import json
from typing import Any, Dict, Optional, Union
from .claims import Claims
from .const import CWT_CLAIM_NAMES
from .key_builder import KeyBuilder
[docs]class ClaimsBuilder:
"""
CBOR Web Token (CWT) Claims Builder.
``cwt.claims`` is a global object of this class initialized with default settings.
"""
[docs] def __init__(self, options: Optional[Dict[str, Any]] = None):
"""
Constructor.
At the current implementation, any ``options`` will be ignored.
"""
self._options = options
self._key_builder = KeyBuilder()
self._private_claim_names: Dict[str, int] = {}
self._claim_names = dict(CWT_CLAIM_NAMES, **self._private_claim_names)
return
[docs] def from_dict(self, claims: Dict[int, Any]) -> Claims:
"""
Create a Claims object from a CBOR-like(Dict[int, Any]) claim object.
Args:
claims (Dict[str, Any]): A CBOR-like(Dict[int, Any]) claim object.
Returns:
Claims: A CWT claims object.
Raises:
ValueError: Invalid arguments.
"""
return Claims(claims, self._claim_names)
[docs] def from_json(self, claims: Union[str, bytes, Dict[str, Any]]) -> Claims:
"""
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,
it will be skipped.
Args:
claims (Union[str, bytes, Dict[str, Any]]): A JWT claims object
to be converted.
Returns:
Claims: A CWT claims object.
Raises:
ValueError: Invalid arguments.
"""
json_claims: Dict[str, Any] = {}
if isinstance(claims, str) or isinstance(claims, bytes):
json_claims = json.loads(claims)
else:
json_claims = claims
for k in json_claims:
if not isinstance(k, int):
break
raise ValueError("It is already CBOR-like format.")
# Convert JSON to CBOR (Convert the type of key from str to int).
cbor_claims: Dict[int, Any] = {}
for k, v in json_claims.items():
if k not in CWT_CLAIM_NAMES:
if k in self._private_claim_names:
cbor_claims[self._private_claim_names[k]] = v
elif k == "cnf":
if not isinstance(v, dict):
raise ValueError("cnf value should be dict.")
if "jwk" in v:
key = self._key_builder.from_jwk(v["jwk"])
cbor_claims[CWT_CLAIM_NAMES[k]] = {1: key.to_dict()}
elif "eck" in v:
cbor_claims[CWT_CLAIM_NAMES[k]] = {2: v["eck"]}
elif "kid" in v:
cbor_claims[CWT_CLAIM_NAMES[k]] = {3: v["kid"].encode("utf-8")}
else:
raise ValueError("Supported cnf value not found.")
else:
cbor_claims[CWT_CLAIM_NAMES[k]] = v
# Convert test string should be bstr into bstr.
# -259: EUPHNonce
# -258: EATMAROEPrefix
# 7: cti
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 Claims(cbor_claims, self._claim_names)
[docs] def set_private_claim_names(self, claim_names: Dict[str, int]):
"""
Sets private claim definitions. The definitions will be used
in :func:`from_json <cwt.ClaimsBuilder.from_json>`.
Args:
claims (Dict[str, int]): A set of private claim definitions which
consist of a readable claim name(str) and a claim key(int).
The claim key should be less than -65536 but you can use the
numbers other than pre-registered numbers listed in
`IANA Registry <https://www.iana.org/assignments/cose/cose.xhtml>`_.
Raises:
ValueError: Invalid arguments.
"""
for v in claim_names.values():
if v in CWT_CLAIM_NAMES.values():
raise ValueError(
"The claim key should be other than the values listed in https://python-cwt.readthedocs.io/en/stable/claims.html."
)
self._private_claim_names = claim_names
self._claim_names = dict(CWT_CLAIM_NAMES, **self._private_claim_names)
return
[docs] def validate(self, claims: Dict[int, Any]):
"""
Validates a CWT claims object.
Args:
claims (Dict[int, Any]): A CWT claims object to be validated.
Raises:
ValueError: Failed to verify.
"""
Claims(claims)
return
# export
claims = ClaimsBuilder()