulist
+            'ulist_null': "group1:x:2000:\x00",
+            'ulist_tab': "group1:x:2000:\x09",
+            'ulist_space': "group1:x:2000: ",
+            'ulist_semicol': "group1:x:2000:;",
+            'ulist_nulls': "group1:x:2000:\x00,\x00",
+            'ulist_tabs': "group1:x:2000:\x09,\x09",
+            'ulist_spaces': "group1:x:2000: , ",
+            'ulist_semicols': "group1:x:2000:;,;",
+            'ulist_comma': "group1:x:2000:,",
+
+        }
+
+        cases['/etc/shadow'] = {
+
+            # a valid line as a template
+            'valid': "user1:%(ep)s:16118:0:99999:7:::",
+
+            # syntax traps
+            'empty_fields': "::::::::",
+            'one_field': "user1\n",
+            'less_fields': "user1:%(ep)s:16118:0:99999:7::",
+            'more_fields': "user1:%(ep)s:16118:0:99999:7::::hey",
+
+            # funny
+            'pegasus': "pegasus:$6$1.d1PKQWTeS.8eXI$qM5NXh0a9RRv7ajn"
+                       "Sigd1wBqZp9l2.cVlJfPtybJUxbilM7HScfv.kW6EWcU"
+                       "YKd3mU2bszTiQab0tKgmehzz5.:16146::::::",
+            'root': "root:$6$s//AqmEc2gzQyFuL$9rUPnSPE6uYpDTBCiel"
+                    "tHK5.5I0iJiiJva4bPnD5QH6/6iFKzJ32Lcrxxszz9In"
+                    "BuorKT3ypIHeHeGvPkaPfO/:16118:0:99999:7:::",
+
+            # field: name
+            'name_empty': ":%(ep)s:16118:0:99999:7:::",
+            'name_null': "\x00:%(ep)s:16118:0:99999:7:::",
+            'name_tab': "\x09:%(ep)s:16118:0:99999:7:::",
+            'name_space': " :%(ep)s:16118:0:99999:7:::",
+            'name_semicol': ";:%(ep)s:16118:0:99999:7:::",
+            'name_comma': ",:%(ep)s:16118:0:99999:7:::",
+            'name_duplicate': "user1:%(ep)s:16118:0:99999:7:::\n"
+                              "user1:%(ep)s:16118:0:99999:7:::",
+
+            # field: password
+            'password_empty': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_null': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_tab': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_space': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_semicol': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_comma': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_2aster': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_2x': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_asterx': "user1:%(ep)s:16118:0:99999:7:::",
+            'password_xaster': "user1:%(ep)s:16118:0:99999:7:::",
+
+            # field: last change
+            'lastch_empty': "user1:%(ep)s::0:99999:7:::",
+            'lastch_null': "user1:%(ep)s:\x00:0:99999:7:::",
+            'lastch_tab': "user1:%(ep)s:\x09:0:99999:7:::",
+            'lastch_space': "user1:%(ep)s: :0:99999:7:::",
+            'lastch_semicol': "user1:%(ep)s:;:0:99999:7:::",
+            'lastch_comma': "user1:%(ep)s:,:0:99999:7:::",
+            'lastch_string': "user1:%(ep)s:hey:0:99999:7:::",
+            'lastch_negative': "user1:%(ep)s:-42:0:99999:7:::",
+            'lastch_over15': "user1:%(ep)s:%(o15)d:0:99999:7:::",
+            'lastch_over32': "user1:%(ep)s:%(o32)d:0:99999:7:::",
+            'lastch_over_maxint': "user1:%(ep)s:%(omi)d:0:99999:7:::",
+            'lastch_maxint': "user1:%(ep)s:%(mi)d:0:99999:7:::",
+
+            # field: minimum age
+            'minage_empty': "user1:%(ep)s:16118::99999:7:::",
+            'minage_null': "user1:%(ep)s:16118:\x00:99999:7:::",
+            'minage_tab': "user1:%(ep)s:16118:\x09:99999:7:::",
+            'minage_space': "user1:%(ep)s:16118: :99999:7:::",
+            'minage_semicol': "user1:%(ep)s:16118:;:99999:7:::",
+            'minage_comma': "user1:%(ep)s:16118:,:99999:7:::",
+            'minage_string': "user1:%(ep)s:16118:hey:99999:7:::",
+            'minage_negative': "user1:%(ep)s:16118:-42:99999:7:::",
+            'minage_over15': "user1:%(ep)s:16118:%(o15)d:99999:7:::",
+            'minage_over32': "user1:%(ep)s:16118:%(o32)d:99999:7:::",
+            'minage_over_maxint': "user1:%(ep)s:16118:%(omi)d:99999:7:::",
+            'minage_maxint': "user1:%(ep)s:16118:%(mi)d:99999:7:::",
+
+            # field: maximum age
+            'maxage_empty': "user1:%(ep)s:16118:0::7:::",
+            'maxage_null': "user1:%(ep)s:16118:0:\x00:7:::",
+            'maxage_tab': "user1:%(ep)s:16118:0:\x09:7:::",
+            'maxage_space': "user1:%(ep)s:16118:0: :7:::",
+            'maxage_semicol': "user1:%(ep)s:16118:0:;:7:::",
+            'maxage_comma': "user1:%(ep)s:16118:0:,:7:::",
+            'maxage_string': "user1:%(ep)s:16118:0:hey:7:::",
+            'maxage_negative': "user1:%(ep)s:16118:0:-42:7:::",
+            'maxage_over15': "user1:%(ep)s:16118:0:%(o15)d:7:::",
+            'maxage_over32': "user1:%(ep)s:16118:0:%(o32)d:7:::",
+            'maxage_over_maxint': "user1:%(ep)s:16118:0:%(omi)d:7:::",
+            'maxage_maxint': "user1:%(ep)s:16118:0:%(mi)d:7:::",
+
+            # field: warning period
+            'wperiod_empty': "user1:%(ep)s:16118:0:99999::::",
+            'wperiod_null': "user1:%(ep)s:16118:0:99999:\x00:::",
+            'wperiod_tab': "user1:%(ep)s:16118:0:99999:\x09:::",
+            'wperiod_space': "user1:%(ep)s:16118:0:99999: :::",
+            'wperiod_semicol': "user1:%(ep)s:16118:0:99999:;:::",
+            'wperiod_comma': "user1:%(ep)s:16118:0:99999:,:::",
+            'wperiod_string': "user1:%(ep)s:16118:0:99999:hey:::",
+            'wperiod_negative': "user1:%(ep)s:16118:0:99999:-42:::",
+            'wperiod_over15': "user1:%(ep)s:16118:0:99999:%(o15)d:::",
+            'wperiod_over32': "user1:%(ep)s:16118:0:99999:%(o32)d:::",
+            'wperiod_over_maxint': "user1:%(ep)s:16118:0:99999:%(omi)d:::",
+            'wperiod_maxint': "user1:%(ep)s:16118:0:99999:%(mi)d:::",
+
+            # field: inactivity period
+            'iperiod_empty': "user1:%(ep)s:16118:0:99999:7:::",
+            'iperiod_null': "user1:%(ep)s:16118:0:99999:7:\x00::",
+            'iperiod_tab': "user1:%(ep)s:16118:0:99999:7:\x09::",
+            'iperiod_space': "user1:%(ep)s:16118:0:99999:7: ::",
+            'iperiod_semicol': "user1:%(ep)s:16118:0:99999:7:;::",
+            'iperiod_comma': "user1:%(ep)s:16118:0:99999:7:,::",
+            'iperiod_string': "user1:%(ep)s:16118:0:99999:7:hey::",
+            'iperiod_negative': "user1:%(ep)s:16118:0:99999:7:-42::",
+            'iperiod_over15': "user1:%(ep)s:16118:0:99999:7:%(o15)d::",
+            'iperiod_over32': "user1:%(ep)s:16118:0:99999:7:%(o32)d::",
+            'iperiod_over_maxint': "user1:%(ep)s:16118:0:99999:7:%(omi)d::",
+            'iperiod_maxint': "user1:%(ep)s:16118:0:99999:7:%(mi)d::",
+
+            # field: account expiration date
+            'expdate_empty': "user1:%(ep)s:16118:0:99999:7:::",
+            'expdate_null': "user1:%(ep)s:16118:0:99999:7::\x00:",
+            'expdate_tab': "user1:%(ep)s:16118:0:99999:7::\x09:",
+            'expdate_space': "user1:%(ep)s:16118:0:99999:7:: :",
+            'expdate_semicol': "user1:%(ep)s:16118:0:99999:7::;:",
+            'expdate_comma': "user1:%(ep)s:16118:0:99999:7::,:",
+            'expdate_string': "user1:%(ep)s:16118:0:99999:7::hey:",
+            'expdate_negative': "user1:%(ep)s:16118:0:99999:7::-42:",
+            'expdate_over15': "user1:%(ep)s:16118:0:99999:7::%(o15)d:",
+            'expdate_over32': "user1:%(ep)s:16118:0:99999:7::%(o32)d:",
+            'expdate_over_maxint': "user1:%(ep)s:16118:0:99999:7::%(omi)d:",
+            'expdate_maxint': "user1:%(ep)s:16118:0:99999:7::%(mi)d:",
+
+        }
+
+        cases['/etc/gshadow'] = {
+
+            # a valid line as a template
+            'valid': "group1:%(ep)s:user1,user2:user3,user4",
+
+            # syntax traps
+            'empty_fields': ":::",
+            'one_field': "user1\n",
+            'less_fields': "group1:%(ep)s:user1,user2",
+            'more_fields': "group1:%(ep)s:user1,user2:user3,user4:hey",
+
+            # funny
+            'pegasus': "pegasus:!::",
+            'root': "root:::",
+
+            # field: name
+            'name_empty': ":%(ep)s:user1,user2:user3,user4",
+            'name_null': "\x00:%(ep)s:user1,user2:user3,user4",
+            'name_tab': "group1:%(ep)s:user1,user2:user3,user4",
+            'name_space': "group1:%(ep)s:user1,user2:user3,user4",
+            'name_semicol': "group1:%(ep)s:user1,user2:user3,user4",
+            'name_comma': "group1:%(ep)s:user1,user2:user3,user4",
+            'name_duplicate': "group1:%(ep)s:user1,user2:user3,user4\n"
+                              "group1:%(ep)s:user1,user2:user3,user4",
+
+            # field: password
+            'password_empty': "group1::user1,user2:user3,user4",
+            'password_null': "group1:\x00:user1,user2:user3,user4",
+            'password_tab': "group1:\x09:user1,user2:user3,user4",
+            'password_space': "group1: :user1,user2:user3,user4",
+            'password_semicol': "group1:;:user1,user2:user3,user4",
+            'password_comma': "group1:,:user1,user2:user3,user4",
+            'password_2aster': "group1:**:user1,user2:user3,user4",
+            'password_2x': "group1:xx:user1,user2:user3,user4",
+            'password_asterx': "group1:*x:user1,user2:user3,user4",
+            'password_xaster': "group1:x*:user1,user2:user3,user4",
+
+            # field: alist
+            'alist_null': "group1:%(ep)s:\x00:user3,user4",
+            'alist_tab': "group1:%(ep)s:\x00:user3,user4",
+            'alist_space': "group1:%(ep)s: :user3,user4",
+            'alist_semicol': "group1:%(ep)s:;:user3,user4",
+            'alist_nulls': "group1:%(ep)s:\x00,\x00:user3,user4",
+            'alist_tabs': "group1:%(ep)s:\x09,\x09:user3,user4",
+            'alist_spaces': "group1:%(ep)s: , :user3,user4",
+            'alist_semicols': "group1:%(ep)s:;,;:user3,user4",
+            'alist_comma': "group1:%(ep)s:,:user3,user4",
+
+            # field: ulist
+            'ulist_null': "group1:%(ep)s:user1,user2:\x00",
+            'ulist_tab': "group1:%(ep)s:user1,user2:\x00",
+            'ulist_space': "group1:%(ep)s:user1,user2: ",
+            'ulist_semicol': "group1:%(ep)s:user1,user2:;",
+            'ulist_nulls': "group1:%(ep)s:user1,user2:\x00,\x00",
+            'ulist_tabs': "group1:%(ep)s:user1,user2:\x09,\x09",
+            'ulist_spaces': "group1:%(ep)s:user1,user2: , ",
+            'ulist_semicols': "group1:%(ep)s:user1,user2:;,;",
+            'ulist_comma': "group1:%(ep)s:user1,user2:,",
+
+        }
+
+        # add common cases
+        #
+        for key in cases:
+            cases[key]['many_fields'] = ":".join(["field"] * 5000)
+
+        # expand data
+        for path in cases:
+            for case in cases[path]:
+                cases[path][case] = cases[path][case] % data
+
+        return cases
+
+
+## ......................................................................... ##
+## Actual test
+## ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ##
+
+class TestAccountInvalidEtc(AccountBase):
+
+    CLASS_NAME = "LMI_Account"
+
+    def setUp(self):
+        self.bs = BackupStorage()
+        self.bs.add_file("/etc/passwd")
+        self.bs.add_file("/etc/shadow")
+        self.bs.add_file("/etc/group")
+        self.bs.add_file("/etc/gshadow")
+        self.inst = self.cim_class.first_instance()
+        self.addCleanup(self.bs.restore_all)
+        self.crippler = PasswdCrippler()
+
+    def assertSane(self):
+        """
+        Assert that main properties can be read
+        """
+        self.assertIsInstance(self.inst, LMIInstance)
+        # check if it provides key properties
+        for attr in ['CreationClassName', 'Name', 'SystemCreationClassName',
+                     'SystemName']:
+            self.assertIsNotNone(self.inst.properties_dict()[attr])
+
+        # check if it provides other properties, which should be set
+        for attr in ['host', 'UserID', 'UserPassword', 'UserPasswordEncoding']:
+            self.assertIsNotNone(self.inst.properties_dict()[attr])
+
+##
+## Here test methods are generated from data in PasswdCrippler instance,
+#
+
+crippler = PasswdCrippler()
+
+for path in crippler.all_paths():
+    for case in crippler.all_cases_for(path):
+        for op in ['append', 'replace']:
+            gen_cripple(path, case, op)
diff --git a/src/account/test/common.py b/src/account/test/common.py
index 2b3b423..862d1d4 100644
--- a/src/account/test/common.py
+++ b/src/account/test/common.py
@@ -13,7 +13,7 @@
 #
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 #
 # Authors: Roman Rakus <rrakus@redhat.com>
 #
@@ -24,6 +24,7 @@ Base class and utilities for all OpenLMI Account tests.
 import hashlib
 import os
 import tempfile
+import string
 import subprocess
 from collections import Counter
 from collections import OrderedDict
@@ -202,3 +203,119 @@ class BackupStorage():
         Destroy the temporary backup
         """
         subprocess.call(["rm", "-rf", self.root])
+
+
+class BaseCrippler:
+    """
+    Helper class for crippling system files.
+
+    To use the class, you need to sub-class it and implement
+    _define_cases method.
+    """
+
+    LINE_LENGTH = 500
+    LINE_COUNT = 50
+    BINARY_LENGTH = 10 * 1024 * 1024
+
+    ## virtual
+    #
+
+    def _define_cases(self):
+        """
+        Define cases per file supported
+
+        This function must return a dict with one set of cases per
+        file: key is path and value is another dict defining cases
+        as pairs of name ([a-zA-Z_]) and content.
+
+        Quick example:
+
+            {
+                '/etc/file1': {
+                    'case1': "some triggering content",
+                    'case2': "some other triggering content",
+                    'case3': "some funny triggering content",
+                },
+                '/etc/file2': {
+                    'case1': "some triggering content",
+                    'case2': "some other triggering content",
+                    'case3': "some funny triggering content",
+                },
+            }
+
+        Note that trailing newline is added automatically to each content
+        string. Also, whether content will be appended or replaced is decided
+        by caller of the BaseCrippler.cripple method.
+        """
+        pass
+
+    ## internal
+    #
+
+    def __init__(self):
+        self.autocases = {
+            'empty': lambda: '',
+            'random_line': self._random_line,
+            'random_lines': self._random_lines,
+            'random_binary': self._random_binary,
+        }
+        self.cases = self._define_cases()
+
+    def _append_to(self, path, content):
+        with open(path, 'a+') as fh:
+            fh.write(content)
+
+    def _clobber(self, path, content):
+        with open(path, 'w+') as fh:
+            fh.write(content)
+
+    def _random_binary(self, size=BINARY_LENGTH):
+        chars = ''.join([chr(i) for i in xrange(256)])
+        return methods.random_string(size, chars)
+
+    def _random_line(self, size=LINE_LENGTH):
+        chars = string.letters + string.punctuation + " \t"
+        return methods.random_string(size, chars) + "\n"
+
+    def _random_lines(self, size=LINE_LENGTH, count=LINE_COUNT):
+        return "".join([self._random_line(size) for i in xrange(count)])
+
+    def _get_content(self, path, case):
+
+        try:
+            content = self.autocases[case]()
+        except KeyError:
+            try:
+                content = self.cases[path][case] + "\n"
+            except KeyError:
+                raise ValueError("unknown case: %s for: %s" % (case, path))
+        return content
+
+    ## public
+    #
+
+    def all_cases_for(self, path):
+        """
+        Return list of cases available for path
+        """
+        return self.cases[path].keys() + self.autocases.keys()
+
+    def all_paths(self):
+        """
+        Return list of paths served by this implementation
+        """
+        return self.cases.keys()
+
+    def cripple(self, path, case, op="replace"):
+        """
+        Cripple file according to selected case.
+
+        op is either "append" or "replace" and means that the content will
+        be appended to the file, otherwise it will replace it.
+        """
+        if op == 'replace':
+            self._clobber(path, self._get_content(path, case))
+        elif op == 'append':
+            self._append_to(path, self._get_content(path, case))
+        else:
+            raise ValueError("unknown op: %s" % op)