From 4f122a3100d6a32a5a5dd08ed037a24360125b7b Mon Sep 17 00:00:00 2001
From: Quentin Gliech <quenting@element.io>
Date: Thu, 19 Dec 2024 10:47:40 +0100
Subject: [PATCH] Setup Regal to lint policies and clean them up

---
 .github/workflows/ci.yaml                     |   7 +-
 .github/workflows/coverage.yaml               |   2 +-
 policies/.regal/config.yaml                   |   6 +
 policies/Makefile                             |  23 +-
 .../authorization_grant.rego                  |  40 ++--
 .../authorization_grant_test.rego             |  95 ++++-----
 .../client_registration.rego                  | 183 ++++++++--------
 .../client_registration_test.rego             | 200 ++++++++++--------
 policies/{ => email}/email.rego               |  16 +-
 policies/email/email_test.rego                |  29 +++
 policies/email_test.rego                      |  26 ---
 policies/{ => register}/register.rego         |  24 ++-
 policies/register/register_test.rego          |  58 +++++
 policies/register_test.rego                   |  52 -----
 policies/util/coveralls.rego                  |  16 +-
 15 files changed, 401 insertions(+), 376 deletions(-)
 create mode 100644 policies/.regal/config.yaml
 rename policies/{ => authorization_grant}/authorization_grant.rego (64%)
 rename policies/{ => authorization_grant}/authorization_grant_test.rego (58%)
 rename policies/{ => client_registration}/client_registration.rego (61%)
 rename policies/{ => client_registration}/client_registration_test.rego (56%)
 rename policies/{ => email}/email.rego (71%)
 create mode 100644 policies/email/email_test.rego
 delete mode 100644 policies/email_test.rego
 rename policies/{ => register}/register.rego (52%)
 create mode 100644 policies/register/register_test.rego
 delete mode 100644 policies/register_test.rego

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index cc2b2c215..167b91808 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -33,7 +33,12 @@ jobs:
       - name: Setup OPA
         uses: open-policy-agent/setup-opa@v2.2.0
         with:
-          version: 0.64.1
+          version: 0.70.0
+
+      - name: Setup Regal
+        uses: StyraInc/setup-regal@v1
+        with:
+          version: 0.29.2
 
       - name: Lint policies
         working-directory: ./policies
diff --git a/.github/workflows/coverage.yaml b/.github/workflows/coverage.yaml
index 074c6a044..98d3a47a4 100644
--- a/.github/workflows/coverage.yaml
+++ b/.github/workflows/coverage.yaml
@@ -29,7 +29,7 @@ jobs:
       - name: Setup OPA
         uses: open-policy-agent/setup-opa@v2.2.0
         with:
-          version: 0.64.1
+          version: 0.70.0
 
       - name: Run OPA tests with coverage
         working-directory: ./policies
diff --git a/policies/.regal/config.yaml b/policies/.regal/config.yaml
new file mode 100644
index 000000000..2088bdbf0
--- /dev/null
+++ b/policies/.regal/config.yaml
@@ -0,0 +1,6 @@
+rules:
+  style:
+    external-reference:
+      level: ignore
+    line-length:
+      level: ignore
diff --git a/policies/Makefile b/policies/Makefile
index 291304a6d..60f037e48 100644
--- a/policies/Makefile
+++ b/policies/Makefile
@@ -1,24 +1,28 @@
 # Set to 1 to run OPA through Docker
 DOCKER := 0
 PODMAN := 0
-OPA_DOCKER_IMAGE := docker.io/openpolicyagent/opa:0.64.1-debug
+OPA_DOCKER_IMAGE := docker.io/openpolicyagent/opa:0.70.0-debug
+REGAL_DOCKER_IMAGE := ghcr.io/styrainc/regal:0.29.2
 
 INPUTS := \
-	client_registration.rego \
-	register.rego \
-	authorization_grant.rego \
-	email.rego
+	client_registration/client_registration.rego \
+	register/register.rego \
+	authorization_grant/authorization_grant.rego \
+	email/email.rego
 
 ifeq ($(DOCKER), 1)
 	OPA := docker run -i -v $(shell pwd):/policies:ro -w /policies --rm $(OPA_DOCKER_IMAGE)
 	OPA_RW := docker run -i -v $(shell pwd):/policies -w /policies --rm $(OPA_DOCKER_IMAGE)
+	REGAL := docker run -i -v $(shell pwd):/policies:ro -w /policies --rm $(REGAL_DOCKER_IMAGE)
 else ifeq ($(PODMAN), 1)
 	# When running rootless, the volume directory may need to be given global write permissions on the host
 	OPA := podman run -i -v $(shell pwd):/policies:ro:Z -w /policies --rm $(OPA_DOCKER_IMAGE)
 	OPA_RW := podman run -i -v $(shell pwd):/policies:Z -w /policies --rm $(OPA_DOCKER_IMAGE)
+	REGAL := podman run -i -v $(shell pwd):/policies:ro:Z -w /policies --rm $(REGAL_DOCKER_IMAGE)
 else
 	OPA := opa
 	OPA_RW := opa
+	REGAL := regal
 endif
 
 policy.wasm: $(INPUTS)
@@ -38,16 +42,17 @@ fmt:
 
 .PHONY: test
 test:
-	$(OPA) test --schema ./schema/ -v ./*.rego
+	$(OPA) test --schema ./schema/ --ignore schema -v ./
 
 .PHONY: coverage
 coverage:
-	$(OPA) test --coverage ./*.rego | $(OPA) eval --format pretty \
+	$(OPA) test --coverage --schema ./schema/ --ignore schema ./ | $(OPA) eval --format pretty \
 		--stdin-input \
 		--data util/coveralls.rego \
 		data.coveralls.from_opa > coverage.json
 
 .PHONY: lint
 lint:
-	$(OPA) fmt -d --fail ./*.rego util/*.rego
-	$(OPA) check --strict --schema schema/ ./*.rego util/*.rego
+	$(OPA) fmt -d --fail .
+	$(OPA) check --strict --schema schema/ --ignore schema .
+	$(REGAL) lint .
diff --git a/policies/authorization_grant.rego b/policies/authorization_grant/authorization_grant.rego
similarity index 64%
rename from policies/authorization_grant.rego
rename to policies/authorization_grant/authorization_grant.rego
index 0ce1d63db..362ba080e 100644
--- a/policies/authorization_grant.rego
+++ b/policies/authorization_grant/authorization_grant.rego
@@ -3,39 +3,39 @@
 #   - input: schema["authorization_grant_input"]
 package authorization_grant
 
-import future.keywords.in
+import rego.v1
 
 default allow := false
 
-allow {
+allow if {
 	count(violation) == 0
 }
 
 # Users can request admin scopes if either:
 # 1. They are in the admin_users list
-can_request_admin(user) {
+can_request_admin(user) if {
 	some admin_user in data.admin_users
 	user.username == admin_user
 }
 
 # 2. They have the can_request_admin flag set to true
-can_request_admin(user) {
+can_request_admin(user) if {
 	user.can_request_admin
 }
 
-interactive_grant_type("authorization_code") = true
+interactive_grant_type("authorization_code") := true
 
-interactive_grant_type("urn:ietf:params:oauth:grant-type:device_code") = true
+interactive_grant_type("urn:ietf:params:oauth:grant-type:device_code") := true
 
 # Special case to make empty scope work
-allowed_scope("") = true
+allowed_scope("") := true
 
-allowed_scope("openid") = true
+allowed_scope("openid") := true
 
-allowed_scope("email") = true
+allowed_scope("email") := true
 
 # This grants access to Synapse's admin API endpoints
-allowed_scope("urn:synapse:admin:*") {
+allowed_scope("urn:synapse:admin:*") if {
 	# Synapse doesn't support user-less tokens yet, so access to the admin API
 	# can only be used with an authorization_code grant or a device code grant
 	# as the user is present
@@ -44,39 +44,41 @@ allowed_scope("urn:synapse:admin:*") {
 }
 
 # This grants access to the /graphql API endpoint
-allowed_scope("urn:mas:graphql:*") = true
+allowed_scope("urn:mas:graphql:*") := true
 
 # This makes it possible to query and do anything in the GraphQL API as an admin
-allowed_scope("urn:mas:admin") {
+allowed_scope("urn:mas:admin") if {
 	interactive_grant_type(input.grant_type)
 	can_request_admin(input.user)
 }
 
 # This makes it possible to get the admin scope for clients that are allowed
-allowed_scope("urn:mas:admin") {
+allowed_scope("urn:mas:admin") if {
 	input.grant_type == "client_credentials"
 	some client in data.admin_clients
 	input.client.id == client
 }
 
-allowed_scope(scope) {
+allowed_scope(scope) if {
 	# Grant access to the C-S API only if there is a user
 	interactive_grant_type(input.grant_type)
-	regex.match("^urn:matrix:org.matrix.msc2967.client:device:[A-Za-z0-9._~!$&'()*+,;=:@/-]{10,}$", scope)
+	regex.match(`^urn:matrix:org.matrix.msc2967.client:device:[A-Za-z0-9._~!$&'()*+,;=:@/-]{10,}$`, scope)
 }
 
-allowed_scope("urn:matrix:org.matrix.msc2967.client:api:*") {
+allowed_scope("urn:matrix:org.matrix.msc2967.client:api:*") if {
 	# Grant access to the C-S API only if there is a user
 	interactive_grant_type(input.grant_type)
 }
 
-violation[{"msg": msg}] {
+# METADATA
+# entrypoint: true
+violation contains {"msg": msg} if {
 	some scope in split(input.scope, " ")
 	not allowed_scope(scope)
 	msg := sprintf("scope '%s' not allowed", [scope])
 }
 
-violation[{"msg": "only one device scope is allowed at a time"}] {
+violation contains {"msg": "only one device scope is allowed at a time"} if {
 	scope_list := split(input.scope, " ")
-	count({key | scope_list[key]; startswith(scope_list[key], "urn:matrix:org.matrix.msc2967.client:device:")}) > 1
+	count({scope | some scope in scope_list; startswith(scope, "urn:matrix:org.matrix.msc2967.client:device:")}) > 1
 }
diff --git a/policies/authorization_grant_test.rego b/policies/authorization_grant/authorization_grant_test.rego
similarity index 58%
rename from policies/authorization_grant_test.rego
rename to policies/authorization_grant/authorization_grant_test.rego
index fc30f353f..3594bfac2 100644
--- a/policies/authorization_grant_test.rego
+++ b/policies/authorization_grant/authorization_grant_test.rego
@@ -1,155 +1,134 @@
-package authorization_grant
+package authorization_grant_test
+
+import data.authorization_grant
+import rego.v1
 
 user := {"username": "john"}
 
 client := {"client_id": "client"}
 
-test_standard_scopes {
-	allow with input.user as user
+test_standard_scopes if {
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as ""
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "openid"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "email"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "openid email"
 
 	# Not supported yet
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "phone"
 
 	# Not supported yet
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "profile"
 }
 
-test_matrix_scopes {
-	allow with input.user as user
+test_matrix_scopes if {
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:api:*"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:api:*"
 
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "client_credentials"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:api:*"
 }
 
-test_device_scopes {
-	allow with input.user as user
+test_device_scopes if {
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd01"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd01-asdasdsa1-2313"
 
 	# Too short
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:abcd"
 
 	# Multiple device scope
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd01 urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd02"
 
 	# Allowed with the device code grant
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd01"
 
-	# Not allowed for the client credentials grant
-	not allow with input.client as client
+	# Not authorization_grant.allowed for the client credentials grant
+	not authorization_grant.allow with input.client as client
 		with input.grant_type as "client_credentials"
 		with input.scope as "urn:matrix:org.matrix.msc2967.client:device:AAbbCCdd01"
 }
 
-test_synapse_admin_scopes {
-	allow with input.user as user
-		with input.client as client
-		with data.admin_users as ["john"]
-		with input.grant_type as "authorization_code"
-		with input.scope as "urn:synapse:admin:*"
+test_synapse_admin_scopes if {
+	some grant_type in ["authorization_code", "urn:ietf:params:oauth:grant-type:device_code"]
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with data.admin_users as ["john"]
-		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
-		with input.scope as "urn:synapse:admin:*"
-
-	not allow with input.user as user
-		with input.client as client
-		with data.admin_users as []
-		with input.grant_type as "authorization_code"
-		with input.scope as "urn:synapse:admin:*"
-
-	not allow with input.user as user
-		with input.client as client
-		with data.admin_users as []
-		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
+		with input.grant_type as grant_type
 		with input.scope as "urn:synapse:admin:*"
 
-	allow with input.user as user
-		with input.user.can_request_admin as true
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with data.admin_users as []
-		with input.grant_type as "authorization_code"
+		with input.grant_type as grant_type
 		with input.scope as "urn:synapse:admin:*"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.user.can_request_admin as true
 		with input.client as client
 		with data.admin_users as []
-		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
+		with input.grant_type as grant_type
 		with input.scope as "urn:synapse:admin:*"
 
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.user.can_request_admin as false
 		with input.client as client
 		with data.admin_users as []
-		with input.grant_type as "authorization_code"
-		with input.scope as "urn:synapse:admin:*"
-
-	not allow with input.user as user
-		with input.user.can_request_admin as false
-		with input.client as client
-		with data.admin_users as []
-		with input.grant_type as "urn:ietf:params:oauth:grant-type:device_code"
+		with input.grant_type as grant_type
 		with input.scope as "urn:synapse:admin:*"
 }
 
-test_mas_scopes {
-	allow with input.user as user
+test_mas_scopes if {
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with input.scope as "urn:mas:graphql:*"
 
-	allow with input.user as user
+	authorization_grant.allow with input.user as user
 		with input.client as client
 		with data.admin_users as ["john"]
 		with input.grant_type as "authorization_code"
 		with input.scope as "urn:mas:admin"
 
-	not allow with input.user as user
+	not authorization_grant.allow with input.user as user
 		with input.client as client
 		with data.admin_users as []
 		with input.grant_type as "authorization_code"
diff --git a/policies/client_registration.rego b/policies/client_registration/client_registration.rego
similarity index 61%
rename from policies/client_registration.rego
rename to policies/client_registration/client_registration.rego
index cd95b0dd1..4f3e28516 100644
--- a/policies/client_registration.rego
+++ b/policies/client_registration/client_registration.rego
@@ -3,26 +3,27 @@
 #   - input: schema["client_registration_input"]
 package client_registration
 
-import future.keywords.in
+import rego.v1
 
 default allow := false
 
-allow {
+allow if {
 	count(violation) == 0
 }
 
-parse_uri(url) = obj {
+parse_uri(url) := obj if {
 	is_string(url)
-	[matches] := regex.find_all_string_submatch_n("^(?P<scheme>[a-z][a-z0-9+.-]*):(?://(?P<host>((?:(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])\\.)*(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])|127.0.0.1|0.0.0.0|\\[::1\\])(?::(?P<port>[0-9]+))?))?(?P<path>/[A-Za-z0-9/.-]*)$", url, 1)
+	url_regex := `^(?P<scheme>[a-z][a-z0-9+.-]*):(?://(?P<host>((?:(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])\.)*(?:[a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])|127.0.0.1|0.0.0.0|\[::1\])(?::(?P<port>[0-9]+))?))?(?P<path>/[A-Za-z0-9/.-]*)$`
+	[matches] := regex.find_all_string_submatch_n(url_regex, url, 1)
 	obj := {"scheme": matches[1], "authority": matches[2], "host": matches[3], "port": matches[4], "path": matches[5]}
 }
 
-secure_url(x) {
+secure_url(x) if {
 	x
 	data.client_registration.allow_insecure_uris
 }
 
-secure_url(x) {
+secure_url(x) if {
 	url := parse_uri(x)
 	url.scheme == "https"
 
@@ -36,14 +37,14 @@ secure_url(x) {
 	url.port == ""
 }
 
-host_matches_client_uri(x) {
+host_matches_client_uri(x) if {
 	x
 
 	# Do not check we allow host mismatch
 	data.client_registration.allow_host_mismatch
 }
 
-host_matches_client_uri(x) {
+host_matches_client_uri(x) if {
 	x
 
 	# Do not check if the client_uri is missing and we allow that
@@ -51,99 +52,41 @@ host_matches_client_uri(x) {
 	not data.client_metadata.client_uri
 }
 
-host_matches_client_uri(x) {
+host_matches_client_uri(x) if {
 	client_uri := parse_uri(input.client_metadata.client_uri)
 	uri := parse_uri(x)
 	is_subdomain(client_uri.host, uri.host)
 }
 
-violation[{"msg": "missing client_uri"}] {
-	not data.client_registration.allow_missing_client_uri
-	not input.client_metadata.client_uri
-}
-
-violation[{"msg": "invalid client_uri"}] {
-	not secure_url(input.client_metadata.client_uri)
-}
-
-violation[{"msg": "invalid tos_uri"}] {
-	input.client_metadata.tos_uri
-	not secure_url(input.client_metadata.tos_uri)
-}
-
-violation[{"msg": "tos_uri not on the same host as the client_uri"}] {
-	input.client_metadata.tos_uri
-	not host_matches_client_uri(input.client_metadata.tos_uri)
-}
-
-violation[{"msg": "invalid policy_uri"}] {
-	input.client_metadata.policy_uri
-	not secure_url(input.client_metadata.policy_uri)
-}
-
-violation[{"msg": "policy_uri not on the same host as the client_uri"}] {
-	input.client_metadata.policy_uri
-	not host_matches_client_uri(input.client_metadata.policy_uri)
-}
-
-violation[{"msg": "invalid logo_uri"}] {
-	input.client_metadata.logo_uri
-	not secure_url(input.client_metadata.logo_uri)
-}
-
-violation[{"msg": "logo_uri not on the same host as the client_uri"}] {
-	input.client_metadata.logo_uri
-	not host_matches_client_uri(input.client_metadata.logo_uri)
-}
-
 # If the grant_types is missing, we assume it is authorization_code
-uses_grant_type("authorization_code") {
-	not input.client_metadata.grant_types
+uses_grant_type("authorization_code", client_metadata) if {
+	not client_metadata.grant_types
 }
 
 # Else, we check that the grant_types contains the given grant_type
-uses_grant_type(grant_type) {
-	some gt in input.client_metadata.grant_types
-	gt == grant_type
+uses_grant_type(grant_type, client_metadata) if {
+	some grant in client_metadata.grant_types
+	grant == grant_type
 }
 
 # Consider a client public if the authentication method is none
-is_public_client {
+is_public_client if {
 	input.client_metadata.token_endpoint_auth_method == "none"
 }
 
-requires_redirect_uris {
-	uses_grant_type("authorization_code")
-}
-
-requires_redirect_uris {
-	uses_grant_type("implicit")
-}
-
-violation[{"msg": "client_credentials grant_type requires some form of client authentication"}] {
-	uses_grant_type("client_credentials")
-	is_public_client
-}
-
-violation[{"msg": "missing redirect_uris"}] {
-	requires_redirect_uris
-	not input.client_metadata.redirect_uris
-}
-
-violation[{"msg": "invalid redirect_uris: it must be an array"}] {
-	not is_array(input.client_metadata.redirect_uris)
+requires_redirect_uris if {
+	uses_grant_type("authorization_code", input.client_metadata)
 }
 
-violation[{"msg": "invalid redirect_uris: it must have at least one redirect_uri"}] {
-	requires_redirect_uris
-	count(input.client_metadata.redirect_uris) == 0
+requires_redirect_uris if {
+	uses_grant_type("implicit", input.client_metadata)
 }
 
 # Used to verify that a reverse-dns formatted scheme is a strict subdomain of
 # another host.
 # This is used so a redirect_uri like 'com.example.app:/' works for
 # a 'client_uri' of 'https://example.com/'
-reverse_dns_match(host, reverse_dns) {
+reverse_dns_match(host, reverse_dns) if {
 	is_string(host)
 	is_string(reverse_dns)
 
@@ -158,7 +101,7 @@ reverse_dns_match(host, reverse_dns) {
 }
 
 # Used to verify that all the various URIs are subdomains of the client_uri
-is_subdomain(host, subdomain) {
+is_subdomain(host, subdomain) if {
 	is_string(host)
 	is_string(subdomain)
 
@@ -172,27 +115,21 @@ is_subdomain(host, subdomain) {
 	array.slice(subdomain_parts, 0, count(host_parts)) == host_parts
 }
 
-valid_native_redirector(x) {
-	url := parse_uri(x)
-	is_localhost(url.host)
-	url.scheme == "http"
-}
+is_localhost("localhost")
 
-is_localhost(host) {
-	host == "localhost"
-}
+is_localhost("127.0.0.1")
 
-is_localhost(host) {
-	host == "127.0.0.1"
-}
+is_localhost("[::1]")
 
-is_localhost(host) {
-	host == "[::1]"
+valid_native_redirector(x) if {
+	url := parse_uri(x)
+	is_localhost(url.host)
+	url.scheme == "http"
 }
 
 # Custom schemes should match the client_uri, reverse-dns style
 # e.g. io.element.app:/ matches https://app.element.io/
-valid_native_redirector(x) {
+valid_native_redirector(x) if {
 	url := parse_uri(x)
 	url.scheme != "http"
 	url.scheme != "https"
@@ -203,17 +140,71 @@ valid_native_redirector(x) {
 	reverse_dns_match(client_uri.host, url.scheme)
 }
 
-valid_redirect_uri(uri) {
+valid_redirect_uri(uri) if {
 	input.client_metadata.application_type == "native"
 	valid_native_redirector(uri)
 }
 
-valid_redirect_uri(uri) {
+valid_redirect_uri(uri) if {
 	secure_url(uri)
 	host_matches_client_uri(uri)
 }
 
-violation[{"msg": "invalid redirect_uri", "redirect_uri": redirect_uri}] {
+# METADATA
+# entrypoint: true
+violation contains {"msg": "missing client_uri"} if {
+	not data.client_registration.allow_missing_client_uri
+	not input.client_metadata.client_uri
+}
+
+violation contains {"msg": "invalid client_uri"} if {
+	not secure_url(input.client_metadata.client_uri)
+}
+
+violation contains {"msg": "invalid tos_uri"} if {
+	not secure_url(input.client_metadata.tos_uri)
+}
+
+violation contains {"msg": "tos_uri not on the same host as the client_uri"} if {
+	not host_matches_client_uri(input.client_metadata.tos_uri)
+}
+
+violation contains {"msg": "invalid policy_uri"} if {
+	not secure_url(input.client_metadata.policy_uri)
+}
+
+violation contains {"msg": "policy_uri not on the same host as the client_uri"} if {
+	not host_matches_client_uri(input.client_metadata.policy_uri)
+}
+
+violation contains {"msg": "invalid logo_uri"} if {
+	not secure_url(input.client_metadata.logo_uri)
+}
+
+violation contains {"msg": "logo_uri not on the same host as the client_uri"} if {
+	not host_matches_client_uri(input.client_metadata.logo_uri)
+}
+
+violation contains {"msg": "client_credentials grant_type requires some form of client authentication"} if {
+	uses_grant_type("client_credentials", input.client_metadata)
+	is_public_client
+}
+
+violation contains {"msg": "missing redirect_uris"} if {
+	requires_redirect_uris
+	not input.client_metadata.redirect_uris
+}
+
+violation contains {"msg": "invalid redirect_uris: it must be an array"} if {
+	not is_array(input.client_metadata.redirect_uris)
+}
+
+violation contains {"msg": "invalid redirect_uris: it must have at least one redirect_uri"} if {
+	requires_redirect_uris
+	count(input.client_metadata.redirect_uris) == 0
+}
+
+violation contains {"msg": "invalid redirect_uri", "redirect_uri": redirect_uri} if {
 	some redirect_uri in input.client_metadata.redirect_uris
 	not valid_redirect_uri(redirect_uri)
 }
diff --git a/policies/client_registration_test.rego b/policies/client_registration/client_registration_test.rego
similarity index 56%
rename from policies/client_registration_test.rego
rename to policies/client_registration/client_registration_test.rego
index fe4f077e2..5bf563d27 100644
--- a/policies/client_registration_test.rego
+++ b/policies/client_registration/client_registration_test.rego
@@ -1,273 +1,297 @@
-package client_registration
+package client_registration_test
 
-test_valid {
-	allow with input.client_metadata as {
+import rego.v1
+
+import data.client_registration
+
+test_valid if {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": ["authorization_code"],
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://example.com/callback"],
 	}
 }
 
-test_missing_client_uri {
-	not allow with input.client_metadata as {"grant_types": []}
+test_missing_client_uri if {
+	not client_registration.allow with input.client_metadata as {"grant_types": []}
 
-	allow with input.client_metadata as {"grant_types": []}
-		with data.client_registration.allow_missing_client_uri as true
+	client_registration.allow with input.client_metadata as {"grant_types": []}
+		with client_registration.allow_missing_client_uri as true
 }
 
-test_insecure_client_uri {
-	not allow with input.client_metadata as {
+test_insecure_client_uri if {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "http://example.com/",
 	}
 }
 
-test_tos_uri {
-	allow with input.client_metadata as {
+test_tos_uri if {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "https://example.com/tos",
 	}
+}
 
+test_tos_uri_insecure if {
 	# Insecure
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "http://example.com/tos",
 	}
 
 	# Insecure, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "http://example.com/tos",
 	}
-		with data.client_registration.allow_insecure_uris as true
+		with client_registration.allow_insecure_uris as true
+}
 
+test_tos_uri_host_mismatch if {
 	# Host mistmatch
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "https://example.org/tos",
 	}
 
 	# TOS on a subdomain of the client_uri host is allowed
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "https://tos.example.com/",
 	}
 
 	# Host mistmatch, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"tos_uri": "https://example.org/tos",
 	}
-		with data.client_registration.allow_host_mismatch as true
+		with client_registration.allow_host_mismatch as true
 }
 
-test_logo_uri {
-	allow with input.client_metadata as {
+test_logo_uri if {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "https://example.com/logo.png",
 	}
+}
 
+test_logo_uri_insecure if {
 	# Insecure
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "http://example.com/logo.png",
 	}
 
 	# Insecure, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "http://example.com/logo.png",
 	}
-		with data.client_registration.allow_insecure_uris as true
+		with client_registration.allow_insecure_uris as true
+}
 
+test_logo_uri_host_mismatch if {
 	# Host mistmatch
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "https://example.org/logo.png",
 	}
 
 	# Logo on a subdomain of the client_uri host is allowed
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "https://static.example.com/logo.png",
 	}
 
 	# Host mistmatch, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"logo_uri": "https://example.org/logo.png",
 	}
-		with data.client_registration.allow_host_mismatch as true
+		with client_registration.allow_host_mismatch as true
 }
 
-test_policy_uri {
-	allow with input.client_metadata as {
+test_policy_uri if {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "https://example.com/policy",
 	}
+}
 
+test_policy_uri_insecure if {
 	# Insecure
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "http://example.com/policy",
 	}
 
 	# Insecure, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "http://example.com/policy",
 	}
-		with data.client_registration.allow_insecure_uris as true
+		with client_registration.allow_insecure_uris as true
+}
 
+test_policy_uri_host_mismatch if {
 	# Host mistmatch
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "https://example.org/policy",
 	}
 
 	# Policy on a subdomain of the client_uri host is allowed
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "https://policy.example.com/",
 	}
 
 	# Host mistmatch, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": [],
 		"client_uri": "https://example.com/",
 		"policy_uri": "https://example.org/policy",
 	}
-		with data.client_registration.allow_host_mismatch as true
+		with client_registration.allow_host_mismatch as true
 }
 
-test_redirect_uris {
+test_redirect_uris if {
 	# Missing redirect_uris
-	not allow with input.client_metadata as {"client_uri": "https://example.com/"}
+	not client_registration.allow with input.client_metadata as {"client_uri": "https://example.com/"}
 
 	# redirect_uris is not an array
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"client_uri": "https://example.com/",
 		"redirect_uris": "https://example.com/callback",
 	}
 
 	# Empty redirect_uris
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"client_uri": "https://example.com/",
 		"redirect_uris": [],
 	}
 
 	# Not required for the client_credentials grant
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials"],
 		"client_uri": "https://example.com/",
 	}
 
 	# Required for the authorization_code grant
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials", "refresh_token", "authorization_code"],
 		"client_uri": "https://example.com/",
 	}
 
 	# Required for the implicit grant
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials", "implicit"],
 		"client_uri": "https://example.com/",
 	}
 }
 
-test_web_redirect_uri {
-	allow with input.client_metadata as {
+test_web_redirect_uri if {
+	client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://example.com/second/callback", "https://example.com/callback"],
 	}
+}
 
+test_web_redirect_uri_insecure if {
 	# Insecure URL
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://example.com/callback", "https://example.com/callback"],
 	}
 
 	# Insecure URL, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://example.com/callback", "https://example.com/callback"],
 	}
-		with data.client_registration.allow_insecure_uris as true
+		with client_registration.allow_insecure_uris as true
+}
 
+test_web_redirect_uri_host_mismatch if {
 	# Host mismatch
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://example.com/second/callback", "https://example.org/callback"],
 	}
 
 	# Host mismatch, but allowed by the config
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://example.com/second/callback", "https://example.org/callback"],
 	}
-		with data.client_registration.allow_host_mismatch as true
+		with client_registration.allow_host_mismatch as true
 
 	# Redirect URI on a subdomain of the client_uri host is allowed
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://app.example.com/callback"],
 	}
+}
 
+test_web_redirect_uri_no_custom_scheme if {
 	# No custom scheme allowed
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["com.example.app:/callback"],
 	}
+}
 
+test_web_redirect_uri_localhost_not_allowed if {
 	# localhost not allowed
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://locahost:1234/callback"],
 	}
 
 	# localhost not allowed
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://127.0.0.1:1234/callback"],
 	}
 
 	# localhost not allowed
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "web",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://[::1]:1234/callback"],
 	}
 }
 
-test_native_redirect_uri {
+test_native_redirect_uri_allowed if {
 	# This has all the redirect URIs types we're supporting for native apps
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": [
@@ -278,89 +302,89 @@ test_native_redirect_uri {
 			"http://127.0.0.1:1234/callback",
 			"http://[::1]/callback",
 			"http://[::1]:1234/callback",
+			"https://example.com/callback",
 		],
 	}
+}
 
-	# We still allow matching URLs for native apps
-	allow with input.client_metadata as {
-		"application_type": "native",
-		"client_uri": "https://example.com/",
-		"redirect_uris": ["https://example.com/"],
-	}
-
+test_native_redirect_uri_denied_domain if {
 	# But not insecure
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://example.com/"],
 	}
 
 	# And not a mismatch
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://bad.com/"],
 	}
+}
 
+test_native_redirect_uri_denied_on_localhost if {
 	# We don't allow HTTPS on localhost
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["https://localhost:1234/"],
 	}
 
 	# Ensure we're not allowing localhost as a prefix
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["http://localhost.com/"],
 	}
+}
 
+test_native_redirect_uri_custom_scheme if {
 	# For custom schemes, it should match the client_uri hostname
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"application_type": "native",
 		"client_uri": "https://example.com/",
 		"redirect_uris": ["org.example.app:/callback"],
 	}
 }
 
-test_reverse_dns_match {
-	client_uri := parse_uri("https://element.io/")
-	redirect_uri := parse_uri("io.element.app:/callback")
-	reverse_dns_match(client_uri.host, redirect_uri.scheme)
+test_reverse_dns_match_parse if {
+	client_uri := client_registration.parse_uri("https://element.io/")
+	redirect_uri := client_registration.parse_uri("io.element.app:/callback")
+	client_registration.reverse_dns_match(client_uri.host, redirect_uri.scheme)
 }
 
-test_client_credentials_grant {
+test_client_credentials_grant if {
 	# Allowed for confidential clients
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials"],
 		"token_endpoint_auth_method": "client_secret_basic",
 		"client_uri": "https://example.com/",
 	}
-	allow with input.client_metadata as {
+	client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials"],
 		# If omitted, defaults to "client_secret_basic"
 		"client_uri": "https://example.com/",
 	}
 
 	# Disallowed for public clients
-	not allow with input.client_metadata as {
+	not client_registration.allow with input.client_metadata as {
 		"grant_types": ["client_credentials"],
 		"token_endpoint_auth_method": "none",
 		"client_uri": "https://example.com/",
 	}
 }
 
-test_is_subdomain {
-	is_subdomain("example.com", "example.com")
-	is_subdomain("example.com", "app.example.com")
-	not is_subdomain("example.com", "example.org")
-	not is_subdomain("test.com", "example.com")
+test_is_subdomain if {
+	client_registration.is_subdomain("example.com", "example.com")
+	client_registration.is_subdomain("example.com", "app.example.com")
+	not client_registration.is_subdomain("example.com", "example.org")
+	not client_registration.is_subdomain("test.com", "example.com")
 }
 
-test_reverse_dns_match {
-	reverse_dns_match("example.com", "com.example")
-	reverse_dns_match("example.com", "com.example.app")
-	not reverse_dns_match("example.com", "org.example")
-	not reverse_dns_match("test.com", "com.example")
+test_reverse_dns_match if {
+	client_registration.reverse_dns_match("example.com", "com.example")
+	client_registration.reverse_dns_match("example.com", "com.example.app")
+	not client_registration.reverse_dns_match("example.com", "org.example")
+	not client_registration.reverse_dns_match("test.com", "com.example")
 }
diff --git a/policies/email.rego b/policies/email/email.rego
similarity index 71%
rename from policies/email.rego
rename to policies/email/email.rego
index fecad108f..00103da26 100644
--- a/policies/email.rego
+++ b/policies/email/email.rego
@@ -3,32 +3,34 @@
 #   - input: schema["email_input"]
 package email
 
-import future.keywords.in
+import rego.v1
 
 default allow := false
 
-allow {
+allow if {
 	count(violation) == 0
 }
 
 # Allow any domains if the data.allowed_domains array is not set
-email_domain_allowed {
+domain_allowed if {
 	not data.allowed_domains
 }
 
 # Allow an email only if its domain is in the list of allowed domains
-email_domain_allowed {
+domain_allowed if {
 	[_, domain] := split(input.email, "@")
 	some allowed_domain in data.allowed_domains
 	glob.match(allowed_domain, ["."], domain)
 }
 
-violation[{"msg": "email domain is not allowed"}] {
-	not email_domain_allowed
+# METADATA
+# entrypoint: true
+violation contains {"msg": "email domain is not allowed"} if {
+	not domain_allowed
 }
 
 # Deny emails with their domain in the domains banlist
-violation[{"msg": "email domain is banned"}] {
+violation contains {"msg": "email domain is banned"} if {
 	[_, domain] := split(input.email, "@")
 	some banned_domain in data.banned_domains
 	glob.match(banned_domain, ["."], domain)
diff --git a/policies/email/email_test.rego b/policies/email/email_test.rego
new file mode 100644
index 000000000..0adcdfad2
--- /dev/null
+++ b/policies/email/email_test.rego
@@ -0,0 +1,29 @@
+package email_test
+
+import data.email
+import rego.v1
+
+test_allow_all_domains if {
+	email.allow with input.email as "hello@staging.element.io"
+}
+
+test_allowed_domain if {
+	email.allow with input.email as "hello@staging.element.io"
+		with data.allowed_domains as ["*.element.io"]
+}
+
+test_not_allowed_domain if {
+	not email.allow with input.email as "hello@staging.element.io"
+		with data.allowed_domains as ["example.com"]
+}
+
+test_banned_domain if {
+	not email.allow with input.email as "hello@staging.element.io"
+		with data.banned_domains as ["*.element.io"]
+}
+
+test_banned_subdomain if {
+	not email.allow with input.email as "hello@staging.element.io"
+		with data.allowed_domains as ["*.element.io"]
+		with data.banned_domains as ["staging.element.io"]
+}
diff --git a/policies/email_test.rego b/policies/email_test.rego
deleted file mode 100644
index efda51bd5..000000000
--- a/policies/email_test.rego
+++ /dev/null
@@ -1,26 +0,0 @@
-package email
-
-test_allow_all_domains {
-	allow with input.email as "hello@staging.element.io"
-}
-
-test_allowed_domain {
-	allow with input.email as "hello@staging.element.io"
-		with data.allowed_domains as ["*.element.io"]
-}
-
-test_not_allowed_domain {
-	not allow with input.email as "hello@staging.element.io"
-		with data.allowed_domains as ["example.com"]
-}
-
-test_banned_domain {
-	not allow with input.email as "hello@staging.element.io"
-		with data.banned_domains as ["*.element.io"]
-}
-
-test_banned_subdomain {
-	not allow with input.email as "hello@staging.element.io"
-		with data.allowed_domains as ["*.element.io"]
-		with data.banned_domains as ["staging.element.io"]
-}
diff --git a/policies/register.rego b/policies/register/register.rego
similarity index 52%
rename from policies/register.rego
rename to policies/register/register.rego
index 051935499..4507a10ca 100644
--- a/policies/register.rego
+++ b/policies/register/register.rego
@@ -3,38 +3,40 @@
 #   - input: schema["register_input"]
 package register
 
-import data.email as email_policy
+import rego.v1
 
-import future.keywords.in
+import data.email as email_policy
 
 default allow := false
 
-allow {
+allow if {
 	count(violation) == 0
 }
 
-violation[{"field": "username", "msg": "username too short"}] {
+# METADATA
+# entrypoint: true
+violation contains {"field": "username", "msg": "username too short"} if {
 	count(input.username) <= 2
 }
 
-violation[{"field": "username", "msg": "username too long"}] {
+violation contains {"field": "username", "msg": "username too long"} if {
 	count(input.username) > 64
 }
 
-violation[{"field": "username", "msg": "username contains invalid characters"}] {
-	not regex.match("^[a-z0-9.=_/-]+$", input.username)
+violation contains {"field": "username", "msg": "username contains invalid characters"} if {
+	not regex.match(`^[a-z0-9.=_/-]+$`, input.username)
 }
 
-violation[{"msg": "unspecified registration method"}] {
+violation contains {"msg": "unspecified registration method"} if {
 	not input.registration_method
 }
 
-violation[{"msg": "unknown registration method"}] {
+violation contains {"msg": "unknown registration method"} if {
 	not input.registration_method in ["password", "upstream-oauth2"]
 }
 
 # Check that we supplied an email for password registration
-violation[{"field": "email", "msg": "email required for password-based registration"}] {
+violation contains {"field": "email", "msg": "email required for password-based registration"} if {
 	input.registration_method == "password"
 
 	not input.email
@@ -42,7 +44,7 @@ violation[{"field": "email", "msg": "email required for password-based registrat
 
 # 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)] {
+violation contains object.union({"field": "email"}, v) if {
 	# Check if we have an email set in the input
 	input.email
 
diff --git a/policies/register/register_test.rego b/policies/register/register_test.rego
new file mode 100644
index 000000000..0d270ec26
--- /dev/null
+++ b/policies/register/register_test.rego
@@ -0,0 +1,58 @@
+package register_test
+
+import data.register
+import rego.v1
+
+mock_registration := {
+	"registration_method": "password",
+	"username": "hello",
+	"email": "hello@staging.element.io",
+}
+
+test_allow_all_domains if {
+	register.allow with input as mock_registration
+}
+
+test_allowed_domain if {
+	register.allow with input as mock_registration
+		with data.allowed_domains as ["*.element.io"]
+}
+
+test_not_allowed_domain if {
+	not register.allow with input as mock_registration
+		with data.allowed_domains as ["example.com"]
+}
+
+test_banned_domain if {
+	not register.allow with input as mock_registration
+		with data.banned_domains as ["*.element.io"]
+}
+
+test_banned_subdomain if {
+	not register.allow with input as mock_registration
+		with data.allowed_domains as ["*.element.io"]
+		with data.banned_domains as ["staging.element.io"]
+}
+
+test_email_required if {
+	not register.allow with input as {"username": "hello", "registration_method": "password"}
+}
+
+test_no_email if {
+	register.allow with input as {"username": "hello", "registration_method": "upstream-oauth2"}
+}
+
+test_short_username if {
+	not register.allow with input as {"username": "a", "registration_method": "upstream-oauth2"}
+}
+
+test_long_username if {
+	not register.allow with input as {
+		"username": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+		"registration_method": "upstream-oauth2",
+	}
+}
+
+test_invalid_username if {
+	not register.allow with input as {"username": "hello world", "registration_method": "upstream-oauth2"}
+}
diff --git a/policies/register_test.rego b/policies/register_test.rego
deleted file mode 100644
index 4d8d5476a..000000000
--- a/policies/register_test.rego
+++ /dev/null
@@ -1,52 +0,0 @@
-package register
-
-mock_registration := {
-	"registration_method": "password",
-	"username": "hello",
-	"email": "hello@staging.element.io",
-}
-
-test_allow_all_domains {
-	allow with input as mock_registration
-}
-
-test_allowed_domain {
-	allow with input as mock_registration
-		with data.allowed_domains as ["*.element.io"]
-}
-
-test_not_allowed_domain {
-	not allow with input as mock_registration
-		with data.allowed_domains as ["example.com"]
-}
-
-test_banned_domain {
-	not allow with input as mock_registration
-		with data.banned_domains as ["*.element.io"]
-}
-
-test_banned_subdomain {
-	not allow with input as mock_registration
-		with data.allowed_domains as ["*.element.io"]
-		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", "registration_method": "upstream-oauth2"}
-}
-
-test_long_username {
-	not allow with input as {"username": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "registration_method": "upstream-oauth2"}
-}
-
-test_invalid_username {
-	not allow with input as {"username": "hello world", "registration_method": "upstream-oauth2"}
-}
diff --git a/policies/util/coveralls.rego b/policies/util/coveralls.rego
index 881c7f6fc..c25208552 100644
--- a/policies/util/coveralls.rego
+++ b/policies/util/coveralls.rego
@@ -1,6 +1,6 @@
-package coveralls
+package util
 
-import future.keywords
+import rego.v1
 
 from_opa := {"source_files": coverage}
 
@@ -9,7 +9,7 @@ coverage contains obj if {
 	obj := {"name": file, "coverage": to_lines(report)}
 }
 
-covered_map(report) = cm if {
+covered_map(report) := cm if {
 	covered := object.get(report, "covered", [])
 	cm := {line: 1 |
 		some item in covered
@@ -17,7 +17,7 @@ covered_map(report) = cm if {
 	}
 }
 
-not_covered_map(report) = ncm if {
+not_covered_map(report) := ncm if {
 	not_covered := object.get(report, "not_covered", [])
 	ncm := {line: 0 |
 		some item in not_covered
@@ -25,7 +25,7 @@ not_covered_map(report) = ncm if {
 	}
 }
 
-to_lines(report) = lines if {
+to_lines(report) := lines if {
 	cm := covered_map(report)
 	ncm := not_covered_map(report)
 	keys := sort([line | some line, _ in object.union(cm, ncm)])
@@ -37,15 +37,15 @@ to_lines(report) = lines if {
 	]
 }
 
-to_value(cm, _, line) = 1 if {
+to_value(cm, _, line) := 1 if {
 	cm[line]
 }
 
-to_value(_, ncm, line) = 0 if {
+to_value(_, ncm, line) := 0 if {
 	ncm[line]
 }
 
-to_value(cm, ncm, line) = null if {
+to_value(cm, ncm, line) := null if {
 	not cm[line]
 	not ncm[line]
 }