Merge pull request #115 from dajiaji/add-new

Add new() as constructor.

CHANGES.rst

@@ -4,6 +4,10 @@ Changes
 Unreleased
 ----------
 
+- Introduce new() into CWT/COSE. `#115 <https://github.com/dajiaji/python-cwt/pull/115>`__
+- Rename Claims.from_dict to Claims.new. `#115 <https://github.com/dajiaji/python-cwt/pull/115>`__
+- Rename COSEKey.from_dict to COSEKey.new. `#115 <https://github.com/dajiaji/python-cwt/pull/115>`__
+- Rename Recipient.from_dict to Recipient.new. `#115 <https://github.com/dajiaji/python-cwt/pull/115>`__
 - Add Signer for encode_and_sign function. `#114 <https://github.com/dajiaji/python-cwt/pull/114>`__
 - Divide CWT options into independent parameters. `#113 <https://github.com/dajiaji/python-cwt/pull/113>`__
 

README.md

@@ -68,7 +68,7 @@ decoded = cwt.decode(token, key)
 # }
 
 # If you want to treat the result like a JWT;
-readable = Claims.from_dict(decoded)
+readable = Claims.new(decoded)
 
 # readable.iss == 'coaps://as.example'
 # readable.sub == 'dajiaji'
@@ -228,7 +228,7 @@ raw = cwt.decode(token, public_key)
 # raw[-70002][0] == "bar"
 # raw[-70003]["baz"] == "qux"
 # raw[-70004] == 123
-readable = Claims.from_dict(raw)
+readable = Claims.new(raw)
 # readable.get(-70001) == "foo"
 # readable.get(-70002)[0] == "bar"
 # readable.get(-70003)["baz"] == "qux"
@@ -267,7 +267,7 @@ token = cwt.encode(
     private_key,
 )
 raw = cwt.decode(token, public_key)
-readable = Claims.from_dict(
+readable = Claims.new(
     raw,
     private_claims_names={
         "ext_1": -70001,
@@ -352,10 +352,10 @@ with open("./public_key_of_issuer.pem") as key_file:
 
 # Verifies and decodes the CWT received from the presenter.
 raw = cwt.decode(token, public_key)
-decoded = Claims.from_dict(raw)
+decoded = Claims.new(raw)
 
 # Extracts the PoP key from the CWT.
-extracted_pop_key = COSEKey.from_dict(decoded.cnf)  # = raw[8][1]
+extracted_pop_key = COSEKey.new(decoded.cnf)  # = raw[8][1]
 
 # Then, verifies the message sent by the presenter
 # with the signature which is also sent by the presenter as follows:

cwt/claims.py

@@ -1,11 +1,9 @@
 import json
-from typing import Any, Dict, List, TypeVar, Union
+from typing import Any, Dict, List, Union
 
 from .const import CWT_CLAIM_NAMES
 from .cose_key import COSEKey
 
-T = TypeVar("T", bound="Claims")
-
 
 class Claims:
     """
@@ -71,9 +69,7 @@ def __init__(
         return
 
     @classmethod
-    def from_dict(
-        cls, claims: Dict[int, Any], private_claim_names: Dict[str, int] = {}
-    ) -> Any:
+    def new(cls, claims: Dict[int, Any], private_claim_names: Dict[str, int] = {}):
         """
         Create a Claims object from a CBOR-like(Dict[int, Any]) claim object.
 
@@ -105,7 +101,7 @@ def from_json(
         cls,
         claims: Union[str, bytes, Dict[str, Any]],
         private_claim_names: Dict[str, int] = {},
-    ) -> T:
+    ):
         """
         Converts a JWT claims object into a CWT claims object which has numeric
         keys. If a key string in JSON data cannot be mapped to a numeric key,
@@ -166,7 +162,7 @@ def from_json(
         for i in [-259, -258, 7]:
             if i in cbor_claims and isinstance(cbor_claims[i], str):
                 cbor_claims[i] = cbor_claims[i].encode("utf-8")
-        return cls.from_dict(cbor_claims, private_claim_names)
+        return cls.new(cbor_claims, private_claim_names)
 
     @classmethod
     def validate(cls, claims: Dict[int, Any]):

cwt/cose.py

@@ -20,6 +20,16 @@ class COSE(CBORProcessor):
     def __init__(
         self, alg_auto_inclusion: int = False, kid_auto_inclusion: int = False
     ):
+        if not isinstance(alg_auto_inclusion, bool):
+            raise ValueError("alg_auto_inclusion should be bool.")
+        self._alg_auto_inclusion = alg_auto_inclusion
+
+        if not isinstance(kid_auto_inclusion, bool):
+            raise ValueError("kid_auto_inclusion should be bool.")
+        self._kid_auto_inclusion = kid_auto_inclusion
+
+    @classmethod
+    def new(cls, alg_auto_inclusion: int = False, kid_auto_inclusion: int = False):
         """
         Constructor.
 
@@ -29,13 +39,7 @@ def __init__(
             kid_auto_inclusion(bool): The indicator whether ``kid`` parameter is included
                 in a proper header bucket automatically or not.
         """
-        if not isinstance(alg_auto_inclusion, bool):
-            raise ValueError("alg_auto_inclusion should be bool.")
-        self._alg_auto_inclusion = alg_auto_inclusion
-
-        if not isinstance(kid_auto_inclusion, bool):
-            raise ValueError("kid_auto_inclusion should be bool.")
-        self._kid_auto_inclusion = kid_auto_inclusion
+        return cls(alg_auto_inclusion, kid_auto_inclusion)
 
     def encode_and_mac(
         self,

cwt/cose_key.py

@@ -56,7 +56,7 @@ class COSEKey:
     """
 
     @staticmethod
-    def from_dict(cose_key: Dict[int, Any]) -> COSEKeyInterface:
+    def new(cose_key: Dict[int, Any]) -> COSEKeyInterface:
         """
         Create a COSE key from a CBOR-like dictionary with numeric keys.
 
@@ -148,7 +148,7 @@ def from_symmetric_key(
             except Exception:
                 raise ValueError("Unsupported or unknown key_ops.")
         cose_key[4] = key_ops_labels
-        return cls.from_dict(cose_key)
+        return cls.new(cose_key)
 
     @classmethod
     def from_bytes(cls, key_data: bytes) -> COSEKeyInterface:
@@ -164,7 +164,7 @@ def from_bytes(cls, key_data: bytes) -> COSEKeyInterface:
             DecodeError: Failed to decode the key data.
         """
         cose_key = cbor2.loads(key_data)
-        return cls.from_dict(cose_key)
+        return cls.new(cose_key)
 
     @classmethod
     def from_jwk(cls, data: Union[str, bytes, Dict[str, Any]]) -> COSEKeyInterface:
@@ -270,7 +270,7 @@ def from_jwk(cls, data: Union[str, bytes, Dict[str, Any]]) -> COSEKeyInterface:
             if use != 0:
                 cose_key[4] = []
                 cose_key[4].append(use)
-        return cls.from_dict(cose_key)
+        return cls.new(cose_key)
 
     @classmethod
     def from_pem(
@@ -438,4 +438,4 @@ def from_pem(
                 )
         else:
             raise ValueError(f"Unsupported or unknown key: {type(k)}.")
-        return cls.from_dict(cose_key)
+        return cls.new(cose_key)

cwt/cwt.py

@@ -29,6 +29,25 @@ class CWT(CBORProcessor):
 
     def __init__(
         self, expires_in: int = CWT_DEFAULT_EXPIRES_IN, leeway: int = CWT_DEFAULT_LEEWAY
+    ):
+        if not isinstance(expires_in, int):
+            raise ValueError("expires_in should be int.")
+        if expires_in <= 0:
+            raise ValueError("expires_in should be positive number.")
+        self._expires_in = expires_in
+
+        if not isinstance(leeway, int):
+            raise ValueError("leeway should be int.")
+        if leeway <= 0:
+            raise ValueError("leeway should be positive number.")
+        self._leeway = leeway
+
+        self._cose = COSE(kid_auto_inclusion=True, alg_auto_inclusion=True)
+        self._claim_names: Dict[str, int] = {}
+
+    @classmethod
+    def new(
+        cls, expires_in: int = CWT_DEFAULT_EXPIRES_IN, leeway: int = CWT_DEFAULT_LEEWAY
     ):
         """
         Constructor.
@@ -42,27 +61,14 @@ def __init__(
         Examples:
 
             >>> from cwt import CWT, COSEKey
-            >>> ctx = CWT(expires_in=3600*24, leeway=10)
+            >>> ctx = CWT.new(expires_in=3600*24, leeway=10)
             >>> key = COSEKey.from_symmetric_key(alg="HS256")
             >>> token = ctx.encode(
             ...     {"iss": "coaps://as.example", "sub": "dajiaji", "cti": "123"},
             ...     key,
             ... )
         """
-        if not isinstance(expires_in, int):
-            raise ValueError("expires_in should be int.")
-        if expires_in <= 0:
-            raise ValueError("expires_in should be positive number.")
-        self._expires_in = expires_in
-
-        if not isinstance(leeway, int):
-            raise ValueError("leeway should be int.")
-        if leeway <= 0:
-            raise ValueError("leeway should be positive number.")
-        self._leeway = leeway
-
-        self._cose = COSE(kid_auto_inclusion=True, alg_auto_inclusion=True)
-        self._claim_names: Dict[str, int] = {}
+        return cls(expires_in, leeway)
 
     @property
     def expires_in(self) -> int:
@@ -81,7 +87,7 @@ def leeway(self) -> int:
 
     def encode(
         self,
-        claims: Union[Claims, Dict[str, Any], Dict[int, Any], bytes, str],
+        claims: Union[Claims, Dict[str, Any], Dict[int, Any], bytes],
         key: COSEKeyInterface,
         nonce: bytes = b"",
         recipients: Optional[List[RecipientInterface]] = None,
@@ -101,7 +107,7 @@ def encode(
         parameter set to identify the usage.
 
         Args:
-            claims (Union[Claims, Dict[str, Any], Dict[int, Any], bytes, str]): A CWT
+            claims (Union[Claims, Dict[str, Any], Dict[int, Any], bytes]): A CWT
                 claims object, or a JWT claims object, text string or byte string.
             key (COSEKeyInterface): A COSE key used to generate a MAC for the claims.
             recipients (List[RecipientInterface]): A list of recipient information structures.

cwt/encrypted_cose_key.py

@@ -75,4 +75,4 @@ def to_cose_key(
             VerifyError: Failed to verify the COSE key.
         """
         res = cbor2.loads(COSE().decode(CBORTag(16, key), encryption_key))
-        return COSEKey.from_dict(res)
+        return COSEKey.new(res)

cwt/recipient.py

@@ -19,7 +19,7 @@ class Recipient:
     """
 
     @classmethod
-    def from_dict(
+    def new(
         cls,
         protected: dict = {},
         unprotected: dict = {},
@@ -120,4 +120,4 @@ def from_json(cls, data: Union[str, bytes, Dict[str, Any]]) -> RecipientInterfac
                 raise ValueError("k should be str.")
             key = base64url_decode(recipient["k"])
 
-        return cls.from_dict(protected, unprotected, key_ops=key_ops, key=key)
+        return cls.new(protected, unprotected, key_ops=key_ops, key=key)

cwt/recipients.py

@@ -42,13 +42,13 @@ def _create_recipient(cls, recipient: List[Any]) -> RecipientInterface:
         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])
+            return Recipient.new(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)
+        return Recipient.new(protected, recipient[1], recipient[2], recipients)
 
     def derive_key(
         self,