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Aids and Tools for Networking Certifications

SHOWACLS.EXE
(from Windows 2000 Resource Kit Help)

This command-line tool enumerates access rights for files, folders, and trees. It allows masking to enumerate only specific ACLs.

ShowACLs works on NTFS partitions only.

The most useful feature of ShowACLs is the ability to show permissions for a particular user. The method that ShowACLs uses to perform this is by enumerating the local and global groups that the particular user belongs to and matching the users security identifier (SID) and the SIDs of the groups the users belongs to, to the SIDs in each ACE entry.

NTFS uses Access Control Lists (ACLs) to set permissions for users and groups on objects. ACLs are made up of Access Control Entries (ACEs). Each ACE entry has information that controls the permissions for a specific user or group. There are currently four ACE type defined; Access Allowed, Access Denied, System Alarm and System Audit. Each ACE entry has a common ACE header and unique data structure. The SID associated with each ACE entry is contained in the data following the ACE header.

One of the problems with a command-line tool like ShowACLs is the amount of information that is contained in the ACL. The first version of ShowACLs attempted to display all the data in the access mask, which was very confusing. The latest version has adopted the "standard" permissions, Full, Change and Read-Only where appropriate. If a mask does not match these predefined values, the a raw dump of the mask is performed.

 

showacls [/s] [/u:domain\user] [filespec]

/s  includes sub-directories
/u:domain\user specifies domain\user
ACE header values
0x1 Object Inherit ACE
0x2 Container Inherit ACE
0x4 No Propagate Inherit ACE
0x8 Inherit Only ACE
Access mask values
Delete. Allows or denies deleting the file or folder. If you don't have Delete permission on a file or folder, you can still delete it if you have been granted the Delete Subfolders and Files permission on the parent folder. D
File Append. Append Data allows or denies making changes to the end of the file but not changing, deleting, or overwriting existing data (applies to files only). a
File Execute. Execute File allows or denies running program files (applies to files only). fx
File Read. File Read allows or denies viewing the attributes of a file or folder, such as read-only and hidden. Attributes are defined by NTFS. r
File Write. Write Data allows or denies making changes to the file and overwriting existing content (applies to files only). w
Generic All A
Generic Execute. Execute File allows or denies running program files (applies to files only). X
Generic Read. Allows or denies viewing the attributes of a file or folder, such as read-only and hidden. Attributes are defined by NTFS. R
Generic Write. Allows or denies changing the attributes of a file or folder, such as read-only or hidden. Attributes are defined by NTFS. W
List Directory. List Folder allows or denies viewing file names and subfolder names within the folder (applies to folders only). l
Read Data. Read Data allows or denies viewing data in files (applies to files only). d
Read EA. Allows or denies viewing the extended attributes of a file or folder. Extended attributes are defined by programs and may vary. rE
Synchronize. Allows or denies different threads to wait on the handle for the file or folder and synchronize with another thread that may signal it. This permission applies only to multithreaded, multiprocess programs. S
Write EA. Allows or denies changing the extended attributes of a file or folder. Extended attributes are defined by programs and may vary. rW