Add dynamic CSS support (#4940)

* Add dynamic CSS support

Together with https://github.com/dani-garcia/bw_web_builds/pull/180 this PR will add support for dynamic CSS changes.

For example, we could hide the register link if signups are not allowed.
In the future show or hide the SSO button depending on if it is enabled or not.

There also is a special `user.vaultwarden.scss` file so that users can add custom CSS without the need to modify the default (static) changes.
This will prevent future changes from not being applied and still have the custom user changes to be added.

Also added a special redirect when someone goes directly to `/index.html` as that might cause issues with loading other scripts and files.

Signed-off-by: BlackDex <[email protected]>

* Add versions and fallback to built-in

- Add both Vaultwarden and web-vault versions to the css_options.
- Fallback to the inner templates if rendering or compiling the scss fails.
  This ensures the basics are always working even if someone breaks the templates.

Signed-off-by: BlackDex <[email protected]>

* Fix fallback code to actually work

The fallback now works by using an alternative `reg!` macro.
This adds an extra template register which prefixes the template with `fallback_`.

Signed-off-by: BlackDex <[email protected]>

* Updated the wiki link in the user template

---------

Signed-off-by: BlackDex <[email protected]>

6 files changed, 266 insertions, 4 deletions

diff --git a/Cargo.lock b/Cargo.lock
index ae469d23..9edd20bf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -553,6 +553,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "codemap"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e769b5c8c8283982a987c6e948e540254f1058d5a74b8794914d4ef5fc2a24"
+
+[[package]]
 name = "concurrent-queue"
 version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1232,6 +1238,19 @@ dependencies = [
 ]
 
 [[package]]
+name = "grass_compiler"
+version = "0.13.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d9e3df7f0222ce5184154973d247c591d9aadc28ce7a73c6cd31100c9facff6"
+dependencies = [
+ "codemap",
+ "indexmap",
+ "lasso",
+ "once_cell",
+ "phf",
+]
+
+[[package]]
 name = "h2"
 version = "0.3.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1887,6 +1906,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "lasso"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e14eda50a3494b3bf7b9ce51c52434a761e383d7238ce1dd5dcec2fbc13e9fb"
+dependencies = [
+ "hashbrown 0.14.5",
+]
+
+[[package]]
 name = "lazy_static"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2484,6 +2512,7 @@ version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ade2d8b8f33c7333b51bcf0428d37e217e9f32192ae4772156f65063b8ce03dc"
 dependencies = [
+ "phf_macros",
  "phf_shared",
 ]
 
@@ -2508,6 +2537,19 @@ dependencies = [
 ]
 
 [[package]]
+name = "phf_macros"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3444646e286606587e49f3bcf1679b8cef1dc2c5ecc29ddacaffc305180d464b"
+dependencies = [
+ "phf_generator",
+ "phf_shared",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "phf_shared"
 version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -4056,6 +4098,7 @@ dependencies = [
  "fern",
  "futures",
  "governor",
+ "grass_compiler",
  "handlebars",
  "hickory-resolver",
  "html5gum",
diff --git a/Cargo.toml b/Cargo.toml
index 78a1a4b5..150b3b9d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -163,6 +163,9 @@ argon2 = "0.5.3"
 # Reading a password from the cli for generating the Argon2id ADMIN_TOKEN
 rpassword = "7.3.1"
 
+# Loading a dynamic CSS Stylesheet
+grass_compiler = { version = "0.13.4", default-features = false }
+
 # Strip debuginfo from the release builds
 # The symbols are the provide better panic traces
 # Also enable fat LTO and use 1 codegen unit for optimizations
diff --git a/src/api/web.rs b/src/api/web.rs
index 6983719b..a96d7e2a 100644
--- a/src/api/web.rs
+++ b/src/api/web.rs
@@ -1,13 +1,20 @@
+use once_cell::sync::Lazy;
 use std::path::{Path, PathBuf};
 
-use rocket::{fs::NamedFile, http::ContentType, response::content::RawHtml as Html, serde::json::Json, Catcher, Route};
+use rocket::{
+    fs::NamedFile,
+    http::ContentType,
+    response::{content::RawCss as Css, content::RawHtml as Html, Redirect},
+    serde::json::Json,
+    Catcher, Route,
+};
 use serde_json::Value;
 
 use crate::{
     api::{core::now, ApiResult, EmptyResult},
     auth::decode_file_download,
     error::Error,
-    util::{Cached, SafeString},
+    util::{get_web_vault_version, Cached, SafeString},
     CONFIG,
 };
 
@@ -16,7 +23,7 @@ pub fn routes() -> Vec<Route> {
     // crate::utils::LOGGED_ROUTES to make sure they appear in the log
     let mut routes = routes![attachments, alive, alive_head, static_files];
     if CONFIG.web_vault_enabled() {
-        routes.append(&mut routes![web_index, web_index_head, app_id, web_files]);
+        routes.append(&mut routes![web_index, web_index_direct, web_index_head, app_id, web_files, vaultwarden_css]);
     }
 
     #[cfg(debug_assertions)]
@@ -45,11 +52,101 @@ fn not_found() -> ApiResult<Html<String>> {
     Ok(Html(text))
 }
 
+#[get("/css/vaultwarden.css")]
+fn vaultwarden_css() -> Cached<Css<String>> {
+    // Configure the web-vault version as an integer so it can be used as a comparison smaller or greater then.
+    // The default is based upon the version since this feature is added.
+    static WEB_VAULT_VERSION: Lazy<u32> = Lazy::new(|| {
+        let re = regex::Regex::new(r"(\d{4})\.(\d{1,2})\.(\d{1,2})").unwrap();
+        let vault_version = get_web_vault_version();
+
+        let (major, minor, patch) = match re.captures(&vault_version) {
+            Some(c) if c.len() == 4 => (
+                c.get(1).unwrap().as_str().parse().unwrap(),
+                c.get(2).unwrap().as_str().parse().unwrap(),
+                c.get(3).unwrap().as_str().parse().unwrap(),
+            ),
+            _ => (2024, 6, 2),
+        };
+        format!("{major}{minor:02}{patch:02}").parse::<u32>().unwrap()
+    });
+
+    // Configure the Vaultwarden version as an integer so it can be used as a comparison smaller or greater then.
+    // The default is based upon the version since this feature is added.
+    static VW_VERSION: Lazy<u32> = Lazy::new(|| {
+        let re = regex::Regex::new(r"(\d{1})\.(\d{1,2})\.(\d{1,2})").unwrap();
+        let vw_version = crate::VERSION.unwrap_or("1.32.1");
+
+        let (major, minor, patch) = match re.captures(vw_version) {
+            Some(c) if c.len() == 4 => (
+                c.get(1).unwrap().as_str().parse().unwrap(),
+                c.get(2).unwrap().as_str().parse().unwrap(),
+                c.get(3).unwrap().as_str().parse().unwrap(),
+            ),
+            _ => (1, 32, 1),
+        };
+        format!("{major}{minor:02}{patch:02}").parse::<u32>().unwrap()
+    });
+
+    let css_options = json!({
+        "web_vault_version": *WEB_VAULT_VERSION,
+        "vw_version": *VW_VERSION,
+        "signup_disabled": !CONFIG.signups_allowed() && CONFIG.signups_domains_whitelist().is_empty(),
+        "mail_enabled": CONFIG.mail_enabled(),
+        "yubico_enabled": CONFIG._enable_yubico() && (CONFIG.yubico_client_id().is_some() == CONFIG.yubico_secret_key().is_some()),
+        "emergency_access_allowed": CONFIG.emergency_access_allowed(),
+        "sends_allowed": CONFIG.sends_allowed(),
+        "load_user_scss": true,
+    });
+
+    let scss = match CONFIG.render_template("scss/vaultwarden.scss", &css_options) {
+        Ok(t) => t,
+        Err(e) => {
+            // Something went wrong loading the template. Use the fallback
+            warn!("Loading scss/vaultwarden.scss.hbs or scss/user.vaultwarden.scss.hbs failed. {e}");
+            CONFIG
+                .render_fallback_template("scss/vaultwarden.scss", &css_options)
+                .expect("Fallback scss/vaultwarden.scss.hbs to render")
+        }
+    };
+
+    let css = match grass_compiler::from_string(
+        scss,
+        &grass_compiler::Options::default().style(grass_compiler::OutputStyle::Compressed),
+    ) {
+        Ok(css) => css,
+        Err(e) => {
+            // Something went wrong compiling the scss. Use the fallback
+            warn!("Compiling the Vaultwarden SCSS styles failed. {e}");
+            let mut css_options = css_options;
+            css_options["load_user_scss"] = json!(false);
+            let scss = CONFIG
+                .render_fallback_template("scss/vaultwarden.scss", &css_options)
+                .expect("Fallback scss/vaultwarden.scss.hbs to render");
+            grass_compiler::from_string(
+                scss,
+                &grass_compiler::Options::default().style(grass_compiler::OutputStyle::Compressed),
+            )
+            .expect("SCSS to compile")
+        }
+    };
+
+    // Cache for one day should be enough and not too much
+    Cached::ttl(Css(css), 86_400, false)
+}
+
 #[get("/")]
 async fn web_index() -> Cached<Option<NamedFile>> {
     Cached::short(NamedFile::open(Path::new(&CONFIG.web_vault_folder()).join("index.html")).await.ok(), false)
 }
 
+// Make sure that `/index.html` redirect to actual domain path.
+// If not, this might cause issues with the web-vault
+#[get("/index.html")]
+fn web_index_direct() -> Redirect {
+    Redirect::to(format!("{}/", CONFIG.domain_path()))
+}
+
 #[head("/")]
 fn web_index_head() -> EmptyResult {
     // Add an explicit HEAD route to prevent uptime monitoring services from
diff --git a/src/config.rs b/src/config.rs
index aa6b1145..61a47b76 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1269,11 +1269,16 @@ impl Config {
             let hb = load_templates(CONFIG.templates_folder());
             hb.render(name, data).map_err(Into::into)
         } else {
-            let hb = &CONFIG.inner.read().unwrap().templates;
+            let hb = &self.inner.read().unwrap().templates;
             hb.render(name, data).map_err(Into::into)
         }
     }
 
+    pub fn render_fallback_template<T: serde::ser::Serialize>(&self, name: &str, data: &T) -> Result<String, Error> {
+        let hb = &self.inner.read().unwrap().templates;
+        hb.render(&format!("fallback_{name}"), data).map_err(Into::into)
+    }
+
     pub fn set_rocket_shutdown_handle(&self, handle: rocket::Shutdown) {
         self.inner.write().unwrap().rocket_shutdown_handle = Some(handle);
     }
@@ -1312,6 +1317,11 @@ where
             reg!($name);
             reg!(concat!($name, $ext));
         }};
+        (@withfallback $name:expr) => {{
+            let template = include_str!(concat!("static/templates/", $name, ".hbs"));
+            hb.register_template_string($name, template).unwrap();
+            hb.register_template_string(concat!("fallback_", $name), template).unwrap();
+        }};
     }
 
     // First register default templates here
@@ -1355,6 +1365,9 @@ where
 
     reg!("404");
 
+    reg!(@withfallback "scss/vaultwarden.scss");
+    reg!("scss/user.vaultwarden.scss");
+
     // And then load user templates to overwrite the defaults
     // Use .hbs extension for the files
     // Templates get registered with their relative name
diff --git a/src/static/templates/scss/user.vaultwarden.scss.hbs b/src/static/templates/scss/user.vaultwarden.scss.hbs
new file mode 100644
index 00000000..c0b8ed2a
--- /dev/null
+++ b/src/static/templates/scss/user.vaultwarden.scss.hbs
@@ -0,0 +1 @@
+/* See the wiki for examples and details: https://github.com/dani-garcia/vaultwarden/wiki/Customize-Vaultwarden-CSS */
diff --git a/src/static/templates/scss/vaultwarden.scss.hbs b/src/static/templates/scss/vaultwarden.scss.hbs
new file mode 100644
index 00000000..3fc3e70e
--- /dev/null
+++ b/src/static/templates/scss/vaultwarden.scss.hbs
@@ -0,0 +1,105 @@
+/**** START Static Vaultwarden changes ****/
+/* This combines all selectors extending it into one */
+%vw-hide {
+  display: none !important;
+}
+
+/* This allows searching for the combined style in the browsers dev-tools (look into the head tag) */
+.vw-hide,
+head {
+  @extend %vw-hide;
+}
+
+/* Hide the Subscription Page tab */
+bit-nav-item[route="settings/subscription"] {
+  @extend %vw-hide;
+}
+
+/* Hide any link pointing to Free Bitwarden Families */
+a[href$="/settings/sponsored-families"] {
+  @extend %vw-hide;
+}
+
+/* Hide the `Enterprise Single Sign-On` button on the login page */
+a[routerlink="/sso"] {
+  @extend %vw-hide;
+}
+
+/* Hide Two-Factor menu in Organization settings */
+bit-nav-item[route="settings/two-factor"],
+a[href$="/settings/two-factor"] {
+  @extend %vw-hide;
+}
+
+/* Hide Business Owned checkbox */
+app-org-info > form:nth-child(1) > div:nth-child(3) {
+  @extend %vw-hide;
+}
+
+/* Hide the `This account is owned by a business` checkbox and label */
+#ownedBusiness,
+label[for^="ownedBusiness"] {
+  @extend %vw-hide;
+}
+
+/* Hide the radio button and label for the `Custom` org user type */
+#userTypeCustom,
+label[for^="userTypeCustom"] {
+  @extend %vw-hide;
+}
+
+/* Hide Business Name */
+app-org-account form div bit-form-field.tw-block:nth-child(3) {
+  @extend %vw-hide;
+}
+
+/* Hide organization plans */
+app-organization-plans > form > bit-section:nth-child(2) {
+  @extend %vw-hide;
+}
+
+/* Hide Device Verification form at the Two Step Login screen */
+app-security > app-two-factor-setup > form {
+  @extend %vw-hide;
+}
+/**** END Static Vaultwarden Changes ****/
+/**** START Dynamic Vaultwarden Changes ****/
+{{#if signup_disabled}}
+/* Hide the register link on the login screen */
+app-frontend-layout > app-login > form > div > div > div > p {
+  @extend %vw-hide;
+}
+{{/if}}
+
+/* Hide `Email` 2FA if mail is not enabled */
+{{#unless mail_enabled}}
+app-two-factor-setup ul.list-group.list-group-2fa li.list-group-item:nth-child(5) {
+  @extend %vw-hide;
+}
+{{/unless}}
+
+/* Hide `YubiKey OTP security key` 2FA if it is not enabled */
+{{#unless yubico_enabled}}
+app-two-factor-setup ul.list-group.list-group-2fa li.list-group-item:nth-child(2) {
+  @extend %vw-hide;
+}
+{{/unless}}
+
+/* Hide Emergency Access if not allowed */
+{{#unless emergency_access_allowed}}
+bit-nav-item[route="settings/emergency-access"] {
+  @extend %vw-hide;
+}
+{{/unless}}
+
+/* Hide Sends if not allowed */
+{{#unless sends_allowed}}
+bit-nav-item[route="sends"] {
+  @extend %vw-hide;
+}
+{{/unless}}
+/**** End Dynamic Vaultwarden Changes ****/
+/**** Include a special user stylesheet for custom changes ****/
+{{#if load_user_scss}}
+{{> scss/user.vaultwarden.scss }}
+{{/if}}