Current File : //lib/python3/dist-packages/pymacaroons/serializers/json_serializer.py
import binascii
import json
from pymacaroons import utils
class JsonSerializer(object):
'''Serializer used to produce JSON macaroon format v1.
'''
def serialize(self, m):
'''Serialize the macaroon in JSON format indicated by the version field.
@param macaroon the macaroon to serialize.
@return JSON macaroon.
'''
from pymacaroons import macaroon
if m.version == macaroon.MACAROON_V1:
return self._serialize_v1(m)
return self._serialize_v2(m)
def _serialize_v1(self, macaroon):
'''Serialize the macaroon in JSON format v1.
@param macaroon the macaroon to serialize.
@return JSON macaroon.
'''
serialized = {
'identifier': utils.convert_to_string(macaroon.identifier),
'signature': macaroon.signature,
}
if macaroon.location:
serialized['location'] = macaroon.location
if macaroon.caveats:
serialized['caveats'] = [
_caveat_v1_to_dict(caveat) for caveat in macaroon.caveats
]
return json.dumps(serialized)
def _serialize_v2(self, macaroon):
'''Serialize the macaroon in JSON format v2.
@param macaroon the macaroon to serialize.
@return JSON macaroon in v2 format.
'''
serialized = {}
_add_json_binary_field(macaroon.identifier_bytes, serialized, 'i')
_add_json_binary_field(binascii.unhexlify(macaroon.signature_bytes),
serialized, 's')
if macaroon.location:
serialized['l'] = macaroon.location
if macaroon.caveats:
serialized['c'] = [
_caveat_v2_to_dict(caveat) for caveat in macaroon.caveats
]
return json.dumps(serialized)
def deserialize(self, serialized):
'''Deserialize a JSON macaroon depending on the format.
@param serialized the macaroon in JSON format.
@return the macaroon object.
'''
deserialized = json.loads(serialized)
if deserialized.get('identifier') is None:
return self._deserialize_v2(deserialized)
else:
return self._deserialize_v1(deserialized)
def _deserialize_v1(self, deserialized):
'''Deserialize a JSON macaroon in v1 format.
@param serialized the macaroon in v1 JSON format.
@return the macaroon object.
'''
from pymacaroons.macaroon import Macaroon, MACAROON_V1
from pymacaroons.caveat import Caveat
caveats = []
for c in deserialized.get('caveats', []):
caveat = Caveat(
caveat_id=c['cid'],
verification_key_id=(
utils.raw_b64decode(c['vid']) if c.get('vid')
else None
),
location=(
c['cl'] if c.get('cl') else None
),
version=MACAROON_V1
)
caveats.append(caveat)
return Macaroon(
location=deserialized.get('location'),
identifier=deserialized['identifier'],
caveats=caveats,
signature=deserialized['signature'],
version=MACAROON_V1
)
def _deserialize_v2(self, deserialized):
'''Deserialize a JSON macaroon v2.
@param serialized the macaroon in JSON format v2.
@return the macaroon object.
'''
from pymacaroons.macaroon import Macaroon, MACAROON_V2
from pymacaroons.caveat import Caveat
caveats = []
for c in deserialized.get('c', []):
caveat = Caveat(
caveat_id=_read_json_binary_field(c, 'i'),
verification_key_id=_read_json_binary_field(c, 'v'),
location=_read_json_binary_field(c, 'l'),
version=MACAROON_V2
)
caveats.append(caveat)
return Macaroon(
location=_read_json_binary_field(deserialized, 'l'),
identifier=_read_json_binary_field(deserialized, 'i'),
caveats=caveats,
signature=binascii.hexlify(
_read_json_binary_field(deserialized, 's')),
version=MACAROON_V2
)
def _caveat_v1_to_dict(c):
''' Return a caveat as a dictionary for export as the JSON
macaroon v1 format.
'''
serialized = {}
if len(c.caveat_id) > 0:
serialized['cid'] = c.caveat_id
if c.verification_key_id:
serialized['vid'] = utils.raw_urlsafe_b64encode(
c.verification_key_id).decode('utf-8')
if c.location:
serialized['cl'] = c.location
return serialized
def _caveat_v2_to_dict(c):
''' Return a caveat as a dictionary for export as the JSON
macaroon v2 format.
'''
serialized = {}
if len(c.caveat_id_bytes) > 0:
_add_json_binary_field(c.caveat_id_bytes, serialized, 'i')
if c.verification_key_id:
_add_json_binary_field(c.verification_key_id, serialized, 'v')
if c.location:
serialized['l'] = c.location
return serialized
def _add_json_binary_field(b, serialized, field):
''' Set the given field to the given val (a bytearray) in the serialized
dictionary.
If the value isn't valid utf-8, we base64 encode it and use field+"64"
as the field name.
'''
try:
val = b.decode("utf-8")
serialized[field] = val
except UnicodeDecodeError:
val = utils.raw_urlsafe_b64encode(b).decode('utf-8')
serialized[field + '64'] = val
def _read_json_binary_field(deserialized, field):
''' Read the value of a JSON field that may be string or base64-encoded.
'''
val = deserialized.get(field)
if val is not None:
return utils.convert_to_bytes(val)
val = deserialized.get(field + '64')
if val is None:
return None
return utils.raw_urlsafe_b64decode(val)
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