diff --git a/CHANGELOG.md b/CHANGELOG.md
index 63c2f0f..3ba3370 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
## [unreleased]
+### Added
+* New style Diaspora private encrypted JSON payloads are now supported in the receiving side. Outbound private Diaspora payloads are still sent as legacy encrypted payloads. ([issue](https://github.com/jaywink/federation/issues/83))
+ * No additional changes need to be made when calling `handle_receive` from your task processing. Just pass in the full received XML or JSON payload as a string with recipient user object as before.
+
### Fixed
* Fix getting sender from a combination of legacy Diaspora encrypted payload and new entity names (for example `author`). This combination probably only existed in this library.
* Correctly extend entity `_children`. Certain Diaspora payloads caused `_children` for an entity to be written over by an empty list, causing for example status message photos to not be saved. Correctly do an extend on it. ([issue](https://github.com/jaywink/federation/issues/89))
@@ -9,6 +13,7 @@
### Removed
* `Post.photos` entity attribute was never used by any code and has been removed. Child entities of type `Image` are stored in the `Post._children` as before.
+* Removed deprecated user private key lookup using `user.key` in Diaspora receive processing. Passed in `user` objects must now have a `private_key` attribute.
## [0.12.0] - 2017-05-22
diff --git a/federation/protocols/base.py b/federation/protocols/base.py
index 0f48de3..e298ce0 100644
--- a/federation/protocols/base.py
+++ b/federation/protocols/base.py
@@ -37,7 +37,7 @@ class BaseProtocol(object):
"""
raise NotImplementedError("Implement in subclass")
- def receive(self, payload, user=None, sender_key_fetcher=None, *args, **kwargs):
+ def receive(self, payload, user=None, sender_key_fetcher=None):
"""Receive a payload.
Args:
diff --git a/federation/protocols/diaspora/encrypted.py b/federation/protocols/diaspora/encrypted.py
new file mode 100644
index 0000000..ccf23a4
--- /dev/null
+++ b/federation/protocols/diaspora/encrypted.py
@@ -0,0 +1,30 @@
+import json
+from base64 import b64decode
+
+from Crypto.Cipher import PKCS1_v1_5, AES
+from lxml import etree
+
+
+def pkcs7_unpad(data):
+ """Remove the padding bytes that were added at point of encryption."""
+ if isinstance(data, str):
+ return data[0:-ord(data[-1])]
+ else:
+ return data[0:-data[-1]]
+
+
+class EncryptedPayload:
+ """Diaspora encrypted JSON payloads."""
+
+ @staticmethod
+ def decrypt(payload, private_key):
+ """Decrypt an encrypted JSON payload and return the Magic Envelope document inside."""
+ cipher = PKCS1_v1_5.new(private_key)
+ aes_key_str = cipher.decrypt(b64decode(payload.get("aes_key")), sentinel=None)
+ aes_key = json.loads(aes_key_str.decode("utf-8"))
+ key = b64decode(aes_key.get("key"))
+ iv = b64decode(aes_key.get("iv"))
+ encrypted_magic_envelope = b64decode(payload.get("encrypted_magic_envelope"))
+ encrypter = AES.new(key, AES.MODE_CBC, iv)
+ content = encrypter.decrypt(encrypted_magic_envelope)
+ return etree.fromstring(pkcs7_unpad(content))
diff --git a/federation/protocols/diaspora/magic_envelope.py b/federation/protocols/diaspora/magic_envelope.py
index ff9cc13..46a9a08 100644
--- a/federation/protocols/diaspora/magic_envelope.py
+++ b/federation/protocols/diaspora/magic_envelope.py
@@ -8,7 +8,7 @@ from lxml import etree
NAMESPACE = "http://salmon-protocol.org/ns/magic-env"
-class MagicEnvelope():
+class MagicEnvelope:
"""Diaspora protocol magic envelope.
See: http://diaspora.github.io/diaspora_federation/federation/magicsig.html
diff --git a/federation/protocols/diaspora/protocol.py b/federation/protocols/diaspora/protocol.py
index e65d3ef..73c417e 100644
--- a/federation/protocols/diaspora/protocol.py
+++ b/federation/protocols/diaspora/protocol.py
@@ -1,6 +1,5 @@
import json
import logging
-import warnings
from base64 import b64decode, urlsafe_b64decode, b64encode, urlsafe_b64encode
from urllib.parse import unquote_plus
@@ -13,7 +12,9 @@ from lxml import etree
from federation.exceptions import EncryptedMessageError, NoSenderKeyFoundError, SignatureVerificationError
from federation.protocols.base import BaseProtocol
+from federation.protocols.diaspora.encrypted import EncryptedPayload
from federation.protocols.diaspora.magic_envelope import MagicEnvelope
+from federation.utils.text import decode_if_bytes
logger = logging.getLogger("federation")
@@ -29,7 +30,7 @@ def identify_payload(payload):
"""
# Private encrypted JSON payload
try:
- data = json.loads(payload)
+ data = json.loads(decode_if_bytes(payload))
if "encrypted_magic_envelope" in data:
return True
except Exception:
@@ -55,17 +56,36 @@ class Protocol(BaseProtocol):
Mostly taken from Pyaspora (https://github.com/lukeross/pyaspora).
"""
- def receive(self, payload, user=None, sender_key_fetcher=None, skip_author_verification=False, *args, **kwargs):
+ def __init__(self):
+ super().__init__()
+ self.encrypted = self.legacy = False
+
+ def get_json_payload_magic_envelope(self, payload):
+ """Encrypted JSON payload"""
+ private_key = self._get_user_key(self.user)
+ return EncryptedPayload.decrypt(payload=payload, private_key=private_key)
+
+ def store_magic_envelope_doc(self, payload):
+ """Get the Magic Envelope, trying JSON first."""
+ try:
+ json_payload = json.loads(decode_if_bytes(payload))
+ except ValueError:
+ # XML payload
+ xml = unquote_plus(payload)
+ xml = xml.lstrip().encode("utf-8")
+ logger.debug("diaspora.protocol.store_magic_envelope_doc: xml payload: %s", xml)
+ self.doc = etree.fromstring(xml)
+ else:
+ logger.debug("diaspora.protocol.store_magic_envelope_doc: json payload: %s", json_payload)
+ self.doc = self.get_json_payload_magic_envelope(json_payload)
+
+ def receive(self, payload, user=None, sender_key_fetcher=None, skip_author_verification=False):
"""Receive a payload.
For testing purposes, `skip_author_verification` can be passed. Authorship will not be verified."""
self.user = user
self.get_contact_key = sender_key_fetcher
- # Prepare payload
- xml = unquote_plus(payload)
- xml = xml.lstrip().encode("utf-8")
- logger.debug("diaspora.protocol.receive: xml content: %s", xml)
- self.doc = etree.fromstring(xml)
+ self.store_magic_envelope_doc(payload)
# Check for a legacy header
self.find_header()
# Open payload and get actual message
@@ -78,17 +98,11 @@ class Protocol(BaseProtocol):
return self.sender_handle, self.content
def _get_user_key(self, user):
- if not hasattr(self.user, "private_key") or not self.user.private_key:
- if hasattr(self.user, "key") and self.user.key:
- warnings.warn("Using `key` in user object for private key has been deprecated. Please "
- "have available `private_key` instead. Usage of `key` will be removed after 0.8.0.",
- DeprecationWarning)
- return self.user.key
+ if not getattr(self.user, "private_key", None):
raise EncryptedMessageError("Cannot decrypt private message without user key")
return self.user.private_key
def find_header(self):
- self.encrypted = self.legacy = False
self.header = self.doc.find(".//{"+PROTOCOL_NS+"}header")
if self.header != None:
# Legacy public header found
diff --git a/federation/tests/protocols/diaspora/test_encrypted.py b/federation/tests/protocols/diaspora/test_encrypted.py
new file mode 100644
index 0000000..5d10988
--- /dev/null
+++ b/federation/tests/protocols/diaspora/test_encrypted.py
@@ -0,0 +1,33 @@
+from unittest.mock import patch, Mock
+
+from Crypto.Cipher import AES
+
+from federation.protocols.diaspora.encrypted import pkcs7_unpad, EncryptedPayload
+
+
+def test_pkcs7_unpad():
+ assert pkcs7_unpad(b"foobar\x02\x02") == b"foobar"
+ assert pkcs7_unpad("foobar\x02\x02") == "foobar"
+
+
+class TestEncryptedPayload:
+ @patch("federation.protocols.diaspora.encrypted.PKCS1_v1_5.new")
+ @patch("federation.protocols.diaspora.encrypted.AES.new")
+ @patch("federation.protocols.diaspora.encrypted.pkcs7_unpad", side_effect=lambda x: x)
+ @patch("federation.protocols.diaspora.encrypted.b64decode", side_effect=lambda x: x)
+ def test_decrypt(self, mock_decode, mock_unpad, mock_aes, mock_pkcs1):
+ mock_decrypt = Mock(return_value=b'{"iv": "foo", "key": "bar"}')
+ mock_pkcs1.return_value = Mock(decrypt=mock_decrypt)
+ mock_encrypter = Mock(return_value="bar")
+ mock_aes.return_value = Mock(decrypt=mock_encrypter)
+ doc = EncryptedPayload.decrypt(
+ {"aes_key": '{"iv": "foo", "key": "bar"}', "encrypted_magic_envelope": "magically encrypted"},
+ "private_key",
+ )
+ mock_pkcs1.assert_called_once_with("private_key")
+ mock_decrypt.assert_called_once_with('{"iv": "foo", "key": "bar"}', sentinel=None)
+ assert mock_decode.call_count == 4
+ mock_aes.assert_called_once_with("bar", AES.MODE_CBC, "foo")
+ mock_encrypter.assert_called_once_with("magically encrypted")
+ assert doc.tag == "foo"
+ assert doc.text == "bar"
diff --git a/federation/tests/protocols/diaspora/test_protocol.py b/federation/tests/protocols/diaspora/test_protocol.py
index 3fd5a37..f33a31a 100644
--- a/federation/tests/protocols/diaspora/test_protocol.py
+++ b/federation/tests/protocols/diaspora/test_protocol.py
@@ -155,3 +155,24 @@ class TestDiasporaProtocol(DiasporaTestBase):
data = protocol.build_send(entity, from_user)
mock_init_message.assert_called_once_with(mock_entity_xml, from_user.handle, from_user.private_key)
assert data == {"xml": "xmldata"}
+
+ @patch("federation.protocols.diaspora.protocol.EncryptedPayload.decrypt")
+ def test_get_json_payload_magic_envelope(self, mock_decrypt):
+ protocol = Protocol()
+ protocol.user = MockUser()
+ protocol.get_json_payload_magic_envelope("payload")
+ mock_decrypt.assert_called_once_with(payload="payload", private_key="foobar")
+
+ @patch.object(Protocol, "get_json_payload_magic_envelope", return_value=etree.fromstring("bar"))
+ def test_store_magic_envelope_doc_json_payload(self, mock_store):
+ protocol = Protocol()
+ protocol.store_magic_envelope_doc('{"foo": "bar"}')
+ mock_store.assert_called_once_with({"foo": "bar"})
+ assert protocol.doc.tag == "foo"
+ assert protocol.doc.text == "bar"
+
+ def test_store_magic_envelope_doc_xml_payload(self):
+ protocol = Protocol()
+ protocol.store_magic_envelope_doc("bar")
+ assert protocol.doc.tag == "foo"
+ assert protocol.doc.text == "bar"
diff --git a/federation/tests/utils/test_text.py b/federation/tests/utils/test_text.py
new file mode 100644
index 0000000..7f629d3
--- /dev/null
+++ b/federation/tests/utils/test_text.py
@@ -0,0 +1,6 @@
+from federation.utils.text import decode_if_bytes
+
+
+def test_decode_if_bytes():
+ assert decode_if_bytes(b"foobar") == "foobar"
+ assert decode_if_bytes("foobar") == "foobar"
diff --git a/federation/utils/text.py b/federation/utils/text.py
new file mode 100644
index 0000000..310a5e1
--- /dev/null
+++ b/federation/utils/text.py
@@ -0,0 +1,5 @@
+def decode_if_bytes(text):
+ try:
+ return text.decode("utf-8")
+ except AttributeError:
+ return text