diff options
Diffstat (limited to 'keystone-moon/keystone/token/providers/fernet/token_formatters.py')
| -rw-r--r-- | keystone-moon/keystone/token/providers/fernet/token_formatters.py | 545 |
1 files changed, 545 insertions, 0 deletions
diff --git a/keystone-moon/keystone/token/providers/fernet/token_formatters.py b/keystone-moon/keystone/token/providers/fernet/token_formatters.py new file mode 100644 index 00000000..50960923 --- /dev/null +++ b/keystone-moon/keystone/token/providers/fernet/token_formatters.py @@ -0,0 +1,545 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. + +import base64 +import datetime +import struct +import uuid + +from cryptography import fernet +import msgpack +from oslo_config import cfg +from oslo_log import log +from oslo_utils import timeutils +import six +from six.moves import urllib + +from keystone.auth import plugins as auth_plugins +from keystone import exception +from keystone.i18n import _ +from keystone.token import provider +from keystone.token.providers.fernet import utils + + +CONF = cfg.CONF +LOG = log.getLogger(__name__) + +# Fernet byte indexes as as computed by pypi/keyless_fernet and defined in +# https://github.com/fernet/spec +TIMESTAMP_START = 1 +TIMESTAMP_END = 9 + + +class TokenFormatter(object): + """Packs and unpacks payloads into tokens for transport.""" + + @property + def crypto(self): + """Return a cryptography instance. + + You can extend this class with a custom crypto @property to provide + your own token encoding / decoding. For example, using a different + cryptography library (e.g. ``python-keyczar``) or to meet arbitrary + security requirements. + + This @property just needs to return an object that implements + ``encrypt(plaintext)`` and ``decrypt(ciphertext)``. + + """ + keys = utils.load_keys() + + if not keys: + raise exception.KeysNotFound() + + fernet_instances = [fernet.Fernet(key) for key in utils.load_keys()] + return fernet.MultiFernet(fernet_instances) + + def pack(self, payload): + """Pack a payload for transport as a token.""" + # base64 padding (if any) is not URL-safe + return urllib.parse.quote(self.crypto.encrypt(payload)) + + def unpack(self, token): + """Unpack a token, and validate the payload.""" + token = urllib.parse.unquote(six.binary_type(token)) + + try: + return self.crypto.decrypt(token) + except fernet.InvalidToken as e: + raise exception.Unauthorized(six.text_type(e)) + + @classmethod + def creation_time(cls, fernet_token): + """Returns the creation time of a valid Fernet token.""" + # tokens may be transmitted as Unicode, but they're just ASCII + # (pypi/cryptography will refuse to operate on Unicode input) + fernet_token = six.binary_type(fernet_token) + + # the base64 padding on fernet tokens is made URL-safe + fernet_token = urllib.parse.unquote(fernet_token) + + # fernet tokens are base64 encoded and the padding made URL-safe + token_bytes = base64.urlsafe_b64decode(fernet_token) + + # slice into the byte array to get just the timestamp + timestamp_bytes = token_bytes[TIMESTAMP_START:TIMESTAMP_END] + + # convert those bytes to an integer + # (it's a 64-bit "unsigned long long int" in C) + timestamp_int = struct.unpack(">Q", timestamp_bytes)[0] + + # and with an integer, it's trivial to produce a datetime object + created_at = datetime.datetime.utcfromtimestamp(timestamp_int) + + return created_at + + def create_token(self, user_id, expires_at, audit_ids, methods=None, + domain_id=None, project_id=None, trust_id=None, + federated_info=None): + """Given a set of payload attributes, generate a Fernet token.""" + if trust_id: + version = TrustScopedPayload.version + payload = TrustScopedPayload.assemble( + user_id, + methods, + project_id, + expires_at, + audit_ids, + trust_id) + elif federated_info: + version = FederatedPayload.version + payload = FederatedPayload.assemble( + user_id, + methods, + expires_at, + audit_ids, + federated_info) + elif project_id: + version = ProjectScopedPayload.version + payload = ProjectScopedPayload.assemble( + user_id, + methods, + project_id, + expires_at, + audit_ids) + elif domain_id: + version = DomainScopedPayload.version + payload = DomainScopedPayload.assemble( + user_id, + methods, + domain_id, + expires_at, + audit_ids) + else: + version = UnscopedPayload.version + payload = UnscopedPayload.assemble( + user_id, + methods, + expires_at, + audit_ids) + + versioned_payload = (version,) + payload + serialized_payload = msgpack.packb(versioned_payload) + token = self.pack(serialized_payload) + + return token + + def validate_token(self, token): + """Validates a Fernet token and returns the payload attributes.""" + # Convert v2 unicode token to a string + if not isinstance(token, six.binary_type): + token = token.encode('ascii') + + serialized_payload = self.unpack(token) + versioned_payload = msgpack.unpackb(serialized_payload) + version, payload = versioned_payload[0], versioned_payload[1:] + + # depending on the formatter, these may or may not be defined + domain_id = None + project_id = None + trust_id = None + federated_info = None + + if version == UnscopedPayload.version: + (user_id, methods, expires_at, audit_ids) = ( + UnscopedPayload.disassemble(payload)) + elif version == DomainScopedPayload.version: + (user_id, methods, domain_id, expires_at, audit_ids) = ( + DomainScopedPayload.disassemble(payload)) + elif version == ProjectScopedPayload.version: + (user_id, methods, project_id, expires_at, audit_ids) = ( + ProjectScopedPayload.disassemble(payload)) + elif version == TrustScopedPayload.version: + (user_id, methods, project_id, expires_at, audit_ids, trust_id) = ( + TrustScopedPayload.disassemble(payload)) + elif version == FederatedPayload.version: + (user_id, methods, expires_at, audit_ids, federated_info) = ( + FederatedPayload.disassemble(payload)) + else: + # If the token_format is not recognized, raise Unauthorized. + raise exception.Unauthorized(_( + 'This is not a recognized Fernet payload version: %s') % + version) + + # rather than appearing in the payload, the creation time is encoded + # into the token format itself + created_at = TokenFormatter.creation_time(token) + created_at = timeutils.isotime(at=created_at, subsecond=True) + expires_at = timeutils.parse_isotime(expires_at) + expires_at = timeutils.isotime(at=expires_at, subsecond=True) + + return (user_id, methods, audit_ids, domain_id, project_id, trust_id, + federated_info, created_at, expires_at) + + +class BasePayload(object): + # each payload variant should have a unique version + version = None + + @classmethod + def assemble(cls, *args): + """Assemble the payload of a token. + + :param args: whatever data should go into the payload + :returns: the payload of a token + + """ + raise NotImplementedError() + + @classmethod + def disassemble(cls, payload): + """Disassemble an unscoped payload into the component data. + + :param payload: this variant of payload + :returns: a tuple of the payloads component data + + """ + raise NotImplementedError() + + @classmethod + def convert_uuid_hex_to_bytes(cls, uuid_string): + """Compress UUID formatted strings to bytes. + + :param uuid_string: uuid string to compress to bytes + :returns: a byte representation of the uuid + + """ + # TODO(lbragstad): Wrap this in an exception. Not sure what the case + # would be where we couldn't handle what we've been given but incase + # the integrity of the token has been compromised. + uuid_obj = uuid.UUID(uuid_string) + return uuid_obj.bytes + + @classmethod + def convert_uuid_bytes_to_hex(cls, uuid_byte_string): + """Generate uuid.hex format based on byte string. + + :param uuid_byte_string: uuid string to generate from + :returns: uuid hex formatted string + + """ + # TODO(lbragstad): Wrap this in an exception. Not sure what the case + # would be where we couldn't handle what we've been given but incase + # the integrity of the token has been compromised. + uuid_obj = uuid.UUID(bytes=uuid_byte_string) + return uuid_obj.hex + + @classmethod + def _convert_time_string_to_int(cls, time_string): + """Convert a time formatted string to a timestamp integer. + + :param time_string: time formatted string + :returns: an integer timestamp + + """ + time_object = timeutils.parse_isotime(time_string) + return (timeutils.normalize_time(time_object) - + datetime.datetime.utcfromtimestamp(0)).total_seconds() + + @classmethod + def _convert_int_to_time_string(cls, time_int): + """Convert a timestamp integer to a string. + + :param time_int: integer representing timestamp + :returns: a time formatted strings + + """ + time_object = datetime.datetime.utcfromtimestamp(int(time_int)) + return timeutils.isotime(time_object) + + @classmethod + def attempt_convert_uuid_hex_to_bytes(cls, value): + """Attempt to convert value to bytes or return value. + + :param value: value to attempt to convert to bytes + :returns: uuid value in bytes or value + + """ + try: + return cls.convert_uuid_hex_to_bytes(value) + except ValueError: + # this might not be a UUID, depending on the situation (i.e. + # federation) + return value + + @classmethod + def attempt_convert_uuid_bytes_to_hex(cls, value): + """Attempt to convert value to hex or return value. + + :param value: value to attempt to convert to hex + :returns: uuid value in hex or value + + """ + try: + return cls.convert_uuid_bytes_to_hex(value) + except ValueError: + return value + + +class UnscopedPayload(BasePayload): + version = 0 + + @classmethod + def assemble(cls, user_id, methods, expires_at, audit_ids): + """Assemble the payload of an unscoped token. + + :param user_id: identifier of the user in the token request + :param methods: list of authentication methods used + :param expires_at: datetime of the token's expiration + :param audit_ids: list of the token's audit IDs + :returns: the payload of an unscoped token + + """ + b_user_id = cls.convert_uuid_hex_to_bytes(user_id) + methods = auth_plugins.convert_method_list_to_integer(methods) + expires_at_int = cls._convert_time_string_to_int(expires_at) + b_audit_ids = list(map(provider.random_urlsafe_str_to_bytes, + audit_ids)) + return (b_user_id, methods, expires_at_int, b_audit_ids) + + @classmethod + def disassemble(cls, payload): + """Disassemble an unscoped payload into the component data. + + :param payload: the payload of an unscoped token + :return: a tuple containing the user_id, auth methods, expires_at, and + audit_ids + + """ + user_id = cls.convert_uuid_bytes_to_hex(payload[0]) + methods = auth_plugins.convert_integer_to_method_list(payload[1]) + expires_at_str = cls._convert_int_to_time_string(payload[2]) + audit_ids = list(map(provider.base64_encode, payload[3])) + return (user_id, methods, expires_at_str, audit_ids) + + +class DomainScopedPayload(BasePayload): + version = 1 + + @classmethod + def assemble(cls, user_id, methods, domain_id, expires_at, audit_ids): + """Assemble the payload of a domain-scoped token. + + :param user_id: ID of the user in the token request + :param methods: list of authentication methods used + :param domain_id: ID of the domain to scope to + :param expires_at: datetime of the token's expiration + :param audit_ids: list of the token's audit IDs + :returns: the payload of a domain-scoped token + + """ + b_user_id = cls.convert_uuid_hex_to_bytes(user_id) + methods = auth_plugins.convert_method_list_to_integer(methods) + try: + b_domain_id = cls.convert_uuid_hex_to_bytes(domain_id) + except ValueError: + # the default domain ID is configurable, and probably isn't a UUID + if domain_id == CONF.identity.default_domain_id: + b_domain_id = domain_id + else: + raise + expires_at_int = cls._convert_time_string_to_int(expires_at) + b_audit_ids = list(map(provider.random_urlsafe_str_to_bytes, + audit_ids)) + return (b_user_id, methods, b_domain_id, expires_at_int, b_audit_ids) + + @classmethod + def disassemble(cls, payload): + """Disassemble a payload into the component data. + + :param payload: the payload of a token + :return: a tuple containing the user_id, auth methods, domain_id, + expires_at_str, and audit_ids + + """ + user_id = cls.convert_uuid_bytes_to_hex(payload[0]) + methods = auth_plugins.convert_integer_to_method_list(payload[1]) + try: + domain_id = cls.convert_uuid_bytes_to_hex(payload[2]) + except ValueError: + # the default domain ID is configurable, and probably isn't a UUID + if payload[2] == CONF.identity.default_domain_id: + domain_id = payload[2] + else: + raise + expires_at_str = cls._convert_int_to_time_string(payload[3]) + audit_ids = list(map(provider.base64_encode, payload[4])) + + return (user_id, methods, domain_id, expires_at_str, audit_ids) + + +class ProjectScopedPayload(BasePayload): + version = 2 + + @classmethod + def assemble(cls, user_id, methods, project_id, expires_at, audit_ids): + """Assemble the payload of a project-scoped token. + + :param user_id: ID of the user in the token request + :param methods: list of authentication methods used + :param project_id: ID of the project to scope to + :param expires_at: datetime of the token's expiration + :param audit_ids: list of the token's audit IDs + :returns: the payload of a project-scoped token + + """ + b_user_id = cls.convert_uuid_hex_to_bytes(user_id) + methods = auth_plugins.convert_method_list_to_integer(methods) + b_project_id = cls.convert_uuid_hex_to_bytes(project_id) + expires_at_int = cls._convert_time_string_to_int(expires_at) + b_audit_ids = list(map(provider.random_urlsafe_str_to_bytes, + audit_ids)) + return (b_user_id, methods, b_project_id, expires_at_int, b_audit_ids) + + @classmethod + def disassemble(cls, payload): + """Disassemble a payload into the component data. + + :param payload: the payload of a token + :return: a tuple containing the user_id, auth methods, project_id, + expires_at_str, and audit_ids + + """ + user_id = cls.convert_uuid_bytes_to_hex(payload[0]) + methods = auth_plugins.convert_integer_to_method_list(payload[1]) + project_id = cls.convert_uuid_bytes_to_hex(payload[2]) + expires_at_str = cls._convert_int_to_time_string(payload[3]) + audit_ids = list(map(provider.base64_encode, payload[4])) + + return (user_id, methods, project_id, expires_at_str, audit_ids) + + +class TrustScopedPayload(BasePayload): + version = 3 + + @classmethod + def assemble(cls, user_id, methods, project_id, expires_at, audit_ids, + trust_id): + """Assemble the payload of a trust-scoped token. + + :param user_id: ID of the user in the token request + :param methods: list of authentication methods used + :param project_id: ID of the project to scope to + :param expires_at: datetime of the token's expiration + :param audit_ids: list of the token's audit IDs + :param trust_id: ID of the trust in effect + :returns: the payload of a trust-scoped token + + """ + b_user_id = cls.convert_uuid_hex_to_bytes(user_id) + methods = auth_plugins.convert_method_list_to_integer(methods) + b_project_id = cls.convert_uuid_hex_to_bytes(project_id) + b_trust_id = cls.convert_uuid_hex_to_bytes(trust_id) + expires_at_int = cls._convert_time_string_to_int(expires_at) + b_audit_ids = list(map(provider.random_urlsafe_str_to_bytes, + audit_ids)) + + return (b_user_id, methods, b_project_id, expires_at_int, b_audit_ids, + b_trust_id) + + @classmethod + def disassemble(cls, payload): + """Validate a trust-based payload. + + :param token_string: a string representing the token + :returns: a tuple containing the user_id, auth methods, project_id, + expires_at_str, audit_ids, and trust_id + + """ + user_id = cls.convert_uuid_bytes_to_hex(payload[0]) + methods = auth_plugins.convert_integer_to_method_list(payload[1]) + project_id = cls.convert_uuid_bytes_to_hex(payload[2]) + expires_at_str = cls._convert_int_to_time_string(payload[3]) + audit_ids = list(map(provider.base64_encode, payload[4])) + trust_id = cls.convert_uuid_bytes_to_hex(payload[5]) + + return (user_id, methods, project_id, expires_at_str, audit_ids, + trust_id) + + +class FederatedPayload(BasePayload): + version = 4 + + @classmethod + def assemble(cls, user_id, methods, expires_at, audit_ids, federated_info): + """Assemble the payload of a federated token. + + :param user_id: ID of the user in the token request + :param methods: list of authentication methods used + :param expires_at: datetime of the token's expiration + :param audit_ids: list of the token's audit IDs + :param federated_info: dictionary containing group IDs, the identity + provider ID, protocol ID, and federated domain + ID + :returns: the payload of a federated token + + """ + def pack_group_ids(group_dict): + return cls.convert_uuid_hex_to_bytes(group_dict['id']) + + b_user_id = cls.attempt_convert_uuid_hex_to_bytes(user_id) + methods = auth_plugins.convert_method_list_to_integer(methods) + b_group_ids = map(pack_group_ids, federated_info['group_ids']) + b_idp_id = cls.attempt_convert_uuid_hex_to_bytes( + federated_info['idp_id']) + protocol_id = federated_info['protocol_id'] + expires_at_int = cls._convert_time_string_to_int(expires_at) + b_audit_ids = map(provider.random_urlsafe_str_to_bytes, audit_ids) + + return (b_user_id, methods, b_group_ids, b_idp_id, protocol_id, + expires_at_int, b_audit_ids) + + @classmethod + def disassemble(cls, payload): + """Validate a federated paylod. + + :param token_string: a string representing the token + :return: a tuple containing the user_id, auth methods, audit_ids, and + a dictionary containing federated information such as the the + group IDs, the identity provider ID, the protocol ID, and the + federated domain ID + + """ + def unpack_group_ids(group_id_in_bytes): + group_id = cls.convert_uuid_bytes_to_hex(group_id_in_bytes) + return {'id': group_id} + + user_id = cls.attempt_convert_uuid_bytes_to_hex(payload[0]) + methods = auth_plugins.convert_integer_to_method_list(payload[1]) + group_ids = map(unpack_group_ids, payload[2]) + idp_id = cls.attempt_convert_uuid_bytes_to_hex(payload[3]) + protocol_id = payload[4] + expires_at_str = cls._convert_int_to_time_string(payload[5]) + audit_ids = map(provider.base64_encode, payload[6]) + federated_info = dict(group_ids=group_ids, idp_id=idp_id, + protocol_id=protocol_id) + return (user_id, methods, expires_at_str, audit_ids, federated_info) |