Merge RecipientsBuilder into Recipients.

CHANGES.rst

@@ -4,9 +4,13 @@ Changes
 Unreleased
 ----------
 
-- Rename RecipientBuilder to COSERecipient. `#99 <https://github.com/dajiaji/python-cwt/pull/99>`__
+- Merge RecipientsBuilder into Recipients. `#103 <https://github.com/dajiaji/python-cwt/pull/103>`__
+- Rename Key to COSEKeyInterface. `#102 <https://github.com/dajiaji/python-cwt/pull/102>`__
+- Rename RecipientBuilder to Recipient. `#101 <https://github.com/dajiaji/python-cwt/pull/101>`__
+- Make Key private. `#100 <https://github.com/dajiaji/python-cwt/pull/100>`__
 - Merge ClaimsBuilder into Claims. `#98 <https://github.com/dajiaji/python-cwt/pull/98>`__
 - Rename KeyBuilder to COSEKey. `#97 <https://github.com/dajiaji/python-cwt/pull/97>`__
+- Rename COSEKey to Key. `#97 <https://github.com/dajiaji/python-cwt/pull/97>`__
 - Add support for external AAD. `#94 <https://github.com/dajiaji/python-cwt/pull/94>`__
 - Make unwrap_key return COSEKey. `#93 <https://github.com/dajiaji/python-cwt/pull/93>`__
 - Fix default HMAC key size. `#91 <https://github.com/dajiaji/python-cwt/pull/91>`__

cwt/cose.py

@@ -6,7 +6,7 @@
 from .const import COSE_ALGORITHMS_RECIPIENT
 from .cose_key_interface import COSEKeyInterface
 from .recipient_interface import RecipientInterface
-from .recipients_builder import RecipientsBuilder
+from .recipients import Recipients
 
 
 class COSE(CBORProcessor):
@@ -26,7 +26,6 @@ def __init__(self, options: Optional[Dict[str, Any]] = None):
                 of COSE. At this time, ``kid_auto_inclusion`` (default value: ``True``)
                 and ``alg_auto_inclusion`` (default value: ``True``) are supported.
         """
-        self._recipients_builder = RecipientsBuilder()
         self._kid_auto_inclusion = True
         self._alg_auto_inclusion = True
         if not options:
@@ -342,7 +341,7 @@ def decode(
             if not isinstance(unprotected, dict):
                 raise ValueError("unprotected header should be dict.")
             nonce = unprotected.get(5, None)
-            recipients = self._recipients_builder.from_list(data.value[3])
+            recipients = Recipients.from_list(data.value[3])
             enc_key = (
                 recipients.derive_key(keys=keys, alg_hint=alg_hint)
                 if key is not None
@@ -379,7 +378,7 @@ def decode(
                     if isinstance(protected, dict) and 1 in protected
                     else 0
                 )
-            recipients = self._recipients_builder.from_list(data.value[4])
+            recipients = Recipients.from_list(data.value[4])
             mac_auth_key = recipients.derive_key(keys=keys, alg_hint=alg_hint)
             mac_auth_key.verify(to_be_maced, data.value[3])
             return data.value[2]

cwt/recipients.py

@@ -1,13 +1,15 @@
-from typing import List, Optional
+from typing import Any, List, Optional
+
+import cbor2
 
-from .cbor_processor import CBORProcessor
 from .const import COSE_ALGORITHMS_KEY_WRAP
 from .cose_key_interface import COSEKeyInterface
+from .recipient import Recipient
 from .recipient_interface import RecipientInterface
 from .utils import base64url_decode, to_cis
 
 
-class Recipients(CBORProcessor):
+class Recipients:
     """
     A Set of COSE Recipients.
     """
@@ -16,6 +18,38 @@ def __init__(self, recipients: List[RecipientInterface]):
         self._recipients = recipients
         return
 
+    @classmethod
+    def from_list(cls, recipients: List[Any]):
+        """
+        Create Recipients from a CBOR-like list.
+        """
+        res: List[RecipientInterface] = []
+        for r in recipients:
+            res.append(cls._create_recipient(r))
+        return cls(res)
+
+    @classmethod
+    def _create_recipient(cls, recipient: List[Any]) -> RecipientInterface:
+        if not isinstance(recipient, list) or (
+            len(recipient) != 3 and len(recipient) != 4
+        ):
+            raise ValueError("Invalid recipient format.")
+        if not isinstance(recipient[0], bytes):
+            raise ValueError("protected header should be bytes.")
+        protected = {} if not recipient[0] else cbor2.loads(recipient[0])
+        if not isinstance(recipient[1], dict):
+            raise ValueError("unprotected header should be dict.")
+        if not isinstance(recipient[2], bytes):
+            raise ValueError("ciphertext should be bytes.")
+        if len(recipient) == 3:
+            return Recipient.from_dict(protected, recipient[1], recipient[2])
+        if not isinstance(recipient[3], list):
+            raise ValueError("recipients should be list.")
+        recipients: List[RecipientInterface] = []
+        for r in recipient[3]:
+            recipients.append(cls._create_recipient(r))
+        return Recipient.from_dict(protected, recipient[1], recipient[2], recipients)
+
     def derive_key(
         self,
         keys: Optional[List[COSEKeyInterface]] = None,

tests/test_recipient.py

@@ -12,7 +12,6 @@
 from cwt import COSEKey, Recipient
 from cwt.recipient_interface import RecipientInterface
 from cwt.recipients import Recipients
-from cwt.recipients_builder import RecipientsBuilder
 
 
 @pytest.fixture(scope="session", autouse=True)
@@ -404,34 +403,25 @@ def test_recipients_derive_key_with_different_kid(self):
             pytest.fail("derive_key() should fail.")
         assert "Failed to derive a key." in str(err.value)
 
-
-class TestRecipientsBuilder:
-    """
-    Tests for RecipientsBuilder.
-    """
-
-    def test_recipients_builder_constructor(self):
-        rb = RecipientsBuilder()
-        assert isinstance(rb, RecipientsBuilder)
-
-    def test_recipients_builder_from_list(self):
-        rb = RecipientsBuilder()
+    def test_recipients_from_list(self):
         try:
-            rb.from_list([[cbor2.dumps({1: -10}), {-20: b"aabbccddeefff"}, b""]])
+            Recipients.from_list(
+                [[cbor2.dumps({1: -10}), {-20: b"aabbccddeefff"}, b""]]
+            )
         except Exception:
             pytest.fail("from_list() should not fail.")
 
-    def test_recipients_builder_from_list_with_empty_recipients(self):
-        rb = RecipientsBuilder()
+    def test_recipients_from_list_with_empty_recipients(self):
         try:
-            rb.from_list([[cbor2.dumps({1: -10}), {-20: b"aabbccddeefff"}, b"", []]])
+            Recipients.from_list(
+                [[cbor2.dumps({1: -10}), {-20: b"aabbccddeefff"}, b"", []]]
+            )
         except Exception:
             pytest.fail("from_list() should not fail.")
 
-    def test_recipients_builder_from_list_with_recipients(self):
-        rb = RecipientsBuilder()
+    def test_recipients_from_list_with_recipients(self):
         try:
-            rb.from_list(
+            Recipients.from_list(
                 [
                     [
                         cbor2.dumps({1: -10}),
@@ -455,6 +445,7 @@ def test_recipients_builder_from_list_with_recipients(self):
             ([["", {}, b""]], "protected header should be bytes."),
             ([[{}, {}, b""]], "protected header should be bytes."),
             ([[[], {}, b""]], "protected header should be bytes."),
+            ([[[], {}, b""]], "protected header should be bytes."),
             ([[123, {}, b""]], "protected header should be bytes."),
             ([[b"", [], b""]], "unprotected header should be dict."),
             ([[b"", "", b""]], "unprotected header should be dict."),
@@ -470,9 +461,8 @@ def test_recipients_builder_from_list_with_recipients(self):
             ([[b"", {}, b"", 123]], "recipients should be list."),
         ],
     )
-    def test_recipients_builder_from_list_with_invalid_args(self, invalid, msg):
-        rb = RecipientsBuilder()
+    def test_recipients_from_list_with_invalid_args(self, invalid, msg):
         with pytest.raises(ValueError) as err:
-            rb.from_list(invalid)
+            Recipients.from_list(invalid)
             pytest.fail("derive_key() should fail.")
         assert msg in str(err.value)