Add tests to check that username can't be changed during su

Users authenticating with su (both to another user and to root)
shouldn't be able to change the username already selected in the
command.

Author: denisonbarbosa

e2e-tests/resources/broker.resource

@@ -106,6 +106,39 @@ Log In With Remote User Through CLI: Local Password
     Match Text    ${username}@ubuntu:~$    120
 
 
+Try Changing Username In sudo su Log In
+    Hid.Type String    sudo su
+    Hid.Keys Combo    Return
+    Try Navigating Back to User Selection
+    Cancel Operation
+
+
+Try Changing Username In su Log In
+    [Arguments]    ${username}
+    Hid.Type String    su ${username}
+    Hid.Keys Combo    Return
+    Try Navigating Back to User Selection
+    Cancel Operation
+
+Try Navigating Back to User Selection
+    # First screen is the autoselected local password mode
+    Match Text    Enter your local password:    120
+    Hid.Keys Combo    Escape
+
+    # The previous screen should be the authentication mode selection
+    Match Text    Select your authentication method    120
+    Hid.Keys Combo    Escape
+
+    # The previous screen should be the broker selection
+    Match Text    Select your provider    120
+    Hid.Keys Combo    Escape
+
+    # The previous screen is the username prompt, but it shouldn't be possible to get there
+    Match Text    Select your provider    120
+    Hid.Keys Combo    Escape
+    Match Text    Select your provider    120
+
+
 # Uses sed to change the broker configuration.
 # It should match both commented and uncommented lines.
 # The full command looks like:

e2e-tests/tests/su_login.robot

@@ -0,0 +1,40 @@
+*** Settings ***
+Resource        resources/utils.resource
+Resource        resources/authd.resource
+Resource        resources/broker.resource
+
+# Test Tags       robot:exit-on-failure
+
+Test Setup    utils.Test Setup    snapshot=%{BROKER}-installed
+Test Teardown   utils.Test Teardown
+
+
+*** Variables ***
+${username}    %{E2E_USER}
+${local_password}    qwer1234
+
+
+*** Test Cases ***
+Test su login
+    [Documentation]    Test login functionality with su command for remote users.
+
+    # Log in with local user
+    Log In
+
+    # Log in with remote user with device authentication
+    Open Terminal
+    Log In With Remote User Through CLI: QR Code    ${username}    ${local_password}
+    # Check remote user is properly added to the system
+    Check If User Was Added Properly    ${username}
+    Log Out From Terminal Session
+    Close Focused Window
+
+    # Log in with remote user with local password
+    Open Terminal In Sudo Mode
+    Log In With Remote User Through CLI: Local Password    ${username}    ${local_password}
+
+    # Try to change username during su login, it should not be possible
+    Try Changing Username In su Log In    ${username}
+
+    # Try to change username during su login with sudo, it should not be possible
+    Try Changing Username In sudo su Log In