Public/Get-MDSCredential.ps1

Function Get-MDSCredential {
    <#
    .SYNOPSIS
    Get a stored credential or list all stored credentials.

    .DESCRIPTION
    Get a stored credential or list all stored credentials. A dynamic parameter of 'Name' allows for tab completion of available credentials.

    .EXAMPLE
    Get-MDSCredential -Name MyCred1

    Get a stored credential

    .EXAMPLE
    Invoke-Command -ComputerName Computer01 -Credential (Get-MDSCredential -Name MyCred1) -ScriptBlock {Get-Service}

    Use a stored credential to populate another cmdlet's credential parameter

    .EXAMPLE
    Get-MDSCredential -ListAvailable

    Disable a single service plan for a single user

    .EXAMPLE
    Get-MDSCredential -SortByName

    Disable a single service plan for a single user

    .NOTES

    #>

    [cmdletbinding(DefaultParameterSetName='Default',PositionalBinding=$False)]
    Param (
        [parameter(ParameterSetName='Default')]
        [switch]$ListAvailable,

        [parameter(ParameterSetName='Sort')]
        [switch]$SortByName
    )

    DynamicParam {
        # Execute a Test-Path to avoid dynamic parameter creation errors
        If ((Test-Path $CredentialFilePath) -eq $True) {
            $Options = @(
                Import-CliXML $CredentialFilePath -ErrorAction Stop |
                        Select-Object -ExpandProperty Keys | Sort-Object
            )
            New-DynamicParam -Name 'Name' -ValidateSet $Options -Position 0 -ParameterSetName 'Name'
        }
    }

    Begin {}
    Process {
        Try {
            If ((Test-Path $CredentialFilePath) -eq $False) {
                Write-Warning "Please use 'Add-MDSCredential' to populate your credential store. The store file will be saved in $CredentialFilePath."
                Return
            }

            $CredentialFile = Import-CliXML $CredentialFilePath -ErrorAction Stop

            # Credential object output
            If ($PSBoundParameters.Name) {
                $Name = $PSBoundParameters.Name
                If ($CredentialFile[$Name]) {
                    Write-Verbose "MDSCredential `'$Name`' found in store $CredentialFilePath"
                    $MDSCredentialEntry = $CredentialFile[$Name]
                }
                Else {
                    Throw "MDSCredential not found for $($Name)"
                }

                New-Object -TypeName System.Management.Automation.PsCredential -ArgumentList $MDSCredentialEntry[0],($MDSCredentialEntry[1] | ConvertTo-SecureString)
            }
            # Array output for human consumption
            ElseIf ($PSCmdlet.ParameterSetName -eq 'Default' -or $SortByName -eq $True) {
                $CredentialFile.GetEnumerator() | Sort-Object Name
            }
            # Hash output for Add/Remove functions
            Else {
                $CredentialFile
            }
        }
        Catch {
            Write-Error $PSItem
        }
    }
    End {}
}