hass-workstation-service/UserInterface/Views/BrokerSettings.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d" d:DesignWidth="500" d:DesignHeight="450"
             x:Class="UserInterface.Views.BrokerSettings">
  <StackPanel Margin="30" HorizontalAlignment="Left" MinWidth="250">
    <ContentControl FontSize="18" FontWeight="Bold">MQTT Broker</ContentControl>
    <TextBlock IsVisible="{Binding IsConnected}" Foreground="Green" Text="{Binding Message}"></TextBlock >
    <TextBlock IsVisible="{Binding !IsConnected}" Foreground="Red" Text="{Binding Message}"></TextBlock >
    <ContentControl Margin="0 20 0 10">IP address or hostname</ContentControl>
    <TextBox Text="{Binding Host}" HorizontalAlignment="Left" Width="100" Watermark="192.168.1.200"/>
    <StackPanel Orientation="Horizontal">
      <StackPanel Orientation="Vertical">
        <ContentControl Margin="0 20 0 10">Port</ContentControl>
        <TextBox Text="{Binding Port}"  HorizontalAlignment="Left" Width="50" Watermark="1883"/>
      </StackPanel>

      <StackPanel Orientation="Vertical" Margin="30 0 0 0">
        <ContentControl Margin="0 20 0 10">Use TLS</ContentControl>
        <CheckBox IsChecked="{Binding UseTLS}" HorizontalAlignment="Left" Margin="0 3 0 0"/>
      </StackPanel>
    </StackPanel>
    <ContentControl  Margin="0 20 0 10">Username</ContentControl>
    <TextBox Text="{Binding Username}" MinWidth="150"/>
    <ContentControl  Margin="0 20 0 10">Password</ContentControl>
    <TextBox Text="{Binding Password}" MinWidth="150" PasswordChar="•"/>

    <Expander Header="Advanced">
      <StackPanel>
        <StackPanel>
          <StackPanel Margin="0 20 0 10" HorizontalAlignment="Left" Orientation="Horizontal">
            <ContentControl>Retain LastWillAndTestament</ContentControl>
            <TextBlock Cursor="Help" Margin="5 0 0 0" VerticalAlignment="Bottom" TextDecorations="Underline">
              (What's this?)
              <ToolTip.Tip>
                <StackPanel>
                  <TextBlock>
[Experimental]
If set, sets Retain on the Last Will and Testament message.
Only turn this off if you use a broker that does not support this(e.g. AWS IoT Core)
Defaults to True
                  </TextBlock>
                </StackPanel>
              </ToolTip.Tip>
            </TextBlock>
          </StackPanel>
          <CheckBox IsChecked="{Binding RetainLWT}" HorizontalAlignment="Left" Margin="0 0 0 0"/>
        </StackPanel>
        <StackPanel Margin="0 20 0 10" HorizontalAlignment="Left" Orientation="Horizontal">

          <ContentControl>Root Cert Path (.pem/.crt)</ContentControl>
          <TextBlock Cursor="Help" Margin="5 0 0 0" VerticalAlignment="Bottom" TextDecorations="Underline">
            (What's this?)
            <ToolTip.Tip>
              <StackPanel>
                <TextBlock>
[Experimental]
If set, use this certificate in the TLS configuration for the MQTT connection.
This will be a pem or crt file provided by your broker.
                </TextBlock>
              </StackPanel>
            </ToolTip.Tip>
          </TextBlock>
        </StackPanel>
        <TextBox Text="{Binding RootCAPath}" MinWidth="150"/>

        <StackPanel Margin="0 20 0 10" HorizontalAlignment="Left" Orientation="Horizontal">
          <ContentControl>Client Cert Path (.pfx)</ContentControl>
          <TextBlock Cursor="Help" Margin="5 0 0 0" VerticalAlignment="Bottom" TextDecorations="Underline">
            (What's this?)
            <ToolTip.Tip>
              <StackPanel>
                <TextBlock>
[Experimental]
If set, use this certificate in the TLS configuration for the MQTT connection.
This should be the private key .pfx file for a device created in your broker corresponding to this Windows PC.
                </TextBlock>
              </StackPanel>
            </ToolTip.Tip>
          </TextBlock>
        </StackPanel>
        <TextBox Text="{Binding ClientCertPath}" MinWidth="150"/>
      </StackPanel>
    </Expander>

    <Button Width="75" HorizontalAlignment="Right" Margin="0 40 0 10" Click="Configure">Save</Button>
  </StackPanel>
</UserControl>