feat: Add support for registering accounts with the web UI

src/web/Cargo.toml

@@ -46,6 +46,8 @@ tower-sessions = { version = "0.15.0", default-features = false, features = ["ax
 tower-sessions-core = { version = "0.15.0", features = ["deletion-task"] }
 serde_urlencoded.workspace = true
 url.workspace = true
+recaptcha-verify = { version = "0.2.0", default-features = false }
+reqwest_recaptcha = { package = "reqwest", version = "0.12.28", default-features = false, features = ["rustls-tls-native-roots-no-provider"]  } # As long as recaptcha-verify's reqwest is outdated
 
 [build-dependencies]
 memory-serve = "2.1.0"

src/web/pages/account/login.rs

@@ -17,7 +17,11 @@ use tower_sessions::Session;
 use crate::{
 	ROUTE_PREFIX, WebError,
 	extract::{Expect, PostForm},
-	pages::{GET_POST, Result, TemplateContext, components::UserCard},
+	pages::{
+		GET_POST, Result, TemplateContext,
+		account::register::{TrustedFlowStatus, UntrustedFlowStatus, registration_flow_status},
+		components::UserCard,
+	},
 	response,
 	session::{LoginQuery, LoginTarget, User, UserSession},
 	template,
@@ -41,6 +45,7 @@ template! {
 enum LoginBody {
 	Unauthenticated {
 		server_name: String,
+		registration_available: bool,
 	},
 	Authenticated {
 		user_card: UserCard,
@@ -65,8 +70,20 @@ async fn route_login(
 	let user_id = user.into_session().map(|session| session.user_id);
 
 	let body = match &user_id {
-		| None => LoginBody::Unauthenticated {
-			server_name: services.globals.server_name().to_string(),
+		| None => {
+			let (trusted_flow_status, untrusted_flow_status) =
+				registration_flow_status(&services).await;
+
+			LoginBody::Unauthenticated {
+				server_name: services.globals.server_name().to_string(),
+				registration_available: matches!(
+					trusted_flow_status,
+					TrustedFlowStatus::Available
+				) || matches!(
+					untrusted_flow_status,
+					UntrustedFlowStatus::Available { .. }
+				),
+			}
 		},
 		| Some(user_id) => {
 			if !reauthenticate {

src/web/pages/account/mod.rs

@@ -31,6 +31,7 @@ pub(crate) mod device;
 pub(crate) mod email;
 pub(crate) mod login;
 pub(crate) mod password;
+pub(crate) mod register;
 
 pub(crate) fn build() -> Router<crate::State> {
 	#[allow(clippy::wildcard_imports)]
@@ -45,6 +46,7 @@ pub(crate) fn build() -> Router<crate::State> {
 		.nest("/cross_signing_reset", cross_signing_reset::build())
 		.nest("/deactivate", deactivate::build())
 		.nest("/device/", device::build())
+		.nest("/register/", register::build())
 }
 
 #[derive(Deserialize, Serialize)]

src/web/pages/account/register.rs

@@ -0,0 +1,541 @@
+use std::{collections::BTreeMap, time::SystemTime};
+
+use axum::{
+	Extension, Router,
+	extract::{Query, State},
+	response::{Redirect, Response},
+	routing::{get, on},
+};
+use conduwuit_core::{config::TermsDocument, warn};
+use conduwuit_service::{
+	mailer::messages, registration_tokens::ValidToken, users::HashedPassword,
+};
+use futures::StreamExt;
+use lettre::{Address, message::Mailbox};
+use ruma::{ClientSecret, OwnedClientSecret, OwnedServerName, OwnedSessionId, OwnedUserId};
+use serde::{Deserialize, Serialize};
+use tower_sessions::Session;
+use validator::{Validate, ValidationError, ValidationErrors};
+
+use crate::{
+	WebError,
+	extract::{Expect, PostForm},
+	pages::{GET_POST, Result, TemplateContext, account::ThreepidQuery},
+	response,
+	session::{LoginTarget, User, UserSession},
+	template,
+};
+
+const COMPLETED_REGISTRATION_KEY: &str = "completed_registration";
+
+pub(crate) fn build() -> Router<crate::State> {
+	Router::new()
+		.route("/", on(GET_POST, route_register))
+		.route("/validate", get(get_register_confirm_email))
+}
+
+template! {
+	struct Register use "register.html.j2" {
+		server_name: OwnedServerName,
+		body: RegisterBody
+	}
+}
+
+#[derive(Debug)]
+enum RegisterBody {
+	Unavailable,
+	UsernamePrompt {
+		allow_federation: bool,
+		trusted_flow_status: TrustedFlowStatus,
+		untrusted_flow_status: UntrustedFlowStatus,
+		username_error: Option<String>,
+	},
+	DetailsPrompt {
+		username: Option<String>,
+		require_email: bool,
+		flow: RegistrationFlowParameters,
+		terms: BTreeMap<String, TermsDocument>,
+		validation_errors: ValidationErrors,
+	},
+}
+
+#[derive(Debug)]
+pub(super) enum TrustedFlowStatus {
+	Unavailable,
+	Available,
+}
+
+#[derive(Debug)]
+pub(super) enum UntrustedFlowStatus {
+	Unavailable,
+	Available {
+		require_email: bool,
+	},
+}
+
+#[derive(Deserialize)]
+struct RegistrationQuery {
+	username: Option<String>,
+	token: Option<String>,
+	flow: Option<RequestedRegistrationFlow>,
+	#[serde(default)]
+	from_landing: bool,
+}
+
+#[derive(Clone, Copy, Deserialize)]
+#[serde(rename_all = "snake_case")]
+enum RequestedRegistrationFlow {
+	Untrusted,
+	Trusted,
+}
+
+#[derive(Debug)]
+enum RegistrationFlowParameters {
+	Untrusted {
+		recaptcha_sitekey: Option<String>,
+	},
+	Trusted {
+		registration_token: Option<String>,
+	},
+}
+
+#[derive(Deserialize, Validate)]
+struct RegistrationForm {
+	flow: RequestedRegistrationFlow,
+	username: String,
+	email: Option<Address>,
+	#[validate(length(min = 1, message = "Password cannot be empty"))]
+	password: String,
+	#[validate(must_match(other = "password", message = "Passwords must match"))]
+	confirm_password: String,
+	registration_token: Option<String>,
+	#[serde(rename = "g-recaptcha-response")]
+	recaptcha_response: Option<String>,
+}
+
+#[derive(Deserialize, Serialize)]
+struct CompletedRegistration {
+	user_id: OwnedUserId,
+	password_hash: HashedPassword,
+	registration_token: Option<ValidToken>,
+}
+
+async fn route_register(
+	State(services): State<crate::State>,
+	Extension(context): Extension<TemplateContext>,
+	session_store: Session,
+	Expect(Query(query)): Expect<Query<RegistrationQuery>>,
+	PostForm(form): PostForm<RegistrationForm>,
+) -> Result {
+	let validation_errors = if let Some(form) = form {
+		match form.validate() {
+			| Ok(()) => {
+				match begin_registration(&services, context.clone(), session_store, form).await? {
+					| Ok(response) => return Ok(response),
+					| Err(err) => err,
+				}
+			},
+			| Err(err) => err,
+		}
+	} else {
+		ValidationErrors::new()
+	};
+
+	let (trusted_flow_status, untrusted_flow_status) = registration_flow_status(&services).await;
+
+	if matches!(trusted_flow_status, TrustedFlowStatus::Unavailable)
+		&& matches!(untrusted_flow_status, UntrustedFlowStatus::Unavailable)
+	{
+		return response!(Register::new(
+			context,
+			services.globals.server_name().to_owned(),
+			RegisterBody::Unavailable
+		));
+	}
+
+	if query.username.is_some() && query.flow.is_none() {
+		return response!(WebError::BadRequest(
+			"A flow must be provided if a username is provided".to_owned()
+		));
+	}
+
+	if let Some(username) = &query.username
+		&& query.from_landing
+	{
+		// Check if the username is valid and available before showing the details form
+		// to keep the user from wasting their time
+
+		if let Err(err) = services
+			.users
+			.determine_registration_user_id(Some(username.to_owned()), None, None)
+			.await
+		{
+			return response!(Register::new(
+				context,
+				services.globals.server_name().to_owned(),
+				RegisterBody::UsernamePrompt {
+					allow_federation: services.config.allow_federation,
+					trusted_flow_status,
+					untrusted_flow_status,
+					username_error: Some(err.message()),
+				}
+			));
+		}
+	}
+
+	let body = {
+		let terms = services.config.registration_terms.documents.clone();
+
+		match (query.flow, query.token) {
+			| (Some(RequestedRegistrationFlow::Trusted), token) | (_, token @ Some(_)) =>
+				RegisterBody::DetailsPrompt {
+					username: query.username,
+					require_email: services
+						.config
+						.smtp
+						.as_ref()
+						.is_some_and(|smtp| smtp.require_email_for_token_registration),
+					flow: RegistrationFlowParameters::Trusted { registration_token: token },
+					terms,
+					validation_errors,
+				},
+			| (Some(RequestedRegistrationFlow::Untrusted), _) => RegisterBody::DetailsPrompt {
+				username: query.username,
+				require_email: services
+					.config
+					.smtp
+					.as_ref()
+					.is_some_and(|smtp| smtp.require_email_for_registration),
+				flow: RegistrationFlowParameters::Untrusted {
+					recaptcha_sitekey: services.config.recaptcha_site_key.clone(),
+				},
+				terms,
+				validation_errors,
+			},
+			| (None, None) => RegisterBody::UsernamePrompt {
+				allow_federation: services.config.allow_federation,
+				trusted_flow_status,
+				untrusted_flow_status,
+				username_error: None,
+			},
+		}
+	};
+
+	response!(Register::new(context, services.globals.server_name().to_owned(), body))
+}
+
+template! {
+	struct RegisterConfirmEmail use "register_confirm_email.html.j2" {
+		session_id: OwnedSessionId,
+		client_secret: OwnedClientSecret,
+		validation_error: bool
+	}
+}
+
+#[derive(Deserialize, Serialize)]
+struct RegisterConfirmEmailQuery {
+	#[serde(flatten)]
+	threepid: ThreepidQuery,
+}
+
+async fn get_register_confirm_email(
+	State(services): State<crate::State>,
+	Extension(context): Extension<TemplateContext>,
+	session_store: Session,
+	Expect(Query(RegisterConfirmEmailQuery {
+		threepid: ThreepidQuery { client_secret, session_id },
+	})): Expect<Query<RegisterConfirmEmailQuery>>,
+) -> Result {
+	let Some(completed_registration) = session_store
+		.get::<CompletedRegistration>(COMPLETED_REGISTRATION_KEY)
+		.await
+		.expect("should be able to deserialize completed session")
+	else {
+		return response!(WebError::BadRequest(
+			"Inapplicable session. What are you doing here?".to_owned()
+		));
+	};
+
+	let Ok(session) = services
+		.threepid
+		.get_valid_session(&session_id, &client_secret)
+		.await
+	else {
+		return response!(RegisterConfirmEmail::new(context, session_id, client_secret, true,));
+	};
+
+	let email = session.consume();
+
+	complete_registration(&services, session_store, completed_registration, Some(email)).await;
+
+	response!(Redirect::to(&LoginTarget::Account.target_path()))
+}
+
+async fn begin_registration(
+	services: &crate::State,
+	context: TemplateContext,
+	session_store: Session,
+	form: RegistrationForm,
+) -> Result<Result<Response, ValidationErrors>> {
+	let open_registration = services
+		.config
+		.yes_i_am_very_very_sure_i_want_an_open_registration_server_prone_to_abuse;
+	let mut errors = ValidationErrors::new();
+
+	let user_id = match services
+		.users
+		.determine_registration_user_id(Some(form.username), form.email.as_ref(), None)
+		.await
+	{
+		| Ok(user_id) => user_id,
+		| Err(err) => {
+			errors.add(
+				"username",
+				ValidationError::new("invalid").with_message(err.message().into()),
+			);
+			return Ok(Err(errors));
+		},
+	};
+
+	let password_hash = match HashedPassword::new(&form.password) {
+		| Ok(password) => password,
+		| Err(err) => {
+			errors.add(
+				"password",
+				ValidationError::new("invalid").with_message(err.message().into()),
+			);
+			return Ok(Err(errors));
+		},
+	};
+
+	let mut registration_token = None;
+
+	// Check flow-specific form fields
+	match form.flow {
+		| RequestedRegistrationFlow::Trusted => {
+			// If the form claims to be using the trusted flow, it has to have a
+			// registration token
+
+			let Some(valid_token) = async {
+				services
+					.registration_tokens
+					.validate_token(form.registration_token?)
+					.await
+			}
+			.await
+			else {
+				errors.add(
+					"registration_token",
+					ValidationError::new("invalid")
+						.with_message("Invalid registration token".into()),
+				);
+				return Ok(Err(errors));
+			};
+
+			registration_token = Some(valid_token);
+		},
+		| RequestedRegistrationFlow::Untrusted => {
+			// Don't check auth for the untrusted flow at all if open reg is enabled
+			if !open_registration {
+				// If the form claims to be using the untrusted flow, it _may_ need to have a
+				// reCAPTCHA response if reCAPTCHA is configured
+
+				if let Some(recaptcha_private_site_key) =
+					&services.config.recaptcha_private_site_key
+				{
+					let Some(recaptcha_response) = form.recaptcha_response else {
+						return Err(WebError::BadRequest(
+							"reCAPTCHA response expected".to_owned(),
+						));
+					};
+
+					if recaptcha_verify::verify_v3(
+						recaptcha_private_site_key,
+						&recaptcha_response,
+						None,
+					)
+					.await
+					.is_err()
+					{
+						errors.add(
+							"recaptcha",
+							ValidationError::new("missing")
+								.with_message("Please complete the CAPTCHA".into()),
+						);
+						return Ok(Err(errors));
+					}
+				}
+			}
+		},
+	}
+
+	let completed_registration = CompletedRegistration {
+		user_id,
+		password_hash,
+		registration_token,
+	};
+
+	// Check if we need to send an email
+	let require_email = services
+		.config
+		.smtp
+		.as_ref()
+		.is_some_and(|smtp| match form.flow {
+			| RequestedRegistrationFlow::Trusted => smtp.require_email_for_token_registration,
+			| RequestedRegistrationFlow::Untrusted =>
+				!open_registration && smtp.require_email_for_registration,
+		});
+
+	if require_email {
+		// If an email is required we have to validate it before we can complete
+		// registration
+		let Some(address) = form.email else {
+			errors.add(
+				"email",
+				ValidationError::new("missing")
+					.with_message("Please provide an email address".into()),
+			);
+			return Ok(Err(errors));
+		};
+
+		if services
+			.threepid
+			.get_localpart_for_email(&address)
+			.await
+			.is_some()
+		{
+			errors.add(
+				"email",
+				ValidationError::new("in_use")
+					.with_message("This email address is already in use.".into()),
+			);
+			return Ok(Err(errors));
+		}
+
+		let client_secret = ClientSecret::new();
+
+		let session_id = {
+			match services
+				.threepid
+				.send_validation_email(
+					Mailbox::new(None, address.clone()),
+					|verification_link| messages::NewAccount {
+						server_name: services.globals.server_name().as_str(),
+						verification_link,
+					},
+					&client_secret,
+					0,
+				)
+				.await
+			{
+				| Ok(session_id) => session_id,
+				| Err(err) => {
+					warn!(
+						"Failed to send new account message for {} to {}: {err}",
+						&completed_registration.user_id, address,
+					);
+
+					errors.add(
+						"email",
+						ValidationError::new("invalid").with_message(
+							"Failed to send validation email. Is this address correct?".into(),
+						),
+					);
+					return Ok(Err(errors));
+				},
+			}
+		};
+
+		session_store
+			.insert(COMPLETED_REGISTRATION_KEY, completed_registration)
+			.await
+			.expect("should have been able to serialize completed registration");
+
+		Ok(response!(RegisterConfirmEmail::new(context, session_id, client_secret, false,)))
+	} else {
+		// If email isn't required we can immediately complete registration
+		complete_registration(services, session_store, completed_registration, None).await;
+
+		Ok(response!(Redirect::to(&LoginTarget::Account.target_path())))
+	}
+}
+
+async fn complete_registration(
+	services: &crate::State,
+	session_store: Session,
+	CompletedRegistration {
+		user_id,
+		password_hash,
+		registration_token,
+	}: CompletedRegistration,
+	email: Option<Address>,
+) {
+	services
+		.users
+		.create_local_account(&user_id, password_hash, email)
+		.await;
+
+	if let Some(registration_token) = registration_token {
+		services
+			.registration_tokens
+			.mark_token_as_used(registration_token);
+	}
+
+	let user_session = UserSession { user_id, last_login: SystemTime::now() };
+
+	session_store
+		.insert(User::KEY, user_session)
+		.await
+		.expect("should be able to serialize user session");
+}
+
+pub(super) async fn registration_flow_status(
+	services: &crate::State,
+) -> (TrustedFlowStatus, UntrustedFlowStatus) {
+	// Allow registration if it's enabled in the config file or if this is the first
+	// run (so the first user account can be created)
+	let allow_registration =
+		services.config.allow_registration || services.firstrun.is_first_run();
+
+	// Trusted flow is only available if any registration tokens exist
+	let trusted_flow_status = {
+		if !allow_registration {
+			TrustedFlowStatus::Unavailable
+		} else if services
+			.registration_tokens
+			.iterate_tokens()
+			.next()
+			.await
+			.is_some()
+		{
+			TrustedFlowStatus::Available
+		} else {
+			TrustedFlowStatus::Unavailable
+		}
+	};
+
+	// Untrusted flow is available if email is required for registration,
+	// or reCAPTCHA is configured, or open registration is enabled
+	let untrusted_flow_status = {
+		let require_email = services
+			.config
+			.smtp
+			.as_ref()
+			.is_some_and(|smtp| smtp.require_email_for_registration);
+
+		if !allow_registration {
+			UntrustedFlowStatus::Unavailable
+		} else if services.config.recaptcha_private_site_key.is_some() || require_email {
+			UntrustedFlowStatus::Available { require_email }
+		} else if services
+			.config
+			.yes_i_am_very_very_sure_i_want_an_open_registration_server_prone_to_abuse
+		{
+			UntrustedFlowStatus::Available { require_email: false }
+		} else {
+			UntrustedFlowStatus::Unavailable
+		}
+	};
+
+	(trusted_flow_status, untrusted_flow_status)
+}

src/web/pages/index.rs

@@ -1,6 +1,9 @@
-use axum::{Extension, Router, extract::State, response::IntoResponse, routing::get};
+use axum::{Extension, Router, extract::State, routing::get};
 
-use crate::{WebError, pages::TemplateContext, template};
+use crate::{
+	pages::{Result, TemplateContext},
+	response, template,
+};
 
 pub(crate) fn build() -> Router<crate::State> {
 	Router::new()
@@ -8,21 +11,20 @@ pub(crate) fn build() -> Router<crate::State> {
 		.route(&format!("{}/", crate::ROUTE_PREFIX), get(index))
 }
 
+template! {
+	struct Index<'a> use "index.html.j2" {
+		server_name: &'a str,
+		first_run: bool
+	}
+}
+
 async fn index(
 	State(services): State<crate::State>,
 	Extension(context): Extension<TemplateContext>,
-) -> Result<impl IntoResponse, WebError> {
-	template! {
-		struct Index<'a> use "index.html.j2" {
-			server_name: &'a str,
-			first_run: bool
-		}
-	}
-
-	Ok(Index::new(
+) -> Result {
+	response!(Index::new(
 		context,
 		services.globals.server_name().as_str(),
 		services.firstrun.is_first_run(),
-	)
-	.into_response())
+	))
 }

src/web/pages/mod.rs

@@ -49,11 +49,17 @@ pub(super) async fn template_context_middleware(
 
 	let mut response = next.run(request).await;
 
+	let child_src = if config.recaptcha_site_key.is_some() {
+		"www.google.com"
+	} else {
+		"'none'"
+	};
+
 	response.headers_mut().insert(
 		header::CONTENT_SECURITY_POLICY,
 		HeaderValue::from_str(&format!(
 			"default-src 'none'; style-src 'self'; img-src 'self' 'https' data:; script-src \
-			 'nonce-{csp_nonce}';"
+			 'nonce-{csp_nonce}'; child-src {child_src};"
 		))
 		.expect("should be able to build CSP header"),
 	);

src/web/pages/resources/common.css

@@ -108,6 +108,11 @@ em {
     }
 }
 
+hr {
+    border-width: 1px;
+    border-color: var(--secondary);
+}
+
 small {
     color: var(--secondary);
 }
@@ -223,6 +228,7 @@ input {
 input[type="checkbox"] {
     display: inline;
     margin: 0;
+    width: auto !important;
 }
 
 button, a.button {

src/web/pages/resources/login.css

@@ -1,5 +1,62 @@
-.reset-password {
+.centered-links {
     display: flex;
-    width: 100%;
-    justify-content: right;
+    justify-content: space-between;
+
+    :last-child {
+        margin-left: auto;
+    }
+}
+
+.text-rule {
+    display: flex;
+    align-items: center;
+    text-align: center;
+    color: var(--secondary);
+    margin-bottom: 0.5em;
+}
+
+.text-rule::before, .text-rule::after {
+  content: '';
+  flex: 1;
+  border-bottom: 1px solid var(--secondary);
+}
+
+.text-rule:not(:empty)::before {
+  margin-right: 1rem;
+}
+
+.text-rule:not(:empty)::after {
+  margin-left: 1rem;
+}
+
+.username-input {
+    display: flex;
+    padding: 0.5em;
+    margin-bottom: 0.5em;
+    line-height: 1;
+
+    border-radius: var(--border-radius-sm);
+    border: 2px solid var(--secondary);
+
+    &:has(input:focus-visible) {
+        outline: 2px solid var(--c1);
+        border-color: transparent;
+    }
+
+    input {
+        flex: 1;
+        padding: 0;
+        margin: 0;
+        border: none;
+        outline: none;
+    }
+
+    span {
+        flex: 0;
+        color: var(--secondary);
+
+        &:first-of-type {
+            margin-inline-end: 0.5em;
+        }
+    }
 }

src/web/pages/templates/device_info.html.j2

@@ -28,8 +28,7 @@ Device information
             {% else %}
                 This device can access and control all features of your Matrix account.
                 <br>
-                <small>❖ <i>This is a legacy device. Legacy devices
-                always have full access to your account.</i></small>
+                <small>❖ <i>This is a legacy device. Legacy devices always have full access to your account.</i></small>
             {% endif %}
         </p>
     </section>

src/web/pages/templates/login.html.j2

@@ -11,7 +11,7 @@ Log in
 {%- block content -%}
 <div class="panel narrow">
     {% match body %}
-        {% when LoginBody::Unauthenticated { server_name } %}
+        {% when LoginBody::Unauthenticated { server_name, registration_available } %}
             <h1 class="with-matrix-icon">
                 {% if has_next %}
                     Log in to continue
@@ -37,6 +37,12 @@ Log in
                 </p>
                 <button type="submit">Log in</button>
             </form>
+            <div class="centered-links">
+                {% if registration_available %}
+                    <a href="{{ crate::ROUTE_PREFIX }}/account/register/">Sign up</a>
+                {% endif %}
+                <a href="{{ crate::ROUTE_PREFIX }}/account/password/reset/">Forgot your password?</a>
+            </div>
         {% when LoginBody::Authenticated { user_card } %}
             <h1>Confirm your identity</h1>
             {{ user_card }}
@@ -48,10 +54,12 @@ Log in
                 </p>
                 <button type="submit">Continue</button>
             </form>
+            <div class="centered-links">
+                <a href="{{ crate::ROUTE_PREFIX }}/account/password/reset/">Forgot your password?</a>
+            </div>
     {% endmatch %}
     {% if let Some(error) = login_error %}
         <small class="error">{{ error }}</small>
     {% endif %}
-    <a class="reset-password" href="password/reset/"><i>Forgot your password?</i></a>
 </div>
 {%- endblock -%}

src/web/pages/templates/register.html.j2

@@ -0,0 +1,159 @@
+{% extends "_layout.html.j2" %}
+{% import "_components/form.html.j2" as form %}
+
+{%- block head -%}
+<link rel="stylesheet" href="{{ crate::ROUTE_PREFIX }}/resources/login.css">
+{%- endblock -%}
+
+{%- block title -%}
+Sign up
+{%- endblock -%}
+
+{%- block content -%}
+<div class="panel narrow">
+    <h1 class="with-matrix-icon">
+        {% if false %}
+            Sign up to continue
+        {% else %}
+            Sign up
+        {% endif %}
+        <a href="https://matrix.org" target="_blank" noreferer>
+            <img class="matrix-icon" alt="Matrix logo" aria-ignore src="{{ crate::ROUTE_PREFIX }}/resources/matrix-icon.svg">
+        </a>
+    </h1>
+    {% match body %}
+        {% when RegisterBody::Unavailable %}
+            <p>
+                This server is not currently accepting new accounts.
+            </p>
+        {% when RegisterBody::UsernamePrompt { allow_federation, untrusted_flow_status, trusted_flow_status, username_error } %}
+            <p>
+                You're about to register a new Matrix account on <em>{{ server_name }}</em>.
+            </p>
+            {% if allow_federation %}
+                <p>
+                    Like email, Matrix is a network of servers. Your account will be able to talk to
+                    users on hundreds of different Matrix servers across the world.
+                </p>
+            {% endif %}
+            <hr>
+            <p>
+                Choose a username to continue.
+            </p>
+            <form method="get">
+                <input type="hidden" name="from_landing" value="true">
+                <p>
+                    <label for="username">Username</label>
+                    <span class="username-input">
+                        <span>@</span>
+                        <input type="text" name="username" autocomplete="username" required>
+                        <span>:{{ server_name }}</span>
+                    </span>
+                    {% if let Some(username_error) = username_error %}
+                        <small class="error">
+                            {{ username_error }}
+                        </small>
+                    {% endif %}
+                </p>
+                {% if let UntrustedFlowStatus::Available { require_email } = untrusted_flow_status %}
+                    {% if require_email %}
+                        <button type="submit" name="flow" value="untrusted">Continue with email</button>
+                    {% else %}
+                        <button type="submit" name="flow" value="untrusted">Continue</button>
+                    {% endif %}
+                {% endif %}
+                {% if let UntrustedFlowStatus::Available { .. } = untrusted_flow_status && let TrustedFlowStatus::Available = trusted_flow_status %}
+                    <div class="text-rule">or</div>
+                {% endif %}
+                {% if let TrustedFlowStatus::Available = trusted_flow_status %}
+                    <button type="submit" name="flow" value="trusted">Continue with a registration token</button>
+                {% endif %}
+            </form>
+        {% when RegisterBody::DetailsPrompt { username, require_email, flow, terms, validation_errors } %}
+            {% let validation_errors = validation_errors.clone() %}
+            {% let field_errors = validation_errors.field_errors() %}
+            <form method="post">
+                <p>
+                    <label for="username">Username</label>
+                    <span class="username-input">
+                        <span>@</span>
+                        {% if let Some(username) = username %}
+                            <input type="text" name="username" value="{{ username }}" autocomplete="username" required>
+                        {% else %}
+                            <input type="text" name="username" autocomplete="username" required>
+                        {% endif %}
+                        <span>:{{ server_name }}</span>
+                    </span>
+                    {{ form::errors(field_errors, std::borrow::Cow::Borrowed("username")) }}
+                </p>
+                <p>
+                    Just a few more details to finish creating your account.
+                </p>
+                <p>
+                    <label for="password">Password</label>
+                    <input type="password" name="password" autocomplete="new-password" required>
+                    {{ form::errors(field_errors, std::borrow::Cow::Borrowed("password")) }}
+                </p>
+                <p>
+                    <label for="confirm_password">Confirm password</label>
+                    <input type="password" name="confirm_password" autocomplete="new-password" required>
+                    {{ form::errors(field_errors, std::borrow::Cow::Borrowed("confirm_password")) }}
+                </p>
+                {% if require_email %}
+                    <p>
+                        <label for="email">Email address</label>
+                        <input type="email" name="email" required>
+                        {{ form::errors(field_errors, std::borrow::Cow::Borrowed("email")) }}
+                    </p>
+                {% endif %}
+                {% match flow %}
+                    {% when RegistrationFlowParameters::Untrusted { recaptcha_sitekey } %}
+                        <input type="hidden" name="flow" value="untrusted">
+                        {% if let Some(recaptcha_sitekey) = recaptcha_sitekey %}
+                            <script src="https://www.google.com/recaptcha/enterprise.js" nonce="{{ context.csp_nonce }}" async defer></script>
+                            <noscript>
+                                <p>
+                                    ⚠️ Please enable JavaScript to complete the reCAPTCHA challenge.
+                                </p>
+                            </noscript>
+                            <p>
+                                <span class="g-recaptcha" data-sitekey="{{ recaptcha_sitekey }}"></span>
+                                {{ form::errors(field_errors, std::borrow::Cow::Borrowed("recaptcha")) }}
+                            </p>
+                        {% endif %}
+                    {% when RegistrationFlowParameters::Trusted { registration_token } %}
+                        <input type="hidden" name="flow" value="trusted">
+                        {% if let Some(registration_token) = registration_token %}
+                            <input type="hidden" name="registration_token" value="{{ registration_token }}">
+                            <div>
+                                {{ form::errors(field_errors, std::borrow::Cow::Borrowed("registration_token")) }}
+                            </div>
+                        {% else %}
+                            <p>
+                                <label for="username">Registration token</label>
+                                <input type="text" name="registration_token" autocomplete="none" required>
+                                {{ form::errors(field_errors, std::borrow::Cow::Borrowed("registration_token")) }}
+                            </p>
+                        {% endif %}
+                {% endmatch %}
+
+                {% if !terms.is_empty() %}
+                    <p>
+                        {% for (id, document) in terms %}
+                            <label for="policy-{{ id }}">
+                                <input
+                                    type="checkbox"
+                                    id="policy-{{ id }}"
+                                    required
+                                >
+                                I agree to the <a target="_blank" href="{{ document.url }}">{{ document.name }}</a>
+                            </label>
+                        {% endfor %}
+                        <small><i>All policy links will open in a new tab.</i></small>
+                    </p>
+                {% endif %}
+                <button type="submit">Continue</button>
+            </form>
+    {% endmatch %}
+</div>
+{%- endblock -%}

src/web/pages/templates/register_confirm_email.html.j2

@@ -0,0 +1,27 @@
+{% extends "_layout.html.j2" %}
+
+{%- block title -%}
+Confirm your email
+{%- endblock -%}
+
+{%- block content -%}
+<div class="panel narrow">
+    <h1>Confirm your email</h1>
+    <p>
+        A message has been sent to your new email address with a validation link.
+        To finish creating your account, click the link and then return to this page.
+        If you do not receive the email:
+        <ul>
+            <li>Check your spam filter.</li>
+        </ul>
+    </p>
+    {% if validation_error %}
+        <small class="error">Validation failed. Have you clicked the link in the email that was sent to you?</small>
+    {% endif %}
+    <form method="get" action="validate">
+        <input type="hidden" name="session_id" value="{{ session_id }}">
+        <input type="hidden" name="client_secret" value="{{ client_secret }}">
+        <button type="submit">Continue</button>
+    </form>
+</div>
+{%- endblock -%}