Set-Acl

Changes the security descriptor of a specified item, such as a file or a registry key.

Syntax

Set-Acl
   [-Path] <String[]>
   [-AclObject] <Object>
   [-ClearCentralAccessPolicy]
   [-Passthru]
   [-Filter <String>]
   [-Include <String[]>]
   [-Exclude <String[]>]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]
Set-Acl
   [-InputObject] <PSObject>
   [-AclObject] <Object>
   [-Passthru]
   [-Filter <String>]
   [-Include <String[]>]
   [-Exclude <String[]>]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]
Set-Acl
   -LiteralPath <String[]>
   [-AclObject] <Object>
   [-ClearCentralAccessPolicy]
   [-Passthru]
   [-Filter <String>]
   [-Include <String[]>]
   [-Exclude <String[]>]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Description

The Set-Acl cmdlet changes the security descriptor of a specified item, such as a file or a registry key, to match the values in a security descriptor that you supply.

To use Set-Acl, use the Path or InputObject parameter to identify the item whose security descriptor you want to change. Then, use the AclObject or SecurityDescriptor parameters to supply a security descriptor that has the values you want to apply. Set-Acl applies the security descriptor that is supplied. It uses the value of the AclObject parameter as a model and changes the values in the item's security descriptor to match the values in the AclObject parameter.

Examples

Example 1: Copy a security descriptor from one file to another

$DogACL = Get-Acl -Path "C:\Dog.txt"
Set-Acl -Path "C:\Cat.txt" -AclObject $DogACL

These commands copy the values from the security descriptor of the Dog.txt file to the security descriptor of the Cat.txt file. When the commands complete, the security descriptors of the Dog.txt and Cat.txt files are identical.

The first command uses the Get-Acl cmdlet to get the security descriptor of the Dog.txt file. The assignment operator (=) stores the security descriptor in the value of the $DogACL variable.

The second command uses Set-Acl to change the values in the ACL of Cat.txt to the values in $DogACL.

The value of the Path parameter is the path to the Cat.txt file. The value of the AclObject parameter is the model ACL, in this case, the ACL of Dog.txt as saved in the $DogACL variable.

Example 2: Use the pipeline operator to pass a descriptor

Get-Acl -Path "C:\Dog.txt" | Set-Acl -Path "C:\Cat.txt"

This command is almost the same as the command in the previous example, except that it uses a pipeline operator (|) to send the security descriptor from a Get-Acl command to a Set-Acl command.

The first command uses the Get-Acl cmdlet to get the security descriptor of the Dog.txt file. The pipeline operator (|) passes an object that represents the Dog.txt security descriptor to the Set-Acl cmdlet.

The second command uses Set-Acl to apply the security descriptor of Dog.txt to Cat.txt. When the command completes, the ACLs of the Dog.txt and Cat.txt files are identical.

Example 3: Apply a security descriptor to multiple files

$NewAcl = Get-Acl File0.txt
Get-ChildItem -Path "C:\temp" -Recurse -Include "*.txt" -Force | Set-Acl -AclObject $NewAcl

These commands apply the security descriptors in the File0.txt file to all text files in the C:\Temp directory and all of its subdirectories.

The first command gets the security descriptor of the File0.txt file in the current directory and uses the assignment operator (=) to store it in the $NewACL variable.

The first command in the pipeline uses the Get-ChildItem cmdlet to get all of the text files in the C:\Temp directory. The Recurse parameter extends the command to all subdirectories of C:\temp. The Include parameter limits the files retrieved to those with the .txt file name extension. The Force parameter gets hidden files, which would otherwise be excluded. (You cannot use c:\temp\*.txt, because the Recurse parameter works on directories, not on files.)

The pipeline operator (|) sends the objects representing the retrieved files to the Set-Acl cmdlet, which applies the security descriptor in the AclObject parameter to all of the files in the pipeline.

In practice, it is best to use the WhatIf parameter with all Set-Acl commands that can affect more than one item. In this case, the second command in the pipeline would be Set-Acl -AclObject $NewAcl -WhatIf. This command lists the files that would be affected by the command. After reviewing the result, you can run the command again without the WhatIf parameter.

Example 4: Disable inheritance and preserve inherited access rules

$NewAcl = Get-Acl -Path "C:\Pets\Dog.txt"
$isProtected = $true
$preserveInheritance = $true
$NewAcl.SetAccessRuleProtection($isProtected, $preserveInheritance)
Set-Acl -Path "C:\Pets\Dog.txt" -AclObject $NewAcl

These commands is will disable access inheritance from parent folders, while still preserving the existing inherited access rules.

The first command uses the Get-Acl cmdlet to get the security descriptor of the Dog.txt file.

Next, variables are created to convert the inherited access rules to explicit access rules. To protect the access rules associated with this from inheritance, set the $isProtected variable to $true.to allow inheritance, set $isProtected to $false. For more information, see set access rule protection. The $preserveInheritance variable set to $true to preserve inherited access rules; false to remove inherited access rules. Then the access rule protection is updated using the SetAccessRuleProtection() method.

The last command uses Set-Acl to apply the security descriptor of to Dog.txt. When the command completes, the ACLs of the Dog.txt that were inherited from the Pets folder will be applied directly to Dog.txt, and new access policies added to Pets will not change the access to Dog.txt.

Example 5: Grant Administrators Full Control of the file

$NewAcl = Get-Acl -Path "C:\Pets\Dog.txt"
# Set properties
$identity = "BUILTIN\Administrators"
$fileSystemRights = "FullControl"
$type = "Allow"
# Create new rule
$fileSystemAccessRuleArgumentList = $identity, $fileSystemRights, $type
$fileSystemAccessRule = New-Object -TypeName System.Security.AccessControl.FileSystemAccessRule -ArgumentList $fileSystemAccessRuleArgumentList
# Apply new rule
$NewAcl.SetAccessRule($fileSystemAccessRule)
Set-Acl -Path "C:\Pets\Dog.txt" -AclObject $NewAcl

This command will grant the BUILTIN\Administrators group Full control of the Dog.txt file.

The first command uses the Get-Acl cmdlet to get the security descriptor of the Dog.txt file.

Next variables are created to grant the BUILTIN\Administrators group full control of the Dog.txt file. The $identity variable set to the name of a user account. The $fileSystemRights variable set to FullControl, and can be any one of the FileSystemRights values that specifies the type of operation associated with the access rule. The $type variable set to "Allow" to specifies whether to allow or deny the operation. The $fileSystemAccessRuleArgumentList variable is an argument list is to be passed when making the new FileSystemAccessRule object. Then a new FileSystemAccessRule object is created, and the FileSystemAccessRule object is passed to the SetAccessRule() method, adds the new access rule.

The last command uses Set-Acl to apply the security descriptor of to Dog.txt. When the command completes, the BUILTIN\Administrators group will have full control of the Dog.txt.

Parameters

-AclObject

Specifies an ACL with the desired property values. Set-Acl changes the ACL of item specified by the Path or InputObject parameter to match the values in the specified security object.

You can save the output of a Get-Acl command in a variable and then use the AclObject parameter to pass the variable, or type a Get-Acl command.

Type:Object
Position:1
Default value:None
Accept pipeline input:True
Accept wildcard characters:False
-ClearCentralAccessPolicy

Removes the central access policy from the specified item.

Beginning in Windows Server 2012, administrators can use Active Directory and Group Policy to set central access policies for users and groups. For more information, see Dynamic Access Control: Scenario Overview.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:False
Accept pipeline input:False
Accept wildcard characters:False
-Confirm

Prompts you for confirmation before running the cmdlet.

Type:SwitchParameter
Aliases:cf
Position:Named
Default value:False
Accept pipeline input:False
Accept wildcard characters:False
-Exclude

Omits the specified items. The value of this parameter qualifies the Path parameter. Enter a path element or pattern, such as *.txt. Wildcards are permitted.

Type:String[]
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:True
-Filter

Specifies a filter in the provider's format or language. The value of this parameter qualifies the Path parameter. The syntax of the filter, including the use of wildcards, depends on the provider. Filters are more efficient than other parameters, because the provider applies them when retrieving the objects, rather than having PowerShell filter the objects after they are retrieved.

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:True
-Include

Changes only the specified items. The value of this parameter qualifies the Path parameter. Enter a path element or pattern, such as *.txt. Wildcards are permitted.

Type:String[]
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:True
-InputObject

Changes the security descriptor of the specified object. Enter a variable that contains the object or a command that gets the object.

You cannot pipe the object to be changed to Set-Acl. Instead, use the InputObject parameter explicitly in the command.

This parameter was introduced in Windows PowerShell 3.0.

Type:PSObject
Position:0
Default value:None
Accept pipeline input:True
Accept wildcard characters:False
-LiteralPath

Changes the security descriptor of the specified item. Unlike Path, the value of the LiteralPath parameter is used exactly as it is typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose it in single quotation marks ('). Single quotation marks tell PowerShell not to interpret any characters as escape sequences.

This parameter was introduced in Windows PowerShell 3.0.

Type:String[]
Aliases:PSPath
Position:Named
Default value:None
Accept pipeline input:True
Accept wildcard characters:False
-Passthru

Returns an object that represents the security descriptor that was changed. By default, this cmdlet does not generate any output.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Path

Changes the security descriptor of the specified item. Enter the path to an item, such as a path to a file or registry key. Wildcards are permitted.

If you pass a security object to Set-Acl (either by using the AclObject or SecurityDescriptor parameters or by passing a security object from Get-Acl to Set-Acl), and you omit the Path parameter (name and value), Set-Acl uses the path that is included in the security object.

Type:String[]
Position:0
Default value:None
Accept pipeline input:True
Accept wildcard characters:True
-WhatIf

Shows what would happen if the cmdlet runs. The cmdlet is not run.

Type:SwitchParameter
Aliases:wi
Position:Named
Default value:False
Accept pipeline input:False
Accept wildcard characters:False

Inputs

System.Security.AccessControl.ObjectSecurity, System.Security.AccessControl.CommonSecurityDescriptor

You can pipe an ACL object or a security descriptor to Set-Acl.

Outputs

FileSecurity

By default, Set-Acl does not generate any output. However, if you use the Passthru parameter, it generates a security object. The type of the security object depends on the type of the item.

Notes

This cmdlet is only available on Windows platforms.

The Set-Acl cmdlet is supported by the PowerShell file system and registry providers. As such, you can use it to change the security descriptors of files, directories, and registry keys.