Fixed issue 3816

Elevated command line is now rendered to a script which is uploaded to the guest and executed. This allows the command line itself to be less than 100 chars to start the script and any user commands are puts into the script which has unlimited* length.

plugins/communicators/winrm/communicator.rb

@@ -69,12 +69,8 @@ module VagrantPlugins
         opts[:good_exit] = Array(opts[:good_exit])
 
         if opts[:elevated]
-          path = File.expand_path("../scripts/elevated_shell.ps1", __FILE__)
+          guest_script_path = create_elevated_shell_script(command)
-          command = Vagrant::Util::TemplateRenderer.render(path, options: {
+          command = "powershell -executionpolicy bypass -file #{guest_script_path}"
-            username: shell.username,
-            password: shell.password,
-            command: command,
-          })
         end
 
         output = shell.send(opts[:shell], command, &block)
@@ -119,6 +115,33 @@ module VagrantPlugins
         )
       end
 
+      # Creates and uploads a PowerShell script which wraps the specified
+      # command in a scheduled task. The scheduled task allows commands to
+      # run on the guest as a true local admin without any of the restrictions
+      # that WinRM puts in place.
+      #
+      # @return The path to elevated_shell.ps1 on the guest 
+      def create_elevated_shell_script(command)
+        path = File.expand_path("../scripts/elevated_shell.ps1", __FILE__)
+        script = Vagrant::Util::TemplateRenderer.render(path, options: {
+          username: shell.username,
+          password: shell.password,
+          command: command,
+        })
+        guest_script_path = "c:/tmp/vagrant-elevated-shell.ps1"
+        file = Tempfile.new(["vagrant-elevated-shell", "ps1"])
+        begin
+          file.write(script)
+          file.fsync
+          file.close
+          upload(file.path, guest_script_path)
+        ensure
+          file.close
+          file.unlink
+        end
+        guest_script_path
+      end
+
       # Handles the raw WinRM shell result and converts it to a
       # standard Vagrant communicator result
       def execution_output(output, opts)

test/unit/plugins/communicators/winrm/communicator_test.rb

@@ -48,11 +48,9 @@ describe VagrantPlugins::CommunicatorWinRM::Communicator do
     end
 
     it "wraps command in elevated shell script when elevated is true" do
+      expect(shell).to receive(:upload).with(kind_of(String), "c:/tmp/vagrant-elevated-shell.ps1")
       expect(shell).to receive(:powershell) do |cmd|
-        expect(cmd).to include("$command = \"dir\"")
+        expect(cmd).to eq("powershell -executionpolicy bypass -file c:/tmp/vagrant-elevated-shell.ps1")
-        expect(cmd).to include("$user = 'vagrant'")
-        expect(cmd).to include("$password = 'password'")
-        expect(cmd).to include("New-Object -ComObject \"Schedule.Service\"")
       end.and_return({ exitcode: 0 })
       expect(subject.execute("dir", { elevated: true })).to eq(0)
     end