Merge "s3api: Prevent XXE injections" into stable/ussuristable/ussuri

3 files changed, 274 insertions, 1 deletions

diff --git a/swift/common/middleware/s3api/etree.py b/swift/common/middleware/s3api/etree.py
index 29adbc38e..49be30810 100644
--- a/swift/common/middleware/s3api/etree.py
+++ b/swift/common/middleware/s3api/etree.py
@@ -130,7 +130,7 @@ class _Element(lxml.etree.ElementBase):
 
 
 parser_lookup = lxml.etree.ElementDefaultClassLookup(element=_Element)
-parser = lxml.etree.XMLParser()
+parser = lxml.etree.XMLParser(resolve_entities=False, no_network=True)
 parser.set_element_class_lookup(parser_lookup)
 
 Element = parser.makeelement
diff --git a/test/functional/s3api/test_xxe_injection.py b/test/functional/s3api/test_xxe_injection.py
new file mode 100644
index 000000000..46297a968
--- /dev/null
+++ b/test/functional/s3api/test_xxe_injection.py
@@ -0,0 +1,233 @@
+#!/usr/bin/env python
+# Copyright (c) 2022 OpenStack Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import requests
+
+import botocore
+
+import test.functional as tf
+from test.functional.s3api import S3ApiBaseBoto3
+
+
+def setUpModule():
+    tf.setup_package()
+
+
+def tearDownModule():
+    tf.teardown_package()
+
+
+class TestS3ApiXxeInjection(S3ApiBaseBoto3):
+
+    def setUp(self):
+        super(TestS3ApiXxeInjection, self).setUp()
+        self.bucket = 'test-s3api-xxe-injection'
+
+    def _create_bucket(self, **kwargs):
+        resp = self.conn.create_bucket(Bucket=self.bucket, **kwargs)
+        response_metadata = resp.pop('ResponseMetadata', {})
+        self.assertEqual(200, response_metadata.get('HTTPStatusCode'))
+
+    @staticmethod
+    def _clear_data(request, **_kwargs):
+        if 'Content-MD5' in request.headers:
+            del request.headers['Content-MD5']
+        request.data = b''
+
+    def _presign_url(self, method, key=None, **kwargs):
+        params = {
+            'Bucket': self.bucket
+        }
+        if key:
+            params['Key'] = key
+        params.update(kwargs)
+        try:
+            # https://github.com/boto/boto3/issues/2192
+            self.conn.meta.events.register(
+                'before-sign.s3.*', self._clear_data)
+            return self.conn.generate_presigned_url(
+                method, Params=params, ExpiresIn=60)
+        finally:
+            self.conn.meta.events.unregister(
+                'before-sign.s3.*', self._clear_data)
+
+    def test_put_bucket_acl(self):
+        if not tf.cluster_info['s3api'].get('s3_acl'):
+            self.skipTest('s3_acl must be enabled')
+
+        self._create_bucket()
+
+        url = self._presign_url('put_bucket_acl')
+        resp = requests.put(url, data="""
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<AccessControlPolicy xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+<Owner>
+    <DisplayName>test:tester</DisplayName>
+    <ID>test:tester</ID>
+</Owner>
+<AccessControlList>
+    <Grant>
+        <Grantee xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="CanonicalUser">
+            <DisplayName>name&xxe;</DisplayName>
+            <ID>id&xxe;</ID>
+        </Grantee>
+        <Permission>WRITE</Permission>
+    </Grant>
+</AccessControlList>
+</AccessControlPolicy>
+""")  # noqa: E501
+        self.assertEqual(200, resp.status_code)
+        self.assertNotIn(b'xxe', resp.content)
+        self.assertNotIn(b'[swift-hash]', resp.content)
+
+        acl = self.conn.get_bucket_acl(Bucket=self.bucket)
+        response_metadata = acl.pop('ResponseMetadata', {})
+        self.assertEqual(200, response_metadata.get('HTTPStatusCode'))
+        self.assertDictEqual({
+            'Owner': {
+                'DisplayName': 'test:tester',
+                'ID': 'test:tester'
+            },
+            'Grants': [
+                {
+                    'Grantee': {
+                        'DisplayName': 'id',
+                        'ID': 'id',
+                        'Type': 'CanonicalUser'
+                    },
+                    'Permission': 'WRITE'
+                }
+            ]
+        }, acl)
+
+    def test_create_bucket(self):
+        url = self._presign_url('create_bucket')
+        resp = requests.put(url, data="""
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<CreateBucketConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+    <LocationConstraint>&xxe;</LocationConstraint>
+</CreateBucketConfiguration>
+""")  # noqa: E501
+        self.assertEqual(400, resp.status_code)
+        self.assertNotIn(b'xxe', resp.content)
+        self.assertNotIn(b'[swift-hash]', resp.content)
+
+        self.assertRaisesRegexp(
+            botocore.exceptions.ClientError, 'Not Found',
+            self.conn.head_bucket, Bucket=self.bucket)
+
+    def test_delete_objects(self):
+        self._create_bucket()
+
+        url = self._presign_url(
+            'delete_objects',
+            Delete={
+                'Objects': [
+                    {
+                        'Key': 'string',
+                        'VersionId': 'string'
+                    }
+                ]
+            })
+        body = """
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<Delete xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+    <Object>
+        <Key>&xxe;</Key>
+    </Object>
+</Delete>
+"""
+        body = body.encode('utf-8')
+        resp = requests.post(url, data=body)
+        self.assertEqual(400, resp.status_code, resp.content)
+        self.assertNotIn(b'xxe', resp.content)
+        self.assertNotIn(b'[swift-hash]', resp.content)
+
+    def test_complete_multipart_upload(self):
+        self._create_bucket()
+
+        resp = self.conn.create_multipart_upload(
+            Bucket=self.bucket, Key='test')
+        response_metadata = resp.pop('ResponseMetadata', {})
+        self.assertEqual(200, response_metadata.get('HTTPStatusCode'))
+        uploadid = resp.get('UploadId')
+
+        try:
+            url = self._presign_url(
+                'complete_multipart_upload',
+                Key='key',
+                MultipartUpload={
+                    'Parts': [
+                        {
+                            'ETag': 'string',
+                            'PartNumber': 1
+                        }
+                    ],
+                },
+                UploadId=uploadid)
+            resp = requests.post(url, data="""
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<CompleteMultipartUpload xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+   <Part>
+      <ETag>"{uploadid}"</ETag>
+      <PartNumber>&xxe;</PartNumber>
+   </Part>
+</CompleteMultipartUpload>
+""")  # noqa: E501
+            self.assertEqual(404, resp.status_code)
+            self.assertNotIn(b'xxe', resp.content)
+            self.assertNotIn(b'[swift-hash]', resp.content)
+
+            resp = requests.post(url, data="""
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<CompleteMultipartUpload xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+   <Part>
+      <ETag>"&xxe;"</ETag>
+      <PartNumber>1</PartNumber>
+   </Part>
+</CompleteMultipartUpload>
+""")  # noqa: E501
+            self.assertEqual(404, resp.status_code)
+            self.assertNotIn(b'xxe', resp.content)
+            self.assertNotIn(b'[swift-hash]', resp.content)
+        finally:
+            resp = self.conn.abort_multipart_upload(
+                Bucket=self.bucket, Key='test', UploadId=uploadid)
+            response_metadata = resp.pop('ResponseMetadata', {})
+            self.assertEqual(204, response_metadata.get('HTTPStatusCode'))
+
+    def test_put_bucket_versioning(self):
+        self._create_bucket()
+
+        url = self._presign_url(
+            'put_bucket_versioning',
+            VersioningConfiguration={
+                'Status': 'Enabled'
+            })
+        resp = requests.put(url, data="""
+<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/swift/swift.conf"> ]>
+<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
+    <Status>&xxe;</Status>
+</VersioningConfiguration>
+""")  # noqa: E501
+        self.assertEqual(400, resp.status_code)
+        self.assertNotIn(b'xxe', resp.content)
+        self.assertNotIn(b'[swift-hash]', resp.content)
+
+        versioning = self.conn.get_bucket_versioning(Bucket=self.bucket)
+        response_metadata = versioning.pop('ResponseMetadata', {})
+        self.assertEqual(200, response_metadata.get('HTTPStatusCode'))
+        self.assertDictEqual({}, versioning)
diff --git a/test/unit/common/middleware/s3api/test_multi_delete.py b/test/unit/common/middleware/s3api/test_multi_delete.py
index 02ee5d32f..1bff1956d 100644
--- a/test/unit/common/middleware/s3api/test_multi_delete.py
+++ b/test/unit/common/middleware/s3api/test_multi_delete.py
@@ -445,6 +445,7 @@ class TestS3ApiMultiDelete(S3ApiTestCase):
                             body=body)
         status, headers, body = self.call_s3api(req)
         self.assertEqual(status.split()[0], '200')
+        self.assertIn(b'<Error><Key>Key1</Key><Code>Server Error</Code>', body)
 
     def _test_object_multi_DELETE(self, account):
         self.keys = ['Key1', 'Key2']
@@ -500,6 +501,45 @@ class TestS3ApiMultiDelete(S3ApiTestCase):
         elem = fromstring(body)
         self.assertEqual(len(elem.findall('Deleted')), len(self.keys))
 
+    def test_object_multi_DELETE_with_system_entity(self):
+        self.keys = ['Key1', 'Key2']
+        self.swift.register(
+            'DELETE', '/v1/AUTH_test/bucket/%s' % self.keys[0],
+            swob.HTTPNotFound, {}, None)
+        self.swift.register(
+            'DELETE', '/v1/AUTH_test/bucket/%s' % self.keys[1],
+            swob.HTTPNoContent, {}, None)
+
+        elem = Element('Delete')
+        for key in self.keys:
+            obj = SubElement(elem, 'Object')
+            SubElement(obj, 'Key').text = key
+        body = tostring(elem, use_s3ns=False)
+        body = body.replace(
+            b'?>\n',
+            b'?>\n<!DOCTYPE foo '
+            b'[<!ENTITY ent SYSTEM "file:///etc/passwd"> ]>\n',
+        ).replace(b'>Key1<', b'>Key1&ent;<')
+        content_md5 = (
+            base64.b64encode(md5(body).digest())
+            .strip())
+
+        req = Request.blank('/bucket?delete',
+                            environ={'REQUEST_METHOD': 'POST'},
+                            headers={
+                                'Authorization': 'AWS test:full_control:hmac',
+                                'Date': self.get_date_header(),
+                                'Content-MD5': content_md5},
+                            body=body)
+        req.date = datetime.now()
+        req.content_type = 'text/plain'
+
+        status, headers, body = self.call_s3api(req)
+        self.assertEqual(status, '200 OK', body)
+        self.assertIn(b'<Deleted><Key>Key2</Key></Deleted>', body)
+        self.assertNotIn(b'root:/root', body)
+        self.assertIn(b'<Deleted><Key>Key1</Key></Deleted>', body)
+
     def _test_no_body(self, use_content_length=False,
                       use_transfer_encoding=False, string_to_md5=b''):
         content_md5 = base64.b64encode(md5(string_to_md5).digest()).strip()