feat: Add support for terms and conditions when registering

conduwuit-example.toml

@@ -523,6 +523,18 @@
 #
 #recaptcha_private_site_key =
 
+# Policy documents, such as terms and conditions or a privacy policy,
+# which users must agree to when registering an account.
+#
+# Example:
+# ```
+# [global.registration_terms.privacy_policy]
+# en = { name = "Privacy Policy", url = "https://homeserver.example/en/privacy_policy.html" }
+# es = { name = "Política de Privacidad", url = "https://homeserver.example/es/privacy_policy.html" }
+# ```
+#
+#registration_terms = false
+
 # Controls whether encrypted rooms and events are allowed.
 #
 #allow_encryption = true

src/api/client/account/register.rs

@@ -462,6 +462,31 @@ async fn create_registration_uiaa_session(
 			flows.push(untrusted_flow);
 		}
 
+		// Require all users to agree to the terms and conditions, if configured
+		let terms = &services.config.registration_terms;
+		if !terms.is_empty() {
+			let mut terms =
+				serde_json::to_value(terms.clone()).expect("failed to serialize terms");
+
+			// Insert a dummy `version` field
+			for (_, documents) in terms.as_object_mut().unwrap() {
+				let documents = documents.as_object_mut().unwrap();
+
+				documents.insert("version".to_owned(), "latest".into());
+			}
+
+			params.insert(
+				AuthType::Terms.as_str().to_owned(),
+				serde_json::json!({
+					"policies": terms,
+				}),
+			);
+
+			for flow in &mut flows {
+				flow.stages.insert(0, AuthType::Terms);
+			}
+		}
+
 		if flows.is_empty() {
 			// No flows are configured. Bail out by default
 			// unless open registration was explicitly enabled.

src/core/config/mod.rs

@@ -4,7 +4,7 @@ pub mod manager;
 pub mod proxy;
 
 use std::{
-	collections::{BTreeMap, BTreeSet},
+	collections::{BTreeMap, BTreeSet, HashMap},
 	net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
 	path::PathBuf,
 };
@@ -22,7 +22,7 @@ use ruma::{
 	OwnedRoomId, OwnedRoomOrAliasId, OwnedServerName, OwnedUserId, RoomVersionId,
 	api::client::discovery::{discover_homeserver::RtcFocusInfo, discover_support::ContactRole},
 };
-use serde::{Deserialize, de::IgnoredAny};
+use serde::{Deserialize, Serialize, de::IgnoredAny};
 use url::Url;
 
 use self::proxy::ProxyConfig;
@@ -655,6 +655,18 @@ pub struct Config {
 	/// even if `recaptcha_site_key` is set.
 	pub recaptcha_private_site_key: Option<String>,
 
+	/// Policy documents, such as terms and conditions or a privacy policy,
+	/// which users must agree to when registering an account.
+	///
+	/// Example:
+	/// ```
+	/// [global.registration_terms.privacy_policy]
+	/// en = { name = "Privacy Policy", url = "https://homeserver.example/en/privacy_policy.html" }
+	/// es = { name = "Política de Privacidad", url = "https://homeserver.example/es/privacy_policy.html" }
+	/// ```
+	#[serde(default)]
+	pub registration_terms: HashMap<String, HashMap<String, TermsDocument>>,
+
 	/// Controls whether encrypted rooms and events are allowed.
 	#[serde(default = "true_fn")]
 	pub allow_encryption: bool,
@@ -2498,6 +2510,13 @@ pub struct SmtpConfig {
 	pub require_email_for_token_registration: bool,
 }
 
+/// A policy document for use with a m.login.terms stage.
+#[derive(Clone, Debug, Deserialize, Serialize)]
+pub struct TermsDocument {
+	pub name: String,
+	pub url: String,
+}
+
 const DEPRECATED_KEYS: &[&str] = &[
 	"cache_capacity",
 	"conduit_cache_capacity_modifier",

src/service/uiaa/mod.rs

@@ -309,6 +309,7 @@ impl Service {
 
 		match auth {
 			| AuthData::Dummy(_) => Ok(AuthType::Dummy),
+			| AuthData::Terms(_) => Ok(AuthType::Terms),
 			| AuthData::EmailIdentity(EmailIdentity {
 				thirdparty_id_creds: ThirdpartyIdCredentials { client_secret, sid, .. },
 				..