Support arbitrary entity attributes

Introduce new configuration option `entity_attributes` that defines a list of
dictionaries each of which represents an <Attribute> element. Each dicrionary has fields
for the NameFormat, the Name, the FriendName and a list of strings that are used to
create <AttributeValue> elements, each with the string as the text node.

    "entity_attributes": [
      {
        "name_format": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri",
        "name": "urn:oasis:names:tc:SAML:profiles:subject-id:req",
        # "friendly_name" is not set
        "values": ["any"],
      },
    ]

Signed-off-by: Ivan Kanakarakis <ivan.kanak@gmail.com>

5 files changed, 116 insertions, 23 deletions

diff --git a/docs/howto/config.rst b/docs/howto/config.rst
index 9f20eba6..a46927a4 100644
--- a/docs/howto/config.rst
+++ b/docs/howto/config.rst
@@ -76,6 +76,29 @@ if you need to include a certificate chain.
 
 Each entry in *additional_cert_files* must be a PEM formatted file with a single certificate.
 
+entity_attributes
+^^^^^^^^^^^^^^^^^
+
+Generates an ``Attribute`` element with the given NameFormat, Name, FriendlyName and
+values, each as an ``AttributeValue`` element.
+
+The element is added under the generated metadata ``EntityDescriptor`` as an
+``Extension`` element under the ``EntityAttributes`` element.
+
+And omit
+
+Example::
+
+    "entity_attributes": [
+      {
+        "name_format": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri",
+        "name": "urn:oasis:names:tc:SAML:profiles:subject-id:req",
+        # "friendly_name" is not set
+        "values": ["any"],
+      },
+    ]
+
+
 assurance_certification
 ^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/src/saml2/config.py b/src/saml2/config.py
index 278aba16..dbf57aa3 100644
--- a/src/saml2/config.py
+++ b/src/saml2/config.py
@@ -54,6 +54,7 @@ COMMON_ARGS = [
     "preferred_binding",
     "session_storage",
     "assurance_certification",
+    "entity_attributes",
     "entity_category",
     "entity_category_support",
     "xmlsec_path",
@@ -226,6 +227,7 @@ class Config(object):
         self.domain = ""
         self.name_qualifier = ""
         self.assurance_certification = []
+        self.entity_attributes = []
         self.entity_category = []
         self.entity_category_support = []
         self.crypto_backend = 'xmlsec1'
diff --git a/src/saml2/metadata.py b/src/saml2/metadata.py
index d80b41ac..50b4ff71 100644
--- a/src/saml2/metadata.py
+++ b/src/saml2/metadata.py
@@ -708,6 +708,24 @@ def entity_descriptor(confd):
     if confd.contact_person is not None:
         entd.contact_person = do_contact_persons_info(confd.contact_person)
 
+    if confd.entity_attributes:
+        if not entd.extensions:
+            entd.extensions = md.Extensions()
+        attributes = [
+            Attribute(
+                name_format=attr.get("format"),
+                name=attr.get("name"),
+                friendly_name=attr.get("friendly_name"),
+                attribute_value=[
+                    AttributeValue(text=value)
+                    for value in attr.get("values", [])
+                ],
+            )
+            for attr in confd.entity_attributes
+        ]
+        for attribute in attributes:
+            _add_attr_to_entity_attributes(entd.extensions, attribute)
+
     if confd.assurance_certification:
         if not entd.extensions:
             entd.extensions = md.Extensions()
diff --git a/tests/sp_mdext_conf.py b/tests/sp_mdext_conf.py
index b1f0cf42..2fe43390 100644
--- a/tests/sp_mdext_conf.py
+++ b/tests/sp_mdext_conf.py
@@ -3,6 +3,20 @@ from pathutils import full_path, xmlsec_path
 CONFIG = {
     "entityid": "urn:mace:example.com:saml:roland:sp",
     "name": "urn:mace:example.com:saml:roland:sp",
+    "entity_attributes": [
+        {
+            "name_format": "urn:oasis:names:tc:SAML:2.0:attrname-format:uri",
+            "name": "urn:oasis:names:tc:SAML:profiles:subject-id:req",
+            # "friendly_name" is not set
+            "values": ["any"],
+        },
+        {
+            "name": "somename",
+            "friendly_name": "somefriendlyname",
+            "name_format": "format",
+            "values": ["x", "y", "z"],
+        },
+    ],
     "description": "My own SP",
     "service": {
         "sp": {
diff --git a/tests/test_83_md_extensions.py b/tests/test_83_md_extensions.py
index dace10a5..35098595 100644
--- a/tests/test_83_md_extensions.py
+++ b/tests/test_83_md_extensions.py
@@ -1,27 +1,63 @@
+from saml2 import create_class_from_xml_string as parse_str_as
+from saml2 import create_class_from_element_tree as parse_element_as
 from saml2.config import Config
-from saml2.metadata import entity_descriptor
 from saml2.extension.sp_type import SPType
+from saml2.metadata import Attribute
+from saml2.metadata import entity_descriptor
 
-__author__ = 'roland'
-
-fil = "sp_mdext_conf.py"
-
-cnf = Config().load_file(fil, metadata_construction=True)
-ed = entity_descriptor(cnf)
-
-print(ed)
-
-assert ed.spsso_descriptor.extensions
-assert len(ed.spsso_descriptor.extensions.extension_elements) == 3
-
-assert ed.extensions
-assert len(ed.extensions.extension_elements) > 1
-
-assert any(e.tag is SPType.c_tag for e in ed.extensions.extension_elements)
-
-cnf.setattr('sp', 'sp_type_in_metadata', False)
-ed = entity_descriptor(cnf)
-
-print(ed)
 
-assert all(e.tag is not SPType.c_tag for e in ed.extensions.extension_elements)
+class TestMDExt():
+    def test_sp_type_true(self):
+        fil = "sp_mdext_conf.py"
+        cnf = Config().load_file(fil, metadata_construction=True)
+        ed = entity_descriptor(cnf)
+
+        assert ed.spsso_descriptor.extensions
+        assert len(ed.spsso_descriptor.extensions.extension_elements) == 3
+        assert ed.extensions
+        assert len(ed.extensions.extension_elements) > 1
+        assert any(e.tag is SPType.c_tag for e in ed.extensions.extension_elements)
+
+    def test_sp_type_false(self):
+        fil = "sp_mdext_conf.py"
+        cnf = Config().load_file(fil, metadata_construction=True)
+        cnf.setattr('sp', 'sp_type_in_metadata', False)
+        ed = entity_descriptor(cnf)
+
+        assert all(e.tag is not SPType.c_tag for e in ed.extensions.extension_elements)
+
+    def test_entity_attributes(self):
+        fil = "sp_mdext_conf.py"
+        cnf = Config().load_file(fil, metadata_construction=True)
+        ed = entity_descriptor(cnf)
+
+        entity_attributes = next(
+            e
+            for e in ed.extensions.extension_elements
+            if e.tag == 'EntityAttributes'
+        )
+        attributes = [
+            parse_str_as(Attribute, e.to_string())
+            for e in entity_attributes.children
+        ]
+        assert all(
+            a.name in [
+                "urn:oasis:names:tc:SAML:profiles:subject-id:req",
+                "somename",
+            ]
+            for a in attributes
+        )
+
+        import saml2.attribute_converter
+        attrc = saml2.attribute_converter.ac_factory()
+
+        import saml2.mdstore
+        mds = saml2.mdstore.MetadataStore(attrc, cnf)
+
+        mds.load("inline", ed.to_string())
+        entityid = ed.entity_id
+        entity_attributes = mds.entity_attributes(entityid)
+        assert entity_attributes == {
+            'urn:oasis:names:tc:SAML:profiles:subject-id:req': ['any'],
+            'somename': ['x', 'y', 'z'],
+        }