Erstellen der Kennwortdatei

Question

Ich habe ein Skript, mit dem ich das lokale Administratorkennwort von Microsoft ändere. https://support.microsoft.com/en-us/kb/2962486?wa=wsignin1.0habe ich es gefunden. Hier ist das Skript für alle, die zu faul zum Klicken sind:

function Invoke-PasswordRoll
{
<#
.SYNOPSIS

This script can be used to set the local account passwords on remote machines to random passwords. The 

username/password/server combination will be saved in a CSV file.
The account passwords stored in the CSV file can be encrypted using a password of the administrators choosing to 

ensure clear-text account passwords aren't written to disk.
The encrypted passwords can be decrypted using another function in this file: ConvertTo-CleartextPassword


Function: Invoke-PasswordRoll
Author: Microsoft
Version: 1.0

.DESCRIPTION

This script can be used to set the local account passwords on remote machines to random passwords. The 

username/password/server combination will be saved in a CSV file.
The account passwords stored in the CSV file can be encrypted using a password of the administrators choosing to 

ensure clear-text account passwords aren't written to disk.
The encrypted passwords can be decrypted using another function in this file: ConvertTo-CleartextPassword

.PARAMETER ComputerName

An array of computers to run the script against using PowerShell remoting.

.PARAMETER LocalAccounts

An array of local accounts whose password should be changed.

.PARAMETER TsvFileName

The file to output the username/password/server combinations to.

.PARAMETER EncryptionKey

A password to encrypt the TSV file with. Uses AES encryption. Only the passwords stored in the TSV file will be 

encrypted, the username and servername will be clear-text.

.PARAMETER PasswordLength

The length of the passwords which will be randomly generated for local accounts.

.PARAMETER NoEncryption

Do not encrypt the account passwords stored in the TSV file. This will result in clear-text passwords being 

written to disk.

.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @

("administrator","CustomLocalAdmin") -TsvFileName "LocalAdminCredentials.tsv" -EncryptionKey "Password1"

Connects to all the computers stored in the file "computerlist.txt". If the local account "administrator" and/or 

"CustomLocalAdmin" are present on the system, their password is changed
to a randomly generated password of length 20 (the default). The username/password/server combinations are 

stored in LocalAdminCredentials.tsv, and the account passwords are AES encrypted using the password "Password1".

.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @("administrator") -TsvFileName 

"LocalAdminCredentials.tsv" -NoEncryption -PasswordLength 40

Connects to all the computers stored in the file "computerlist.txt". If the local account "administrator" is 

present on the system, its password is changed to a random generated
password of length 40. The username/password/server combinations are stored in LocalAdminCredentials.tsv 

unencrypted.

.NOTES
Requirements: 
-PowerShellv2 or above must be installed
-PowerShell remoting must be enabled on all systems the script will be run against

Script behavior:
-If a local account is present on the system, but not specified in the LocalAccounts parameter, the script will 

write a warning to the screen to alert you to the presence of this local account. The script will continue 

running when this happens.
-If a local account is specified in the LocalAccounts parameter, but the account does not exist on the computer, 

nothing will happen (an account will NOT be created).
-The function ConvertTo-CleartextPassword, contained in this file, can be used to decrypt passwords that are 

stored encrypted in the TSV file.
-If a server specified in ComputerName cannot be connected to, PowerShell will output an error message.
-Microsoft advises companies to regularly roll all local and domain account passwords.

#>
    [CmdletBinding(DefaultParameterSetName="Encryption")]
    Param(
        [Parameter(Mandatory=$true)]
        [String[]]
        $ComputerName,

        [Parameter(Mandatory=$true)]
        [String[]]
        $LocalAccounts,

        [Parameter(Mandatory=$true)]
        [String]
        $TsvFileName,

        [Parameter(ParameterSetName="Encryption", Mandatory=$true)]
        [String]
        $EncryptionKey,

        [Parameter()]
        [ValidateRange(20,120)]
        [Int]
        $PasswordLength = 20,

        [Parameter(ParameterSetName="NoEncryption", Mandatory=$true)]
        [Switch]
        $NoEncryption
    )


    #Load any needed .net classes
    Add-Type -AssemblyName "System.Web" -ErrorAction Stop


    #This is the scriptblock that will be executed on every computer specified in ComputerName
    $RemoteRollScript = {
        Param(
            [Parameter(Mandatory=$true, Position=1)]
            [String[]]
            $Passwords,

            [Parameter(Mandatory=$true, Position=2)]
            [String[]]
            $LocalAccounts,

            #This is here so I can record what the server name that the script connected to was, sometimes the 

DNS records get messed up, it can be nice to have this.
            [Parameter(Mandatory=$true, Position=3)]
            [String]
            $TargettedServerName
        )

        $LocalUsers = Get-WmiObject Win32_UserAccount -Filter "LocalAccount=true" | Foreach {$_.Name}

        #Check if the computer has any local user accounts whose passwords are not going to be rolled by this 

script
        foreach ($User in $LocalUsers)
        {
            if ($LocalAccounts -inotcontains $User)
            {
                Write-Warning "Server: '$($TargettedServerName)' has a local account '$($User)' whos password is 

NOT being changed by this script"
            }
        }

        #For every local account specified that exists on this server, change the password
        $PasswordIndex = 0
        foreach ($LocalAdmin in $LocalAccounts)
        {
            $Password = $Passwords[$PasswordIndex]

            if ($LocalUsers -icontains $LocalAdmin)
            {
                try
                {
                    $objUser = [ADSI]"WinNT://localhost/$($LocalAdmin), user"
                    $objUser.psbase.Invoke("SetPassword", $Password)

                    $Properties = @{
                        TargettedServerName = $TargettedServerName
                        Username =  $LocalAdmin
                        Password = $Password
                        RealServerName = $env:computername
                    }

                    $ReturnData = New-Object PSObject -Property $Properties
                    Write-Output $ReturnData
                }
                catch
                {
                    Write-Error "Error changing password for user:$($LocalAdmin) on server:

$($TargettedServerName)"
                }
            }

            $PasswordIndex++
        }
    }


    #Generate the password on the client running this script, not on the remote machine. System.Web.Security 

isn't available in the .NET Client profile. Making this call
    #    on the client running the script ensures only 1 computer needs the full .NET runtime installed (as 

opposed to every system having the password rolled).
    function Create-RandomPassword
    {
        Param(
            [Parameter(Mandatory=$true)]
            [ValidateRange(20,120)]
            [Int]
            $PasswordLength
        )

        $Password = [System.Web.Security.Membership]::GeneratePassword($PasswordLength, $PasswordLength / 4)

        #This should never fail, but I'm putting a sanity check here anyways
        if ($Password.Length -ne $PasswordLength)
        {
            throw new Exception("Password returned by GeneratePassword is not the same length as required. 

Required length: $($PasswordLength). Generated length: $($Password.Length)")
        }

        return $Password
    }


    #Main functionality - Generate a password and remote in to machines to change the password of local accounts 

specified
    if ($PsCmdlet.ParameterSetName -ieq "Encryption")
    {
        try
        {
            $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
            $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes

($EncryptionKey))
        }
        catch
        {
            Write-Error "Error creating TSV encryption key" -ErrorAction Stop
        }
    }

    foreach ($Computer in $ComputerName)
    {
        #Need to generate 1 password for each account that could be changed
        $Passwords = @()
        for ($i = 0; $i -lt $LocalAccounts.Length; $i++)
        {
            $Passwords += Create-RandomPassword -PasswordLength $PasswordLength
        }

        Write-Output "Connecting to server '$($Computer)' to roll specified local admin passwords"
        $Result = Invoke-Command -ScriptBlock $RemoteRollScript -ArgumentList @($Passwords, $LocalAccounts, 

$Computer) -ComputerName $Computer
        #If encryption is being used, encrypt the password with the user supplied key prior to writing to disk
        if ($Result -ne $null)
        {
            if ($PsCmdlet.ParameterSetName -ieq "NoEncryption")
            {
                $Result | Select-Object Username,Password,TargettedServerName,RealServerName | Export-Csv -

Append -Path $TsvFileName -NoTypeInformation
            }
            else
            {
                #Filters out $null entries returned
                $Result = $Result | Select-Object Username,Password,TargettedServerName,RealServerName

                foreach ($Record in $Result)
                {
                    $PasswordSecureString = ConvertTo-SecureString -AsPlainText -Force -String 

($Record.Password)
                    $Record | Add-Member -MemberType NoteProperty -Name EncryptedPassword -Value (ConvertFrom-

SecureString -Key $SecureStringKey -SecureString $PasswordSecureString)
                    $Record.PSObject.Properties.Remove("Password")
                    $Record | Select-Object Username,EncryptedPassword,TargettedServerName,RealServerName | 

Export-Csv -Append -Path $TsvFileName -NoTypeInformation
                }
            }
        }
    }
}


function ConvertTo-CleartextPassword
{
<#
.SYNOPSIS
This function can be used to decrypt passwords that were stored encrypted by the function Invoke-PasswordRoll.

Function: ConvertTo-CleartextPassword
Author: Microsoft
Version: 1.0

.DESCRIPTION
This function can be used to decrypt passwords that were stored encrypted by the function Invoke-PasswordRoll.


.PARAMETER EncryptedPassword

The encrypted password that was stored in a TSV file.

.PARAMETER EncryptionKey

The password used to do the encryption.


.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
ConvertTo-CleartextPassword -EncryptionKey "Password1" -EncryptedPassword 

76492d1116743f0423413b16050a5345MgB8AGcAZgBaAHUAaQBwADAAQgB2AGgAcABNADMASwBaAFoAQQBzADEAeABjAEEAPQA9AHwAZgBiAGYA

MAA1ADYANgA2ADEANwBkADQAZgAwADMANABjAGUAZQAxAGIAMABiADkANgBiADkAMAA4ADcANwBhADMAYQA3AGYAOABkADcAMQA5ADQAMwBmAGYA

NQBhADEAYQBjADcANABkADIANgBhADUANwBlADgAMAAyADQANgA1ADIAOQA0AGMAZQA0ADEAMwAzADcANQAyADUANAAzADYAMAA1AGEANgAzADEA

MQA5ADAAYwBmADQAZAA2AGQA"

Decrypts the encrypted password which was stored in the TSV file.

#>
    Param(
        [Parameter(Mandatory=$true)]
        [String]
        $EncryptedPassword,

        [Parameter(Mandatory=$true)]
        [String]
        $EncryptionKey
    )

    $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
    $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionKey))

    [SecureString]$SecureStringPassword = ConvertTo-SecureString -String $EncryptedPassword -Key 

$SecureStringKey
    Write-Output ([System.Runtime.InteropServices.Marshal]::PtrToStringAuto

([System.Runtime.InteropServices.Marshal]::SecureStringToCoTaskMemUnicode($SecureStringPassword)))
}

Wenn ich das Skript ausführe mit:

Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @("administrator","CustomLocalAdmin") -TsvFileName "LocalAdminCredentials.tsv" -EncryptionKey "Password1"

es ändert das Passwort auf den Zielcomputern, aber nicht in „Password1“. Was genau macht dieses Skript?

Answer 1

Wie Tomasz und Zoredache sagten: Das von Microsoft bereitgestellte Skript kann nur verwendet werden, um die lokalen Kontokennwörter auf Remotecomputern auf zufällige Kennwörter festzulegen. Die in der CSV-Datei gespeicherten Kontokennwörter können mit einem vom Administrator gewählten Kennwort (dem Parameter -EncryptionKey) verschlüsselt werden, um sicherzustellen, dass Kontokennwörter im Klartext nicht auf die Festplatte geschrieben werden.

Die verschlüsselten Passwörter (gespeichert in der TSV-Datei) können mit einer anderen Funktion in derselben Datei entschlüsselt werden: ConvertTo-CleartextPassword.

In unserer Umgebung möchten wir das Passwort auch regelmäßig ändern, also haben wir zwei Skripte erstellt: eines, um eine neue Datei mit einem verschlüsselten Passwort (unserer Wahl) zu erstellen und diese Datei an alle unsere Arbeitsstationen zu verteilen. Ein zweites Skript (ebenfalls an die Arbeitsstationen verteilt) wird alle X Stunden ausgeführt und setzt das Passwort basierend auf dem Inhalt der Datei zurück. Natürlich wird das zum Verschlüsseln und Entschlüsseln verwendete Passwort weiterhin im Klartext gespeichert, das Passwort selbst jedoch nicht. Auf diese Weise müssen Sie wirklich wissen, was Sie tun, um das lokale Administratorpasswort abzurufen, und da die Verschlüsselungsdatei und das Skript an verschiedenen Orten gespeichert sind, ist es ziemlich sicher.

Erstellen der Kennwortdatei

Wir verwenden das folgende Skript (ich habe die Fehlerprotokollierung und Try/Catch-Befehle entfernt), um eine Kennwortdatei zu erstellen:

$LocalAdminPW = "0urAdminP@ssword" #the password that is used to set as the local admin password
$EncryptionPW = "0urEncryptionP@ssword" #password to encrypt and decrypt the password
$File = "C:\Temp\Password.tsv" #file to create

#Create encryption key
$Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
$SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionPW))

#Encrypt the password with the user supplied encryption password
PasswordSecureString = ConvertTo-SecureString -AsPlainText -Force -String $LocalAdminPW

#Create TSV-File with the encrypted password
ConvertFrom-SecureString -Key $SecureStringKey -SecureString $PasswordSecureString | Out-File -Force -FilePath "$File"

#Gathering the new encrypted password for the local administrator account
$LocalAdminPW = Get-Content $FileLocation

Legen Sie das lokale Administratorkennwort mit der erstellten Kennwortdatei fest

Wir verwenden das folgende Skript, um das Passwort aus der Passwortdatei zu entschlüsseln und verwenden es, um das Administratorpasswort festzulegen (die Fehlerbehandlung und Protokollierung habe ich entfernt):

#function to get decrypted password
Function Get-DecryptedPassword {
    [CmdletBinding()]
    param(
        $EncryptedPW,
        $LocalAdminPW
    )

    #Decrypt the password with the user supplied encryption password
    $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
    $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionPW))
    [SecureString]$SecureStringPassword = ConvertTo-SecureString -String $LocalAdminPW -Key $SecureStringKey
    return ([System.Runtime.InteropServices.Marshal]::PtrToStringAuto([System.Runtime.InteropServices.Marshal]::SecureStringToCoTaskMemUnicode($SecureStringPassword)))
}

#Change password local admin account
$LocalAdmin = "Administrator"
$objUser = [ADSI]"WinNT://localhost/$($LocalAdmin), user"
$objUser.psbase.Invoke("SetPassword", (Get-DecryptedPassword -EncryptedPW $EncryptionPW  -LocalAdminPW $LocalAdminPW))

Answer 2

Das Speichern von Passwörtern in einer Tabelle ist nicht optimal, und wenn Sie für alle Ihre Computer dasselbe Passwort festlegen, ist das ein ganz anderes Problem bei der Diebstahl von Anmeldeinformationen (selbst wenn Sie es regelmäßig ändern). Mit dem LAPS-Tool können Sie lokale Administratorpasswörter sicher zufällig erstellen. Wenn Sie versuchen, die in diesem Artikel beschriebenen Probleme zu lösen, sollten Sie die Verwendung von Domänenanmeldeinformationen in Betracht ziehen. Wenn Sie einfach nur versuchen, die Passwörter zu ändern, verwenden Sie das LAPS-Tool (https://technet.microsoft.com/en-us/library/security/3062591.aspx)

Answer 3

Lesen Sie einfach die Kommentare im eingefügten Skript:

Wenn die lokalen Konten „Administrator“ und/oder „CustomLocalAdmin“ auf dem System vorhanden sind, wird deren Passwort in ein zufällig generiertes Passwort mit der Länge 20 (Standard) geändert.

Die Benutzername/Passwort/Server-Kombinationen werden in LocalAdminCredentials.tsv gespeichert und die Kontopasswörter werden mit dem Passwort „Password1“ AES-verschlüsselt.