Make Auth Broker authoritative for managed passwords

docs/architecture.md

@@ -62,6 +62,15 @@ plus six digits. It searches `BaseDn` by `sAMAccountName`, creates the user when
 absent, moves it to the mapped OU when required, sets `userPrincipalName`, and
 passes the submitted password directly to ADSI `SetPassword`.
 
+Before an account becomes usable, the broker applies explicit deny ACEs for the
+Active Directory `Change Password` extended right to SELF and Everyone. Users
+beneath `OU=Usuarios-SGU` therefore cannot replace the synchronized password
+from Windows, Ctrl+Alt+Delete, LDAP or another client. The broker's
+administrative `SetPassword` operation uses the separate `Reset Password` right
+and remains able to synchronize the current institutional credential after each
+successful SGU authentication. Repeated synchronizations detect the existing
+ACEs and do not duplicate them.
+
 When the authenticated HTML exposes recognized stable IDs, the broker also
 updates the applicable `displayName`, `givenName`, `sn`, `mail`, `title`,
 `department`, `employeeType`, `employeeID`, `streetAddress`, `l`, `st`, and

docs/release-0.6.5.md

@@ -0,0 +1,26 @@
+# SGU Credential Provider 0.6.5
+
+Esta versión actualiza los fondos de bienvenida de Windows y Linux sin agregar
+dependencias ni trabajo de composición durante el inicio de sesión.
+
+## Identidad visual
+
+- El fondo base azul incorpora de forma permanente el logotipo blanco oficial
+  de Universidad La Salle México.
+- El generador utiliza directamente ese JPEG: no abre, redimensiona ni compone
+  un segundo archivo de logotipo cada vez que inicia una sesión.
+- Se conservan las dimensiones institucionales de `1600x1000` y el área central
+  disponible para el saludo personalizado.
+
+## Texto de ubicación
+
+- La sala aparece en una primera línea de mayor tamaño.
+- La dependencia aparece debajo con una tipografía menor.
+- La redacción neutral usa `Acceso a...`; cuando Active Directory contiene el
+  sexo enriquecido, usa `Estás ubicado...` o `Estás ubicada...`.
+- La misma lógica está incluida en los enrolamientos de Windows y Linux.
+- Si faltan el sexo o los metadatos de ubicación, permanecen los fallbacks
+  neutrales documentados y el inicio de sesión no se bloquea.
+
+Los perfiles de usuario locales y el rollback de roaming introducido en 0.6.4
+no cambian en esta versión.

docs/release-0.6.6.md

@@ -0,0 +1,16 @@
+# SGU Credential Provider 0.6.6
+
+Esta versión ajusta la composición del fondo institucional introducido en
+0.6.5.
+
+- El logotipo blanco oficial de Universidad La Salle México queda integrado en
+  la esquina inferior derecha.
+- Su tamaño se reduce ligeramente y se conserva un margen interior respecto de
+  ambos bordes para acercarlo visualmente al centro.
+- El fondo original de `1600x1000`, el área central del saludo y la composición
+  dinámica de nombre y ubicación permanecen sin cambios.
+- El generador sigue sin cargar ni componer un logotipo durante el inicio de
+  sesión.
+
+No se modifican la autenticación, el enrolamiento, las políticas del dominio ni
+el comportamiento de perfiles locales establecido en 0.6.4.

docs/release-0.6.7.md

@@ -0,0 +1,17 @@
+# SGU Credential Provider 0.6.7
+
+Esta versión separa la imagen de la pantalla de bloqueo de la base utilizada
+para generar el escritorio personalizado.
+
+- `darkblue-lockscreen.jpg` contiene únicamente el fondo azul institucional,
+  sin logotipo ni datos personales.
+- `darkblue.jpg` continúa como base del escritorio de cada sesión y conserva el
+  logotipo oficial integrado.
+- El logo de escritorio se reduce nuevamente y se desplaza ligeramente hacia
+  arriba, sin interferir con el saludo central.
+- El instalador, la GPO clásica, `PersonalizationCSP` y los paquetes de servidor
+  y cliente utilizan explícitamente el archivo correspondiente a cada función.
+- Linux continúa usando sólo la base de escritorio personalizada.
+
+No se modifican la autenticación, los perfiles locales ni las reglas de
+enrolamiento.

docs/release-0.6.8.md

@@ -0,0 +1,17 @@
+# SGU Credential Provider 0.6.8
+
+Esta versión declara al Auth Broker como la única autoridad de contraseñas para
+todas las cuentas administradas bajo `OU=Usuarios-SGU`.
+
+- Cada creación, movimiento o actualización de una cuenta agrega de forma
+  idempotente las denegaciones SELF y Everyone para el derecho extendido de
+  Active Directory `Change Password`.
+- El usuario no puede cambiar la contraseña desde Windows, Ctrl+Alt+Delete,
+  LDAP ni herramientas equivalentes.
+- El broker conserva el derecho administrativo separado `Reset Password` y
+  continúa sincronizando la contraseña institucional exacta mediante
+  `SetPassword` después de una autenticación SGU válida.
+- El despliegue del broker recorre todas las cuentas existentes en
+  `Usuarios-SGU` y corrige aquellas que todavía permiten cambios directos.
+
+No se modifica la contraseña institucional ni se almacena una copia adicional.

docs/security.md

@@ -18,6 +18,9 @@ the same source list. RDP uses a separate allowlist. See
   `Marshal.ZeroFreeGlobalAllocUnicode`; managed references are released as soon
   as each request completes.
 - The broker uses the exact received value for both NTLM and AD `SetPassword`.
+- Managed `Usuarios-SGU` accounts deny the SELF and Everyone `Change Password`
+  extended right. Only an administrator or the broker through the separate
+  `Reset Password` right can replace the AD password.
 - There is no HMAC password, pepper, local password cache, Supabase password, or
   other derived credential in this Windows path.
 - Neither application logs request bodies or passwords. Deployment configuration

docs/welcome-wallpaper.md

@@ -1,9 +1,15 @@
 # Fondo de bienvenida personalizado
 
-El enrolamiento instala un fondo base azul, las familias `Indivisa Text Sans` y
+El enrolamiento instala dos fondos base azules. El escritorio personalizado usa
-`Indivisa Text Serif`, y un generador local. La GPO de equipos
+`assets/branding/darkblue.jpg`, que contiene el logotipo blanco oficial de
+Universidad La Salle México, pequeño y elevado en el sector inferior derecho.
+La pantalla de bloqueo usa `assets/branding/darkblue-lockscreen.jpg`, que sólo
+contiene el fondo azul y nunca muestra el logo. También instala las familias
+`Indivisa Text Sans` y `Indivisa Text Serif`, y un generador local. El logotipo
+está horneado únicamente en la base de escritorio: el generador no carga,
+redimensiona ni compone otro logo durante el inicio de sesión. La GPO de equipos
 `SGU - Windows client experience` ejecuta el generador al abrir cada sesión y
-mantiene el fondo base en la pantalla de bloqueo.
+mantiene la base limpia independiente en la pantalla de bloqueo.
 
 Windows no conoce todavía la identidad que se autenticará mientras muestra la
 pantalla previa al inicio de sesión. Por ello, esa pantalla utiliza el fondo base
@@ -28,12 +34,18 @@ restaura el comando genérico de inicio.
 
 El saludo usa `Bienvenido/ubicado` para `Male` y `Bienvenida/ubicada` para
 `Female`. Cuando el enriquecimiento no produjo este dato, utiliza la redacción
-neutral `Te damos la bienvenida` y `Ubicación:`. El texto secundario sigue estas
+neutral `Te damos la bienvenida` y `Acceso`. La ubicación se divide en dos
-reglas:
+líneas: la sala ocupa la primera y la dependencia aparece debajo con un tamaño
+menor. Sigue estas reglas:
 
-1. Con `location` y OU: `Acceso al Aula Flexible del Centro de Experiencia Digital.`
+1. Sin sexo: `Acceso a la Sala de Aplicaciones`, seguido por
-2. Con sólo uno de los datos: muestra únicamente el dato disponible.
+   `del Laboratorio de Cómputo de Ingeniería.`
-3. Sin ambos: el texto adaptado `Bienvenido/Bienvenida al Laboratorio...`; sin
+2. Masculino: `Estás ubicado en el Aula Flexible`, seguido por
+   `del Centro de Experiencia Digital.`
+3. Femenino: `Estás ubicada en la Sala de Redes`, seguido por
+   `del Laboratorio de Cómputo de Ingeniería.`
+4. Con sólo uno de los datos: muestra únicamente el dato disponible.
+5. Sin ambos: el texto adaptado `Bienvenido/Bienvenida al Laboratorio...`; sin
    sexo disponible, la forma neutral `Acceso al Laboratorio de Cómputo de Ingeniería.`
 
 La ausencia de AD, de un atributo o de una tipografía nunca bloquea la sesión.

scripts/Deploy-AuthBroker.ps1

@@ -201,6 +201,19 @@ if ($RemoteDesktopGroupDn) {
     }
 }
 
+$managedUsersPasswordChangeCorrected = 0
+if ($PSCmdlet.ShouldProcess($usersOuDn, 'Deny direct password changes for every managed SGU user')) {
+    $managedUsers = @(Get-ADUser -Filter * -SearchBase $usersOuDn -SearchScope Subtree `
+        -Properties CannotChangePassword -Server $LdapHost -ErrorAction Stop)
+    foreach ($managedUser in $managedUsers) {
+        if (-not $managedUser.CannotChangePassword) {
+            Set-ADAccountControl -Identity $managedUser.DistinguishedName `
+                -CannotChangePassword $true -Server $LdapHost -Confirm:$false
+            $managedUsersPasswordChangeCorrected++
+        }
+    }
+}
+
 foreach ($file in @('SGU.AuthBroker.exe', 'SGU.AuthBroker.dll', 'appsettings.json')) {
     if (-not (Test-Path -LiteralPath (Join-Path $PublishPath $file))) {
         throw "PublishPath is missing $file."
@@ -356,4 +369,5 @@ if ($PSCmdlet.ShouldProcess($installPath, 'Install the SGU Authentication Broker
 }
 
 Get-Service -Name $serviceName | Select-Object Name, Status, StartType,
-    @{ Name = 'EventLog'; Expression = { $brokerEventLogName } }
+    @{ Name = 'EventLog'; Expression = { $brokerEventLogName } },
+    @{ Name = 'ExistingUsersPasswordChangeDenied'; Expression = { $managedUsersPasswordChangeCorrected } }

scripts/Install-CredentialProvider.ps1

@@ -38,6 +38,7 @@ $interactiveLogonPolicyPath = 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\P
 $accountPictureSourcePath = Join-Path $PublishPath 'branding\user.png'
 $accountPictureDirectory = Join-Path $env:ProgramData 'Microsoft\User Account Pictures'
 $welcomeWallpaperSourcePath = Join-Path $PublishPath 'branding\darkblue.jpg'
+$welcomeLockScreenSourcePath = Join-Path $PublishPath 'branding\darkblue-lockscreen.jpg'
 $welcomeWallpaperScriptSourcePath = Join-Path $PublishPath 'branding\Set-SguWelcomeWallpaper.ps1'
 $welcomeFontsSourcePath = Join-Path $PublishPath 'branding\fonts'
 $welcomeWallpaperDirectory = Join-Path $env:ProgramData 'SGU\Branding'
@@ -128,6 +129,7 @@ function Install-DefaultAccountPicture {
 
 function Install-WelcomeWallpaperAssets {
     if (-not (Test-Path -LiteralPath $welcomeWallpaperSourcePath -PathType Leaf) -or
+        -not (Test-Path -LiteralPath $welcomeLockScreenSourcePath -PathType Leaf) -or
         -not (Test-Path -LiteralPath $welcomeWallpaperScriptSourcePath -PathType Leaf)) {
         return $false
     }
@@ -135,6 +137,8 @@ function Install-WelcomeWallpaperAssets {
     New-Item -ItemType Directory -Path $welcomeWallpaperDirectory -Force | Out-Null
     Copy-Item -LiteralPath $welcomeWallpaperSourcePath `
         -Destination (Join-Path $welcomeWallpaperDirectory 'darkblue.jpg') -Force
+    Copy-Item -LiteralPath $welcomeLockScreenSourcePath `
+        -Destination (Join-Path $welcomeWallpaperDirectory 'darkblue-lockscreen.jpg') -Force
     Copy-Item -LiteralPath $welcomeWallpaperScriptSourcePath `
         -Destination (Join-Path $welcomeWallpaperDirectory 'Set-SguWelcomeWallpaper.ps1') -Force
     if (Test-Path -LiteralPath $welcomeFontsSourcePath -PathType Container) {
@@ -358,5 +362,6 @@ catch {
     SystemPasswordProviderPreserved = $true
     WelcomeWallpaperAssetsInstalled =
         (Test-Path -LiteralPath (Join-Path $welcomeWallpaperDirectory 'darkblue.jpg') -PathType Leaf) -and
+        (Test-Path -LiteralPath (Join-Path $welcomeWallpaperDirectory 'darkblue-lockscreen.jpg') -PathType Leaf) -and
         (Test-Path -LiteralPath (Join-Path $welcomeWallpaperDirectory 'Set-SguWelcomeWallpaper.ps1') -PathType Leaf)
 }

scripts/New-SguBootstrapPackages.ps1

@@ -143,6 +143,8 @@ Copy-RequiredFile -Source (Join-Path $repositoryRoot 'assets\branding\lasalle-ma
     -Destination (Join-Path $clientRoot 'payload\credential-provider\branding\user.png')
 Copy-RequiredFile -Source (Join-Path $repositoryRoot 'assets\branding\darkblue.jpg') `
     -Destination (Join-Path $clientRoot 'payload\credential-provider\branding\darkblue.jpg')
+Copy-RequiredFile -Source (Join-Path $repositoryRoot 'assets\branding\darkblue-lockscreen.jpg') `
+    -Destination (Join-Path $clientRoot 'payload\credential-provider\branding\darkblue-lockscreen.jpg')
 Copy-RequiredFile -Source (Join-Path $PSScriptRoot 'Set-SguWelcomeWallpaper.ps1') `
     -Destination (Join-Path $clientRoot 'payload\credential-provider\branding\Set-SguWelcomeWallpaper.ps1')
 foreach ($fontName in $welcomeFontNames) {
@@ -238,6 +240,8 @@ Copy-RequiredFile -Source (Join-Path $PSScriptRoot 'Set-SguWelcomeWallpaper.ps1'
     -Destination (Join-Path $serverContentTarget 'welcome-wallpaper\Set-SguWelcomeWallpaper.ps1')
 Copy-RequiredFile -Source (Join-Path $repositoryRoot 'assets\branding\darkblue.jpg') `
     -Destination (Join-Path $serverContentTarget 'welcome-wallpaper\darkblue.jpg')
+Copy-RequiredFile -Source (Join-Path $repositoryRoot 'assets\branding\darkblue-lockscreen.jpg') `
+    -Destination (Join-Path $serverContentTarget 'welcome-wallpaper\darkblue-lockscreen.jpg')
 foreach ($fontName in $welcomeFontNames) {
     Copy-RequiredFile -Source (Join-Path $repositoryRoot "assets\branding\fonts\$fontName") `
         -Destination (Join-Path $serverContentTarget "welcome-wallpaper\fonts\$fontName")

scripts/Set-SguDomainComputerPolicies.ps1

@@ -5,7 +5,8 @@ param(
     [string]$DomainController = $env:COMPUTERNAME,
     [string]$EventCollectorFqdn,
     [string]$WelcomeWallpaperScriptPath = 'C:\ProgramData\SGU\Branding\Set-SguWelcomeWallpaper.ps1',
-    [string]$WelcomeWallpaperBasePath = 'C:\ProgramData\SGU\Branding\darkblue.jpg'
+    [string]$WelcomeWallpaperBasePath = 'C:\ProgramData\SGU\Branding\darkblue.jpg',
+    [string]$WelcomeLockScreenBasePath = 'C:\ProgramData\SGU\Branding\darkblue-lockscreen.jpg'
 )
 
 $ErrorActionPreference = 'Stop'
@@ -113,14 +114,14 @@ $policies = @(
     # The machine GPO remains the authority for every interactive session. The
     # local payload lets the first desktop render without depending on SMB.
     @{ Key = $runPolicyKey; Name = 'SGUWelcomeWallpaper'; Type = 'String'; Value = $welcomeWallpaperCommand },
-    @{ Key = $personalizationPolicyKey; Name = 'LockScreenImage'; Type = 'String'; Value = $WelcomeWallpaperBasePath },
+    @{ Key = $personalizationPolicyKey; Name = 'LockScreenImage'; Type = 'String'; Value = $WelcomeLockScreenBasePath },
     @{ Key = $personalizationPolicyKey; Name = 'NoChangingLockScreen'; Type = 'DWord'; Value = 1 },
 
     # Windows 11 Pro can ignore the legacy lock-screen policy even though it is
     # present in the registry. PersonalizationCSP provides the same local image
     # to Pro while remaining harmless on Enterprise and LTSC editions.
-    @{ Key = $personalizationCspKey; Name = 'LockScreenImagePath'; Type = 'String'; Value = $WelcomeWallpaperBasePath },
+    @{ Key = $personalizationCspKey; Name = 'LockScreenImagePath'; Type = 'String'; Value = $WelcomeLockScreenBasePath },
-    @{ Key = $personalizationCspKey; Name = 'LockScreenImageUrl'; Type = 'String'; Value = $WelcomeWallpaperBasePath },
+    @{ Key = $personalizationCspKey; Name = 'LockScreenImageUrl'; Type = 'String'; Value = $WelcomeLockScreenBasePath },
     @{ Key = $personalizationCspKey; Name = 'LockScreenImageStatus'; Type = 'DWord'; Value = 1 },
     @{ Key = $cloudContentPolicyKey; Name = 'DisableWindowsSpotlightFeatures'; Type = 'DWord'; Value = 1 },
     @{ Key = $cloudContentPolicyKey; Name = 'DisableWindowsSpotlightOnLockScreen'; Type = 'DWord'; Value = 1 }
@@ -176,6 +177,6 @@ $linkEnabled = $link -and (
     PolicyCount = $configuredPolicies.Count
     EventCollector = $EventCollectorFqdn
     WelcomeWallpaperCommand = $welcomeWallpaperCommand
-    LockScreenImage = $WelcomeWallpaperBasePath
+    LockScreenImage = $WelcomeLockScreenBasePath
     Policies = [pscustomobject]$configuredPolicies
 }

scripts/Set-SguWelcomeWallpaper.ps1

@@ -189,7 +189,7 @@ function Get-WelcomeLocationText {
     $located = switch ($Gender) {
         'Male' { 'Est{0}s ubicado en' -f [char]0x00E1 }
         'Female' { 'Est{0}s ubicada en' -f [char]0x00E1 }
-        default { 'Ubicaci{0}n:' -f [char]0x00F3 }
+        default { $null }
     }
     $engineeringLab = switch ($Gender) {
         'Male' { 'Bienvenido al Laboratorio de C{0}mputo de Ingenier{1}a.' -f [char]0x00F3,[char]0x00ED }
@@ -202,7 +202,10 @@ function Get-WelcomeLocationText {
     if ($Room -and $OuName) {
         $roomArticle = Get-SpanishArticle -Value $Room
         $ouArticle = Get-SpanishArticle -Value $OuName
-        $roomPhrase = if ($roomArticle -eq 'el') {
+        $roomPhrase = if ($Gender) {
+            if ($roomArticle) { "$roomArticle $Room" } else { $Room }
+        }
+        elseif ($roomArticle -eq 'el') {
             "al $Room"
         }
         elseif ($roomArticle) {
@@ -212,17 +215,26 @@ function Get-WelcomeLocationText {
             "a $Room"
         }
         $ouPhrase = if ($ouArticle -eq 'el') { "del $OuName" } elseif ($ouArticle) { "de $ouArticle $OuName" } else { "de $OuName" }
-        return "Acceso $roomPhrase $ouPhrase."
+        $primary = if ($Gender) { "$located $roomPhrase" } else { "Acceso $roomPhrase" }
+        return "$primary`n$ouPhrase."
     }
     if ($Room) {
         $article = Get-SpanishArticle -Value $Room
-        $phrase = if ($article) { "$article $Room" } else { $Room }
+        if ($Gender) {
-        return "$located $phrase."
+            $phrase = if ($article) { "$article $Room" } else { $Room }
+            return "$located $phrase."
+        }
+        $destination = if ($article -eq 'el') { "al $Room" } elseif ($article) { "a $article $Room" } else { "a $Room" }
+        return "Acceso $destination."
     }
     if ($OuName) {
         $article = Get-SpanishArticle -Value $OuName
-        $phrase = if ($article) { "$article $OuName" } else { $OuName }
+        if ($Gender) {
-        return "$located $phrase."
+            $phrase = if ($article) { "$article $OuName" } else { $OuName }
+            return "$located $phrase."
+        }
+        $destination = if ($article -eq 'el') { "al $OuName" } elseif ($article) { "a $article $OuName" } else { "a $OuName" }
+        return "Acceso $destination."
     }
     return $engineeringLab
 }
@@ -350,6 +362,9 @@ if (-not $PSBoundParameters.ContainsKey('OrganizationalUnit')) {
     }
 }
 $locationText = Get-WelcomeLocationText -Room $Location -OuName $OrganizationalUnit -Gender $Gender
+$locationLines = @($locationText -split '\r?\n', 2)
+$locationPrimaryText = $locationLines[0]
+$locationSecondaryText = if ($locationLines.Count -gt 1) { $locationLines[1] } else { $null }
 
 if (-not $CanvasWidth -or -not $CanvasHeight) {
     try {
@@ -436,6 +451,8 @@ try {
             -PreferredStyle ([Drawing.FontStyle]::Bold -bor [Drawing.FontStyle]::Italic)
         $locationFont = New-WelcomeFont -Family $sansFamily -Size ([single](27 * $scale)) `
             -PreferredStyle ([Drawing.FontStyle]::Regular)
+        $locationSecondaryFont = New-WelcomeFont -Family $sansFamily -Size ([single](20 * $scale)) `
+            -PreferredStyle ([Drawing.FontStyle]::Regular)
         $format = [Drawing.StringFormat]::new()
         $format.Alignment = [Drawing.StringAlignment]::Center
         $format.LineAlignment = [Drawing.StringAlignment]::Center
@@ -447,11 +464,20 @@ try {
             Draw-CenteredText -Graphics $graphics -Text $DisplayName -Font $nameFont `
                 -Brush $whiteBrush -Bounds ([Drawing.RectangleF]::new($panelX + 30*$scale, $panelY + 64*$scale, $panelWidth - 60*$scale, 105*$scale)) -Format $format
             $graphics.DrawLine($linePen, $panelX + 150*$scale, $panelY + 180*$scale, $panelX + $panelWidth - 150*$scale, $panelY + 180*$scale)
-            Draw-CenteredText -Graphics $graphics -Text $locationText -Font $locationFont `
+            if ($locationSecondaryText) {
-                -Brush $accentBrush -Bounds ([Drawing.RectangleF]::new($panelX + 60*$scale, $panelY + 190*$scale, $panelWidth - 120*$scale, 94*$scale)) -Format $format
+                Draw-CenteredText -Graphics $graphics -Text $locationPrimaryText -Font $locationFont `
+                    -Brush $accentBrush -Bounds ([Drawing.RectangleF]::new($panelX + 60*$scale, $panelY + 190*$scale, $panelWidth - 120*$scale, 46*$scale)) -Format $format
+                Draw-CenteredText -Graphics $graphics -Text $locationSecondaryText -Font $locationSecondaryFont `
+                    -Brush $accentBrush -Bounds ([Drawing.RectangleF]::new($panelX + 60*$scale, $panelY + 235*$scale, $panelWidth - 120*$scale, 38*$scale)) -Format $format
+            }
+            else {
+                Draw-CenteredText -Graphics $graphics -Text $locationPrimaryText -Font $locationFont `
+                    -Brush $accentBrush -Bounds ([Drawing.RectangleF]::new($panelX + 60*$scale, $panelY + 195*$scale, $panelWidth - 120*$scale, 78*$scale)) -Format $format
+            }
         }
         finally {
             $format.Dispose()
+            $locationSecondaryFont.Dispose()
             $locationFont.Dispose()
             $nameFont.Dispose()
             $welcomeFont.Dispose()
@@ -519,6 +545,8 @@ Write-WelcomeLog -Message ("OK computer={0}; gender={1}; location={2}; ou={3}; o
     Gender = $Gender
     WelcomeHeading = $welcomeHeading
     LocationText = $locationText
+    LocationPrimaryText = $locationPrimaryText
+    LocationSecondaryText = $locationSecondaryText
     OutputPath = $OutputPath
     Applied = -not $SkipApply
 }

scripts/Set-SguWelcomeWallpaper.sh

@@ -129,8 +129,8 @@ fi
 article_for() {
     local value=${1,,}
     case "$value" in
-        sala*|aula*|facultad*|unidad*|biblioteca*|oficina*|coordinación*) printf la ;;
+        sala*|facultad*|unidad*|biblioteca*|oficina*|coordinación*) printf la ;;
-        laboratorio*|centro*|edificio*|campus*|taller*|auditorio*) printf el ;;
+        aula*|laboratorio*|centro*|edificio*|campus*|taller*|auditorio*) printf el ;;
         *) printf '' ;;
     esac
 }
@@ -159,29 +159,60 @@ case "$gender" in
         ;;
     *)
         welcome_text='Te damos la bienvenida,'
-        located_text='Ubicación:'
+        located_text=''
         engineering_lab_text='Acceso al Laboratorio de Cómputo de Ingeniería.'
         ;;
 esac
 
+location_primary=''
+location_secondary=''
 if [[ -n $location && -n $organizational_unit ]]; then
-    room_phrase=$(with_article "$location")
+    room_article=$(article_for "$location")
+    if [[ -n $gender ]]; then
+        room_phrase=$(with_article "$location")
+        location_primary="${located_text} ${room_phrase}"
+    elif [[ $room_article == el ]]; then
+        location_primary="Acceso al ${location}"
+    elif [[ -n $room_article ]]; then
+        location_primary="Acceso a ${room_article} ${location}"
+    else
+        location_primary="Acceso a ${location}"
+    fi
     ou_article=$(article_for "$organizational_unit")
     if [[ $ou_article == el ]]; then
-        ou_phrase="del ${organizational_unit}"
+        location_secondary="del ${organizational_unit}."
     elif [[ -n $ou_article ]]; then
-        ou_phrase="de ${ou_article} ${organizational_unit}"
+        location_secondary="de ${ou_article} ${organizational_unit}."
     else
-        ou_phrase="de ${organizational_unit}"
+        location_secondary="de ${organizational_unit}."
     fi
-    location_text="${located_text} ${room_phrase} ${ou_phrase}."
 elif [[ -n $location ]]; then
-    location_text="${located_text} $(with_article "$location")."
+    room_article=$(article_for "$location")
+    if [[ -n $gender ]]; then
+        location_primary="${located_text} $(with_article "$location")."
+    elif [[ $room_article == el ]]; then
+        location_primary="Acceso al ${location}."
+    elif [[ -n $room_article ]]; then
+        location_primary="Acceso a ${room_article} ${location}."
+    else
+        location_primary="Acceso a ${location}."
+    fi
 elif [[ -n $organizational_unit ]]; then
-    location_text="${located_text} $(with_article "$organizational_unit")."
+    ou_article=$(article_for "$organizational_unit")
+    if [[ -n $gender ]]; then
+        location_primary="${located_text} $(with_article "$organizational_unit")."
+    elif [[ $ou_article == el ]]; then
+        location_primary="Acceso al ${organizational_unit}."
+    elif [[ -n $ou_article ]]; then
+        location_primary="Acceso a ${ou_article} ${organizational_unit}."
+    else
+        location_primary="Acceso a ${organizational_unit}."
+    fi
 else
-    location_text=$engineering_lab_text
+    location_primary=$engineering_lab_text
 fi
+location_text=$location_primary
+[[ -n $location_secondary ]] && location_text+=$'\n'"$location_secondary"
 
 width=1600
 height=1000
@@ -202,6 +233,7 @@ scale=$(( height * 100 / 1000 ))
 welcome_size=$(( 34 * scale / 100 ))
 name_size=$(( 70 * scale / 100 ))
 location_size=$(( 27 * scale / 100 ))
+location_secondary_size=$(( 20 * scale / 100 ))
 panel_width=$(( width * 76 / 100 ))
 panel_height=$(( 310 * scale / 100 ))
 panel_x1=$(( (width - panel_width) / 2 ))
@@ -232,6 +264,17 @@ if [[ $serif_font == DejaVu-Serif ]] && command -v fc-list >/dev/null 2>&1; then
     fi
 fi
 
+location_annotations=(
+    -font "$sans_font" -weight 400 -style Normal -pointsize "$location_size"
+    -fill '#D3E2FF' -stroke none -annotate "+0+$(( 76 * scale / 100 ))" "$location_primary"
+)
+if [[ -n $location_secondary ]]; then
+    location_annotations+=(
+        -font "$sans_font" -weight 400 -style Normal -pointsize "$location_secondary_size"
+        -fill '#D3E2FF' -stroke none -annotate "+0+$(( 116 * scale / 100 ))" "$location_secondary"
+    )
+fi
+
 if ! "${image_command[@]}" "$BASE_IMAGE" \
     -resize "${width}x${height}^" -gravity center -extent "${width}x${height}" \
     -fill 'rgba(0,13,58,0.30)' -draw "rectangle ${panel_x1},${panel_y1} ${panel_x2},${panel_y2}" \
@@ -241,8 +284,7 @@ if ! "${image_command[@]}" "$BASE_IMAGE" \
     -annotate "+0-$(( 92 * scale / 100 ))" "$welcome_text" \
     -font "$serif_font" -weight 700 -style Italic -pointsize "$name_size" \
     -fill white -annotate "+0-$(( 22 * scale / 100 ))" "$display_name" \
-    -font "$sans_font" -weight 400 -style Normal -pointsize "$location_size" \
+    "${location_annotations[@]}" \
-    -fill '#D3E2FF' -annotate "+0+$(( 88 * scale / 100 ))" "$location_text" \
     -quality 94 "$output_path" 2>>"$log_path"; then
     fail_softly 'ImageMagick could not render the welcome wallpaper.'
 fi

src/SGU.AuthBroker/BrokerEventIds.cs

@@ -22,4 +22,5 @@ internal static class BrokerEventIds
     internal static readonly EventId DirectoryOptionalMetadataFailure = new(1301, nameof(DirectoryOptionalMetadataFailure));
     internal static readonly EventId DirectoryGroupMembershipFailure = new(1302, nameof(DirectoryGroupMembershipFailure));
     internal static readonly EventId DirectoryRoleGroupMembershipAdded = new(1303, nameof(DirectoryRoleGroupMembershipAdded));
+    internal static readonly EventId DirectoryPasswordChangeDenied = new(1304, nameof(DirectoryPasswordChangeDenied));
 }

src/SGU.AuthBroker/Services/ActiveDirectorySynchronizer.cs

@@ -1,5 +1,7 @@
 using System.Collections.Concurrent;
 using System.DirectoryServices;
+using System.Security.AccessControl;
+using System.Security.Principal;
 using SGU.AuthBroker.Core.Directory;
 using SGU.AuthBroker.Core.Identity;
 using SGU.AuthBroker.Core.Profiles;
@@ -15,6 +17,12 @@ public sealed class ActiveDirectorySynchronizer(
     private const int InfoAttributeMaximumLength = 1024;
     private const int AccountDisabled = 0x0002;
     private const int NormalAccount = 0x0200;
+    private static readonly Guid ChangePasswordExtendedRight =
+        new("AB721A53-1E2F-11D0-9819-00AA0040529B");
+    private static readonly SecurityIdentifier EveryoneSid =
+        new(WellKnownSidType.WorldSid, null);
+    private static readonly SecurityIdentifier SelfSid =
+        new(WellKnownSidType.SelfSid, null);
     private static readonly AuthenticationTypes BindFlags =
         AuthenticationTypes.Secure | AuthenticationTypes.Signing | AuthenticationTypes.Sealing;
 
@@ -117,6 +125,12 @@ public sealed class ActiveDirectorySynchronizer(
             // account without its required classification.
             EnsureRoleGroupMembership(user, identity);
 
+            // SGU remains the password authority. Deny the user's Change
+            // Password extended right before making the account usable. This
+            // does not deny the broker's administrative Reset Password right,
+            // which ADSI SetPassword uses for each successful authentication.
+            EnsureCannotChangePassword(user, identity.UserName);
+
             // The exact institutional password received by the broker is passed to AD.
             // It is not derived, transformed, written to disk, or included in logs.
             user.Invoke("SetPassword", [password]);
@@ -143,6 +157,52 @@ public sealed class ActiveDirectorySynchronizer(
         }
     }
 
+    private void EnsureCannotChangePassword(DirectoryEntry user, string institutionalUser)
+    {
+        user.Options!.SecurityMasks = SecurityMasks.Dacl;
+        ActiveDirectorySecurity security = user.ObjectSecurity;
+        if (!EnsureCannotChangePassword(security))
+        {
+            return;
+        }
+
+        user.ObjectSecurity = security;
+        user.CommitChanges();
+        logger.LogInformation(
+            BrokerEventIds.DirectoryPasswordChangeDenied,
+            "Denied direct password changes for managed Active Directory user {InstitutionalUser}; SGU Auth Broker remains the password authority.",
+            institutionalUser);
+    }
+
+    internal static bool EnsureCannotChangePassword(ActiveDirectorySecurity security)
+    {
+        bool changed = false;
+        foreach (SecurityIdentifier identity in new[] { EveryoneSid, SelfSid })
+        {
+            bool exists = security
+                .GetAccessRules(includeExplicit: true, includeInherited: false, typeof(SecurityIdentifier))
+                .OfType<ActiveDirectoryAccessRule>()
+                .Any(rule =>
+                    rule.AccessControlType == AccessControlType.Deny &&
+                    rule.IdentityReference.Equals(identity) &&
+                    rule.ObjectType == ChangePasswordExtendedRight &&
+                    (rule.ActiveDirectoryRights & ActiveDirectoryRights.ExtendedRight) != 0);
+            if (exists)
+            {
+                continue;
+            }
+
+            security.AddAccessRule(new ActiveDirectoryAccessRule(
+                identity,
+                ActiveDirectoryRights.ExtendedRight,
+                AccessControlType.Deny,
+                ChangePasswordExtendedRight));
+            changed = true;
+        }
+
+        return changed;
+    }
+
     private static void TryApplyProfile(
         DirectoryEntry user,
         UserIdentity identity,

tests/AuthBrokerPasswordAuthority.Tests.ps1

@@ -0,0 +1,21 @@
+$repositoryRoot = (Resolve-Path (Join-Path $PSScriptRoot '..')).Path
+$synchronizerPath = Join-Path $repositoryRoot 'src\SGU.AuthBroker\Services\ActiveDirectorySynchronizer.cs'
+$deployPath = Join-Path $repositoryRoot 'scripts\Deploy-AuthBroker.ps1'
+$synchronizer = Get-Content -LiteralPath $synchronizerPath -Raw
+$deploy = Get-Content -LiteralPath $deployPath -Raw
+
+Describe 'SGU Auth Broker password authority' {
+    It 'denies the Change Password extended right to SELF and Everyone before SetPassword' {
+        $synchronizer | Should Match 'AB721A53-1E2F-11D0-9819-00AA0040529B'
+        $synchronizer | Should Match 'WellKnownSidType\.WorldSid'
+        $synchronizer | Should Match 'WellKnownSidType\.SelfSid'
+        $synchronizer | Should Match 'AccessControlType\.Deny'
+        $synchronizer.IndexOf('EnsureCannotChangePassword(user', [StringComparison]::Ordinal) |
+            Should BeLessThan $synchronizer.IndexOf('user.Invoke("SetPassword"', [StringComparison]::Ordinal)
+    }
+
+    It 'repairs every existing account below Usuarios-SGU during broker deployment' {
+        $deploy | Should Match 'Get-ADUser.*-SearchBase \$usersOuDn.*-SearchScope Subtree'
+        $deploy | Should Match '(?s)Set-ADAccountControl.*-CannotChangePassword \$true'
+    }
+}

tests/ClientEnrollmentScripts.Tests.ps1

@@ -83,4 +83,15 @@ Describe 'SGU Windows client enrollment scripts' {
         (Get-Content -LiteralPath $computerPolicyScriptPath -Raw) |
             Should Match "Name = 'HideFastUserSwitching'; Type = 'DWord'; Value = 1"
     }
+
+    It 'separates the clean lock screen base from the branded desktop base' {
+        $installerSource = Get-Content -LiteralPath $credentialProviderInstallerPath -Raw
+        $policySource = Get-Content -LiteralPath $computerPolicyScriptPath -Raw
+        $packageSource = Get-Content -LiteralPath $packageScriptPath -Raw
+        $installerSource | Should Match 'darkblue-lockscreen\.jpg'
+        $packageSource | Should Match 'darkblue-lockscreen\.jpg'
+        $policySource | Should Match "LockScreenImage.*WelcomeLockScreenBasePath"
+        $policySource | Should Match "LockScreenImagePath.*WelcomeLockScreenBasePath"
+        $policySource | Should Match "LockScreenImageUrl.*WelcomeLockScreenBasePath"
+    }
 }

tests/SGU.AuthBroker.Tests/ActiveDirectorySynchronizerTests.cs

@@ -1,3 +1,6 @@
+using System.DirectoryServices;
+using System.Security.AccessControl;
+using System.Security.Principal;
 using SGU.AuthBroker.Core.Profiles;
 using SGU.AuthBroker.Services;
 using Xunit;
@@ -31,4 +34,29 @@ public sealed class ActiveDirectorySynchronizerTests
 
         Assert.Null(updated);
     }
+
+    [Fact]
+    public void CannotChangePasswordRulesAreCompleteAndIdempotent()
+    {
+        ActiveDirectorySecurity security = new();
+
+        Assert.True(ActiveDirectorySynchronizer.EnsureCannotChangePassword(security));
+        Assert.False(ActiveDirectorySynchronizer.EnsureCannotChangePassword(security));
+
+        Guid changePasswordRight = new("AB721A53-1E2F-11D0-9819-00AA0040529B");
+        ActiveDirectoryAccessRule[] rules = security
+            .GetAccessRules(includeExplicit: true, includeInherited: false, typeof(SecurityIdentifier))
+            .OfType<ActiveDirectoryAccessRule>()
+            .Where(rule =>
+                rule.AccessControlType == AccessControlType.Deny &&
+                rule.ObjectType == changePasswordRight &&
+                (rule.ActiveDirectoryRights & ActiveDirectoryRights.ExtendedRight) != 0)
+            .ToArray();
+
+        Assert.Equal(2, rules.Length);
+        Assert.Contains(rules, rule => rule.IdentityReference.Equals(
+            new SecurityIdentifier(WellKnownSidType.WorldSid, null)));
+        Assert.Contains(rules, rule => rule.IdentityReference.Equals(
+            new SecurityIdentifier(WellKnownSidType.SelfSid, null)));
+    }
 }

tests/WelcomeWallpaper.Tests.ps1

@@ -89,7 +89,29 @@ Describe 'Welcome wallpaper with AD metadata' {
         $result = Invoke-WelcomeFixture -DirectoryGender $null `
             -DirectoryLocation 'Aula Flexible' `
             -DirectoryOu 'Centro de Experiencia Digital'
-        $result.LocationText | Should Be 'Acceso al Aula Flexible del Centro de Experiencia Digital.'
+        $result.LocationText | Should Be "Acceso al Aula Flexible`ndel Centro de Experiencia Digital."
+        $result.LocationPrimaryText | Should Be 'Acceso al Aula Flexible'
+        $result.LocationSecondaryText | Should Be 'del Centro de Experiencia Digital.'
+    }
+
+    It 'uses the requested neutral, masculine and feminine location wording' {
+        $neutral = Invoke-WelcomeFixture -DirectoryGender $null `
+            -DirectoryLocation 'Sala de Aplicaciones' `
+            -DirectoryOu 'Laboratorio de Cómputo de Ingeniería'
+        $neutral.LocationPrimaryText | Should Be 'Acceso a la Sala de Aplicaciones'
+        $neutral.LocationSecondaryText | Should Be 'del Laboratorio de Cómputo de Ingeniería.'
+
+        $male = Invoke-WelcomeFixture -DirectoryGender 'Male' `
+            -DirectoryLocation 'Aula Flexible' `
+            -DirectoryOu 'Centro de Experiencia Digital'
+        $male.LocationPrimaryText | Should Be 'Estás ubicado en el Aula Flexible'
+        $male.LocationSecondaryText | Should Be 'del Centro de Experiencia Digital.'
+
+        $female = Invoke-WelcomeFixture -DirectoryGender 'Female' `
+            -DirectoryLocation 'Sala de Redes' `
+            -DirectoryOu 'Laboratorio de Cómputo de Ingeniería'
+        $female.LocationPrimaryText | Should Be 'Estás ubicada en la Sala de Redes'
+        $female.LocationSecondaryText | Should Be 'del Laboratorio de Cómputo de Ingeniería.'
     }
 
     It 'keeps machine location metadata when the GPO command has no location arguments' {
@@ -98,6 +120,55 @@ Describe 'Welcome wallpaper with AD metadata' {
             -DirectoryOu 'Laboratorio' `
             -MachineLocation 'Aula Flexible' `
             -MachineOu 'Centro de Experiencia Digital'
-        $result.LocationText | Should Be 'Acceso al Aula Flexible del Centro de Experiencia Digital.'
+        $result.LocationText | Should Be "Acceso al Aula Flexible`ndel Centro de Experiencia Digital."
+    }
+
+    It 'ships the logo at the lower right of the base image instead of compositing it at runtime' {
+        $source | Should Not Match 'lasalle-logo-blanco|DrawImage.*logo|composite.*logo'
+        $bitmap = [Drawing.Bitmap]::FromFile((Join-Path $repositoryRoot 'assets\branding\darkblue.jpg'))
+        try {
+            $upperLeftWhitePixels = 0
+            for ($x = 60; $x -lt 390; $x += 2) {
+                for ($y = 45; $y -lt 175; $y += 2) {
+                    $pixel = $bitmap.GetPixel($x, $y)
+                    if ($pixel.R -gt 220 -and $pixel.G -gt 220 -and $pixel.B -gt 220) {
+                        $upperLeftWhitePixels++
+                    }
+                }
+            }
+            $lowerRightWhitePixels = 0
+            for ($x = 1260; $x -lt 1510; $x += 2) {
+                for ($y = 740; $y -lt 860; $y += 2) {
+                    $pixel = $bitmap.GetPixel($x, $y)
+                    if ($pixel.R -gt 220 -and $pixel.G -gt 220 -and $pixel.B -gt 220) {
+                        $lowerRightWhitePixels++
+                    }
+                }
+            }
+            ($upperLeftWhitePixels -lt 25) | Should Be $true
+            ($lowerRightWhitePixels -gt 250) | Should Be $true
+        }
+        finally {
+            $bitmap.Dispose()
+        }
+    }
+
+    It 'keeps the lock screen base free of the desktop logo' {
+        $bitmap = [Drawing.Bitmap]::FromFile((Join-Path $repositoryRoot 'assets\branding\darkblue-lockscreen.jpg'))
+        try {
+            $whitePixels = 0
+            for ($x = 0; $x -lt $bitmap.Width; $x += 4) {
+                for ($y = 0; $y -lt $bitmap.Height; $y += 4) {
+                    $pixel = $bitmap.GetPixel($x, $y)
+                    if ($pixel.R -gt 220 -and $pixel.G -gt 220 -and $pixel.B -gt 220) {
+                        $whitePixels++
+                    }
+                }
+            }
+            ($whitePixels -lt 10) | Should Be $true
+        }
+        finally {
+            $bitmap.Dispose()
+        }
     }
 }