Tuesday, 5 May 2020

Get-Credential

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.security/get-credential?view=powershell-7


Get-Credential

Gets a credential object based on a user name and password.

Syntax

PowerShell
Get-Credential
   [[-Credential] <PSCredential>]
   [<CommonParameters>]
PowerShell
Get-Credential
   [-Message <String>]
   [[-UserName] <String>]
   [-Title <String>]
   [<CommonParameters>]

Description

The Get-Credential cmdlet creates a credential object for a specified user name and password. You can use the credential object in security operations.
Beginning in PowerShell 3.0, you can use the Message parameter to specify a customized message on the dialog box that prompts the user for their name and password.
The Get-Credential cmdlet prompts the user for a password or a user name and password. By default, an authentication dialog box appears to prompt the user. However, in some host programs, such as the PowerShell console, you can prompt the user at the command line by changing a registry entry. For more information about this registry entry, see the notes and examples.

Examples

Example 1
PowerShell
$c = Get-Credential
This command gets a credential object and saves it in the $c variable.
When you enter the command, a dialog box appears requesting a user name and password. When you enter the requested information, the cmdlet creates a PSCredential object representing the credentials of the user and saves it in the $c variable.
You can use the object as input to cmdlets that request user authentication, such as those with a Credential parameter. However, some providers that are installed with PowerShell do not support the Credential parameter.
Example 2
PowerShell
$c = Get-Credential
Get-CimInstance Win32_DiskDrive -ComputerName Server01 -Credential $c
These commands use a credential object that the Get-Credential cmdlet returns to authenticate a user on a remote computer so they can use Windows Management Instrumentation (WMI) to manage the computer.
The first command gets a credential object and saves it in the $c variable. The second command uses the credential object in a Get-CimInstance command. This command gets information about the disk drives on the Server01 computer.
Example 3
PowerShell
Get-CimInstance Win32_BIOS -ComputerName Server01 -Credential (Get-Credential -Credential Domain01\User01)
This command shows how to include a Get-Credential command in a Get-CimInstance command.
This command uses the Get-CimInstance cmdlet to get information about the BIOS on the Server01 computer. It uses the Credential parameter to authenticate the user, Domain01\User01, and a Get-Credential command as the value of the Credential parameter.
Example 4
PowerShell
$c = Get-Credential -credential User01
$c.Username
User01
This example creates a credential that includes a user name without a domain name.
The first command gets a credential with the user name User01 and stores it in the $c variable. The second command displays the value of the Username property of the resulting credential object.
Example 5
PowerShell
$Credential = $host.ui.PromptForCredential("Need credentials", "Please enter your user name and password.", "", "NetBiosUserName")
This command uses the PromptForCredential method to prompt the user for their user name and password. The command saves the resulting credentials in the $Credential variable.
The PromptForCredential method is an alternative to using the Get-Credential cmdlet. When you use PromptForCredential, you can specify the caption, messages, and user name that appear in the message box.
Example 6
PowerShell
Set-ItemProperty "HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds" -Name ConsolePrompting -Value $true
This example shows how to modify the registry so that the user is prompted at the command line, instead of by using a dialog box.
The command creates the ConsolePrompting registry entry and sets its value to True. To run this command, start PowerShell with the "Run as administrator" option.
To use a dialog box for prompting, set the value of the ConsolePrompting to false ($false) or use the Remove-ItemProperty cmdlet to delete it.
The ConsolePrompting registry entry works in some host programs, such as the PowerShell console. It might not work in all host programs.
Example 7
This example shows how to create a credential object that is identical to the object that Get-Credential returns without prompting the user. This method requires a plain text password, which might violate the security standards in some enterprises.
PowerShell
$User = "Domain01\User01"
$PWord = ConvertTo-SecureString -String "P@sSwOrd" -AsPlainText -Force
$Credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $User, $PWord
The first command saves the user account name in the $User parameter. The value must have the "Domain\User" or "ComputerName\User" format.
The second command uses the ConvertTo-SecureString cmdlet to create a secure string from a plain text password. The command uses the AsPlainText parameter to indicate that the string is plain text and the Force parameter to confirm that you understand the risks of using plain text.
The third command uses the New-Object cmdlet to create a PSCredential object from the values in the $User and $PWord variables.
Example 8
PowerShell
Get-Credential -Message "Credential are required for access to the \\Server1\Scripts file share." -User Server01\PowerUser

PowerShell Credential Request
Credential are required for access to the \\Server1\Scripts file share.
Password for user Server01\PowerUser:
This command uses the Message and UserName parameters of the Get-Credential cmdlet. This command format is designed for shared scripts and functions. In this case, the message tells the user why credentials are needed and gives them confidence that the request is legitimate.
Example 9
PowerShell
Invoke-Command -ComputerName Server01 {Get-Credential Domain01\User02}

PowerShell Credential Request : PowerShell Credential Request
Warning: This credential is being requested by a script or application on the SERVER01 remote computer. Enter your credentials only if you
 trust the remote computer and the application or script requesting it.

Enter your credentials.
Password for user Domain01\User02: ***************

PSComputerName     : Server01
RunspaceId         : 422bdf52-9886-4ada-ab2f-130497c6777f
PSShowComputerName : True
UserName           : Domain01\User01
Password           : System.Security.SecureString
This command gets a credential from the Server01 remote computer. The command uses the Invoke-Command cmdlet to run a Get-Credential command on the remote computer. The output shows the remote security message that Get-Credential includes in the authentication prompt.

Parameters

-Credential
Specifies a user name for the credential, such as User01 or Domain01\User01. The parameter name, -Credential, is optional.
When you submit the command and specify a user name, you're prompted for a password. If you omit this parameter, you're prompted for a user name and a password.
Starting in PowerShell 3.0, if you enter a user name without a domain, Get-Credential no longer inserts a backslash before the name.
Credentials are stored in a PSCredential object and the password is stored as a SecureString.
 Note
For more information about SecureString data protection, see How secure is SecureString?.
TABLE 1
Type:PSCredential
Position:1
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Message
Specifies a message that appears in the authentication prompt. This parameter is designed for use in a function or script. You can use the message to explain to the user why you are requesting credentials and how they will be used.
This parameter was introduced in PowerShell 3.0.
TABLE 2
Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Title
Sets the text of the title bar for the authentication dialog.
This parameter was introduced in PowerShell 6.0.
TABLE 3
Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-UserName
Specifies a user name. The authentication prompt requests a password for the user name. By default, the user name is blank and the authentication prompt requests both a user name and password.
When the authentication prompt appears in a dialog box, the user can edit the specified user name. However, the user cannot change the user name when the prompt appears at the command line. When using this parameter in a shared function or script, consider all possible presentations.
This parameter was introduced in PowerShell 3.0.
TABLE 4
Type:String
Position:1
Default value:None (blank)
Accept pipeline input:False
Accept wildcard characters:False

Inputs

None
You cannot pipe input to this cmdlet.

Outputs

Get-Credential returns a credential object.

Notes

You can use the PSCredential object that Get-Credential creates in cmdlets that request user authentication, such as those with a Credential parameter.
By default, the authentication prompt appears in a dialog box. To display the authentication prompt at the command line, add the ConsolePrompting registry entry (HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds\ConsolePrompting) and set its value to True. If the ConsolePrompting registry entry does not exist or if its value is False, the authentication prompt appears in a dialog box. For instructions, see the examples.
The ConsolePrompting registry entry works in the PowerShell console, but it does not work in all host programs.
For example, it has no effect in the PowerShell Integrated Scripting Environment (ISE). For information about the effect of the ConsolePrompting registry entry, see the help topics for the host program.
The Credential parameter is not supported by all providers that are installed with PowerShell. Beginning in PowerShell 3.0, it is supported on selected cmdlet, such as the Get-WmiObject and New-PSDrive cmdlets.

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