Toby Ovod-Everett > Win32-Security > Win32::Security::NamedObject

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NAME ^

Win32::Security::NamedObject - Security manipulation for named objects

SYNOPSIS ^

        use Win32::Security::NamedObject;

        my $noFoo = Win32::Security::NamedObject->('FILE', "C:\\Foo\\foo.txt");
        my $dacl = $noFoo->dacl();
        print $dacl->dump();

DESCRIPTION ^

This module provide an object-oriented interface for manipulating security information on named objects (i.e. files, registry keys, etc.). Note that, like the rest of Win32-Security, it currently only provides support for files. It has been architected to eventually support all object types supported by the GetNamedSecurityInfo Win32 API call. Also, it currently only supports access to the DACL and Owner information - SACL access will come later.

Installation instructions

Win32::Security::NamedObject installs as part of Win32-Security and depends upon the other modules in the distribution. There are three options for installing this distribution:

Dependencies

The suite of Win32-Security modules depends upon:

Class::Prototyped 0.98 or later

Support for prototype-based programming in Perl. Win32::Security::ACE uses this to programmatically generate large number of classes that use multiple-inheritance. Win32::Security::ACL and Win32::Security::NamedObject use this to support programmatic generation of classes that interact with the Win32::Security::ACE classes. Win32::Security::Recursor uses this to allow for flexible behavior modification (since Win32::Security::Recursor objects are really behavioral, not stateful).

Data::BitMask 0.13 or later

Flexible support for manipulating masks and constants.

Win32::API

Support for making arbitrary Win32 API calls from Perl. There is no C code anywhere in Win32-Security. Win32::API is why.

All of the above modules should be available on CPAN, and also via PPM.

Win32-Security MODULES ^

Win32::Security::SID

Win32::Security::SID provides a set of functions for doing SID manipulation (binary to text and vice-versa) as well as wrappers around Win32::LookupAccountName and Win32::LookupAccountSID that make them friendlier.

Win32::Security::Raw

Win32::Security::Raw provides a number of function wrappers around a number of Win32 API calls. Each wrapper wraps around a single Win32 API call and provides rudimentary data structure marshalling and parsing. This is the only module that uses Win32::API to make API calls - all of the other modules make their API calls through the wrappers provided by this module.

Win32::Security::ACE

Win32::Security::ACE provides an object-oriented interface for parsing, creating, and manipulating Access Control Entries (ACEs).

Win32::Security::ACL

Win32::Security::ACE provides an object-oriented interface for manipulating Access Control Lists (ACLs).

Win32::Security::NamedObject

Win32::Security::NamedObject provides support for accessing and modifying the security information attached to Named Objects.

Win32::Security::Recursor

Win32::Security::Recursor provides support for recursing through trees of Named Objects and inspecting and/or modifying the security settings for those objects.

Win32-Security SCRIPTS ^

Provided for your use are a few utilities that make use of the above modules. These scripts were the raison d'etre for the modules, and so it seemed justifiable to ship them with it. The scripts should be automatically installed to Perl\bin, so if perl.exe is in your path, these scripts should be in your path as well (i.e. you should be able to type "PermDump.pl -h" at the command prompt). The scripts have documentation (use the -h option), but here is a quick overview of them so that you don't overlook them.

PermDump.pl

This utility dumps permissions on files. It supports distinguishing between inherited and explicit permissions along with determining when there are problems with inherited permissions. It has a number of options, and it's designed to output in either TDF or CSV format for easy parsing and viewing.

I would personally recommend that all system administrators set up a nightly task to dump all the permissions on shared server volumes to a text file. This makes it easy to recover should you make a mistake while doing permissions manipulation, and it also gives you a searchable file for looking for permissions without waiting for the script to dump permissions. While the script is very fast and generally scans several hundred files per second, if you have a volume with hundreds of thousands of files, it can still take a while to run. Such a command line might look like:

  PermDump.pl -c -r D:\Shared > D:\Shared_Perms.csv

or, if you want the paths to be relative:

  D: && cd D:\Shared && PermDump.pl -c -r . > D:\Shared_Perms.csv

PermFix.pl

WARNING: This utility is in beta. It has not undergone extensive testing yet, and the test suite for this script is still under development. I strongly encourage users to use PermDump.pl to take a snapshot of the existing permissions before using this script in case there are problems, and to examine the resulting permissions closely for signs of error.

This utility is designed to do one simple task: fix problems with inherited permissions resulting from files and/or folders being moved between two folders on the same volume that have differing inheritable permissions.

PermChg.pl

WARNING: This utility is in beta. It has not undergone extensive testing yet, and the test suite for this script is still under development. I strongly encourage users to use PermDump.pl to take a snapshot of the existing permissions before using this script in case there are problems, and to examine the resulting permissions closely for signs of error.

NOTES: The owner modification support in the script is not yet finished. Also, the -file option has not had very extensive testing.

This utility is the counterpart to PermDump.pl. It allows you to change the permissions. Unlike X?CACLS.EXE, this utility properly understands and interacts with inherited permissions. It supports two modes for specifying permissions. The first allows you to specify permissions using the command line much like X?CACLS.EXE. The second allows you to pass the permissions in a text file using the same format as is outputted by PermDump.pl.

Say you get a call from an executive insisting that Jane be given access to everything that John currently has access to. The first step is to make Jane a member of all of the groups that John is in, but that doesn't address explicitly assigned permissions. To deal with that, dump all the permissions on the volume using PermDump.pl. Open the file up in Excel and sort on the Trustee. Copy the lines for John into another spreadsheet and replace the Trustee name with Jane's. Then pass that into PermChg.pl with the -file option and you're done!

TESTING ^

For a set of modules like Win32-Security that are intended to interact with permissions, the only way to really test them is to have them interact with real permissions. Unfortunately, the only viable to do that is to modify a live filesystem and see what happens. However, I felt uncomfortable running such tests as part of a default test suite, so I have disabled them by default.

The tests in question are in the t\extended.t and t\scripts.t files. They create a single directory in %TEMP% named Win32-Security_TestDir_$$ (where $$ is the process ID>. They create directories and files in that test directory and apply permissions to them. The tests require CACLS.EXE (which should be present on all Windows 2000/XP/2003 installs) and that a usable version of perl.exe be in the path.

The tests take a while to run (five minutes on my 1.8 GHz machine) because they are very extensive (7500+ tests in extended.t alone), but I strongly urge you to consider running them and reporting any errors.

To enable them, open t\extended.t and t\scripts.t and change line 11 in each to read "$enabled = 1;". I strongly encourage testing using every OS you plan to use the modules with, and using both privileged and non-privileged accounts.

ARCHITECTURE ^

Win32::Security::NamedObject uses the same class architecture as Win32::Security::ACL. Unlike Win32::Security::ACE and Win32::Security::ACL, it doesn't use the flyweight design pattern. (For obvious reasons - you're unlikely to create multiple Win32::Security::NamedObject objects for the same thing!)

Method Reference ^

new

This creates a new Win32::Security::NamedObject object.

The various calling forms are:

Note that when using $objectType in the package name, the value needs to be canonicalized (i.e. SE_FILE_OBJECT, not the shortcut FILE). If the $objectType has already been canonicalized, improved performance can be realized by making the call on the fully-qualified package name and thus avoiding the call to redo the canonicalization. Aliases are permitted when $objectName is passed as a parameter.

The currently permitted objectName formats (text copied from http://msdn.microsoft.com/library/default.asp?url=/library/en-us/security/security/se_object_type.asp ) are:

SE_FILE_OBJECT

Indicates a file or directory. The name string that identifies a file or directory object can be:

  • A relative path, such as "abc.dat" or "..\\abc.dat"
  • An absolute path, such as "\\abc.dat", "c:\\dir1\\abc.dat", or "g:\\remote_dir\\abc.dat"
  • A UNC name, such as "\\\\computer_name\\share_name\\abc.dat"
  • A local file system root, such as "\\\\\\\\.\\\\c:". Security set on a file system root does not persist when the system is restarted
SE_REGISTRY_KEY

Indicates a registry key. A registry key object can be in the local registry, such as "CLASSES_ROOT\\some_path"; or in a remote registry, such as "\\\\computer_name\\CLASSES_ROOT\\some_path". The names of registry keys must use the following literal strings to identify the predefined registry keys: "CLASSES_ROOT", "CURRENT_USER", "MACHINE", and "USERS".

In addition, the following literal strings will be mapped to the legal literals:

  • HKEY_CLASSES_ROOT -> CLASSES_ROOT
  • HKEY_CURRENT_USER -> CURRENT_USER
  • HKEY_LOCAL_MACHINE -> MACHINE
  • HKEY_USERS -> USERS

dbmObjectType

Returns the Data::BitMask object for interacting with Object Types

See Win32::Security::ACE->dbmObjectType() for more explanation.

objectType

Returns the type of object to which the ACE is or should be attached.

objectName

Returns the name of the object.

dacl

Gets or sets the DACL for the object. If no parameters are passed, it reads the DACL for the object and returns a Win32::Security::ACL class object. To set the DACL, pass the desired Win32::Security::ACL for the object and an optional SECURITY_INFORMATION mask for specifying the bits UNPROTECTED_DACL_SECURITY_INFORMATION or PROTECTED_DACL_SECURITY_INFORMATION. If the UNPROTECTED_DACL_SECURITY_INFORMATION is set, then permissions are inherited. If PROTECTED_DACL_SECURITY_INFORMATION is set, then permissions are NOT inherited (i.e. inheritance is blocked). If neither is set, then the existing setting is maintained.

Be forewarned that when setting the DACL, under Windows 2000 and more recent OSes, the call to SetNamedSecurityInfo results in the automatic propagation of inheritable ACEs to existing child objects (see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/security/securi ty/setnamedsecurityinfo.asp for more information). This does not happen under Windows NT, and if you need propagation of inheritable permissions under Windows NT, you need to write your own code to implement that. Under OSes that support automatic propagation, the call to set a DACL can take a very long time to return if there are a lot of child objects! Finally, any errors in the inherited DACLs buried in the tree will be automatically fixed by this call, constrained by the privileges of the account executing the code.

When setting the DACL under Windows 2000 and more recent OSes, if UNPROTECTED_DACL_SECURITY_INFORMATION is specified, or if the SECURITY_INFORMATION mask is unspecified and the object is currently inheriting permissions, then any ACEs in the passed DACL that have the INHERITED_ACE bit set in aceFlags are automatically ignored. The OS will automatically propagate the inheritable ACEs and will only explicitly set those ACEs in the passed DACL that do not have the INHERITED_ACE bit set in aceFlags.

If PROTECTED_DACL_SECURITY_INFORMATION is specified, or if the SECURITY_INFORMATION mask is unspecified and the object is currently blocking inherited permissions, than the INHERITED_ACE bit in aceFlags for all ACEs in the passed DACL is automatically cleared. That is to say, all passed ACEs are treated as explicit, independent of the INHERITED_ACE bit in aceFlags.

ownerTrustee

Gets or sets the Trustee for the Owner of the object. If no parameters are passed, it reads the Owner for the object and returns a Trustee name. To set the Owner, pass the desired Trustee. It calls ownerSid, so see that method for information on SeRestorePrivilege.

ownerSid

Gets or sets the binary SID for the Owner of the object. If no parameters are passed, it reads the Owner for the object and returns a binary SID. To set the Owner, pass the desired binary SID. The first time this is called in set mode, it will attempt to enable the SeRestorePrivilege, which permits setting the Owner of an object to anyone. If this fails, the call will croak.

control

Returns the Data::BitMask::break_mask form of the Security Descriptor Control (i.e. a hash containing all matching constants for the control mask of the SD).

fixDacl

Fixes the inherited ACEs in the DACL. See the caveats concerning setting DACLS using dacl for further information.

AUTHOR ^

Toby Ovod-Everett, toby@ovod-everett.org

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