Run the registration policy on upstream OAuth registration

crates/axum-utils/src/fancy_error.rs

@@ -24,6 +24,7 @@ pub struct FancyError {
 }
 
 impl FancyError {
+    #[must_use]
     pub fn new(context: ErrorContext) -> Self {
         Self { context }
     }

crates/handlers/src/upstream_oauth2/link.rs

@@ -21,18 +21,20 @@ use hyper::StatusCode;
 use mas_axum_utils::{
     cookies::CookieJar,
     csrf::{CsrfExt, ProtectedForm},
-    SessionInfoExt,
+    FancyError, SessionInfoExt,
 };
 use mas_data_model::{UpstreamOAuthProviderImportPreference, User};
 use mas_jose::jwt::Jwt;
+use mas_policy::Policy;
 use mas_storage::{
     job::{JobRepositoryExt, ProvisionUserJob},
     upstream_oauth2::{UpstreamOAuthLinkRepository, UpstreamOAuthSessionRepository},
     user::{BrowserSessionRepository, UserEmailRepository, UserRepository},
     BoxClock, BoxRepository, BoxRng, RepositoryAccess,
 };
 use mas_templates::{
-    TemplateContext, Templates, UpstreamExistingLinkContext, UpstreamRegister, UpstreamSuggestLink,
+    ErrorContext, TemplateContext, Templates, UpstreamExistingLinkContext, UpstreamRegister,
+    UpstreamSuggestLink,
 };
 use serde::Deserialize;
 use thiserror::Error;
@@ -76,6 +78,11 @@ pub(crate) enum RouteError {
     #[error("Missing username")]
     MissingUsername,
 
+    #[error("Policy violation: {violations:?}")]
+    PolicyViolation {
+        violations: Vec<mas_policy::Violation>,
+    },
+
     #[error(transparent)]
     Internal(Box<dyn std::error::Error>),
 }
@@ -84,13 +91,24 @@ impl_from_error_for_route!(mas_templates::TemplateError);
 impl_from_error_for_route!(mas_axum_utils::csrf::CsrfError);
 impl_from_error_for_route!(super::cookie::UpstreamSessionNotFound);
 impl_from_error_for_route!(mas_storage::RepositoryError);
+impl_from_error_for_route!(mas_policy::EvaluationError);
 impl_from_error_for_route!(mas_jose::jwt::JwtDecodeError);
 
 impl IntoResponse for RouteError {
     fn into_response(self) -> axum::response::Response {
         sentry::capture_error(&self);
         match self {
             Self::LinkNotFound => (StatusCode::NOT_FOUND, "Link not found").into_response(),
+            Self::PolicyViolation { violations } => {
+                let details = violations.iter().map(|v| v.msg.clone()).collect::<Vec<_>>();
+                let details = details.join("\n");
+                let ctx = ErrorContext::new()
+                    .with_description(
+                        "Account registration denied because of policy violation".to_owned(),
+                    )
+                    .with_details(details);
+                FancyError::new(ctx).into_response()
+            }
             Self::Internal(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
             e => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
         }
@@ -358,6 +376,7 @@ pub(crate) async fn post(
     mut repo: BoxRepository,
     cookie_jar: CookieJar,
     user_agent: Option<TypedHeader<headers::UserAgent>>,
+    mut policy: Policy,
     Path(link_id): Path<Ulid>,
     Form(form): Form<ProtectedForm<FormData>>,
 ) -> Result<impl IntoResponse, RouteError> {
@@ -478,6 +497,16 @@ pub(crate) async fn post(
 
             let username = username.ok_or(RouteError::MissingUsername)?;
 
+            // Policy check
+            let res = policy
+                .evaluate_upstream_oauth_register(&username, email.as_deref())
+                .await?;
+            if !res.valid() {
+                return Err(RouteError::PolicyViolation {
+                    violations: res.violations,
+                });
+            }
+
             // Now we can create the user
             let user = repo.user().add(&mut rng, &clock, username).await?;
 

crates/policy/src/lib.rs

@@ -251,6 +251,31 @@ impl Policy {
         Ok(res)
     }
 
+    #[tracing::instrument(
+        name = "policy.evaluate.upstream_oauth_register",
+        skip_all,
+        fields(
+            input.registration_method = "password",
+            input.user.username = username,
+            input.user.email = email,
+        ),
+        err,
+    )]
+    pub async fn evaluate_upstream_oauth_register(
+        &mut self,
+        username: &str,
+        email: Option<&str>,
+    ) -> Result<EvaluationResult, EvaluationError> {
+        let input = RegisterInput::UpstreamOAuth2 { username, email };
+
+        let [res]: [EvaluationResult; 1] = self
+            .instance
+            .evaluate(&mut self.store, &self.entrypoints.register, &input)
+            .await?;
+
+        Ok(res)
+    }
+
     #[tracing::instrument(skip(self))]
     pub async fn evaluate_client_registration(
         &mut self,

crates/policy/src/model.rs

@@ -56,14 +56,23 @@ impl EvaluationResult {
 
 /// Input for the user registration policy.
 #[derive(Serialize, Debug)]
-#[serde(tag = "registration_method", rename_all = "snake_case")]
+#[serde(tag = "registration_method")]
 #[cfg_attr(feature = "jsonschema", derive(schemars::JsonSchema))]
 pub enum RegisterInput<'a> {
+    #[serde(rename = "password")]
     Password {
         username: &'a str,
         password: &'a str,
         email: &'a str,
     },
+
+    #[serde(rename = "upstream-oauth2")]
+    UpstreamOAuth2 {
+        username: &'a str,
+
+        #[serde(skip_serializing_if = "Option::is_none")]
+        email: Option<&'a str>,
+    },
 }
 
 /// Input for the client registration policy.

policies/Makefile

@@ -46,5 +46,5 @@ coverage:
 
 .PHONY: lint
 lint:
-	$(OPA) fmt -d --fail .
-	$(OPA) check --strict .
+	$(OPA) fmt -d --fail ./*.rego util/*.rego
+	$(OPA) check --strict --schema schema/ ./*.rego util/*.rego

policies/email_test.rego

@@ -0,0 +1,26 @@
+package email
+
+test_allow_all_domains {
+	allow with input.email as "[email protected]"
+}
+
+test_allowed_domain {
+	allow with input.email as "[email protected]"
+		with data.allowed_domains as ["*.element.io"]
+}
+
+test_not_allowed_domain {
+	not allow with input.email as "[email protected]"
+		with data.allowed_domains as ["example.com"]
+}
+
+test_banned_domain {
+	not allow with input.email as "[email protected]"
+		with data.banned_domains as ["*.element.io"]
+}
+
+test_banned_subdomain {
+	not allow with input.email as "[email protected]"
+		with data.allowed_domains as ["*.element.io"]
+		with data.banned_domains as ["staging.element.io"]
+}

policies/password_test.rego

@@ -0,0 +1,29 @@
+package password
+
+test_password_require_number {
+	allow with data.passwords.require_number as true
+
+	not allow with input.password as "hunter"
+		with data.passwords.require_number as true
+}
+
+test_password_require_lowercase {
+	allow with data.passwords.require_lowercase as true
+
+	not allow with input.password as "HUNTER2"
+		with data.passwords.require_lowercase as true
+}
+
+test_password_require_uppercase {
+	allow with data.passwords.require_uppercase as true
+
+	not allow with input.password as "hunter2"
+		with data.passwords.require_uppercase as true
+}
+
+test_password_min_length {
+	allow with data.passwords.min_length as 6
+
+	not allow with input.password as "short"
+		with data.passwords.min_length as 6
+}

policies/register.rego

@@ -22,6 +22,18 @@ violation[{"field": "username", "msg": "username too long"}] {
 	count(input.username) >= 15
 }
 
+violation[{"field": "username", "msg": "username contains invalid characters"}] {
+	not regex.match("^[a-z0-9.=_/-]+$", input.username)
+}
+
+violation[{"msg": "unspecified registration method"}] {
+	not input.registration_method
+}
+
+violation[{"msg": "unknown registration method"}] {
+	not input.registration_method in ["password", "upstream-oauth2"]
+}
+
 violation[object.union({"field": "password"}, v)] {
 	# Check if the registration method is password
 	input.registration_method == "password"
@@ -30,9 +42,19 @@ violation[object.union({"field": "password"}, v)] {
 	some v in password_policy.violation
 }
 
+# Check that we supplied an email for password registration
+violation[{"field": "email", "msg": "email required for password-based registration"}] {
+	input.registration_method == "password"
+
+	not input.email
+}
+
 # Check if the email is valid using the email policy
 # and add the email field to the violation object
 violation[object.union({"field": "email"}, v)] {
+	# Check if we have an email set in the input
+	input.email
+
 	# Get the violation object from the email policy
 	some v in email_policy.violation
 }

policies/register_test.rego

@@ -32,54 +32,58 @@ test_banned_subdomain {
 		with data.banned_domains as ["staging.element.io"]
 }
 
+test_email_required {
+	not allow with input as {"username": "hello", "registration_method": "password"}
+}
+
+test_no_email {
+	allow with input as {"username": "hello", "registration_method": "upstream-oauth2"}
+}
+
 test_short_username {
-	not allow with input as {"username": "a", "email": "[email protected]"}
+	not allow with input as {"username": "a", "registration_method": "upstream-oauth2"}
 }
 
 test_long_username {
-	not allow with input as {"username": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "email": "[email protected]"}
+	not allow with input as {"username": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "registration_method": "upstream-oauth2"}
+}
+
+test_invalid_username {
+	not allow with input as {"username": "hello world", "registration_method": "upstream-oauth2"}
 }
 
 test_password_require_number {
 	allow with input as mock_registration
-		with input.registration_method as "password"
 		with data.passwords.require_number as true
 
 	not allow with input as mock_registration
-		with input.registration_method as "password"
 		with input.password as "hunter"
 		with data.passwords.require_number as true
 }
 
 test_password_require_lowercase {
 	allow with input as mock_registration
-		with input.registration_method as "password"
 		with data.passwords.require_lowercase as true
 
 	not allow with input as mock_registration
-		with input.registration_method as "password"
 		with input.password as "HUNTER2"
 		with data.passwords.require_lowercase as true
 }
 
 test_password_require_uppercase {
 	allow with input as mock_registration
-		with input.registration_method as "password"
 		with data.passwords.require_uppercase as true
 
 	not allow with input as mock_registration
-		with input.registration_method as "password"
 		with input.password as "hunter2"
 		with data.passwords.require_uppercase as true
 }
 
 test_password_min_length {
 	allow with input as mock_registration
-		with input.registration_method as "password"
 		with data.passwords.min_length as 6
 
 	not allow with input as mock_registration
-		with input.registration_method as "password"
 		with input.password as "short"
 		with data.passwords.min_length as 6
 }

policies/schema/register_input.json

@@ -28,6 +28,27 @@
           "type": "string"
         }
       }
+    },
+    {
+      "type": "object",
+      "required": [
+        "registration_method",
+        "username"
+      ],
+      "properties": {
+        "email": {
+          "type": "string"
+        },
+        "registration_method": {
+          "type": "string",
+          "enum": [
+            "upstream-oauth2"
+          ]
+        },
+        "username": {
+          "type": "string"
+        }
+      }
     }
   ]
 }

templates/components/field.html

@@ -14,7 +14,7 @@
 limitations under the License.
 #}
 
-{% macro input(label, name, type="text", form_state=false, autocomplete=false, class="", inputmode="text", autocorrect=false, autocapitalize=false, disabled=false) %}
+{% macro input(label, name, type="text", form_state=false, autocomplete=false, class="", inputmode="text", autocorrect=false, autocapitalize=false, disabled=false, required=false) %}
   {% if not form_state %}
     {% set form_state = dict(errors=[], fields=dict()) %}
   {% endif %}
@@ -35,6 +35,7 @@
       class="z-0 px-3 py-2 bg-white dark:bg-black-900 rounded-lg {{ border_color }} border-2 focus:border-accent focus:ring-0 focus:outline-0"
       type="{{ type }}" 
       inputmode="{{ inputmode }}"
+      {% if required %} required {% endif %}
       {% if disabled %} disabled {% endif %}
       {% if autocomplete %} autocomplete="{{ autocomplete }}" {% endif %} 
       {% if autocorrect %} autocorrect="{{ autocorrect }}" {% endif %}

templates/pages/account/emails/add.html

@@ -33,7 +33,7 @@ <h1 class="text-lg text-center font-medium">Add an email address</h1>
       {% endif %}
 
       <input type="hidden" name="csrf" value="{{ csrf_token }}" />
-      {{ field::input(label="Email", name="email", type="email", form_state=form, autocomplete="email") }}
+      {{ field::input(label="Email", name="email", type="email", form_state=form, autocomplete="email", required=true) }}
       {{ button::button(text="Next") }}
   </section>
 {% endblock content %}