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Created November 27, 2016 19:23
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# Copyright (c) Microsoft Corporation. All rights reserved.
# For personal use only. Provided AS IS and WITH ALL FAULTS.
# Set-WmiNamespaceSecurity.ps1
# Example: Set-WmiNamespaceSecurity root/cimv2 add steve Enable,RemoteAccess
# https://blogs.msdn.microsoft.com/wmi/2009/07/27/scripting-wmi-namespace-security-part-3-of-3/
Param (
[parameter(Mandatory=$true,Position=0)][string] $namespace,
[parameter(Mandatory=$true,Position=1)][string] $operation,
[parameter(Mandatory=$true,Position=2)][string] $account,
[parameter(Position=3)][string[]] $permissions = $null,
[bool] $allowInherit = $false,
[bool] $deny = $false,
[string] $computerName = '.',
[System.Management.Automation.PSCredential] $credential = $null
)
Process {
$ErrorActionPreference = 'Stop'
Function Get-AccessMaskFromPermission($permissions) {
$WBEM_ENABLE = 1
$WBEM_METHOD_EXECUTE = 2
$WBEM_FULL_WRITE_REP = 4
$WBEM_PARTIAL_WRITE_REP = 8
$WBEM_WRITE_PROVIDER = 0x10
$WBEM_REMOTE_ACCESS = 0x20
$WBEM_RIGHT_SUBSCRIBE = 0x40
$WBEM_RIGHT_PUBLISH = 0x80
$READ_CONTROL = 0x20000
$WRITE_DAC = 0x40000
$WBEM_RIGHTS_FLAGS = $WBEM_ENABLE,$WBEM_METHOD_EXECUTE,$WBEM_FULL_WRITE_REP,$WBEM_PARTIAL_WRITE_REP,$WBEM_WRITE_PROVIDER,$WBEM_REMOTE_ACCESS,$READ_CONTROL,$WRITE_DAC
$WBEM_RIGHTS_STRINGS = 'Enable','MethodExecute','FullWrite','PartialWrite','ProviderWrite','RemoteAccess','ReadSecurity','WriteSecurity'
$permissionTable = @{}
for ($i = 0; $i -lt $WBEM_RIGHTS_FLAGS.Length; $i++) {
$permissionTable.Add($WBEM_RIGHTS_STRINGS[$i].ToLower(),$WBEM_RIGHTS_FLAGS[$i])
}
$accessMask = 0
foreach ($permission in $permissions) {
if (-not $permissionTable.ContainsKey($permission.ToLower())) {
throw "Unknown permission: $permission`nValid permissions: $($permissionTable.Keys)"
}
$accessMask += $permissionTable[$permission.ToLower()]
}
$accessMask
}
if ($PSBoundParameters.ContainsKey('Credential')) {
$remoteparams = @{ComputerName=$computer;Credential=$credential}
} else {
$remoteparams = @{}
}
$invokeparams = @{Namespace=$namespace;Path='__systemsecurity=@'} + $remoteParams
$output = Invoke-WmiMethod @invokeparams -Name GetSecurityDescriptor
if ($output.ReturnValue -ne 0) {
throw "GetSecurityDescriptor failed: $($output.ReturnValue)"
}
$acl = $output.Descriptor
$computerName = (Get-WmiObject @remoteparams Win32_ComputerSystem).Name
if ($account.Contains(‘\’)) {
$domainaccount = $account.Split(‘\’)
$domain = $domainaccount[0]
if (($domain -eq '.') -or ($domain -eq 'BUILTIN')) {
$domain = $computerName
}
$accountname = $domainaccount[1]
} elseif ($account.Contains('@')) {
$domainaccount = $account.Split('@')
$domain = $domainaccount[1].Split('.')[0]
$accountname = $domainaccount[0]
} else {
$domain = $computerName
$accountname = $account
}
$getparams = @{Class='Win32_Account';Filter="Domain='$domain' and Name='$accountname'"} + $remoteParams
$win32account = Get-WmiObject @getparams
if ($win32account -eq $null) {
throw "Account was not found: $account"
}
switch ($operation) {
'add' {
if ($permissions -eq $null) {
throw '-Permissions must be specified for an add operation'
}
$accessMask = Get-AccessMaskFromPermission($permissions)
$ace = (New-Object System.Management.ManagementClass('win32_Ace')).CreateInstance()
$ace.AccessMask = $accessMask
$CONTAINER_INHERIT_ACE_FLAG = 0x2
if ($allowInherit) {
$ace.AceFlags = $CONTAINER_INHERIT_ACE_FLAG
} else {
$ace.AceFlags = 0
}
$trustee = (New-Object System.Management.ManagementClass('win32_Trustee')).CreateInstance()
$trustee.SidString = $win32account.Sid
$ace.Trustee = $trustee
$ACCESS_ALLOWED_ACE_TYPE = 0x0
$ACCESS_DENIED_ACE_TYPE = 0x1
if ($deny) {
$ace.AceType = $ACCESS_DENIED_ACE_TYPE
} else {
$ace.AceType = $ACCESS_ALLOWED_ACE_TYPE
}
$acl.DACL += $ace.psobject.immediateBaseObject
}
'delete' {
if ($permissions -ne $null) {
throw 'Permissions cannot be specified for a delete operation'
}
[System.Management.ManagementBaseObject[]]$newDACL = @()
foreach ($ace in $acl.DACL) {
if ($ace.Trustee.SidString -ne $win32account.Sid) {
$newDACL += $ace.psobject.immediateBaseObject
}
}
$acl.DACL = $newDACL.psobject.immediateBaseObject
}
default {
throw "Unknown operation: $operation`nAllowed operations: add delete"
}
}
$setparams = @{Name='SetSecurityDescriptor';ArgumentList=$acl.psobject.immediateBaseObject} + $invokeParams
$output = Invoke-WmiMethod @setparams
if ($output.ReturnValue -ne 0) {
throw "SetSecurityDescriptor failed: $($output.ReturnValue)"
}
}
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