How to do it...

To create a credential object, we can use the Get-Credential cmdlet. In this example, we store the credential object in a variable that can be used by the Get-Mailbox cmdlet:

$credential = Get-Credential
Get-Mailbox -Credential $credential

How it works...

When you run the Get-Credential cmdlet, you are presented with a Windows authentication dialog box requesting your username and password. In the previous example, we assigned the Get-Credential cmdlet to the $credential variable. After typing your username and password into the authentication dialog box, the credentials are saved as an object that can then be assigned to the -Credential parameter of a cmdlet. The cmdlet that utilizes the credential object will then run using the credentials of the specified user.

Supplying credentials to a command doesn't have to be an interactive process. You can programmatically create a credential object within your script without using the Get-Credential cmdlet:

$user = "contoso\administrator"
$pass = ConvertTo-SecureString -AsPlainText P@ssw0rd01 -Force
$credential = New-Object System.Management.Automation.PSCredential `
-ArgumentList $user,$pass

You can see here that we've created a credential object from scratch without using the Get-Credential cmdlet. In order to create a credential object, we need to supply the password as a secure string type. The ConvertTo-SecureString cmdlet can be used to create a secure string object. We then use the New-Object cmdlet to create a credential object specifying the desired user name and password as arguments.

If you need to prompt a user for their credentials but you do not want to invoke the Windows authentication dialog box, you can use this alternative syntax to prompt the user in the shell for their credentials:

$user = Read-Host "Please enter your username"
$pass = Read-Host "Please enter your password" -AsSecureString
$credential = New-Object System.Management.Automation.PSCredential `
-ArgumentList $user,$pass

This syntax uses the Read-Host cmdlet to prompt the user for both their username and password. Notice that when creating the $pass object we use Read-Host with the -AsSecureString parameter to ensure that the object is stored as a secure string.

There's more...

After you've created a credential object, you may need to access the properties of that object to retrieve the username and password. We can access the username and password properties of the $credential object created previously using the following commands:

You can see here that we can simply grab the username stored in the object by accessing the UserNameproperty of the credential object. Since the Password property is stored as a secure string, we need to use the GetNetworkCredential method to convert the credential to a NetworkCredential object that exposes the Password property as a simple string.