Handle password strength verification through OPA

crates/handlers/src/views/register.rs

@@ -133,7 +133,7 @@ pub(crate) async fn post(
 
         let mut policy = policy_factory.instantiate().await?;
         let res = policy
-            .evaluate_register(&form.username, &form.email)
+            .evaluate_register(&form.username, &form.password, &form.email)
             .await?;
 
         for violation in res.violations {
@@ -150,6 +150,12 @@ pub(crate) async fn post(
                         message: violation.msg,
                     },
                 ),
+                Some("password") => state.add_error_on_field(
+                    RegisterFormField::Password,
+                    FieldError::Policy {
+                        message: violation.msg,
+                    },
+                ),
                 _ => state.add_error_on_form(FormError::Policy {
                     message: violation.msg,
                 }),

crates/policy/policies/register.rego

@@ -16,6 +16,26 @@ violation[{"field": "username", "msg": "username too long"}] {
 	count(input.user.username) >= 15
 }
 
+violation[{"field": "password", "msg": msg}] {
+	count(input.user.password) < data.passwords.min_length
+	msg := sprintf("needs to be at least %d characters", [data.passwords.min_length])
+}
+
+violation[{"field": "password", "msg": "requires at least one number"}] {
+	data.passwords.require_number
+	not regex.match("[0-9]", input.user.password)
+}
+
+violation[{"field": "password", "msg": "requires at least one lowercase letter"}] {
+	data.passwords.require_lowercase
+	not regex.match("[a-z]", input.user.password)
+}
+
+violation[{"field": "password", "msg": "requires at least one uppercase letter"}] {
+	data.passwords.require_uppercase
+	not regex.match("[A-Z]", input.user.password)
+}
+
 # Allow any domains if the data.allowed_domains array is not set
 email_domain_allowed {
 	not data.allowed_domains

crates/policy/policies/register_test.rego

@@ -1,6 +1,6 @@
 package register
 
-mock_user := {"username": "hello", "email": "hello@staging.element.io"}
+mock_user := {"username": "hello", "password": "Hunter2", "email": "hello@staging.element.io"}
 
 test_allow_all_domains {
 	allow with input.user as mock_user
@@ -34,3 +34,39 @@ test_short_username {
 test_long_username {
 	not allow with input.user as {"username": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "email": "hello@element.io"}
 }
+
+test_password_require_number {
+	allow with input.user as mock_user
+		with data.passwords.require_number as true
+
+	not allow with input.user as mock_user
+		with input.user.password as "hunter"
+		with data.passwords.require_number as true
+}
+
+test_password_require_lowercase {
+	allow with input.user as mock_user
+		with data.passwords.require_lowercase as true
+
+	not allow with input.user as mock_user
+		with input.user.password as "HUNTER2"
+		with data.passwords.require_lowercase as true
+}
+
+test_password_require_uppercase {
+	allow with input.user as mock_user
+		with data.passwords.require_uppercase as true
+
+	not allow with input.user as mock_user
+		with input.user.password as "hunter2"
+		with data.passwords.require_uppercase as true
+}
+
+test_password_min_length {
+	allow with input.user as mock_user
+		with data.passwords.min_length as 6
+
+	not allow with input.user as mock_user
+		with input.user.password as "short"
+		with data.passwords.min_length as 6
+}

crates/policy/src/lib.rs

@@ -122,13 +122,13 @@ impl PolicyFactory {
     }
 }
 
-#[derive(Deserialize)]
+#[derive(Deserialize, Debug)]
 pub struct Violation {
     pub msg: String,
     pub field: Option<String>,
 }
 
-#[derive(Deserialize)]
+#[derive(Deserialize, Debug)]
 pub struct EvaluationResult {
     #[serde(rename = "result")]
     pub violations: Vec<Violation>,
@@ -153,11 +153,13 @@ impl Policy {
     pub async fn evaluate_register(
         &mut self,
         username: &str,
+        password: &str,
         email: &str,
     ) -> Result<EvaluationResult, anyhow::Error> {
         let input = serde_json::json!({
             "user": {
                 "username": username,
+                "password": password,
                 "email": email
             }
         });