PowerShell - Base64

<#
.Synopsis
   Function to convert strings or byte arrays to base 64 encoded strings
.DESCRIPTION
   Function to convert strings or byte arrays to base 64 encoded strings
.EXAMPLE
   ConvertTo-Base64 "marius"
.EXAMPLE
   ConvertTo-Base64 -ByteArray ([system.Text.Encoding]::UTF8).GetBytes("marius")
.EXAMPLE
   "marius" | ConvertTo-Base64
#>
function ConvertTo-Base64
{
    [CmdletBinding(DefaultParameterSetName='String')]
    [OutputType([String])]
    Param
    (
        # String to convert to base64
        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromRemainingArguments=$false,
                   Position=0,
                   ParameterSetName='String')]
        [ValidateNotNull()]
        [ValidateNotNullOrEmpty()]
        [string]
        $String,

        # Param2 help description
        [Parameter(ParameterSetName='ByteArray')]
        [ValidateNotNull()]
        [ValidateNotNullOrEmpty()]
        [byte[]]
        $ByteArray
    )

    if($String) {
        return [System.Convert]::ToBase64String(([System.Text.Encoding]::UTF8.GetBytes($String)));
    } else {
        return [System.Convert]::ToBase64String($ByteArray);
    }
}


<#
.Synopsis
   Function to convert strings or byte arrays to base 64 encoded strings
.DESCRIPTION
   Function to convert strings or byte arrays to base 64 encoded strings
.EXAMPLE
   "bWFyaXVz" | ConvertFrom-Base64
#>
function ConvertFrom-Base64 {
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory=$True,
                   Position=0,
                   ValueFromPipeline=$true)]
        [ValidateNotNull()]
        [ValidateNotNullOrEmpty()]
        [string]
        $Base64String
    )

    return [System.Text.Encoding]::UTF8.GetString(([System.Convert]::FromBase64String($Base64String)));
}