policies/expression: migrate to raw python instead of jinja2 (#49)

* policies/expression: migrate to raw python instead of jinja2

* lib/expression: create base evaluator, custom subclass for policies

* core: rewrite propertymappings to use python

* providers/saml: update to new PropertyMappings

* sources/ldap: update to new PropertyMappings

* docs: update docs for new propertymappings

* root: remove jinja2

* root: re-add jinja to lock file as its implicitly required

passbook/sources/ldap/connector.py

@@ -164,9 +164,10 @@ class Connector:
                 continue
             mapping: LDAPPropertyMapping
             try:
-                properties[mapping.object_field] = mapping.evaluate(
-                    user=None, request=None, ldap=attributes
-                )
+                value = mapping.evaluate(user=None, request=None, ldap=attributes)
+                if value is None:
+                    continue
+                properties[mapping.object_field] = value
             except PropertyMappingExpressionException as exc:
                 LOGGER.warning("Mapping failed to evaluate", exc=exc, mapping=mapping)
                 continue

passbook/sources/ldap/forms.py

@@ -5,6 +5,7 @@ from django.contrib.admin.widgets import FilteredSelectMultiple
 from django.utils.translation import gettext_lazy as _
 
 from passbook.admin.forms.source import SOURCE_FORM_FIELDS
+from passbook.core.expression import PropertyMappingEvaluator
 from passbook.sources.ldap.models import LDAPPropertyMapping, LDAPSource
 
 
@@ -52,6 +53,13 @@ class LDAPPropertyMappingForm(forms.ModelForm):
 
     template_name = "ldap/property_mapping_form.html"
 
+    def clean_expression(self):
+        """Test Syntax"""
+        expression = self.cleaned_data.get("expression")
+        evaluator = PropertyMappingEvaluator()
+        evaluator.validate(expression)
+        return expression
+
     class Meta:
 
         model = LDAPPropertyMapping

passbook/sources/ldap/migrations/0003_default_ldap_property_mappings.py

@@ -7,11 +7,11 @@ from django.db import migrations
 def create_default_ad_property_mappings(apps: Apps, schema_editor):
     LDAPPropertyMapping = apps.get_model("passbook_sources_ldap", "LDAPPropertyMapping")
     mapping = {
-        "name": "{{ ldap.name }}",
-        "first_name": "{{ ldap.givenName }}",
-        "last_name": "{{ ldap.sn }}",
-        "username": "{{ ldap.sAMAccountName }}",
-        "email": "{{ ldap.mail }}",
+        "name": "return ldap.get('name')",
+        "first_name": "return ldap.get('givenName')",
+        "last_name": "return ldap.get('sn')",
+        "username": "return ldap.get('sAMAccountName')",
+        "email": "return ldap.get('mail')",
     }
     db_alias = schema_editor.connection.alias
     for object_field, expression in mapping.items():