add -Unencrypted parameter

this enables unencrypted connections to $HomeServer, which is
often the case if the bot runs in an internal network with direct
access to the homeserver c-s listener

bot.ps1

@@ -14,10 +14,26 @@ param (
     [ValidateNotNullOrEmpty()]
     [securestring]
     $AccessToken = ((Get-Content -Path $env:ACCESSTOKEN_FILE -Raw).Trim() `
-                    | ConvertTo-SecureString -AsPlainText -Force)
+                    | ConvertTo-SecureString -AsPlainText -Force),
+
+    [switch]
+    $Unencrypted = $false #is alternatively set with $env:UNENCRYPTED
 )
 $ErrorActionPreference = 'Stop'
 
+
+if($env:UNENCRYPTED -eq 'TRUE') {
+    $Unencrypted = $true
+}
+
+#used in Invoke-RestMethod
+$authentication_headers = @{
+    Authentication = 'Bearer'
+    Token = $AccessToken
+    ContentType = 'application/json'
+    AllowUnencryptedAuthentication = $Unencrypted
+}
+
 $account_data_type_prefix = 'de.lubiland.pingposh.'
 $account_data_types = @{
     next_batch = $account_data_type_prefix+'next_batch'
@@ -44,18 +60,13 @@ function Send-MatrixEvent {
 
     $uri = '{0}_matrix/client/r0/rooms/{1}/send/{2}/{3}' -f $HomeServer,$RoomId,$EventType,$txn_id
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
         Method = 'Put'
         Body = $Event
     }
 
-    $response = Invoke-RestMethod @header_splat @http_splat
+    $response = Invoke-RestMethod @authentication_headers @http_splat
     if($response.event_id) {
         Write-Host ('Event {0} sent to room {1}' -f $response.event_id,$RoomId)
     }
@@ -215,17 +226,12 @@ function Join-MatrixRoom {
 
     $uri = '{0}_matrix/client/r0/rooms/{1}/join' -f $HomeServer,$RoomId
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
         Method = 'Post'
     }
 
-    $response = Invoke-RestMethod @header_splat @http_splat
+    $response = Invoke-RestMethod @authentication_headers @http_splat
     if($response.room_id) {
         Write-Host ('Joined room {0}' -f $RoomId)
     } else {
@@ -241,17 +247,12 @@ function Get-MatrixAccountData {
 
     $uri = '{0}_matrix/client/r0/user/{1}/account_data/{2}' -f $HomeServer,$UserId,$Type
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
         Method = 'Get'
     }
 
-    $response = Invoke-RestMethod @header_splat @http_splat
+    $response = Invoke-RestMethod @authentication_headers @http_splat
     return $response
 }
 function Set-MatrixAccountData {
@@ -267,18 +268,13 @@ function Set-MatrixAccountData {
 
     $uri = '{0}_matrix/client/r0/user/{1}/account_data/{2}' -f $HomeServer,$UserId,$Type
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
         Method = 'Put'
         Body = $Content | ConvertTo-Json -Compress
     }
 
-    Invoke-RestMethod @header_splat @http_splat | Out-Null
+    Invoke-RestMethod @authentication_headers @http_splat | Out-Null
 }
 function Get-NextBatchToken {
     $account_data = Get-MatrixAccountData -Type $account_data_types.next_batch
@@ -313,16 +309,11 @@ function Invoke-MatrixSync {
         $uri += '&filter={0}' -f $FilterId
     }
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
     }
 
-    $response = Invoke-RestMethod @header_splat @http_splat
+    $response = Invoke-RestMethod @authentication_headers @http_splat
 
     #.PSObject.Properties because the rooms under .join are [NoteProperty]
     $room_ids = $response.rooms.join.PSObject.Properties.Name
@@ -352,11 +343,6 @@ function Get-MatrixFilterId {
 
     $uri = '{0}_matrix/client/r0/user/{1}/filter' -f $HomeServer,$UserId
 
-    $header_splat = @{
-        Authentication = 'Bearer'
-        Token = $AccessToken
-        ContentType = 'application/json'
-    }
     $http_splat = @{
         Uri = $uri
         Method = 'Post'
@@ -365,7 +351,7 @@ function Get-MatrixFilterId {
         Body = $Filter | ConvertTo-Json -Compress -Depth 3
     }
 
-    $response = Invoke-RestMethod @header_splat @http_splat
+    $response = Invoke-RestMethod @authentication_headers @http_splat
 
     return $response.filter_id
 }